linux - Documentation/virt/kvm/api.rst

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1	.. SPDX-License-Identifier: GPL-2.0
2
3	===================================================================
4	The Definitive KVM (Kernel-based Virtual Machine) API Documentation
5	===================================================================
6
7	1. General description
8	======================
9
10	The kvm API is centered around different kinds of file descriptors
11	and ioctls that can be issued to these file descriptors. An initial
12	open("/dev/kvm") obtains a handle to the kvm subsystem; this handle
13	can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this
14	handle will create a VM file descriptor which can be used to issue VM
15	ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will
16	create a virtual cpu or device and return a file descriptor pointing to
17	the new resource.
18
19	In other words, the kvm API is a set of ioctls that are issued to
20	different kinds of file descriptor in order to control various aspects of
21	a virtual machine. Depending on the file descriptor that accepts them,
22	ioctls belong to the following classes:
23
24	- System ioctls: These query and set global attributes which affect the
25	whole kvm subsystem. In addition a system ioctl is used to create
26	virtual machines.
27
28	- VM ioctls: These query and set attributes that affect an entire virtual
29	machine, for example memory layout. In addition a VM ioctl is used to
30	create virtual cpus (vcpus) and devices.
31
32	VM ioctls must be issued from the same process (address space) that was
33	used to create the VM.
34
35	- vcpu ioctls: These query and set attributes that control the operation
36	of a single virtual cpu.
37
38	vcpu ioctls should be issued from the same thread that was used to create
39	the vcpu, except for asynchronous vcpu ioctl that are marked as such in
40	the documentation. Otherwise, the first ioctl after switching threads
41	could see a performance impact.
42
43	- device ioctls: These query and set attributes that control the operation
44	of a single device.
45
46	device ioctls must be issued from the same process (address space) that
47	was used to create the VM.
48
49	While most ioctls are specific to one kind of file descriptor, in some
50	cases the same ioctl can belong to more than one class.
51
52	The KVM API grew over time. For this reason, KVM defines many constants
53	of the form ``KVM_CAP_*``, each corresponding to a set of functionality
54	provided by one or more ioctls. Availability of these "capabilities" can
55	be checked with :ref:`KVM_CHECK_EXTENSION <KVM_CHECK_EXTENSION>`. Some
56	capabilities also need to be enabled for VMs or VCPUs where their
57	functionality is desired (see :ref:`cap_enable` and :ref:`cap_enable_vm`).
58
59
60	2. Restrictions
61	===============
62
63	In general file descriptors can be migrated among processes by means
64	of fork() and the SCM_RIGHTS facility of unix domain socket. These
65	kinds of tricks are explicitly not supported by kvm. While they will
66	not cause harm to the host, their actual behavior is not guaranteed by
67	the API. See "General description" for details on the ioctl usage
68	model that is supported by KVM.
69
70	It is important to note that although VM ioctls may only be issued from
71	the process that created the VM, a VM's lifecycle is associated with its
72	file descriptor, not its creator (process). In other words, the VM and
73	its resources, including the associated address space, are not freed
74	until the last reference to the VM's file descriptor has been released.
75	For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will
76	not be freed until both the parent (original) process and its child have
77	put their references to the VM's file descriptor.
78
79	Because a VM's resources are not freed until the last reference to its
80	file descriptor is released, creating additional references to a VM
81	via fork(), dup(), etc... without careful consideration is strongly
82	discouraged and may have unwanted side effects, e.g. memory allocated
83	by and on behalf of the VM's process may not be freed/unaccounted when
84	the VM is shut down.
85
86
87	3. Extensions
88	=============
89
90	As of Linux 2.6.22, the KVM ABI has been stabilized: no backward
91	incompatible change are allowed. However, there is an extension
92	facility that allows backward-compatible extensions to the API to be
93	queried and used.
94
95	The extension mechanism is not based on the Linux version number.
96	Instead, kvm defines extension identifiers and a facility to query
97	whether a particular extension identifier is available. If it is, a
98	set of ioctls is available for application use.
99
100
101	4. API description
102	==================
103
104	This section describes ioctls that can be used to control kvm guests.
105	For each ioctl, the following information is provided along with a
106	description:
107
108	Capability:
109	which KVM extension provides this ioctl. Can be 'basic',
110	which means that is will be provided by any kernel that supports
111	API version 12 (see :ref:`KVM_GET_API_VERSION <KVM_GET_API_VERSION>`),
112	or a KVM_CAP_xyz constant that can be checked with
113	:ref:`KVM_CHECK_EXTENSION <KVM_CHECK_EXTENSION>`.
114
115	Architectures:
116	which instruction set architectures provide this ioctl.
117	x86 includes both i386 and x86_64.
118
119	Type:
120	system, vm, or vcpu.
121
122	Parameters:
123	what parameters are accepted by the ioctl.
124
125	Returns:
126	the return value. General error numbers (EBADF, ENOMEM, EINVAL)
127	are not detailed, but errors with specific meanings are.
128
129
130	.. _KVM_GET_API_VERSION:
131
132	4.1 KVM_GET_API_VERSION
133	-----------------------
134
135	:Capability: basic
136	:Architectures: all
137	:Type: system ioctl
138	:Parameters: none
139	:Returns: the constant KVM_API_VERSION (=12)
140
141	This identifies the API version as the stable kvm API. It is not
142	expected that this number will change. However, Linux 2.6.20 and
143	2.6.21 report earlier versions; these are not documented and not
144	supported. Applications should refuse to run if KVM_GET_API_VERSION
145	returns a value other than 12. If this check passes, all ioctls
146	described as 'basic' will be available.
147
148
149	4.2 KVM_CREATE_VM
150	-----------------
151
152	:Capability: basic
153	:Architectures: all
154	:Type: system ioctl
155	:Parameters: machine type identifier (KVM_VM_*)
156	:Returns: a VM fd that can be used to control the new virtual machine.
157
158	The new VM has no virtual cpus and no memory.
159	You probably want to use 0 as machine type.
160
161	X86:
162	^^^^
163
164	Supported X86 VM types can be queried via KVM_CAP_VM_TYPES.
165
166	S390:
167	^^^^^
168
169	In order to create user controlled virtual machines on S390, check
170	KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as
171	privileged user (CAP_SYS_ADMIN).
172
173	MIPS:
174	^^^^^
175
176	To use hardware assisted virtualization on MIPS (VZ ASE) rather than
177	the default trap & emulate implementation (which changes the virtual
178	memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the
179	flag KVM_VM_MIPS_VZ.
180
181	ARM64:
182	^^^^^^
183
184	On arm64, the physical address size for a VM (IPA Size limit) is limited
185	to 40bits by default. The limit can be configured if the host supports the
186	extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use
187	KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type
188	identifier, where IPA_Bits is the maximum width of any physical
189	address used by the VM. The IPA_Bits is encoded in bits[7-0] of the
190	machine type identifier.
191
192	e.g, to configure a guest to use 48bit physical address size::
193
194	vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48));
195
196	The requested size (IPA_Bits) must be:
197
198	== =========================================================
199	0 Implies default size, 40bits (for backward compatibility)
200	N Implies N bits, where N is a positive integer such that,
201	32 <= N <= Host_IPA_Limit
202	== =========================================================
203
204	Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and
205	is dependent on the CPU capability and the kernel configuration. The limit can
206	be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION
207	ioctl() at run-time.
208
209	Creation of the VM will fail if the requested IPA size (whether it is
210	implicit or explicit) is unsupported on the host.
211
212	Please note that configuring the IPA size does not affect the capability
213	exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects
214	size of the address translated by the stage2 level (guest physical to
215	host physical address translations).
216
217
218	4.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST
219	----------------------------------------------------------
220
221	:Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST
222	:Architectures: x86
223	:Type: system ioctl
224	:Parameters: struct kvm_msr_list (in/out)
225	:Returns: 0 on success; -1 on error
226
227	Errors:
228
229	====== ============================================================
230	EFAULT the msr index list cannot be read from or written to
231	E2BIG the msr index list is too big to fit in the array specified by
232	the user.
233	====== ============================================================
234
235	::
236
237	struct kvm_msr_list {
238	__u32 nmsrs; /* number of msrs in entries */
239	__u32 indices[0];
240	};
241
242	The user fills in the size of the indices array in nmsrs, and in return
243	kvm adjusts nmsrs to reflect the actual number of msrs and fills in the
244	indices array with their numbers.
245
246	KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported. The list
247	varies by kvm version and host processor, but does not change otherwise.
248
249	Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are
250	not returned in the MSR list, as different vcpus can have a different number
251	of banks, as set via the KVM_X86_SETUP_MCE ioctl.
252
253	KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed
254	to the KVM_GET_MSRS system ioctl. This lets userspace probe host capabilities
255	and processor features that are exposed via MSRs (e.g., VMX capabilities).
256	This list also varies by kvm version and host processor, but does not change
257	otherwise.
258
259
260	.. _KVM_CHECK_EXTENSION:
261
262	4.4 KVM_CHECK_EXTENSION
263	-----------------------
264
265	:Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl
266	:Architectures: all
267	:Type: system ioctl, vm ioctl
268	:Parameters: extension identifier (KVM_CAP_*)
269	:Returns: 0 if unsupported; 1 (or some other positive integer) if supported
270
271	The API allows the application to query about extensions to the core
272	kvm API. Userspace passes an extension identifier (an integer) and
273	receives an integer that describes the extension availability.
274	Generally 0 means no and 1 means yes, but some extensions may report
275	additional information in the integer return value.
276
277	Based on their initialization different VMs may have different capabilities.
278	It is thus encouraged to use the vm ioctl to query for capabilities (available
279	with KVM_CAP_CHECK_EXTENSION_VM on the vm fd)
280
281	4.5 KVM_GET_VCPU_MMAP_SIZE
282	--------------------------
283
284	:Capability: basic
285	:Architectures: all
286	:Type: system ioctl
287	:Parameters: none
288	:Returns: size of vcpu mmap area, in bytes
289
290	The KVM_RUN ioctl (cf.) communicates with userspace via a shared
291	memory region. This ioctl returns the size of that region. See the
292	KVM_RUN documentation for details.
293
294	Besides the size of the KVM_RUN communication region, other areas of
295	the VCPU file descriptor can be mmap-ed, including:
296
297	- if KVM_CAP_COALESCED_MMIO is available, a page at
298	KVM_COALESCED_MMIO_PAGE_OFFSET * PAGE_SIZE; for historical reasons,
299	this page is included in the result of KVM_GET_VCPU_MMAP_SIZE.
300	KVM_CAP_COALESCED_MMIO is not documented yet.
301
302	- if KVM_CAP_DIRTY_LOG_RING is available, a number of pages at
303	KVM_DIRTY_LOG_PAGE_OFFSET * PAGE_SIZE. For more information on
304	KVM_CAP_DIRTY_LOG_RING, see :ref:`KVM_CAP_DIRTY_LOG_RING`.
305
306
307	4.7 KVM_CREATE_VCPU
308	-------------------
309
310	:Capability: basic
311	:Architectures: all
312	:Type: vm ioctl
313	:Parameters: vcpu id (apic id on x86)
314	:Returns: vcpu fd on success, -1 on error
315
316	This API adds a vcpu to a virtual machine. No more than max_vcpus may be added.
317	The vcpu id is an integer in the range [0, max_vcpu_id).
318
319	The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of
320	the KVM_CHECK_EXTENSION ioctl() at run-time.
321	The maximum possible value for max_vcpus can be retrieved using the
322	KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time.
323
324	If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
325	cpus max.
326	If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is
327	same as the value returned from KVM_CAP_NR_VCPUS.
328
329	The maximum possible value for max_vcpu_id can be retrieved using the
330	KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time.
331
332	If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id
333	is the same as the value returned from KVM_CAP_MAX_VCPUS.
334
335	On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
336	threads in one or more virtual CPU cores. (This is because the
337	hardware requires all the hardware threads in a CPU core to be in the
338	same partition.) The KVM_CAP_PPC_SMT capability indicates the number
339	of vcpus per virtual core (vcore). The vcore id is obtained by
340	dividing the vcpu id by the number of vcpus per vcore. The vcpus in a
341	given vcore will always be in the same physical core as each other
342	(though that might be a different physical core from time to time).
343	Userspace can control the threading (SMT) mode of the guest by its
344	allocation of vcpu ids. For example, if userspace wants
345	single-threaded guest vcpus, it should make all vcpu ids be a multiple
346	of the number of vcpus per vcore.
347
348	For virtual cpus that have been created with S390 user controlled virtual
349	machines, the resulting vcpu fd can be memory mapped at page offset
350	KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual
351	cpu's hardware control block.
352
353
354	4.8 KVM_GET_DIRTY_LOG
355	---------------------
356
357	:Capability: basic
358	:Architectures: all
359	:Type: vm ioctl
360	:Parameters: struct kvm_dirty_log (in/out)
361	:Returns: 0 on success, -1 on error
362
363	::
364
365	/* for KVM_GET_DIRTY_LOG */
366	struct kvm_dirty_log {
367	__u32 slot;
368	__u32 padding;
369	union {
370	void __user dirty_bitmap; / one bit per page */
371	__u64 padding;
372	};
373	};
374
375	Given a memory slot, return a bitmap containing any pages dirtied
376	since the last call to this ioctl. Bit 0 is the first page in the
377	memory slot. Ensure the entire structure is cleared to avoid padding
378	issues.
379
380	If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies
381	the address space for which you want to return the dirty bitmap. See
382	KVM_SET_USER_MEMORY_REGION for details on the usage of slot field.
383
384	The bits in the dirty bitmap are cleared before the ioctl returns, unless
385	KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information,
386	see the description of the capability.
387
388	Note that the Xen shared_info page, if configured, shall always be assumed
389	to be dirty. KVM will not explicitly mark it such.
390
391
392	4.10 KVM_RUN
393	------------
394
395	:Capability: basic
396	:Architectures: all
397	:Type: vcpu ioctl
398	:Parameters: none
399	:Returns: 0 on success, -1 on error
400
401	Errors:
402
403	======= ==============================================================
404	EINTR an unmasked signal is pending
405	ENOEXEC the vcpu hasn't been initialized or the guest tried to execute
406	instructions from device memory (arm64)
407	ENOSYS data abort outside memslots with no syndrome info and
408	KVM_CAP_ARM_NISV_TO_USER not enabled (arm64)
409	EPERM SVE feature set but not finalized (arm64)
410	======= ==============================================================
411
412	This ioctl is used to run a guest virtual cpu. While there are no
413	explicit parameters, there is an implicit parameter block that can be
414	obtained by mmap()ing the vcpu fd at offset 0, with the size given by
415	KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct
416	kvm_run' (see below).
417
418
419	4.11 KVM_GET_REGS
420	-----------------
421
422	:Capability: basic
423	:Architectures: all except arm64
424	:Type: vcpu ioctl
425	:Parameters: struct kvm_regs (out)
426	:Returns: 0 on success, -1 on error
427
428	Reads the general purpose registers from the vcpu.
429
430	::
431
432	/* x86 */
433	struct kvm_regs {
434	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
435	__u64 rax, rbx, rcx, rdx;
436	__u64 rsi, rdi, rsp, rbp;
437	__u64 r8, r9, r10, r11;
438	__u64 r12, r13, r14, r15;
439	__u64 rip, rflags;
440	};
441
442	/* mips */
443	struct kvm_regs {
444	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
445	__u64 gpr[32];
446	__u64 hi;
447	__u64 lo;
448	__u64 pc;
449	};
450
451	/* LoongArch */
452	struct kvm_regs {
453	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
454	unsigned long gpr[32];
455	unsigned long pc;
456	};
457
458
459	4.12 KVM_SET_REGS
460	-----------------
461
462	:Capability: basic
463	:Architectures: all except arm64
464	:Type: vcpu ioctl
465	:Parameters: struct kvm_regs (in)
466	:Returns: 0 on success, -1 on error
467
468	Writes the general purpose registers into the vcpu.
469
470	See KVM_GET_REGS for the data structure.
471
472
473	4.13 KVM_GET_SREGS
474	------------------
475
476	:Capability: basic
477	:Architectures: x86, ppc
478	:Type: vcpu ioctl
479	:Parameters: struct kvm_sregs (out)
480	:Returns: 0 on success, -1 on error
481
482	Reads special registers from the vcpu.
483
484	::
485
486	/* x86 */
487	struct kvm_sregs {
488	struct kvm_segment cs, ds, es, fs, gs, ss;
489	struct kvm_segment tr, ldt;
490	struct kvm_dtable gdt, idt;
491	__u64 cr0, cr2, cr3, cr4, cr8;
492	__u64 efer;
493	__u64 apic_base;
494	__u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64];
495	};
496
497	/* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */
498
499	interrupt_bitmap is a bitmap of pending external interrupts. At most
500	one bit may be set. This interrupt has been acknowledged by the APIC
501	but not yet injected into the cpu core.
502
503
504	4.14 KVM_SET_SREGS
505	------------------
506
507	:Capability: basic
508	:Architectures: x86, ppc
509	:Type: vcpu ioctl
510	:Parameters: struct kvm_sregs (in)
511	:Returns: 0 on success, -1 on error
512
513	Writes special registers into the vcpu. See KVM_GET_SREGS for the
514	data structures.
515
516
517	4.15 KVM_TRANSLATE
518	------------------
519
520	:Capability: basic
521	:Architectures: x86
522	:Type: vcpu ioctl
523	:Parameters: struct kvm_translation (in/out)
524	:Returns: 0 on success, -1 on error
525
526	Translates a virtual address according to the vcpu's current address
527	translation mode.
528
529	::
530
531	struct kvm_translation {
532	/* in */
533	__u64 linear_address;
534
535	/* out */
536	__u64 physical_address;
537	__u8 valid;
538	__u8 writeable;
539	__u8 usermode;
540	__u8 pad[5];
541	};
542
543
544	4.16 KVM_INTERRUPT
545	------------------
546
547	:Capability: basic
548	:Architectures: x86, ppc, mips, riscv, loongarch
549	:Type: vcpu ioctl
550	:Parameters: struct kvm_interrupt (in)
551	:Returns: 0 on success, negative on failure.
552
553	Queues a hardware interrupt vector to be injected.
554
555	::
556
557	/* for KVM_INTERRUPT */
558	struct kvm_interrupt {
559	/* in */
560	__u32 irq;
561	};
562
563	X86:
564	^^^^
565
566	:Returns:
567
568	========= ===================================
569	0 on success,
570	-EEXIST if an interrupt is already enqueued
571	-EINVAL the irq number is invalid
572	-ENXIO if the PIC is in the kernel
573	-EFAULT if the pointer is invalid
574	========= ===================================
575
576	Note 'irq' is an interrupt vector, not an interrupt pin or line. This
577	ioctl is useful if the in-kernel PIC is not used.
578
579	PPC:
580	^^^^
581
582	Queues an external interrupt to be injected. This ioctl is overloaded
583	with 3 different irq values:
584
585	a) KVM_INTERRUPT_SET
586
587	This injects an edge type external interrupt into the guest once it's ready
588	to receive interrupts. When injected, the interrupt is done.
589
590	b) KVM_INTERRUPT_UNSET
591
592	This unsets any pending interrupt.
593
594	Only available with KVM_CAP_PPC_UNSET_IRQ.
595
596	c) KVM_INTERRUPT_SET_LEVEL
597
598	This injects a level type external interrupt into the guest context. The
599	interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET
600	is triggered.
601
602	Only available with KVM_CAP_PPC_IRQ_LEVEL.
603
604	Note that any value for 'irq' other than the ones stated above is invalid
605	and incurs unexpected behavior.
606
607	This is an asynchronous vcpu ioctl and can be invoked from any thread.
608
609	MIPS:
610	^^^^^
611
612	Queues an external interrupt to be injected into the virtual CPU. A negative
613	interrupt number dequeues the interrupt.
614
615	This is an asynchronous vcpu ioctl and can be invoked from any thread.
616
617	RISC-V:
618	^^^^^^^
619
620	Queues an external interrupt to be injected into the virtual CPU. This ioctl
621	is overloaded with 2 different irq values:
622
623	a) KVM_INTERRUPT_SET
624
625	This sets external interrupt for a virtual CPU and it will receive
626	once it is ready.
627
628	b) KVM_INTERRUPT_UNSET
629
630	This clears pending external interrupt for a virtual CPU.
631
632	This is an asynchronous vcpu ioctl and can be invoked from any thread.
633
634	LOONGARCH:
635	^^^^^^^^^^
636
637	Queues an external interrupt to be injected into the virtual CPU. A negative
638	interrupt number dequeues the interrupt.
639
640	This is an asynchronous vcpu ioctl and can be invoked from any thread.
641
642
643	4.18 KVM_GET_MSRS
644	-----------------
645
646	:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system)
647	:Architectures: x86
648	:Type: system ioctl, vcpu ioctl
649	:Parameters: struct kvm_msrs (in/out)
650	:Returns: number of msrs successfully returned;
651	-1 on error
652
653	When used as a system ioctl:
654	Reads the values of MSR-based features that are available for the VM. This
655	is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values.
656	The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST
657	in a system ioctl.
658
659	When used as a vcpu ioctl:
660	Reads model-specific registers from the vcpu. Supported msr indices can
661	be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl.
662
663	::
664
665	struct kvm_msrs {
666	__u32 nmsrs; /* number of msrs in entries */
667	__u32 pad;
668
669	struct kvm_msr_entry entries[0];
670	};
671
672	struct kvm_msr_entry {
673	__u32 index;
674	__u32 reserved;
675	__u64 data;
676	};
677
678	Application code should set the 'nmsrs' member (which indicates the
679	size of the entries array) and the 'index' member of each array entry.
680	kvm will fill in the 'data' member.
681
682
683	4.19 KVM_SET_MSRS
684	-----------------
685
686	:Capability: basic
687	:Architectures: x86
688	:Type: vcpu ioctl
689	:Parameters: struct kvm_msrs (in)
690	:Returns: number of msrs successfully set (see below), -1 on error
691
692	Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the
693	data structures.
694
695	Application code should set the 'nmsrs' member (which indicates the
696	size of the entries array), and the 'index' and 'data' members of each
697	array entry.
698
699	It tries to set the MSRs in array entries[] one by one. If setting an MSR
700	fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated
701	by KVM, etc..., it stops processing the MSR list and returns the number of
702	MSRs that have been set successfully.
703
704
705	4.20 KVM_SET_CPUID
706	------------------
707
708	:Capability: basic
709	:Architectures: x86
710	:Type: vcpu ioctl
711	:Parameters: struct kvm_cpuid (in)
712	:Returns: 0 on success, -1 on error
713
714	Defines the vcpu responses to the cpuid instruction. Applications
715	should use the KVM_SET_CPUID2 ioctl if available.
716
717	Caveat emptor:
718	- If this IOCTL fails, KVM gives no guarantees that previous valid CPUID
719	configuration (if there is) is not corrupted. Userspace can get a copy
720	of the resulting CPUID configuration through KVM_GET_CPUID2 in case.
721	- Using KVM_SET_CPUID{,2} after KVM_RUN, i.e. changing the guest vCPU model
722	after running the guest, may cause guest instability.
723	- Using heterogeneous CPUID configurations, modulo APIC IDs, topology, etc...
724	may cause guest instability.
725
726	::
727
728	struct kvm_cpuid_entry {
729	__u32 function;
730	__u32 eax;
731	__u32 ebx;
732	__u32 ecx;
733	__u32 edx;
734	__u32 padding;
735	};
736
737	/* for KVM_SET_CPUID */
738	struct kvm_cpuid {
739	__u32 nent;
740	__u32 padding;
741	struct kvm_cpuid_entry entries[0];
742	};
743
744
745	4.21 KVM_SET_SIGNAL_MASK
746	------------------------
747
748	:Capability: basic
749	:Architectures: all
750	:Type: vcpu ioctl
751	:Parameters: struct kvm_signal_mask (in)
752	:Returns: 0 on success, -1 on error
753
754	Defines which signals are blocked during execution of KVM_RUN. This
755	signal mask temporarily overrides the threads signal mask. Any
756	unblocked signal received (except SIGKILL and SIGSTOP, which retain
757	their traditional behaviour) will cause KVM_RUN to return with -EINTR.
758
759	Note the signal will only be delivered if not blocked by the original
760	signal mask.
761
762	::
763
764	/* for KVM_SET_SIGNAL_MASK */
765	struct kvm_signal_mask {
766	__u32 len;
767	__u8 sigset[0];
768	};
769
770
771	4.22 KVM_GET_FPU
772	----------------
773
774	:Capability: basic
775	:Architectures: x86, loongarch
776	:Type: vcpu ioctl
777	:Parameters: struct kvm_fpu (out)
778	:Returns: 0 on success, -1 on error
779
780	Reads the floating point state from the vcpu.
781
782	::
783
784	/* x86: for KVM_GET_FPU and KVM_SET_FPU */
785	struct kvm_fpu {
786	__u8 fpr[8][16];
787	__u16 fcw;
788	__u16 fsw;
789	__u8 ftwx; /* in fxsave format */
790	__u8 pad1;
791	__u16 last_opcode;
792	__u64 last_ip;
793	__u64 last_dp;
794	__u8 xmm[16][16];
795	__u32 mxcsr;
796	__u32 pad2;
797	};
798
799	/* LoongArch: for KVM_GET_FPU and KVM_SET_FPU */
800	struct kvm_fpu {
801	__u32 fcsr;
802	__u64 fcc;
803	struct kvm_fpureg {
804	__u64 val64[4];
805	}fpr[32];
806	};
807
808
809	4.23 KVM_SET_FPU
810	----------------
811
812	:Capability: basic
813	:Architectures: x86, loongarch
814	:Type: vcpu ioctl
815	:Parameters: struct kvm_fpu (in)
816	:Returns: 0 on success, -1 on error
817
818	Writes the floating point state to the vcpu.
819
820	::
821
822	/* x86: for KVM_GET_FPU and KVM_SET_FPU */
823	struct kvm_fpu {
824	__u8 fpr[8][16];
825	__u16 fcw;
826	__u16 fsw;
827	__u8 ftwx; /* in fxsave format */
828	__u8 pad1;
829	__u16 last_opcode;
830	__u64 last_ip;
831	__u64 last_dp;
832	__u8 xmm[16][16];
833	__u32 mxcsr;
834	__u32 pad2;
835	};
836
837	/* LoongArch: for KVM_GET_FPU and KVM_SET_FPU */
838	struct kvm_fpu {
839	__u32 fcsr;
840	__u64 fcc;
841	struct kvm_fpureg {
842	__u64 val64[4];
843	}fpr[32];
844	};
845
846
847	4.24 KVM_CREATE_IRQCHIP
848	-----------------------
849
850	:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390)
851	:Architectures: x86, arm64, s390
852	:Type: vm ioctl
853	:Parameters: none
854	:Returns: 0 on success, -1 on error
855
856	Creates an interrupt controller model in the kernel.
857	On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up
858	future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both
859	PIC and IOAPIC; GSI 16-23 only go to the IOAPIC. This ioctl can only be
860	called before creating any vcpus.
861	On arm64, a GICv2 is created. Any other GIC versions require the usage of
862	KVM_CREATE_DEVICE, which also supports creating a GICv2. Using
863	KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2.
864	On s390, a dummy irq routing table is created.
865
866	On x86, subsequent vcpu creation may install a private 4 KiB memory slot at the
867	default APIC base address (0xfee00000). User memory regions must not overlap
868	this address; doing so will cause vcpu creation to fail with ``EEXIST``, or the
869	memory region to be rejected if created after the vcpu. This occurs when
870	APIC access acceleration is enabled (APICv on Intel, AVIC on AMD), which is
871	the default on supported hardware. The same constraint applies when using
872	``KVM_CAP_SPLIT_IRQCHIP``.
873
874	Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled
875	before KVM_CREATE_IRQCHIP can be used.
876
877
878	4.25 KVM_IRQ_LINE
879	-----------------
880
881	:Capability: KVM_CAP_IRQCHIP
882	:Architectures: x86, arm64
883	:Type: vm ioctl
884	:Parameters: struct kvm_irq_level
885	:Returns: 0 on success, -1 on error
886
887	Sets the level of a GSI input to the interrupt controller model in the kernel.
888	On some architectures it is required that an interrupt controller model has
889	been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered
890	interrupts require the level to be set to 1 and then back to 0.
891
892	On real hardware, interrupt pins can be active-low or active-high. This
893	does not matter for the level field of struct kvm_irq_level: 1 always
894	means active (asserted), 0 means inactive (deasserted).
895
896	x86 allows the operating system to program the interrupt polarity
897	(active-low/active-high) for level-triggered interrupts, and KVM used
898	to consider the polarity. However, due to bitrot in the handling of
899	active-low interrupts, the above convention is now valid on x86 too.
900	This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace
901	should not present interrupts to the guest as active-low unless this
902	capability is present (or unless it is not using the in-kernel irqchip,
903	of course).
904
905
906	arm64 can signal an interrupt either at the CPU level, or at the
907	in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to
908	use PPIs designated for specific cpus. The irq field is interpreted
909	like this::
910
911	bits: \| 31 ... 28 \| 27 ... 24 \| 23 ... 16 \| 15 ... 0 \|
912	field: \| vcpu2_index \| irq_type \| vcpu_index \| irq_id \|
913
914	The irq_type field has the following values:
915
916	- KVM_ARM_IRQ_TYPE_CPU:
917	out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ
918	- KVM_ARM_IRQ_TYPE_SPI:
919	in-kernel GICv2/GICv3: SPI, irq_id between 32 and 1019 (incl.)
920	(the vcpu_index field is ignored)
921	in-kernel GICv5: SPI, irq_id between 0 and 65535 (incl.)
922	- KVM_ARM_IRQ_TYPE_PPI:
923	in-kernel GICv2/GICv3: PPI, irq_id between 16 and 31 (incl.)
924	in-kernel GICv5: PPI, irq_id between 0 and 127 (incl.)
925
926	(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs)
927
928	In both cases, level is used to assert/deassert the line.
929
930	When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is
931	identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index
932	must be zero.
933
934	Note that on arm64, the KVM_CAP_IRQCHIP capability only conditions
935	injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always
936	be used for a userspace interrupt controller.
937
938	::
939
940	struct kvm_irq_level {
941	union {
942	__u32 irq; /* GSI */
943	__s32 status; /* not used for KVM_IRQ_LEVEL */
944	};
945	__u32 level; /* 0 or 1 */
946	};
947
948
949	4.26 KVM_GET_IRQCHIP
950	--------------------
951
952	:Capability: KVM_CAP_IRQCHIP
953	:Architectures: x86
954	:Type: vm ioctl
955	:Parameters: struct kvm_irqchip (in/out)
956	:Returns: 0 on success, -1 on error
957
958	Reads the state of a kernel interrupt controller created with
959	KVM_CREATE_IRQCHIP into a buffer provided by the caller.
960
961	::
962
963	struct kvm_irqchip {
964	__u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
965	__u32 pad;
966	union {
967	char dummy[512]; /* reserving space */
968	struct kvm_pic_state pic;
969	struct kvm_ioapic_state ioapic;
970	} chip;
971	};
972
973
974	4.27 KVM_SET_IRQCHIP
975	--------------------
976
977	:Capability: KVM_CAP_IRQCHIP
978	:Architectures: x86
979	:Type: vm ioctl
980	:Parameters: struct kvm_irqchip (in)
981	:Returns: 0 on success, -1 on error
982
983	Sets the state of a kernel interrupt controller created with
984	KVM_CREATE_IRQCHIP from a buffer provided by the caller.
985
986	::
987
988	struct kvm_irqchip {
989	__u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
990	__u32 pad;
991	union {
992	char dummy[512]; /* reserving space */
993	struct kvm_pic_state pic;
994	struct kvm_ioapic_state ioapic;
995	} chip;
996	};
997
998
999	4.28 KVM_XEN_HVM_CONFIG
1000	-----------------------
1001
1002	:Capability: KVM_CAP_XEN_HVM
1003	:Architectures: x86
1004	:Type: vm ioctl
1005	:Parameters: struct kvm_xen_hvm_config (in)
1006	:Returns: 0 on success, -1 on error
1007
1008	Sets the MSR that the Xen HVM guest uses to initialize its hypercall
1009	page, and provides the starting address and size of the hypercall
1010	blobs in userspace. When the guest writes the MSR, kvm copies one
1011	page of a blob (32- or 64-bit, depending on the vcpu mode) to guest
1012	memory.
1013
1014	The MSR index must be in the range [0x40000000, 0x4fffffff], i.e. must reside
1015	in the range that is unofficially reserved for use by hypervisors. The min/max
1016	values are enumerated via KVM_XEN_MSR_MIN_INDEX and KVM_XEN_MSR_MAX_INDEX.
1017
1018	::
1019
1020	struct kvm_xen_hvm_config {
1021	__u32 flags;
1022	__u32 msr;
1023	__u64 blob_addr_32;
1024	__u64 blob_addr_64;
1025	__u8 blob_size_32;
1026	__u8 blob_size_64;
1027	__u8 pad2[30];
1028	};
1029
1030	If certain flags are returned from the KVM_CAP_XEN_HVM check, they may
1031	be set in the flags field of this ioctl:
1032
1033	The KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag requests KVM to generate
1034	the contents of the hypercall page automatically; hypercalls will be
1035	intercepted and passed to userspace through KVM_EXIT_XEN. In this
1036	case, all of the blob size and address fields must be zero.
1037
1038	The KVM_XEN_HVM_CONFIG_EVTCHN_SEND flag indicates to KVM that userspace
1039	will always use the KVM_XEN_HVM_EVTCHN_SEND ioctl to deliver event
1040	channel interrupts rather than manipulating the guest's shared_info
1041	structures directly. This, in turn, may allow KVM to enable features
1042	such as intercepting the SCHEDOP_poll hypercall to accelerate PV
1043	spinlock operation for the guest. Userspace may still use the ioctl
1044	to deliver events if it was advertised, even if userspace does not
1045	send this indication that it will always do so
1046
1047	No other flags are currently valid in the struct kvm_xen_hvm_config.
1048
1049	4.29 KVM_GET_CLOCK
1050	------------------
1051
1052	:Capability: KVM_CAP_ADJUST_CLOCK
1053	:Architectures: x86
1054	:Type: vm ioctl
1055	:Parameters: struct kvm_clock_data (out)
1056	:Returns: 0 on success, -1 on error
1057
1058	Gets the current timestamp of kvmclock as seen by the current guest. In
1059	conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios
1060	such as migration.
1061
1062	When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the
1063	set of bits that KVM can return in struct kvm_clock_data's flag member.
1064
1065	The following flags are defined:
1066
1067	KVM_CLOCK_TSC_STABLE
1068	If set, the returned value is the exact kvmclock
1069	value seen by all VCPUs at the instant when KVM_GET_CLOCK was called.
1070	If clear, the returned value is simply CLOCK_MONOTONIC plus a constant
1071	offset; the offset can be modified with KVM_SET_CLOCK. KVM will try
1072	to make all VCPUs follow this clock, but the exact value read by each
1073	VCPU could differ, because the host TSC is not stable.
1074
1075	KVM_CLOCK_REALTIME
1076	If set, the `realtime` field in the kvm_clock_data
1077	structure is populated with the value of the host's real time
1078	clocksource at the instant when KVM_GET_CLOCK was called. If clear,
1079	the `realtime` field does not contain a value.
1080
1081	KVM_CLOCK_HOST_TSC
1082	If set, the `host_tsc` field in the kvm_clock_data
1083	structure is populated with the value of the host's timestamp counter (TSC)
1084	at the instant when KVM_GET_CLOCK was called. If clear, the `host_tsc` field
1085	does not contain a value.
1086
1087	::
1088
1089	struct kvm_clock_data {
1090	__u64 clock; /* kvmclock current value */
1091	__u32 flags;
1092	__u32 pad0;
1093	__u64 realtime;
1094	__u64 host_tsc;
1095	__u32 pad[4];
1096	};
1097
1098
1099	4.30 KVM_SET_CLOCK
1100	------------------
1101
1102	:Capability: KVM_CAP_ADJUST_CLOCK
1103	:Architectures: x86
1104	:Type: vm ioctl
1105	:Parameters: struct kvm_clock_data (in)
1106	:Returns: 0 on success, -1 on error
1107
1108	Sets the current timestamp of kvmclock to the value specified in its parameter.
1109	In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios
1110	such as migration.
1111
1112	The following flags can be passed:
1113
1114	KVM_CLOCK_REALTIME
1115	If set, KVM will compare the value of the `realtime` field
1116	with the value of the host's real time clocksource at the instant when
1117	KVM_SET_CLOCK was called. The difference in elapsed time is added to the final
1118	kvmclock value that will be provided to guests.
1119
1120	Other flags returned by ``KVM_GET_CLOCK`` are accepted but ignored.
1121
1122	::
1123
1124	struct kvm_clock_data {
1125	__u64 clock; /* kvmclock current value */
1126	__u32 flags;
1127	__u32 pad0;
1128	__u64 realtime;
1129	__u64 host_tsc;
1130	__u32 pad[4];
1131	};
1132
1133
1134	4.31 KVM_GET_VCPU_EVENTS
1135	------------------------
1136
1137	:Capability: KVM_CAP_VCPU_EVENTS
1138	:Extended by: KVM_CAP_INTR_SHADOW
1139	:Architectures: x86, arm64
1140	:Type: vcpu ioctl
1141	:Parameters: struct kvm_vcpu_events (out)
1142	:Returns: 0 on success, -1 on error
1143
1144	X86:
1145	^^^^
1146
1147	Gets currently pending exceptions, interrupts, and NMIs as well as related
1148	states of the vcpu.
1149
1150	::
1151
1152	struct kvm_vcpu_events {
1153	struct {
1154	__u8 injected;
1155	__u8 nr;
1156	__u8 has_error_code;
1157	__u8 pending;
1158	__u32 error_code;
1159	} exception;
1160	struct {
1161	__u8 injected;
1162	__u8 nr;
1163	__u8 soft;
1164	__u8 shadow;
1165	} interrupt;
1166	struct {
1167	__u8 injected;
1168	__u8 pending;
1169	__u8 masked;
1170	__u8 pad;
1171	} nmi;
1172	__u32 sipi_vector;
1173	__u32 flags;
1174	struct {
1175	__u8 smm;
1176	__u8 pending;
1177	__u8 smm_inside_nmi;
1178	__u8 latched_init;
1179	} smi;
1180	__u8 reserved[27];
1181	__u8 exception_has_payload;
1182	__u64 exception_payload;
1183	};
1184
1185	The following bits are defined in the flags field:
1186
1187	- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that
1188	interrupt.shadow contains a valid state.
1189
1190	- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a
1191	valid state.
1192
1193	- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the
1194	exception_has_payload, exception_payload, and exception.pending
1195	fields contain a valid state. This bit will be set whenever
1196	KVM_CAP_EXCEPTION_PAYLOAD is enabled.
1197
1198	- KVM_VCPUEVENT_VALID_TRIPLE_FAULT may be set to signal that the
1199	triple_fault_pending field contains a valid state. This bit will
1200	be set whenever KVM_CAP_X86_TRIPLE_FAULT_EVENT is enabled.
1201
1202	ARM64:
1203	^^^^^^
1204
1205	If the guest accesses a device that is being emulated by the host kernel in
1206	such a way that a real device would generate a physical SError, KVM may make
1207	a virtual SError pending for that VCPU. This system error interrupt remains
1208	pending until the guest takes the exception by unmasking PSTATE.A.
1209
1210	Running the VCPU may cause it to take a pending SError, or make an access that
1211	causes an SError to become pending. The event's description is only valid while
1212	the VPCU is not running.
1213
1214	This API provides a way to read and write the pending 'event' state that is not
1215	visible to the guest. To save, restore or migrate a VCPU the struct representing
1216	the state can be read then written using this GET/SET API, along with the other
1217	guest-visible registers. It is not possible to 'cancel' an SError that has been
1218	made pending.
1219
1220	A device being emulated in user-space may also wish to generate an SError. To do
1221	this the events structure can be populated by user-space. The current state
1222	should be read first, to ensure no existing SError is pending. If an existing
1223	SError is pending, the architecture's 'Multiple SError interrupts' rules should
1224	be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
1225	Serviceability (RAS) Specification").
1226
1227	SError exceptions always have an ESR value. Some CPUs have the ability to
1228	specify what the virtual SError's ESR value should be. These systems will
1229	advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will
1230	always have a non-zero value when read, and the agent making an SError pending
1231	should specify the ISS field in the lower 24 bits of exception.serror_esr. If
1232	the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events
1233	with exception.has_esr as zero, KVM will choose an ESR.
1234
1235	Specifying exception.has_esr on a system that does not support it will return
1236	-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
1237	will return -EINVAL.
1238
1239	It is not possible to read back a pending external abort (injected via
1240	KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered
1241	directly to the virtual CPU).
1242
1243	Calling this ioctl on a vCPU that hasn't been initialized will return
1244	-ENOEXEC.
1245
1246	::
1247
1248	struct kvm_vcpu_events {
1249	struct {
1250	__u8 serror_pending;
1251	__u8 serror_has_esr;
1252	__u8 ext_dabt_pending;
1253	/* Align it to 8 bytes */
1254	__u8 pad[5];
1255	__u64 serror_esr;
1256	} exception;
1257	__u32 reserved[12];
1258	};
1259
1260	4.32 KVM_SET_VCPU_EVENTS
1261	------------------------
1262
1263	:Capability: KVM_CAP_VCPU_EVENTS
1264	:Extended by: KVM_CAP_INTR_SHADOW
1265	:Architectures: x86, arm64
1266	:Type: vcpu ioctl
1267	:Parameters: struct kvm_vcpu_events (in)
1268	:Returns: 0 on success, -1 on error
1269
1270	X86:
1271	^^^^
1272
1273	Set pending exceptions, interrupts, and NMIs as well as related states of the
1274	vcpu.
1275
1276	See KVM_GET_VCPU_EVENTS for the data structure.
1277
1278	Fields that may be modified asynchronously by running VCPUs can be excluded
1279	from the update. These fields are nmi.pending, sipi_vector, smi.smm,
1280	smi.pending. Keep the corresponding bits in the flags field cleared to
1281	suppress overwriting the current in-kernel state. The bits are:
1282
1283	=============================== ==================================
1284	KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel
1285	KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector
1286	KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct.
1287	=============================== ==================================
1288
1289	If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in
1290	the flags field to signal that interrupt.shadow contains a valid state and
1291	shall be written into the VCPU.
1292
1293	KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available.
1294
1295	If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD
1296	can be set in the flags field to signal that the
1297	exception_has_payload, exception_payload, and exception.pending fields
1298	contain a valid state and shall be written into the VCPU.
1299
1300	If KVM_CAP_X86_TRIPLE_FAULT_EVENT is enabled, KVM_VCPUEVENT_VALID_TRIPLE_FAULT
1301	can be set in flags field to signal that the triple_fault field contains
1302	a valid state and shall be written into the VCPU.
1303
1304	ARM64:
1305	^^^^^^
1306
1307	User space may need to inject several types of events to the guest.
1308
1309	Set the pending SError exception state for this VCPU. It is not possible to
1310	'cancel' an Serror that has been made pending.
1311
1312	If the guest performed an access to I/O memory which could not be handled by
1313	userspace, for example because of missing instruction syndrome decode
1314	information or because there is no device mapped at the accessed IPA, then
1315	userspace can ask the kernel to inject an external abort using the address
1316	from the exiting fault on the VCPU. It is a programming error to set
1317	ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO,
1318	KVM_EXIT_ARM_NISV, or KVM_EXIT_ARM_LDST64B. This feature is only available if
1319	the system supports KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which
1320	provides commonality in how userspace reports accesses for the above cases to
1321	guests, across different userspace implementations. Nevertheless, userspace
1322	can still emulate all Arm exceptions by manipulating individual registers
1323	using the KVM_SET_ONE_REG API.
1324
1325	See KVM_GET_VCPU_EVENTS for the data structure.
1326
1327	Calling this ioctl on a vCPU that hasn't been initialized will return
1328	-ENOEXEC.
1329
1330	4.33 KVM_GET_DEBUGREGS
1331	----------------------
1332
1333	:Capability: KVM_CAP_DEBUGREGS
1334	:Architectures: x86
1335	:Type: vcpu ioctl
1336	:Parameters: struct kvm_debugregs (out)
1337	:Returns: 0 on success, -1 on error
1338
1339	Reads debug registers from the vcpu.
1340
1341	::
1342
1343	struct kvm_debugregs {
1344	__u64 db[4];
1345	__u64 dr6;
1346	__u64 dr7;
1347	__u64 flags;
1348	__u64 reserved[9];
1349	};
1350
1351
1352	4.34 KVM_SET_DEBUGREGS
1353	----------------------
1354
1355	:Capability: KVM_CAP_DEBUGREGS
1356	:Architectures: x86
1357	:Type: vcpu ioctl
1358	:Parameters: struct kvm_debugregs (in)
1359	:Returns: 0 on success, -1 on error
1360
1361	Writes debug registers into the vcpu.
1362
1363	See KVM_GET_DEBUGREGS for the data structure. The flags field is unused
1364	yet and must be cleared on entry.
1365
1366
1367	4.35 KVM_SET_USER_MEMORY_REGION
1368	-------------------------------
1369
1370	:Capability: KVM_CAP_USER_MEMORY
1371	:Architectures: all
1372	:Type: vm ioctl
1373	:Parameters: struct kvm_userspace_memory_region (in)
1374	:Returns: 0 on success, -1 on error
1375
1376	::
1377
1378	struct kvm_userspace_memory_region {
1379	__u32 slot;
1380	__u32 flags;
1381	__u64 guest_phys_addr;
1382	__u64 memory_size; /* bytes */
1383	__u64 userspace_addr; /* start of the userspace allocated memory */
1384	};
1385
1386	/* for kvm_userspace_memory_region::flags */
1387	#define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0)
1388	#define KVM_MEM_READONLY (1UL << 1)
1389
1390	This ioctl allows the user to create, modify or delete a guest physical
1391	memory slot. Bits 0-15 of "slot" specify the slot id and this value
1392	should be less than the maximum number of user memory slots supported per
1393	VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS.
1394	Slots may not overlap in guest physical address space.
1395
1396	If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot"
1397	specifies the address space which is being modified. They must be
1398	less than the value that KVM_CHECK_EXTENSION returns for the
1399	KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces
1400	are unrelated; the restriction on overlapping slots only applies within
1401	each address space.
1402
1403	Deleting a slot is done by passing zero for memory_size. When changing
1404	an existing slot, it may be moved in the guest physical memory space,
1405	or its flags may be modified, but it may not be resized.
1406
1407	Memory for the region is taken starting at the address denoted by the
1408	field userspace_addr, which must point at user addressable memory for
1409	the entire memory slot size. Any object may back this memory, including
1410	anonymous memory, ordinary files, and hugetlbfs. Changes in the backing
1411	of the memory region are automatically reflected into the guest.
1412	For example, an mmap() that affects the region will be made visible
1413	immediately. Another example is madvise(MADV_DROP).
1414
1415	On architectures that support a form of address tagging, userspace_addr must
1416	be an untagged address.
1417
1418	It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
1419	be identical. This allows large pages in the guest to be backed by large
1420	pages in the host.
1421
1422	The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and
1423	KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of
1424	writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to
1425	use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it,
1426	to make a new slot read-only. In this case, writes to this memory will be
1427	posted to userspace as KVM_EXIT_MMIO exits.
1428
1429	For TDX guest, deleting/moving memory region loses guest memory contents.
1430	Read only region isn't supported. Only as-id 0 is supported.
1431
1432	Note: On arm64, a write generated by the page-table walker (to update
1433	the Access and Dirty flags, for example) never results in a
1434	KVM_EXIT_MMIO exit when the slot has the KVM_MEM_READONLY flag. This
1435	is because KVM cannot provide the data that would be written by the
1436	page-table walker, making it impossible to emulate the access.
1437	Instead, an abort (data abort if the cause of the page-table update
1438	was a load or a store, instruction abort if it was an instruction
1439	fetch) is injected in the guest.
1440
1441	S390:
1442	^^^^^
1443
1444	Returns -EINVAL or -EEXIST if the VM has the KVM_VM_S390_UCONTROL flag set.
1445	Returns -EINVAL if called on a protected VM.
1446
1447	4.36 KVM_SET_TSS_ADDR
1448	---------------------
1449
1450	:Capability: KVM_CAP_SET_TSS_ADDR
1451	:Architectures: x86
1452	:Type: vm ioctl
1453	:Parameters: unsigned long tss_address (in)
1454	:Returns: 0 on success, -1 on error
1455
1456	This ioctl defines the physical address of a three-page region in the guest
1457	physical address space. The region must be within the first 4GB of the
1458	guest physical address space and must not conflict with any memory slot
1459	or any mmio address. The guest may malfunction if it accesses this memory
1460	region.
1461
1462	This ioctl is required on Intel-based hosts. This is needed on Intel hardware
1463	because of a quirk in the virtualization implementation (see the internals
1464	documentation when it pops into existence).
1465
1466
1467	.. _KVM_ENABLE_CAP:
1468
1469	4.37 KVM_ENABLE_CAP
1470	-------------------
1471
1472	:Capability: KVM_CAP_ENABLE_CAP
1473	:Architectures: mips, ppc, s390, x86, loongarch
1474	:Type: vcpu ioctl
1475	:Parameters: struct kvm_enable_cap (in)
1476	:Returns: 0 on success; -1 on error
1477
1478	:Capability: KVM_CAP_ENABLE_CAP_VM
1479	:Architectures: all
1480	:Type: vm ioctl
1481	:Parameters: struct kvm_enable_cap (in)
1482	:Returns: 0 on success; -1 on error
1483
1484	.. note::
1485
1486	Not all extensions are enabled by default. Using this ioctl the application
1487	can enable an extension, making it available to the guest.
1488
1489	On systems that do not support this ioctl, it always fails. On systems that
1490	do support it, it only works for extensions that are supported for enablement.
1491
1492	To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should
1493	be used.
1494
1495	::
1496
1497	struct kvm_enable_cap {
1498	/* in */
1499	__u32 cap;
1500
1501	The capability that is supposed to get enabled.
1502
1503	::
1504
1505	__u32 flags;
1506
1507	A bitfield indicating future enhancements. Has to be 0 for now.
1508
1509	::
1510
1511	__u64 args[4];
1512
1513	Arguments for enabling a feature. If a feature needs initial values to
1514	function properly, this is the place to put them.
1515
1516	::
1517
1518	__u8 pad[64];
1519	};
1520
1521	The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl
1522	for vm-wide capabilities.
1523
1524	4.38 KVM_GET_MP_STATE
1525	---------------------
1526
1527	:Capability: KVM_CAP_MP_STATE
1528	:Architectures: x86, s390, arm64, riscv, loongarch
1529	:Type: vcpu ioctl
1530	:Parameters: struct kvm_mp_state (out)
1531	:Returns: 0 on success; -1 on error
1532
1533	::
1534
1535	struct kvm_mp_state {
1536	__u32 mp_state;
1537	};
1538
1539	Returns the vcpu's current "multiprocessing state" (though also valid on
1540	uniprocessor guests).
1541
1542	Possible values are:
1543
1544	========================== ===============================================
1545	KVM_MP_STATE_RUNNABLE the vcpu is currently running
1546	[x86,arm64,riscv,loongarch]
1547	KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP)
1548	which has not yet received an INIT signal [x86]
1549	KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is
1550	now ready for a SIPI [x86]
1551	KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and
1552	is waiting for an interrupt [x86]
1553	KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector
1554	accessible via KVM_GET_VCPU_EVENTS) [x86]
1555	KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm64,riscv]
1556	KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390]
1557	KVM_MP_STATE_OPERATING the vcpu is operating (running or halted)
1558	[s390]
1559	KVM_MP_STATE_LOAD the vcpu is in a special load/startup state
1560	[s390]
1561	KVM_MP_STATE_SUSPENDED the vcpu is in a suspend state and is waiting
1562	for a wakeup event [arm64]
1563	========================== ===============================================
1564
1565	On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
1566	in-kernel irqchip, the multiprocessing state must be maintained by userspace on
1567	these architectures.
1568
1569	For arm64:
1570	^^^^^^^^^^
1571
1572	If a vCPU is in the KVM_MP_STATE_SUSPENDED state, KVM will emulate the
1573	architectural execution of a WFI instruction.
1574
1575	If a wakeup event is recognized, KVM will exit to userspace with a
1576	KVM_SYSTEM_EVENT exit, where the event type is KVM_SYSTEM_EVENT_WAKEUP. If
1577	userspace wants to honor the wakeup, it must set the vCPU's MP state to
1578	KVM_MP_STATE_RUNNABLE. If it does not, KVM will continue to await a wakeup
1579	event in subsequent calls to KVM_RUN.
1580
1581	.. warning::
1582
1583	If userspace intends to keep the vCPU in a SUSPENDED state, it is
1584	strongly recommended that userspace take action to suppress the
1585	wakeup event (such as masking an interrupt). Otherwise, subsequent
1586	calls to KVM_RUN will immediately exit with a KVM_SYSTEM_EVENT_WAKEUP
1587	event and inadvertently waste CPU cycles.
1588
1589	Additionally, if userspace takes action to suppress a wakeup event,
1590	it is strongly recommended that it also restores the vCPU to its
1591	original state when the vCPU is made RUNNABLE again. For example,
1592	if userspace masked a pending interrupt to suppress the wakeup,
1593	the interrupt should be unmasked before returning control to the
1594	guest.
1595
1596	For riscv:
1597	^^^^^^^^^^
1598
1599	The only states that are valid are KVM_MP_STATE_STOPPED and
1600	KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not.
1601
1602	On LoongArch, only the KVM_MP_STATE_RUNNABLE state is used to reflect
1603	whether the vcpu is runnable.
1604
1605	4.39 KVM_SET_MP_STATE
1606	---------------------
1607
1608	:Capability: KVM_CAP_MP_STATE
1609	:Architectures: x86, s390, arm64, riscv, loongarch
1610	:Type: vcpu ioctl
1611	:Parameters: struct kvm_mp_state (in)
1612	:Returns: 0 on success; -1 on error
1613
1614	Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for
1615	arguments.
1616
1617	On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
1618	in-kernel irqchip, the multiprocessing state must be maintained by userspace on
1619	these architectures.
1620
1621	For arm64/riscv:
1622	^^^^^^^^^^^^^^^^
1623
1624	The only states that are valid are KVM_MP_STATE_STOPPED and
1625	KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not.
1626
1627	On LoongArch, only the KVM_MP_STATE_RUNNABLE state is used to reflect
1628	whether the vcpu is runnable.
1629
1630	4.40 KVM_SET_IDENTITY_MAP_ADDR
1631	------------------------------
1632
1633	:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR
1634	:Architectures: x86
1635	:Type: vm ioctl
1636	:Parameters: unsigned long identity (in)
1637	:Returns: 0 on success, -1 on error
1638
1639	This ioctl defines the physical address of a one-page region in the guest
1640	physical address space. The region must be within the first 4GB of the
1641	guest physical address space and must not conflict with any memory slot
1642	or any mmio address. The guest may malfunction if it accesses this memory
1643	region.
1644
1645	Setting the address to 0 will result in resetting the address to its default
1646	(0xfffbc000).
1647
1648	This ioctl is required on Intel-based hosts. This is needed on Intel hardware
1649	because of a quirk in the virtualization implementation (see the internals
1650	documentation when it pops into existence).
1651
1652	Fails if any VCPU has already been created.
1653
1654	4.41 KVM_SET_BOOT_CPU_ID
1655	------------------------
1656
1657	:Capability: KVM_CAP_SET_BOOT_CPU_ID
1658	:Architectures: x86
1659	:Type: vm ioctl
1660	:Parameters: unsigned long vcpu_id
1661	:Returns: 0 on success, -1 on error
1662
1663	Define which vcpu is the Bootstrap Processor (BSP). Values are the same
1664	as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default
1665	is vcpu 0. This ioctl has to be called before vcpu creation,
1666	otherwise it will return EBUSY error.
1667
1668
1669	4.42 KVM_GET_XSAVE
1670	------------------
1671
1672	:Capability: KVM_CAP_XSAVE
1673	:Architectures: x86
1674	:Type: vcpu ioctl
1675	:Parameters: struct kvm_xsave (out)
1676	:Returns: 0 on success, -1 on error
1677
1678
1679	::
1680
1681	struct kvm_xsave {
1682	__u32 region[1024];
1683	__u32 extra[0];
1684	};
1685
1686	This ioctl would copy current vcpu's xsave struct to the userspace.
1687
1688
1689	4.43 KVM_SET_XSAVE
1690	------------------
1691
1692	:Capability: KVM_CAP_XSAVE and KVM_CAP_XSAVE2
1693	:Architectures: x86
1694	:Type: vcpu ioctl
1695	:Parameters: struct kvm_xsave (in)
1696	:Returns: 0 on success, -1 on error
1697
1698	::
1699
1700
1701	struct kvm_xsave {
1702	__u32 region[1024];
1703	__u32 extra[0];
1704	};
1705
1706	This ioctl would copy userspace's xsave struct to the kernel. It copies
1707	as many bytes as are returned by KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2),
1708	when invoked on the vm file descriptor. The size value returned by
1709	KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2) will always be at least 4096.
1710	Currently, it is only greater than 4096 if a dynamic feature has been
1711	enabled with ``arch_prctl()``, but this may change in the future.
1712
1713	The offsets of the state save areas in struct kvm_xsave follow the
1714	contents of CPUID leaf 0xD on the host.
1715
1716
1717	4.44 KVM_GET_XCRS
1718	-----------------
1719
1720	:Capability: KVM_CAP_XCRS
1721	:Architectures: x86
1722	:Type: vcpu ioctl
1723	:Parameters: struct kvm_xcrs (out)
1724	:Returns: 0 on success, -1 on error
1725
1726	::
1727
1728	struct kvm_xcr {
1729	__u32 xcr;
1730	__u32 reserved;
1731	__u64 value;
1732	};
1733
1734	struct kvm_xcrs {
1735	__u32 nr_xcrs;
1736	__u32 flags;
1737	struct kvm_xcr xcrs[KVM_MAX_XCRS];
1738	__u64 padding[16];
1739	};
1740
1741	This ioctl would copy current vcpu's xcrs to the userspace.
1742
1743
1744	4.45 KVM_SET_XCRS
1745	-----------------
1746
1747	:Capability: KVM_CAP_XCRS
1748	:Architectures: x86
1749	:Type: vcpu ioctl
1750	:Parameters: struct kvm_xcrs (in)
1751	:Returns: 0 on success, -1 on error
1752
1753	::
1754
1755	struct kvm_xcr {
1756	__u32 xcr;
1757	__u32 reserved;
1758	__u64 value;
1759	};
1760
1761	struct kvm_xcrs {
1762	__u32 nr_xcrs;
1763	__u32 flags;
1764	struct kvm_xcr xcrs[KVM_MAX_XCRS];
1765	__u64 padding[16];
1766	};
1767
1768	This ioctl would set vcpu's xcr to the value userspace specified.
1769
1770
1771	4.46 KVM_GET_SUPPORTED_CPUID
1772	----------------------------
1773
1774	:Capability: KVM_CAP_EXT_CPUID
1775	:Architectures: x86
1776	:Type: system ioctl
1777	:Parameters: struct kvm_cpuid2 (in/out)
1778	:Returns: 0 on success, -1 on error
1779
1780	::
1781
1782	struct kvm_cpuid2 {
1783	__u32 nent;
1784	__u32 padding;
1785	struct kvm_cpuid_entry2 entries[0];
1786	};
1787
1788	#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0)
1789	#define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */
1790	#define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */
1791
1792	struct kvm_cpuid_entry2 {
1793	__u32 function;
1794	__u32 index;
1795	__u32 flags;
1796	__u32 eax;
1797	__u32 ebx;
1798	__u32 ecx;
1799	__u32 edx;
1800	__u32 padding[3];
1801	};
1802
1803	This ioctl returns x86 cpuid features which are supported by both the
1804	hardware and kvm in its default configuration. Userspace can use the
1805	information returned by this ioctl to construct cpuid information (for
1806	KVM_SET_CPUID2) that is consistent with hardware, kernel, and
1807	userspace capabilities, and with user requirements (for example, the
1808	user may wish to constrain cpuid to emulate older hardware, or for
1809	feature consistency across a cluster).
1810
1811	Dynamically-enabled feature bits need to be requested with
1812	``arch_prctl()`` before calling this ioctl. Feature bits that have not
1813	been requested are excluded from the result.
1814
1815	Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may
1816	expose cpuid features (e.g. MONITOR) which are not supported by kvm in
1817	its default configuration. If userspace enables such capabilities, it
1818	is responsible for modifying the results of this ioctl appropriately.
1819
1820	Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure
1821	with the 'nent' field indicating the number of entries in the variable-size
1822	array 'entries'. If the number of entries is too low to describe the cpu
1823	capabilities, an error (E2BIG) is returned. If the number is too high,
1824	the 'nent' field is adjusted and an error (ENOMEM) is returned. If the
1825	number is just right, the 'nent' field is adjusted to the number of valid
1826	entries in the 'entries' array, which is then filled.
1827
1828	The entries returned are the host cpuid as returned by the cpuid instruction,
1829	with unknown or unsupported features masked out. Some features (for example,
1830	x2apic), may not be present in the host cpu, but are exposed by kvm if it can
1831	emulate them efficiently. The fields in each entry are defined as follows:
1832
1833	function:
1834	the eax value used to obtain the entry
1835
1836	index:
1837	the ecx value used to obtain the entry (for entries that are
1838	affected by ecx)
1839
1840	flags:
1841	an OR of zero or more of the following:
1842
1843	KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
1844	if the index field is valid
1845
1846	eax, ebx, ecx, edx:
1847	the values returned by the cpuid instruction for
1848	this function/index combination
1849
1850	x2APIC (CPUID leaf 1, ecx[21) and TSC deadline timer (CPUID leaf 1, ecx[24])
1851	may be returned as true, but they depend on KVM_CREATE_IRQCHIP for in-kernel
1852	emulation of the local APIC. TSC deadline timer support is also reported via::
1853
1854	ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER)
1855
1856	if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the
1857	feature in userspace, then you can enable the feature for KVM_SET_CPUID2.
1858
1859	Enabling x2APIC in KVM_SET_CPUID2 requires KVM_CREATE_IRQCHIP as KVM doesn't
1860	support forwarding x2APIC MSR accesses to userspace, i.e. KVM does not support
1861	emulating x2APIC in userspace.
1862
1863	4.47 KVM_PPC_GET_PVINFO
1864	-----------------------
1865
1866	:Capability: KVM_CAP_PPC_GET_PVINFO
1867	:Architectures: ppc
1868	:Type: vm ioctl
1869	:Parameters: struct kvm_ppc_pvinfo (out)
1870	:Returns: 0 on success, !0 on error
1871
1872	::
1873
1874	struct kvm_ppc_pvinfo {
1875	__u32 flags;
1876	__u32 hcall[4];
1877	__u8 pad[108];
1878	};
1879
1880	This ioctl fetches PV specific information that need to be passed to the guest
1881	using the device tree or other means from vm context.
1882
1883	The hcall array defines 4 instructions that make up a hypercall.
1884
1885	If any additional field gets added to this structure later on, a bit for that
1886	additional piece of information will be set in the flags bitmap.
1887
1888	The flags bitmap is defined as::
1889
1890	/* the host supports the ePAPR idle hcall
1891	#define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0)
1892
1893	4.52 KVM_SET_GSI_ROUTING
1894	------------------------
1895
1896	:Capability: KVM_CAP_IRQ_ROUTING
1897	:Architectures: x86 s390 arm64
1898	:Type: vm ioctl
1899	:Parameters: struct kvm_irq_routing (in)
1900	:Returns: 0 on success, -1 on error
1901
1902	Sets the GSI routing table entries, overwriting any previously set entries.
1903
1904	On arm64, GSI routing has the following limitation:
1905
1906	- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD.
1907
1908	::
1909
1910	struct kvm_irq_routing {
1911	__u32 nr;
1912	__u32 flags;
1913	struct kvm_irq_routing_entry entries[0];
1914	};
1915
1916	No flags are specified so far, the corresponding field must be set to zero.
1917
1918	::
1919
1920	struct kvm_irq_routing_entry {
1921	__u32 gsi;
1922	__u32 type;
1923	__u32 flags;
1924	__u32 pad;
1925	union {
1926	struct kvm_irq_routing_irqchip irqchip;
1927	struct kvm_irq_routing_msi msi;
1928	struct kvm_irq_routing_s390_adapter adapter;
1929	struct kvm_irq_routing_hv_sint hv_sint;
1930	struct kvm_irq_routing_xen_evtchn xen_evtchn;
1931	__u32 pad[8];
1932	} u;
1933	};
1934
1935	/* gsi routing entry types */
1936	#define KVM_IRQ_ROUTING_IRQCHIP 1
1937	#define KVM_IRQ_ROUTING_MSI 2
1938	#define KVM_IRQ_ROUTING_S390_ADAPTER 3
1939	#define KVM_IRQ_ROUTING_HV_SINT 4
1940	#define KVM_IRQ_ROUTING_XEN_EVTCHN 5
1941
1942	On s390, adding a KVM_IRQ_ROUTING_S390_ADAPTER is rejected on ucontrol VMs with
1943	error -EINVAL.
1944
1945	flags:
1946
1947	- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry
1948	type, specifies that the devid field contains a valid value. The per-VM
1949	KVM_CAP_MSI_DEVID capability advertises the requirement to provide
1950	the device ID. If this capability is not available, userspace should
1951	never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail.
1952	- zero otherwise
1953
1954	::
1955
1956	struct kvm_irq_routing_irqchip {
1957	__u32 irqchip;
1958	__u32 pin;
1959	};
1960
1961	struct kvm_irq_routing_msi {
1962	__u32 address_lo;
1963	__u32 address_hi;
1964	__u32 data;
1965	union {
1966	__u32 pad;
1967	__u32 devid;
1968	};
1969	};
1970
1971	If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier
1972	for the device that wrote the MSI message. For PCI, this is usually a
1973	BDF identifier in the lower 16 bits.
1974
1975	On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS
1976	feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled,
1977	address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of
1978	address_hi must be zero.
1979
1980	::
1981
1982	struct kvm_irq_routing_s390_adapter {
1983	__u64 ind_addr;
1984	__u64 summary_addr;
1985	__u64 ind_offset;
1986	__u32 summary_offset;
1987	__u32 adapter_id;
1988	};
1989
1990	struct kvm_irq_routing_hv_sint {
1991	__u32 vcpu;
1992	__u32 sint;
1993	};
1994
1995	struct kvm_irq_routing_xen_evtchn {
1996	__u32 port;
1997	__u32 vcpu;
1998	__u32 priority;
1999	};
2000
2001
2002	When KVM_CAP_XEN_HVM includes the KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL bit
2003	in its indication of supported features, routing to Xen event channels
2004	is supported. Although the priority field is present, only the value
2005	KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL is supported, which means delivery by
2006	2 level event channels. FIFO event channel support may be added in
2007	the future.
2008
2009
2010	4.55 KVM_SET_TSC_KHZ
2011	--------------------
2012
2013	:Capability: KVM_CAP_TSC_CONTROL / KVM_CAP_VM_TSC_CONTROL
2014	:Architectures: x86
2015	:Type: vcpu ioctl / vm ioctl
2016	:Parameters: virtual tsc_khz
2017	:Returns: 0 on success, -1 on error
2018
2019	Specifies the tsc frequency for the virtual machine. The unit of the
2020	frequency is KHz.
2021
2022	If the KVM_CAP_VM_TSC_CONTROL capability is advertised, this can also
2023	be used as a vm ioctl to set the initial tsc frequency of subsequently
2024	created vCPUs. Note, the vm ioctl is only allowed prior to creating vCPUs.
2025
2026	For TSC protected Confidential Computing (CoCo) VMs where TSC frequency
2027	is configured once at VM scope and remains unchanged during VM's
2028	lifetime, the vm ioctl should be used to configure the TSC frequency
2029	and the vcpu ioctl is not supported.
2030
2031	Example of such CoCo VMs: TDX guests.
2032
2033	4.56 KVM_GET_TSC_KHZ
2034	--------------------
2035
2036	:Capability: KVM_CAP_GET_TSC_KHZ / KVM_CAP_VM_TSC_CONTROL
2037	:Architectures: x86
2038	:Type: vcpu ioctl / vm ioctl
2039	:Parameters: none
2040	:Returns: virtual tsc-khz on success, negative value on error
2041
2042	Returns the tsc frequency of the guest. The unit of the return value is
2043	KHz. If the host has unstable tsc this ioctl returns -EIO instead as an
2044	error.
2045
2046
2047	4.57 KVM_GET_LAPIC
2048	------------------
2049
2050	:Capability: KVM_CAP_IRQCHIP
2051	:Architectures: x86
2052	:Type: vcpu ioctl
2053	:Parameters: struct kvm_lapic_state (out)
2054	:Returns: 0 on success, -1 on error
2055
2056	::
2057
2058	#define KVM_APIC_REG_SIZE 0x400
2059	struct kvm_lapic_state {
2060	char regs[KVM_APIC_REG_SIZE];
2061	};
2062
2063	Reads the Local APIC registers and copies them into the input argument. The
2064	data format and layout are the same as documented in the architecture manual.
2065
2066	If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is
2067	enabled, then the format of APIC_ID register depends on the APIC mode
2068	(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in
2069	the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID
2070	which is stored in bits 31-24 of the APIC register, or equivalently in
2071	byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then
2072	be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR.
2073
2074	If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state
2075	always uses xAPIC format.
2076
2077
2078	4.58 KVM_SET_LAPIC
2079	------------------
2080
2081	:Capability: KVM_CAP_IRQCHIP
2082	:Architectures: x86
2083	:Type: vcpu ioctl
2084	:Parameters: struct kvm_lapic_state (in)
2085	:Returns: 0 on success, -1 on error
2086
2087	::
2088
2089	#define KVM_APIC_REG_SIZE 0x400
2090	struct kvm_lapic_state {
2091	char regs[KVM_APIC_REG_SIZE];
2092	};
2093
2094	Copies the input argument into the Local APIC registers. The data format
2095	and layout are the same as documented in the architecture manual.
2096
2097	The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's
2098	regs field) depends on the state of the KVM_CAP_X2APIC_API capability.
2099	See the note in KVM_GET_LAPIC.
2100
2101
2102	4.59 KVM_IOEVENTFD
2103	------------------
2104
2105	:Capability: KVM_CAP_IOEVENTFD
2106	:Architectures: all
2107	:Type: vm ioctl
2108	:Parameters: struct kvm_ioeventfd (in)
2109	:Returns: 0 on success, !0 on error
2110
2111	This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address
2112	within the guest. A guest write in the registered address will signal the
2113	provided event instead of triggering an exit.
2114
2115	::
2116
2117	struct kvm_ioeventfd {
2118	__u64 datamatch;
2119	__u64 addr; /* legal pio/mmio address */
2120	__u32 len; /* 0, 1, 2, 4, or 8 bytes */
2121	__s32 fd;
2122	__u32 flags;
2123	__u8 pad[36];
2124	};
2125
2126	For the special case of virtio-ccw devices on s390, the ioevent is matched
2127	to a subchannel/virtqueue tuple instead.
2128
2129	The following flags are defined::
2130
2131	#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
2132	#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
2133	#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)
2134	#define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \
2135	(1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify)
2136
2137	If datamatch flag is set, the event will be signaled only if the written value
2138	to the registered address is equal to datamatch in struct kvm_ioeventfd.
2139
2140	For virtio-ccw devices, addr contains the subchannel id and datamatch the
2141	virtqueue index.
2142
2143	With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and
2144	the kernel will ignore the length of guest write and may get a faster vmexit.
2145	The speedup may only apply to specific architectures, but the ioeventfd will
2146	work anyway.
2147
2148	4.60 KVM_DIRTY_TLB
2149	------------------
2150
2151	:Capability: KVM_CAP_SW_TLB
2152	:Architectures: ppc
2153	:Type: vcpu ioctl
2154	:Parameters: struct kvm_dirty_tlb (in)
2155	:Returns: 0 on success, -1 on error
2156
2157	::
2158
2159	struct kvm_dirty_tlb {
2160	__u64 bitmap;
2161	__u32 num_dirty;
2162	};
2163
2164	This must be called whenever userspace has changed an entry in the shared
2165	TLB, prior to calling KVM_RUN on the associated vcpu.
2166
2167	The "bitmap" field is the userspace address of an array. This array
2168	consists of a number of bits, equal to the total number of TLB entries as
2169	determined by the last successful call to ``KVM_ENABLE_CAP(KVM_CAP_SW_TLB)``,
2170	rounded up to the nearest multiple of 64.
2171
2172	Each bit corresponds to one TLB entry, ordered the same as in the shared TLB
2173	array.
2174
2175	The array is little-endian: the bit 0 is the least significant bit of the
2176	first byte, bit 8 is the least significant bit of the second byte, etc.
2177	This avoids any complications with differing word sizes.
2178
2179	The "num_dirty" field is a performance hint for KVM to determine whether it
2180	should skip processing the bitmap and just invalidate everything. It must
2181	be set to the number of set bits in the bitmap.
2182
2183
2184	4.62 KVM_CREATE_SPAPR_TCE
2185	-------------------------
2186
2187	:Capability: KVM_CAP_SPAPR_TCE
2188	:Architectures: powerpc
2189	:Type: vm ioctl
2190	:Parameters: struct kvm_create_spapr_tce (in)
2191	:Returns: file descriptor for manipulating the created TCE table
2192
2193	This creates a virtual TCE (translation control entry) table, which
2194	is an IOMMU for PAPR-style virtual I/O. It is used to translate
2195	logical addresses used in virtual I/O into guest physical addresses,
2196	and provides a scatter/gather capability for PAPR virtual I/O.
2197
2198	::
2199
2200	/* for KVM_CAP_SPAPR_TCE */
2201	struct kvm_create_spapr_tce {
2202	__u64 liobn;
2203	__u32 window_size;
2204	};
2205
2206	The liobn field gives the logical IO bus number for which to create a
2207	TCE table. The window_size field specifies the size of the DMA window
2208	which this TCE table will translate - the table will contain one 64
2209	bit TCE entry for every 4kiB of the DMA window.
2210
2211	When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE
2212	table has been created using this ioctl(), the kernel will handle it
2213	in real mode, updating the TCE table. H_PUT_TCE calls for other
2214	liobns will cause a vm exit and must be handled by userspace.
2215
2216	The return value is a file descriptor which can be passed to mmap(2)
2217	to map the created TCE table into userspace. This lets userspace read
2218	the entries written by kernel-handled H_PUT_TCE calls, and also lets
2219	userspace update the TCE table directly which is useful in some
2220	circumstances.
2221
2222
2223	4.64 KVM_NMI
2224	------------
2225
2226	:Capability: KVM_CAP_USER_NMI
2227	:Architectures: x86
2228	:Type: vcpu ioctl
2229	:Parameters: none
2230	:Returns: 0 on success, -1 on error
2231
2232	Queues an NMI on the thread's vcpu. Note this is well defined only
2233	when KVM_CREATE_IRQCHIP has not been called, since this is an interface
2234	between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP
2235	has been called, this interface is completely emulated within the kernel.
2236
2237	To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the
2238	following algorithm:
2239
2240	- pause the vcpu
2241	- read the local APIC's state (KVM_GET_LAPIC)
2242	- check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1)
2243	- if so, issue KVM_NMI
2244	- resume the vcpu
2245
2246	Some guests configure the LINT1 NMI input to cause a panic, aiding in
2247	debugging.
2248
2249
2250	4.65 KVM_S390_UCAS_MAP
2251	----------------------
2252
2253	:Capability: KVM_CAP_S390_UCONTROL
2254	:Architectures: s390
2255	:Type: vcpu ioctl
2256	:Parameters: struct kvm_s390_ucas_mapping (in)
2257	:Returns: 0 in case of success
2258
2259	The parameter is defined like this::
2260
2261	struct kvm_s390_ucas_mapping {
2262	__u64 user_addr;
2263	__u64 vcpu_addr;
2264	__u64 length;
2265	};
2266
2267	This ioctl maps the memory at "user_addr" with the length "length" to
2268	the vcpu's address space starting at "vcpu_addr". All parameters need to
2269	be aligned by 1 megabyte.
2270
2271
2272	4.66 KVM_S390_UCAS_UNMAP
2273	------------------------
2274
2275	:Capability: KVM_CAP_S390_UCONTROL
2276	:Architectures: s390
2277	:Type: vcpu ioctl
2278	:Parameters: struct kvm_s390_ucas_mapping (in)
2279	:Returns: 0 in case of success
2280
2281	The parameter is defined like this::
2282
2283	struct kvm_s390_ucas_mapping {
2284	__u64 user_addr;
2285	__u64 vcpu_addr;
2286	__u64 length;
2287	};
2288
2289	This ioctl unmaps the memory in the vcpu's address space starting at
2290	"vcpu_addr" with the length "length". The field "user_addr" is ignored.
2291	All parameters need to be aligned by 1 megabyte.
2292
2293
2294	4.67 KVM_S390_VCPU_FAULT
2295	------------------------
2296
2297	:Capability: KVM_CAP_S390_UCONTROL
2298	:Architectures: s390
2299	:Type: vcpu ioctl
2300	:Parameters: vcpu absolute address (in)
2301	:Returns: 0 in case of success
2302
2303	This call creates a page table entry on the virtual cpu's address space
2304	(for user controlled virtual machines) or the virtual machine's address
2305	space (for regular virtual machines). This only works for minor faults,
2306	thus it's recommended to access subject memory page via the user page
2307	table upfront. This is useful to handle validity intercepts for user
2308	controlled virtual machines to fault in the virtual cpu's lowcore pages
2309	prior to calling the KVM_RUN ioctl.
2310
2311
2312	4.68 KVM_SET_ONE_REG
2313	--------------------
2314
2315	:Capability: KVM_CAP_ONE_REG
2316	:Architectures: all
2317	:Type: vcpu ioctl
2318	:Parameters: struct kvm_one_reg (in)
2319	:Returns: 0 on success, negative value on failure
2320
2321	Errors:
2322
2323	====== ============================================================
2324	ENOENT no such register
2325	EINVAL invalid register ID, or no such register or used with VMs in
2326	protected virtualization mode on s390
2327	EPERM (arm64) register access not allowed before vcpu finalization
2328	EBUSY (riscv) changing register value not allowed after the vcpu
2329	has run at least once
2330	====== ============================================================
2331
2332	(These error codes are indicative only: do not rely on a specific error
2333	code being returned in a specific situation.)
2334
2335	::
2336
2337	struct kvm_one_reg {
2338	__u64 id;
2339	__u64 addr;
2340	};
2341
2342	Using this ioctl, a single vcpu register can be set to a specific value
2343	defined by user space with the passed in struct kvm_one_reg, where id
2344	refers to the register identifier as described below and addr is a pointer
2345	to a variable with the respective size. There can be architecture agnostic
2346	and architecture specific registers. Each have their own range of operation
2347	and their own constants and width. To keep track of the implemented
2348	registers, find a list below:
2349
2350	======= =============================== ============
2351	Arch Register Width (bits)
2352	======= =============================== ============
2353	PPC KVM_REG_PPC_HIOR 64
2354	PPC KVM_REG_PPC_IAC1 64
2355	PPC KVM_REG_PPC_IAC2 64
2356	PPC KVM_REG_PPC_IAC3 64
2357	PPC KVM_REG_PPC_IAC4 64
2358	PPC KVM_REG_PPC_DAC1 64
2359	PPC KVM_REG_PPC_DAC2 64
2360	PPC KVM_REG_PPC_DABR 64
2361	PPC KVM_REG_PPC_DSCR 64
2362	PPC KVM_REG_PPC_PURR 64
2363	PPC KVM_REG_PPC_SPURR 64
2364	PPC KVM_REG_PPC_DAR 64
2365	PPC KVM_REG_PPC_DSISR 32
2366	PPC KVM_REG_PPC_AMR 64
2367	PPC KVM_REG_PPC_UAMOR 64
2368	PPC KVM_REG_PPC_MMCR0 64
2369	PPC KVM_REG_PPC_MMCR1 64
2370	PPC KVM_REG_PPC_MMCRA 64
2371	PPC KVM_REG_PPC_MMCR2 64
2372	PPC KVM_REG_PPC_MMCRS 64
2373	PPC KVM_REG_PPC_MMCR3 64
2374	PPC KVM_REG_PPC_SIAR 64
2375	PPC KVM_REG_PPC_SDAR 64
2376	PPC KVM_REG_PPC_SIER 64
2377	PPC KVM_REG_PPC_SIER2 64
2378	PPC KVM_REG_PPC_SIER3 64
2379	PPC KVM_REG_PPC_PMC1 32
2380	PPC KVM_REG_PPC_PMC2 32
2381	PPC KVM_REG_PPC_PMC3 32
2382	PPC KVM_REG_PPC_PMC4 32
2383	PPC KVM_REG_PPC_PMC5 32
2384	PPC KVM_REG_PPC_PMC6 32
2385	PPC KVM_REG_PPC_PMC7 32
2386	PPC KVM_REG_PPC_PMC8 32
2387	PPC KVM_REG_PPC_FPR0 64
2388	...
2389	PPC KVM_REG_PPC_FPR31 64
2390	PPC KVM_REG_PPC_VR0 128
2391	...
2392	PPC KVM_REG_PPC_VR31 128
2393	PPC KVM_REG_PPC_VSR0 128
2394	...
2395	PPC KVM_REG_PPC_VSR31 128
2396	PPC KVM_REG_PPC_FPSCR 64
2397	PPC KVM_REG_PPC_VSCR 32
2398	PPC KVM_REG_PPC_VPA_ADDR 64
2399	PPC KVM_REG_PPC_VPA_SLB 128
2400	PPC KVM_REG_PPC_VPA_DTL 128
2401	PPC KVM_REG_PPC_EPCR 32
2402	PPC KVM_REG_PPC_EPR 32
2403	PPC KVM_REG_PPC_TCR 32
2404	PPC KVM_REG_PPC_TSR 32
2405	PPC KVM_REG_PPC_OR_TSR 32
2406	PPC KVM_REG_PPC_CLEAR_TSR 32
2407	PPC KVM_REG_PPC_MAS0 32
2408	PPC KVM_REG_PPC_MAS1 32
2409	PPC KVM_REG_PPC_MAS2 64
2410	PPC KVM_REG_PPC_MAS7_3 64
2411	PPC KVM_REG_PPC_MAS4 32
2412	PPC KVM_REG_PPC_MAS6 32
2413	PPC KVM_REG_PPC_MMUCFG 32
2414	PPC KVM_REG_PPC_TLB0CFG 32
2415	PPC KVM_REG_PPC_TLB1CFG 32
2416	PPC KVM_REG_PPC_TLB2CFG 32
2417	PPC KVM_REG_PPC_TLB3CFG 32
2418	PPC KVM_REG_PPC_TLB0PS 32
2419	PPC KVM_REG_PPC_TLB1PS 32
2420	PPC KVM_REG_PPC_TLB2PS 32
2421	PPC KVM_REG_PPC_TLB3PS 32
2422	PPC KVM_REG_PPC_EPTCFG 32
2423	PPC KVM_REG_PPC_ICP_STATE 64
2424	PPC KVM_REG_PPC_VP_STATE 128
2425	PPC KVM_REG_PPC_TB_OFFSET 64
2426	PPC KVM_REG_PPC_SPMC1 32
2427	PPC KVM_REG_PPC_SPMC2 32
2428	PPC KVM_REG_PPC_IAMR 64
2429	PPC KVM_REG_PPC_TFHAR 64
2430	PPC KVM_REG_PPC_TFIAR 64
2431	PPC KVM_REG_PPC_TEXASR 64
2432	PPC KVM_REG_PPC_FSCR 64
2433	PPC KVM_REG_PPC_PSPB 32
2434	PPC KVM_REG_PPC_EBBHR 64
2435	PPC KVM_REG_PPC_EBBRR 64
2436	PPC KVM_REG_PPC_BESCR 64
2437	PPC KVM_REG_PPC_TAR 64
2438	PPC KVM_REG_PPC_DPDES 64
2439	PPC KVM_REG_PPC_DAWR 64
2440	PPC KVM_REG_PPC_DAWRX 64
2441	PPC KVM_REG_PPC_CIABR 64
2442	PPC KVM_REG_PPC_IC 64
2443	PPC KVM_REG_PPC_VTB 64
2444	PPC KVM_REG_PPC_CSIGR 64
2445	PPC KVM_REG_PPC_TACR 64
2446	PPC KVM_REG_PPC_TCSCR 64
2447	PPC KVM_REG_PPC_PID 64
2448	PPC KVM_REG_PPC_ACOP 64
2449	PPC KVM_REG_PPC_VRSAVE 32
2450	PPC KVM_REG_PPC_LPCR 32
2451	PPC KVM_REG_PPC_LPCR_64 64
2452	PPC KVM_REG_PPC_PPR 64
2453	PPC KVM_REG_PPC_ARCH_COMPAT 32
2454	PPC KVM_REG_PPC_DABRX 32
2455	PPC KVM_REG_PPC_WORT 64
2456	PPC KVM_REG_PPC_SPRG9 64
2457	PPC KVM_REG_PPC_DBSR 32
2458	PPC KVM_REG_PPC_TIDR 64
2459	PPC KVM_REG_PPC_PSSCR 64
2460	PPC KVM_REG_PPC_DEC_EXPIRY 64
2461	PPC KVM_REG_PPC_PTCR 64
2462	PPC KVM_REG_PPC_HASHKEYR 64
2463	PPC KVM_REG_PPC_HASHPKEYR 64
2464	PPC KVM_REG_PPC_DAWR1 64
2465	PPC KVM_REG_PPC_DAWRX1 64
2466	PPC KVM_REG_PPC_DEXCR 64
2467	PPC KVM_REG_PPC_TM_GPR0 64
2468	...
2469	PPC KVM_REG_PPC_TM_GPR31 64
2470	PPC KVM_REG_PPC_TM_VSR0 128
2471	...
2472	PPC KVM_REG_PPC_TM_VSR63 128
2473	PPC KVM_REG_PPC_TM_CR 64
2474	PPC KVM_REG_PPC_TM_LR 64
2475	PPC KVM_REG_PPC_TM_CTR 64
2476	PPC KVM_REG_PPC_TM_FPSCR 64
2477	PPC KVM_REG_PPC_TM_AMR 64
2478	PPC KVM_REG_PPC_TM_PPR 64
2479	PPC KVM_REG_PPC_TM_VRSAVE 64
2480	PPC KVM_REG_PPC_TM_VSCR 32
2481	PPC KVM_REG_PPC_TM_DSCR 64
2482	PPC KVM_REG_PPC_TM_TAR 64
2483	PPC KVM_REG_PPC_TM_XER 64
2484
2485	MIPS KVM_REG_MIPS_R0 64
2486	...
2487	MIPS KVM_REG_MIPS_R31 64
2488	MIPS KVM_REG_MIPS_HI 64
2489	MIPS KVM_REG_MIPS_LO 64
2490	MIPS KVM_REG_MIPS_PC 64
2491	MIPS KVM_REG_MIPS_CP0_INDEX 32
2492	MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64
2493	MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64
2494	MIPS KVM_REG_MIPS_CP0_CONTEXT 64
2495	MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32
2496	MIPS KVM_REG_MIPS_CP0_USERLOCAL 64
2497	MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64
2498	MIPS KVM_REG_MIPS_CP0_PAGEMASK 32
2499	MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32
2500	MIPS KVM_REG_MIPS_CP0_SEGCTL0 64
2501	MIPS KVM_REG_MIPS_CP0_SEGCTL1 64
2502	MIPS KVM_REG_MIPS_CP0_SEGCTL2 64
2503	MIPS KVM_REG_MIPS_CP0_PWBASE 64
2504	MIPS KVM_REG_MIPS_CP0_PWFIELD 64
2505	MIPS KVM_REG_MIPS_CP0_PWSIZE 64
2506	MIPS KVM_REG_MIPS_CP0_WIRED 32
2507	MIPS KVM_REG_MIPS_CP0_PWCTL 32
2508	MIPS KVM_REG_MIPS_CP0_HWRENA 32
2509	MIPS KVM_REG_MIPS_CP0_BADVADDR 64
2510	MIPS KVM_REG_MIPS_CP0_BADINSTR 32
2511	MIPS KVM_REG_MIPS_CP0_BADINSTRP 32
2512	MIPS KVM_REG_MIPS_CP0_COUNT 32
2513	MIPS KVM_REG_MIPS_CP0_ENTRYHI 64
2514	MIPS KVM_REG_MIPS_CP0_COMPARE 32
2515	MIPS KVM_REG_MIPS_CP0_STATUS 32
2516	MIPS KVM_REG_MIPS_CP0_INTCTL 32
2517	MIPS KVM_REG_MIPS_CP0_CAUSE 32
2518	MIPS KVM_REG_MIPS_CP0_EPC 64
2519	MIPS KVM_REG_MIPS_CP0_PRID 32
2520	MIPS KVM_REG_MIPS_CP0_EBASE 64
2521	MIPS KVM_REG_MIPS_CP0_CONFIG 32
2522	MIPS KVM_REG_MIPS_CP0_CONFIG1 32
2523	MIPS KVM_REG_MIPS_CP0_CONFIG2 32
2524	MIPS KVM_REG_MIPS_CP0_CONFIG3 32
2525	MIPS KVM_REG_MIPS_CP0_CONFIG4 32
2526	MIPS KVM_REG_MIPS_CP0_CONFIG5 32
2527	MIPS KVM_REG_MIPS_CP0_CONFIG7 32
2528	MIPS KVM_REG_MIPS_CP0_XCONTEXT 64
2529	MIPS KVM_REG_MIPS_CP0_ERROREPC 64
2530	MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64
2531	MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64
2532	MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64
2533	MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64
2534	MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64
2535	MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64
2536	MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64
2537	MIPS KVM_REG_MIPS_COUNT_CTL 64
2538	MIPS KVM_REG_MIPS_COUNT_RESUME 64
2539	MIPS KVM_REG_MIPS_COUNT_HZ 64
2540	MIPS KVM_REG_MIPS_FPR_32(0..31) 32
2541	MIPS KVM_REG_MIPS_FPR_64(0..31) 64
2542	MIPS KVM_REG_MIPS_VEC_128(0..31) 128
2543	MIPS KVM_REG_MIPS_FCR_IR 32
2544	MIPS KVM_REG_MIPS_FCR_CSR 32
2545	MIPS KVM_REG_MIPS_MSA_IR 32
2546	MIPS KVM_REG_MIPS_MSA_CSR 32
2547	======= =============================== ============
2548
2549	ARM registers are mapped using the lower 32 bits. The upper 16 of that
2550	is the register group type, or coprocessor number:
2551
2552	ARM core registers have the following id bit patterns::
2553
2554	0x4020 0000 0010 <index into the kvm_regs struct:16>
2555
2556	ARM 32-bit CP15 registers have the following id bit patterns::
2557
2558	0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>
2559
2560	ARM 64-bit CP15 registers have the following id bit patterns::
2561
2562	0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>
2563
2564	ARM CCSIDR registers are demultiplexed by CSSELR value::
2565
2566	0x4020 0000 0011 00 <csselr:8>
2567
2568	ARM 32-bit VFP control registers have the following id bit patterns::
2569
2570	0x4020 0000 0012 1 <regno:12>
2571
2572	ARM 64-bit FP registers have the following id bit patterns::
2573
2574	0x4030 0000 0012 0 <regno:12>
2575
2576	ARM firmware pseudo-registers have the following bit pattern::
2577
2578	0x4030 0000 0014 <regno:16>
2579
2580
2581	arm64 registers are mapped using the lower 32 bits. The upper 16 of
2582	that is the register group type, or coprocessor number:
2583
2584	arm64 core/FP-SIMD registers have the following id bit patterns. Note
2585	that the size of the access is variable, as the kvm_regs structure
2586	contains elements ranging from 32 to 128 bits. The index is a 32bit
2587	value in the kvm_regs structure seen as a 32bit array::
2588
2589	0x60x0 0000 0010 <index into the kvm_regs struct:16>
2590
2591	Specifically:
2592
2593	======================= ========= ===== =======================================
2594	Encoding Register Bits kvm_regs member
2595	======================= ========= ===== =======================================
2596	0x6030 0000 0010 0000 X0 64 regs.regs[0]
2597	0x6030 0000 0010 0002 X1 64 regs.regs[1]
2598	...
2599	0x6030 0000 0010 003c X30 64 regs.regs[30]
2600	0x6030 0000 0010 003e SP 64 regs.sp
2601	0x6030 0000 0010 0040 PC 64 regs.pc
2602	0x6030 0000 0010 0042 PSTATE 64 regs.pstate
2603	0x6030 0000 0010 0044 SP_EL1 64 sp_el1
2604	0x6030 0000 0010 0046 ELR_EL1 64 elr_el1
2605	0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC)
2606	0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT]
2607	0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND]
2608	0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ]
2609	0x6030 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ]
2610	0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_
2611	0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_
2612	...
2613	0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_
2614	0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr
2615	0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr
2616	======================= ========= ===== =======================================
2617
2618	.. [1] These encodings are not accepted for SVE-enabled vcpus. See
2619	:ref:`KVM_ARM_VCPU_INIT`.
2620
2621	The equivalent register content can be accessed via bits [127:0] of
2622	the corresponding SVE Zn registers instead for vcpus that have SVE
2623	enabled (see below).
2624
2625	arm64 CCSIDR registers are demultiplexed by CSSELR value::
2626
2627	0x6020 0000 0011 00 <csselr:8>
2628
2629	arm64 system registers have the following id bit patterns::
2630
2631	0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3>
2632
2633	.. warning::
2634
2635	Two system register IDs do not follow the specified pattern. These
2636	are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to
2637	system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These
2638	two had their values accidentally swapped, which means TIMER_CVAL is
2639	derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is
2640	derived from the register encoding for CNTV_CVAL_EL0. As this is
2641	API, it must remain this way.
2642
2643	arm64 firmware pseudo-registers have the following bit pattern::
2644
2645	0x6030 0000 0014 <regno:16>
2646
2647	arm64 SVE registers have the following bit patterns::
2648
2649	0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048slice + 2047 : 2048slice]
2650	0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256slice + 255 : 256slice]
2651	0x6050 0000 0015 060 <slice:5> FFR bits[256slice + 255 : 256slice]
2652	0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register
2653
2654	Access to register IDs where 2048 * slice >= 128 * max_vq will fail with
2655	ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit
2656	quadwords: see [2]_ below.
2657
2658	These registers are only accessible on vcpus for which SVE is enabled.
2659	See KVM_ARM_VCPU_INIT for details.
2660
2661	In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not
2662	accessible until the vcpu's SVE configuration has been finalized
2663	using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT
2664	and KVM_ARM_VCPU_FINALIZE for more information about this procedure.
2665
2666	KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector
2667	lengths supported by the vcpu to be discovered and configured by
2668	userspace. When transferred to or from user memory via KVM_GET_ONE_REG
2669	or KVM_SET_ONE_REG, the value of this register is of type
2670	__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as
2671	follows::
2672
2673	__u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS];
2674
2675	if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX &&
2676	((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >>
2677	((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1))
2678	/* Vector length vq * 16 bytes supported */
2679	else
2680	/* Vector length vq * 16 bytes not supported */
2681
2682	.. [2] The maximum value vq for which the above condition is true is
2683	max_vq. This is the maximum vector length available to the guest on
2684	this vcpu, and determines which register slices are visible through
2685	this ioctl interface.
2686
2687	(See Documentation/arch/arm64/sve.rst for an explanation of the "vq"
2688	nomenclature.)
2689
2690	KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT.
2691	KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that
2692	the host supports.
2693
2694	Userspace may subsequently modify it if desired until the vcpu's SVE
2695	configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE).
2696
2697	Apart from simply removing all vector lengths from the host set that
2698	exceed some value, support for arbitrarily chosen sets of vector lengths
2699	is hardware-dependent and may not be available. Attempting to configure
2700	an invalid set of vector lengths via KVM_SET_ONE_REG will fail with
2701	EINVAL.
2702
2703	After the vcpu's SVE configuration is finalized, further attempts to
2704	write this register will fail with EPERM.
2705
2706	arm64 bitmap feature firmware pseudo-registers have the following bit pattern::
2707
2708	0x6030 0000 0016 <regno:16>
2709
2710	The bitmap feature firmware registers exposes the hypercall services that
2711	are available for userspace to configure. The set bits corresponds to the
2712	services that are available for the guests to access. By default, KVM
2713	sets all the supported bits during VM initialization. The userspace can
2714	discover the available services via KVM_GET_ONE_REG, and write back the
2715	bitmap corresponding to the features that it wishes guests to see via
2716	KVM_SET_ONE_REG.
2717
2718	Note: These registers are immutable once any of the vCPUs of the VM has
2719	run at least once. A KVM_SET_ONE_REG in such a scenario will return
2720	a -EBUSY to userspace.
2721
2722	(See Documentation/virt/kvm/arm/hypercalls.rst for more details.)
2723
2724
2725	MIPS registers are mapped using the lower 32 bits. The upper 16 of that is
2726	the register group type:
2727
2728	MIPS core registers (see above) have the following id bit patterns::
2729
2730	0x7030 0000 0000 <reg:16>
2731
2732	MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit
2733	patterns depending on whether they're 32-bit or 64-bit registers::
2734
2735	0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit)
2736	0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit)
2737
2738	Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64
2739	versions of the EntryLo registers regardless of the word size of the host
2740	hardware, host kernel, guest, and whether XPA is present in the guest, i.e.
2741	with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and
2742	the PFNX field starting at bit 30.
2743
2744	MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit
2745	patterns::
2746
2747	0x7030 0000 0001 01 <reg:8>
2748
2749	MIPS KVM control registers (see above) have the following id bit patterns::
2750
2751	0x7030 0000 0002 <reg:16>
2752
2753	MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following
2754	id bit patterns depending on the size of the register being accessed. They are
2755	always accessed according to the current guest FPU mode (Status.FR and
2756	Config5.FRE), i.e. as the guest would see them, and they become unpredictable
2757	if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector
2758	registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they
2759	overlap the FPU registers::
2760
2761	0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers)
2762	0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers)
2763	0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers)
2764
2765	MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the
2766	following id bit patterns::
2767
2768	0x7020 0000 0003 01 <0:3> <reg:5>
2769
2770	MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the
2771	following id bit patterns::
2772
2773	0x7020 0000 0003 02 <0:3> <reg:5>
2774
2775	RISC-V registers are mapped using the lower 32 bits. The upper 8 bits of
2776	that is the register group type.
2777
2778	RISC-V config registers are meant for configuring a Guest VCPU and it has
2779	the following id bit patterns::
2780
2781	0x8020 0000 01 <index into the kvm_riscv_config struct:24> (32bit Host)
2782	0x8030 0000 01 <index into the kvm_riscv_config struct:24> (64bit Host)
2783
2784	Following are the RISC-V config registers:
2785
2786	======================= ========= =============================================
2787	Encoding Register Description
2788	======================= ========= =============================================
2789	0x80x0 0000 0100 0000 isa ISA feature bitmap of Guest VCPU
2790	======================= ========= =============================================
2791
2792	The isa config register can be read anytime but can only be written before
2793	a Guest VCPU runs. It will have ISA feature bits matching underlying host
2794	set by default.
2795
2796	RISC-V core registers represent the general execution state of a Guest VCPU
2797	and it has the following id bit patterns::
2798
2799	0x8020 0000 02 <index into the kvm_riscv_core struct:24> (32bit Host)
2800	0x8030 0000 02 <index into the kvm_riscv_core struct:24> (64bit Host)
2801
2802	Following are the RISC-V core registers:
2803
2804	======================= ========= =============================================
2805	Encoding Register Description
2806	======================= ========= =============================================
2807	0x80x0 0000 0200 0000 regs.pc Program counter
2808	0x80x0 0000 0200 0001 regs.ra Return address
2809	0x80x0 0000 0200 0002 regs.sp Stack pointer
2810	0x80x0 0000 0200 0003 regs.gp Global pointer
2811	0x80x0 0000 0200 0004 regs.tp Task pointer
2812	0x80x0 0000 0200 0005 regs.t0 Caller saved register 0
2813	0x80x0 0000 0200 0006 regs.t1 Caller saved register 1
2814	0x80x0 0000 0200 0007 regs.t2 Caller saved register 2
2815	0x80x0 0000 0200 0008 regs.s0 Callee saved register 0
2816	0x80x0 0000 0200 0009 regs.s1 Callee saved register 1
2817	0x80x0 0000 0200 000a regs.a0 Function argument (or return value) 0
2818	0x80x0 0000 0200 000b regs.a1 Function argument (or return value) 1
2819	0x80x0 0000 0200 000c regs.a2 Function argument 2
2820	0x80x0 0000 0200 000d regs.a3 Function argument 3
2821	0x80x0 0000 0200 000e regs.a4 Function argument 4
2822	0x80x0 0000 0200 000f regs.a5 Function argument 5
2823	0x80x0 0000 0200 0010 regs.a6 Function argument 6
2824	0x80x0 0000 0200 0011 regs.a7 Function argument 7
2825	0x80x0 0000 0200 0012 regs.s2 Callee saved register 2
2826	0x80x0 0000 0200 0013 regs.s3 Callee saved register 3
2827	0x80x0 0000 0200 0014 regs.s4 Callee saved register 4
2828	0x80x0 0000 0200 0015 regs.s5 Callee saved register 5
2829	0x80x0 0000 0200 0016 regs.s6 Callee saved register 6
2830	0x80x0 0000 0200 0017 regs.s7 Callee saved register 7
2831	0x80x0 0000 0200 0018 regs.s8 Callee saved register 8
2832	0x80x0 0000 0200 0019 regs.s9 Callee saved register 9
2833	0x80x0 0000 0200 001a regs.s10 Callee saved register 10
2834	0x80x0 0000 0200 001b regs.s11 Callee saved register 11
2835	0x80x0 0000 0200 001c regs.t3 Caller saved register 3
2836	0x80x0 0000 0200 001d regs.t4 Caller saved register 4
2837	0x80x0 0000 0200 001e regs.t5 Caller saved register 5
2838	0x80x0 0000 0200 001f regs.t6 Caller saved register 6
2839	0x80x0 0000 0200 0020 mode Privilege mode (1 = S-mode or 0 = U-mode)
2840	======================= ========= =============================================
2841
2842	RISC-V csr registers represent the supervisor mode control/status registers
2843	of a Guest VCPU and it has the following id bit patterns::
2844
2845	0x8020 0000 03 <index into the kvm_riscv_csr struct:24> (32bit Host)
2846	0x8030 0000 03 <index into the kvm_riscv_csr struct:24> (64bit Host)
2847
2848	Following are the RISC-V csr registers:
2849
2850	======================= ========= =============================================
2851	Encoding Register Description
2852	======================= ========= =============================================
2853	0x80x0 0000 0300 0000 sstatus Supervisor status
2854	0x80x0 0000 0300 0001 sie Supervisor interrupt enable
2855	0x80x0 0000 0300 0002 stvec Supervisor trap vector base
2856	0x80x0 0000 0300 0003 sscratch Supervisor scratch register
2857	0x80x0 0000 0300 0004 sepc Supervisor exception program counter
2858	0x80x0 0000 0300 0005 scause Supervisor trap cause
2859	0x80x0 0000 0300 0006 stval Supervisor bad address or instruction
2860	0x80x0 0000 0300 0007 sip Supervisor interrupt pending
2861	0x80x0 0000 0300 0008 satp Supervisor address translation and protection
2862	======================= ========= =============================================
2863
2864	RISC-V timer registers represent the timer state of a Guest VCPU and it has
2865	the following id bit patterns::
2866
2867	0x8030 0000 04 <index into the kvm_riscv_timer struct:24>
2868
2869	Following are the RISC-V timer registers:
2870
2871	======================= ========= =============================================
2872	Encoding Register Description
2873	======================= ========= =============================================
2874	0x8030 0000 0400 0000 frequency Time base frequency (read-only)
2875	0x8030 0000 0400 0001 time Time value visible to Guest
2876	0x8030 0000 0400 0002 compare Time compare programmed by Guest
2877	0x8030 0000 0400 0003 state Time compare state (1 = ON or 0 = OFF)
2878	======================= ========= =============================================
2879
2880	RISC-V F-extension registers represent the single precision floating point
2881	state of a Guest VCPU and it has the following id bit patterns::
2882
2883	0x8020 0000 05 <index into the __riscv_f_ext_state struct:24>
2884
2885	Following are the RISC-V F-extension registers:
2886
2887	======================= ========= =============================================
2888	Encoding Register Description
2889	======================= ========= =============================================
2890	0x8020 0000 0500 0000 f[0] Floating point register 0
2891	...
2892	0x8020 0000 0500 001f f[31] Floating point register 31
2893	0x8020 0000 0500 0020 fcsr Floating point control and status register
2894	======================= ========= =============================================
2895
2896	RISC-V D-extension registers represent the double precision floating point
2897	state of a Guest VCPU and it has the following id bit patterns::
2898
2899	0x8020 0000 06 <index into the __riscv_d_ext_state struct:24> (fcsr)
2900	0x8030 0000 06 <index into the __riscv_d_ext_state struct:24> (non-fcsr)
2901
2902	Following are the RISC-V D-extension registers:
2903
2904	======================= ========= =============================================
2905	Encoding Register Description
2906	======================= ========= =============================================
2907	0x8030 0000 0600 0000 f[0] Floating point register 0
2908	...
2909	0x8030 0000 0600 001f f[31] Floating point register 31
2910	0x8020 0000 0600 0020 fcsr Floating point control and status register
2911	======================= ========= =============================================
2912
2913	LoongArch registers are mapped using the lower 32 bits. The upper 16 bits of
2914	that is the register group type.
2915
2916	LoongArch csr registers are used to control guest cpu or get status of guest
2917	cpu, and they have the following id bit patterns::
2918
2919	0x9030 0000 0001 00 <reg:5> <sel:3> (64-bit)
2920
2921	LoongArch KVM control registers are used to implement some new defined functions
2922	such as set vcpu counter or reset vcpu, and they have the following id bit patterns::
2923
2924	0x9030 0000 0002 <reg:16>
2925
2926	x86 MSR registers have the following id bit patterns::
2927	0x2030 0002 <msr number:32>
2928
2929	Following are the KVM-defined registers for x86:
2930
2931	======================= ========= =============================================
2932	Encoding Register Description
2933	======================= ========= =============================================
2934	0x2030 0003 0000 0000 SSP Shadow Stack Pointer
2935	======================= ========= =============================================
2936
2937	4.69 KVM_GET_ONE_REG
2938	--------------------
2939
2940	:Capability: KVM_CAP_ONE_REG
2941	:Architectures: all
2942	:Type: vcpu ioctl
2943	:Parameters: struct kvm_one_reg (in and out)
2944	:Returns: 0 on success, negative value on failure
2945
2946	Errors include:
2947
2948	======== ============================================================
2949	ENOENT no such register
2950	EINVAL invalid register ID, or no such register or used with VMs in
2951	protected virtualization mode on s390
2952	EPERM (arm64) register access not allowed before vcpu finalization
2953	======== ============================================================
2954
2955	(These error codes are indicative only: do not rely on a specific error
2956	code being returned in a specific situation.)
2957
2958	This ioctl allows to receive the value of a single register implemented
2959	in a vcpu. The register to read is indicated by the "id" field of the
2960	kvm_one_reg struct passed in. On success, the register value can be found
2961	at the memory location pointed to by "addr".
2962
2963	The list of registers accessible using this interface is identical to the
2964	list in 4.68.
2965
2966
2967	4.70 KVM_KVMCLOCK_CTRL
2968	----------------------
2969
2970	:Capability: KVM_CAP_KVMCLOCK_CTRL
2971	:Architectures: Any that implement pvclocks (currently x86 only)
2972	:Type: vcpu ioctl
2973	:Parameters: None
2974	:Returns: 0 on success, -1 on error
2975
2976	This ioctl sets a flag accessible to the guest indicating that the specified
2977	vCPU has been paused by the host userspace.
2978
2979	The host will set a flag in the pvclock structure that is checked from the
2980	soft lockup watchdog. The flag is part of the pvclock structure that is
2981	shared between guest and host, specifically the second bit of the flags
2982	field of the pvclock_vcpu_time_info structure. It will be set exclusively by
2983	the host and read/cleared exclusively by the guest. The guest operation of
2984	checking and clearing the flag must be an atomic operation so
2985	load-link/store-conditional, or equivalent must be used. There are two cases
2986	where the guest will clear the flag: when the soft lockup watchdog timer resets
2987	itself or when a soft lockup is detected. This ioctl can be called any time
2988	after pausing the vcpu, but before it is resumed.
2989
2990
2991	4.71 KVM_SIGNAL_MSI
2992	-------------------
2993
2994	:Capability: KVM_CAP_SIGNAL_MSI
2995	:Architectures: x86 arm64
2996	:Type: vm ioctl
2997	:Parameters: struct kvm_msi (in)
2998	:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error
2999
3000	Directly inject a MSI message. Only valid with in-kernel irqchip that handles
3001	MSI messages.
3002
3003	::
3004
3005	struct kvm_msi {
3006	__u32 address_lo;
3007	__u32 address_hi;
3008	__u32 data;
3009	__u32 flags;
3010	__u32 devid;
3011	__u8 pad[12];
3012	};
3013
3014	flags:
3015	KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM
3016	KVM_CAP_MSI_DEVID capability advertises the requirement to provide
3017	the device ID. If this capability is not available, userspace
3018	should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail.
3019
3020	If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier
3021	for the device that wrote the MSI message. For PCI, this is usually a
3022	BDF identifier in the lower 16 bits.
3023
3024	On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS
3025	feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled,
3026	address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of
3027	address_hi must be zero.
3028
3029
3030	4.71 KVM_CREATE_PIT2
3031	--------------------
3032
3033	:Capability: KVM_CAP_PIT2
3034	:Architectures: x86
3035	:Type: vm ioctl
3036	:Parameters: struct kvm_pit_config (in)
3037	:Returns: 0 on success, -1 on error
3038
3039	Creates an in-kernel device model for the i8254 PIT. This call is only valid
3040	after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following
3041	parameters have to be passed::
3042
3043	struct kvm_pit_config {
3044	__u32 flags;
3045	__u32 pad[15];
3046	};
3047
3048	Valid flags are::
3049
3050	#define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */
3051
3052	PIT timer interrupts may use a per-VM kernel thread for injection. If it
3053	exists, this thread will have a name of the following pattern::
3054
3055	kvm-pit/<owner-process-pid>
3056
3057	When running a guest with elevated priorities, the scheduling parameters of
3058	this thread may have to be adjusted accordingly.
3059
3060	This IOCTL replaces the obsolete KVM_CREATE_PIT.
3061
3062
3063	4.72 KVM_GET_PIT2
3064	-----------------
3065
3066	:Capability: KVM_CAP_PIT_STATE2
3067	:Architectures: x86
3068	:Type: vm ioctl
3069	:Parameters: struct kvm_pit_state2 (out)
3070	:Returns: 0 on success, -1 on error
3071
3072	Retrieves the state of the in-kernel PIT model. Only valid after
3073	KVM_CREATE_PIT2. The state is returned in the following structure::
3074
3075	struct kvm_pit_state2 {
3076	struct kvm_pit_channel_state channels[3];
3077	__u32 flags;
3078	__u32 reserved[9];
3079	};
3080
3081	Valid flags are::
3082
3083	/* disable PIT in HPET legacy mode */
3084	#define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001
3085	/* speaker port data bit enabled */
3086	#define KVM_PIT_FLAGS_SPEAKER_DATA_ON 0x00000002
3087
3088	This IOCTL replaces the obsolete KVM_GET_PIT.
3089
3090
3091	4.73 KVM_SET_PIT2
3092	-----------------
3093
3094	:Capability: KVM_CAP_PIT_STATE2
3095	:Architectures: x86
3096	:Type: vm ioctl
3097	:Parameters: struct kvm_pit_state2 (in)
3098	:Returns: 0 on success, -1 on error
3099
3100	Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2.
3101	See KVM_GET_PIT2 for details on struct kvm_pit_state2.
3102
3103	.. Tip::
3104	``KVM_SET_PIT2`` strictly adheres to the spec of Intel 8254 PIT. For example,
3105	a ``count`` value of 0 in ``struct kvm_pit_channel_state`` is interpreted as
3106	65536, which is the maximum count value. Refer to `Intel 8254 programmable
3107	interval timer <https://www.scs.stanford.edu/10wi-cs140/pintos/specs/8254.pdf>`_.
3108
3109	This IOCTL replaces the obsolete KVM_SET_PIT.
3110
3111
3112	4.74 KVM_PPC_GET_SMMU_INFO
3113	--------------------------
3114
3115	:Capability: KVM_CAP_PPC_GET_SMMU_INFO
3116	:Architectures: powerpc
3117	:Type: vm ioctl
3118	:Parameters: None
3119	:Returns: 0 on success, -1 on error
3120
3121	This populates and returns a structure describing the features of
3122	the "Server" class MMU emulation supported by KVM.
3123	This can in turn be used by userspace to generate the appropriate
3124	device-tree properties for the guest operating system.
3125
3126	The structure contains some global information, followed by an
3127	array of supported segment page sizes::
3128
3129	struct kvm_ppc_smmu_info {
3130	__u64 flags;
3131	__u32 slb_size;
3132	__u32 pad;
3133	struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
3134	};
3135
3136	The supported flags are:
3137
3138	- KVM_PPC_PAGE_SIZES_REAL:
3139	When that flag is set, guest page sizes must "fit" the backing
3140	store page sizes. When not set, any page size in the list can
3141	be used regardless of how they are backed by userspace.
3142
3143	- KVM_PPC_1T_SEGMENTS
3144	The emulated MMU supports 1T segments in addition to the
3145	standard 256M ones.
3146
3147	- KVM_PPC_NO_HASH
3148	This flag indicates that HPT guests are not supported by KVM,
3149	thus all guests must use radix MMU mode.
3150
3151	The "slb_size" field indicates how many SLB entries are supported
3152
3153	The "sps" array contains 8 entries indicating the supported base
3154	page sizes for a segment in increasing order. Each entry is defined
3155	as follow::
3156
3157	struct kvm_ppc_one_seg_page_size {
3158	__u32 page_shift; /* Base page shift of segment (or 0) */
3159	__u32 slb_enc; /* SLB encoding for BookS */
3160	struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ];
3161	};
3162
3163	An entry with a "page_shift" of 0 is unused. Because the array is
3164	organized in increasing order, a lookup can stop when encountering
3165	such an entry.
3166
3167	The "slb_enc" field provides the encoding to use in the SLB for the
3168	page size. The bits are in positions such as the value can directly
3169	be OR'ed into the "vsid" argument of the slbmte instruction.
3170
3171	The "enc" array is a list which for each of those segment base page
3172	size provides the list of supported actual page sizes (which can be
3173	only larger or equal to the base page size), along with the
3174	corresponding encoding in the hash PTE. Similarly, the array is
3175	8 entries sorted by increasing sizes and an entry with a "0" shift
3176	is an empty entry and a terminator::
3177
3178	struct kvm_ppc_one_page_size {
3179	__u32 page_shift; /* Page shift (or 0) */
3180	__u32 pte_enc; /* Encoding in the HPTE (>>12) */
3181	};
3182
3183	The "pte_enc" field provides a value that can OR'ed into the hash
3184	PTE's RPN field (ie, it needs to be shifted left by 12 to OR it
3185	into the hash PTE second double word).
3186
3187	4.75 KVM_IRQFD
3188	--------------
3189
3190	:Capability: KVM_CAP_IRQFD
3191	:Architectures: x86 s390 arm64
3192	:Type: vm ioctl
3193	:Parameters: struct kvm_irqfd (in)
3194	:Returns: 0 on success, -1 on error
3195
3196	Allows setting an eventfd to directly trigger a guest interrupt.
3197	kvm_irqfd.fd specifies the file descriptor to use as the eventfd and
3198	kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When
3199	an event is triggered on the eventfd, an interrupt is injected into
3200	the guest using the specified gsi pin. The irqfd is removed using
3201	the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd
3202	and kvm_irqfd.gsi.
3203
3204	With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify
3205	mechanism allowing emulation of level-triggered, irqfd-based
3206	interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an
3207	additional eventfd in the kvm_irqfd.resamplefd field. When operating
3208	in resample mode, posting of an interrupt through kvm_irq.fd asserts
3209	the specified gsi in the irqchip. When the irqchip is resampled, such
3210	as from an EOI, the gsi is de-asserted and the user is notified via
3211	kvm_irqfd.resamplefd. It is the user's responsibility to re-queue
3212	the interrupt if the device making use of it still requires service.
3213	Note that closing the resamplefd is not sufficient to disable the
3214	irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment
3215	and need not be specified with KVM_IRQFD_FLAG_DEASSIGN.
3216
3217	On arm64, gsi routing being supported, the following can happen:
3218
3219	- in case no routing entry is associated to this gsi, injection fails
3220	- in case the gsi is associated to an irqchip routing entry,
3221	irqchip.pin + 32 corresponds to the injected SPI ID.
3222	- in case the gsi is associated to an MSI routing entry, the MSI
3223	message and device ID are translated into an LPI (support restricted
3224	to GICv3 ITS in-kernel emulation).
3225
3226	4.76 KVM_PPC_ALLOCATE_HTAB
3227	--------------------------
3228
3229	:Capability: KVM_CAP_PPC_ALLOC_HTAB
3230	:Architectures: powerpc
3231	:Type: vm ioctl
3232	:Parameters: Pointer to u32 containing hash table order (in/out)
3233	:Returns: 0 on success, -1 on error
3234
3235	This requests the host kernel to allocate an MMU hash table for a
3236	guest using the PAPR paravirtualization interface. This only does
3237	anything if the kernel is configured to use the Book 3S HV style of
3238	virtualization. Otherwise the capability doesn't exist and the ioctl
3239	returns an ENOTTY error. The rest of this description assumes Book 3S
3240	HV.
3241
3242	There must be no vcpus running when this ioctl is called; if there
3243	are, it will do nothing and return an EBUSY error.
3244
3245	The parameter is a pointer to a 32-bit unsigned integer variable
3246	containing the order (log base 2) of the desired size of the hash
3247	table, which must be between 18 and 46. On successful return from the
3248	ioctl, the value will not be changed by the kernel.
3249
3250	If no hash table has been allocated when any vcpu is asked to run
3251	(with the KVM_RUN ioctl), the host kernel will allocate a
3252	default-sized hash table (16 MB).
3253
3254	If this ioctl is called when a hash table has already been allocated,
3255	with a different order from the existing hash table, the existing hash
3256	table will be freed and a new one allocated. If this is ioctl is
3257	called when a hash table has already been allocated of the same order
3258	as specified, the kernel will clear out the existing hash table (zero
3259	all HPTEs). In either case, if the guest is using the virtualized
3260	real-mode area (VRMA) facility, the kernel will re-create the VMRA
3261	HPTEs on the next KVM_RUN of any vcpu.
3262
3263	4.77 KVM_S390_INTERRUPT
3264	-----------------------
3265
3266	:Capability: basic
3267	:Architectures: s390
3268	:Type: vm ioctl, vcpu ioctl
3269	:Parameters: struct kvm_s390_interrupt (in)
3270	:Returns: 0 on success, -1 on error
3271
3272	Allows to inject an interrupt to the guest. Interrupts can be floating
3273	(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type.
3274
3275	Interrupt parameters are passed via kvm_s390_interrupt::
3276
3277	struct kvm_s390_interrupt {
3278	__u32 type;
3279	__u32 parm;
3280	__u64 parm64;
3281	};
3282
3283	type can be one of the following:
3284
3285	KVM_S390_SIGP_STOP (vcpu)
3286	- sigp stop; optional flags in parm
3287	KVM_S390_PROGRAM_INT (vcpu)
3288	- program check; code in parm
3289	KVM_S390_SIGP_SET_PREFIX (vcpu)
3290	- sigp set prefix; prefix address in parm
3291	KVM_S390_RESTART (vcpu)
3292	- restart
3293	KVM_S390_INT_CLOCK_COMP (vcpu)
3294	- clock comparator interrupt
3295	KVM_S390_INT_CPU_TIMER (vcpu)
3296	- CPU timer interrupt
3297	KVM_S390_INT_VIRTIO (vm)
3298	- virtio external interrupt; external interrupt
3299	parameters in parm and parm64
3300	KVM_S390_INT_SERVICE (vm)
3301	- sclp external interrupt; sclp parameter in parm
3302	KVM_S390_INT_EMERGENCY (vcpu)
3303	- sigp emergency; source cpu in parm
3304	KVM_S390_INT_EXTERNAL_CALL (vcpu)
3305	- sigp external call; source cpu in parm
3306	KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm)
3307	- compound value to indicate an
3308	I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel);
3309	I/O interruption parameters in parm (subchannel) and parm64 (intparm,
3310	interruption subclass)
3311	KVM_S390_MCHK (vm, vcpu)
3312	- machine check interrupt; cr 14 bits in parm, machine check interrupt
3313	code in parm64 (note that machine checks needing further payload are not
3314	supported by this ioctl)
3315
3316	This is an asynchronous vcpu ioctl and can be invoked from any thread.
3317
3318	4.78 KVM_PPC_GET_HTAB_FD
3319	------------------------
3320
3321	:Capability: KVM_CAP_PPC_HTAB_FD
3322	:Architectures: powerpc
3323	:Type: vm ioctl
3324	:Parameters: Pointer to struct kvm_get_htab_fd (in)
3325	:Returns: file descriptor number (>= 0) on success, -1 on error
3326
3327	This returns a file descriptor that can be used either to read out the
3328	entries in the guest's hashed page table (HPT), or to write entries to
3329	initialize the HPT. The returned fd can only be written to if the
3330	KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and
3331	can only be read if that bit is clear. The argument struct looks like
3332	this::
3333
3334	/* For KVM_PPC_GET_HTAB_FD */
3335	struct kvm_get_htab_fd {
3336	__u64 flags;
3337	__u64 start_index;
3338	__u64 reserved[2];
3339	};
3340
3341	/* Values for kvm_get_htab_fd.flags */
3342	#define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1)
3343	#define KVM_GET_HTAB_WRITE ((__u64)0x2)
3344
3345	The 'start_index' field gives the index in the HPT of the entry at
3346	which to start reading. It is ignored when writing.
3347
3348	Reads on the fd will initially supply information about all
3349	"interesting" HPT entries. Interesting entries are those with the
3350	bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise
3351	all entries. When the end of the HPT is reached, the read() will
3352	return. If read() is called again on the fd, it will start again from
3353	the beginning of the HPT, but will only return HPT entries that have
3354	changed since they were last read.
3355
3356	Data read or written is structured as a header (8 bytes) followed by a
3357	series of valid HPT entries (16 bytes) each. The header indicates how
3358	many valid HPT entries there are and how many invalid entries follow
3359	the valid entries. The invalid entries are not represented explicitly
3360	in the stream. The header format is::
3361
3362	struct kvm_get_htab_header {
3363	__u32 index;
3364	__u16 n_valid;
3365	__u16 n_invalid;
3366	};
3367
3368	Writes to the fd create HPT entries starting at the index given in the
3369	header; first 'n_valid' valid entries with contents from the data
3370	written, then 'n_invalid' invalid entries, invalidating any previously
3371	valid entries found.
3372
3373	4.79 KVM_CREATE_DEVICE
3374	----------------------
3375
3376	:Capability: KVM_CAP_DEVICE_CTRL
3377	:Architectures: all
3378	:Type: vm ioctl
3379	:Parameters: struct kvm_create_device (in/out)
3380	:Returns: 0 on success, -1 on error
3381
3382	Errors:
3383
3384	====== =======================================================
3385	ENODEV The device type is unknown or unsupported
3386	EEXIST Device already created, and this type of device may not
3387	be instantiated multiple times
3388	====== =======================================================
3389
3390	Other error conditions may be defined by individual device types or
3391	have their standard meanings.
3392
3393	Creates an emulated device in the kernel. The file descriptor returned
3394	in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR.
3395
3396	If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the
3397	device type is supported (not necessarily whether it can be created
3398	in the current vm).
3399
3400	Individual devices should not define flags. Attributes should be used
3401	for specifying any behavior that is not implied by the device type
3402	number.
3403
3404	::
3405
3406	struct kvm_create_device {
3407	__u32 type; /* in: KVM_DEV_TYPE_xxx */
3408	__u32 fd; /* out: device handle */
3409	__u32 flags; /* in: KVM_CREATE_DEVICE_xxx */
3410	};
3411
3412	4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR
3413	--------------------------------------------
3414
3415	:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
3416	KVM_CAP_VCPU_ATTRIBUTES for vcpu device
3417	KVM_CAP_SYS_ATTRIBUTES for system (/dev/kvm) device (no set)
3418	:Architectures: x86, arm64, s390
3419	:Type: device ioctl, vm ioctl, vcpu ioctl
3420	:Parameters: struct kvm_device_attr
3421	:Returns: 0 on success, -1 on error
3422
3423	Errors:
3424
3425	===== =============================================================
3426	ENXIO The group or attribute is unknown/unsupported for this device
3427	or hardware support is missing.
3428	EPERM The attribute cannot (currently) be accessed this way
3429	(e.g. read-only attribute, or attribute that only makes
3430	sense when the device is in a different state)
3431	===== =============================================================
3432
3433	Other error conditions may be defined by individual device types.
3434
3435	Gets/sets a specified piece of device configuration and/or state. The
3436	semantics are device-specific. See individual device documentation in
3437	the "devices" directory. As with ONE_REG, the size of the data
3438	transferred is defined by the particular attribute.
3439
3440	::
3441
3442	struct kvm_device_attr {
3443	__u32 flags; /* no flags currently defined */
3444	__u32 group; /* device-defined */
3445	__u64 attr; /* group-defined */
3446	__u64 addr; /* userspace address of attr data */
3447	};
3448
3449	4.81 KVM_HAS_DEVICE_ATTR
3450	------------------------
3451
3452	:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
3453	KVM_CAP_VCPU_ATTRIBUTES for vcpu device
3454	KVM_CAP_SYS_ATTRIBUTES for system (/dev/kvm) device
3455	:Type: device ioctl, vm ioctl, vcpu ioctl
3456	:Parameters: struct kvm_device_attr
3457	:Returns: 0 on success, -1 on error
3458
3459	Errors:
3460
3461	===== =============================================================
3462	ENXIO The group or attribute is unknown/unsupported for this device
3463	or hardware support is missing.
3464	===== =============================================================
3465
3466	Tests whether a device supports a particular attribute. A successful
3467	return indicates the attribute is implemented. It does not necessarily
3468	indicate that the attribute can be read or written in the device's
3469	current state. "addr" is ignored.
3470
3471	.. _KVM_ARM_VCPU_INIT:
3472
3473	4.82 KVM_ARM_VCPU_INIT
3474	----------------------
3475
3476	:Capability: basic
3477	:Architectures: arm64
3478	:Type: vcpu ioctl
3479	:Parameters: struct kvm_vcpu_init (in)
3480	:Returns: 0 on success; -1 on error
3481
3482	Errors:
3483
3484	====== =================================================================
3485	EINVAL the target is unknown, or the combination of features is invalid.
3486	ENOENT a features bit specified is unknown.
3487	====== =================================================================
3488
3489	This tells KVM what type of CPU to present to the guest, and what
3490	optional features it should have. This will cause a reset of the cpu
3491	registers to their initial values. If this is not called, KVM_RUN will
3492	return ENOEXEC for that vcpu.
3493
3494	The initial values are defined as:
3495	- Processor state:
3496	* AArch64: EL1h, D, A, I and F bits set. All other bits
3497	are cleared.
3498	* AArch32: SVC, A, I and F bits set. All other bits are
3499	cleared.
3500	- General Purpose registers, including PC and SP: set to 0
3501	- FPSIMD/NEON registers: set to 0
3502	- SVE registers: set to 0
3503	- System registers: Reset to their architecturally defined
3504	values as for a warm reset to EL1 (resp. SVC) or EL2 (in the
3505	case of EL2 being enabled).
3506
3507	Note that because some registers reflect machine topology, all vcpus
3508	should be created before this ioctl is invoked.
3509
3510	Userspace can call this function multiple times for a given vcpu, including
3511	after the vcpu has been run. This will reset the vcpu to its initial
3512	state. All calls to this function after the initial call must use the same
3513	target and same set of feature flags, otherwise EINVAL will be returned.
3514
3515	Possible features:
3516
3517	- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
3518	Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on
3519	and execute guest code when KVM_RUN is called.
3520	- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
3521	Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
3522	- KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision
3523	backward compatible with v0.2) for the CPU.
3524	Depends on KVM_CAP_ARM_PSCI_0_2.
3525	- KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
3526	Depends on KVM_CAP_ARM_PMU_V3.
3527	- KVM_ARM_VCPU_PMU_V3_STRICT: Enable strict PMUv3 UAPI.
3528	Requires KVM_ARM_VCPU_PMU_V3. Depends on KVM_CAP_ARM_PMU_V3_STRICT.
3529	When enabled:
3530
3531	* Userspace must explicitly select a PMU implementation before
3532	initializing the PMU or configuring a PMU event filter
3533
3534	* If the PMU implements FEAT_PMUv3p4, PMMIR_EL1.SLOTS provides the
3535	hardware value of the underlying implementation
3536
3537	* Writes to PMCR_EL0.N via KVM_SET_ONE_REG are ignored
3538
3539	- KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication
3540	for arm64 only.
3541	Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS.
3542	If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
3543	both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
3544	KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
3545	requested.
3546
3547	- KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication
3548	for arm64 only.
3549	Depends on KVM_CAP_ARM_PTRAUTH_GENERIC.
3550	If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
3551	both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
3552	KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
3553	requested.
3554
3555	- KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only).
3556	Depends on KVM_CAP_ARM_SVE.
3557	Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
3558
3559	* After KVM_ARM_VCPU_INIT:
3560
3561	- KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the
3562	initial value of this pseudo-register indicates the best set of
3563	vector lengths possible for a vcpu on this host.
3564
3565	* Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
3566
3567	- KVM_RUN and KVM_GET_REG_LIST are not available;
3568
3569	- KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access
3570	the scalable architectural SVE registers
3571	KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or
3572	KVM_REG_ARM64_SVE_FFR;
3573
3574	- KVM_REG_ARM64_SVE_VLS may optionally be written using
3575	KVM_SET_ONE_REG, to modify the set of vector lengths available
3576	for the vcpu.
3577
3578	* After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
3579
3580	- the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can
3581	no longer be written using KVM_SET_ONE_REG.
3582
3583	- KVM_ARM_VCPU_HAS_EL2: Enable Nested Virtualisation support,
3584	booting the guest from EL2 instead of EL1.
3585	Depends on KVM_CAP_ARM_EL2.
3586	The VM is running with HCR_EL2.E2H being RES1 (VHE) unless
3587	KVM_ARM_VCPU_HAS_EL2_E2H0 is also set.
3588
3589	- KVM_ARM_VCPU_HAS_EL2_E2H0: Restrict Nested Virtualisation
3590	support to HCR_EL2.E2H being RES0 (non-VHE).
3591	Depends on KVM_CAP_ARM_EL2_E2H0.
3592	KVM_ARM_VCPU_HAS_EL2 must also be set.
3593
3594	4.83 KVM_ARM_PREFERRED_TARGET
3595	-----------------------------
3596
3597	:Capability: basic
3598	:Architectures: arm64
3599	:Type: vm ioctl
3600	:Parameters: struct kvm_vcpu_init (out)
3601	:Returns: 0 on success; -1 on error
3602
3603	Errors:
3604
3605	====== ==========================================
3606	ENODEV no preferred target available for the host
3607	====== ==========================================
3608
3609	This queries KVM for preferred CPU target type which can be emulated
3610	by KVM on underlying host.
3611
3612	The ioctl returns struct kvm_vcpu_init instance containing information
3613	about preferred CPU target type and recommended features for it. The
3614	kvm_vcpu_init->features bitmap returned will have feature bits set if
3615	the preferred target recommends setting these features, but this is
3616	not mandatory.
3617
3618	The information returned by this ioctl can be used to prepare an instance
3619	of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in
3620	VCPU matching underlying host.
3621
3622
3623	4.84 KVM_GET_REG_LIST
3624	---------------------
3625
3626	:Capability: basic
3627	:Architectures: arm64, mips, riscv, x86 (if KVM_CAP_ONE_REG)
3628	:Type: vcpu ioctl
3629	:Parameters: struct kvm_reg_list (in/out)
3630	:Returns: 0 on success; -1 on error
3631
3632	Errors:
3633
3634	===== ==============================================================
3635	E2BIG the reg index list is too big to fit in the array specified by
3636	the user (the number required will be written into n).
3637	===== ==============================================================
3638
3639	::
3640
3641	struct kvm_reg_list {
3642	__u64 n; /* number of registers in reg[] */
3643	__u64 reg[0];
3644	};
3645
3646	This ioctl returns the guest registers that are supported for the
3647	KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
3648
3649	Note that s390 does not support KVM_GET_REG_LIST for historical reasons
3650	(read: nobody cared). The set of registers in kernels 4.x and newer is:
3651
3652	- KVM_REG_S390_TODPR
3653
3654	- KVM_REG_S390_EPOCHDIFF
3655
3656	- KVM_REG_S390_CPU_TIMER
3657
3658	- KVM_REG_S390_CLOCK_COMP
3659
3660	- KVM_REG_S390_PFTOKEN
3661
3662	- KVM_REG_S390_PFCOMPARE
3663
3664	- KVM_REG_S390_PFSELECT
3665
3666	- KVM_REG_S390_PP
3667
3668	- KVM_REG_S390_GBEA
3669
3670	Note, for x86, all MSRs enumerated by KVM_GET_MSR_INDEX_LIST are supported as
3671	type KVM_X86_REG_TYPE_MSR, but are NOT enumerated via KVM_GET_REG_LIST.
3672
3673	4.85 KVM_ARM_SET_DEVICE_ADDR (deprecated)
3674	-----------------------------------------
3675
3676	:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
3677	:Architectures: arm64
3678	:Type: vm ioctl
3679	:Parameters: struct kvm_arm_device_address (in)
3680	:Returns: 0 on success, -1 on error
3681
3682	Errors:
3683
3684	====== ============================================
3685	ENODEV The device id is unknown
3686	ENXIO Device not supported on current system
3687	EEXIST Address already set
3688	E2BIG Address outside guest physical address space
3689	EBUSY Address overlaps with other device range
3690	====== ============================================
3691
3692	::
3693
3694	struct kvm_arm_device_addr {
3695	__u64 id;
3696	__u64 addr;
3697	};
3698
3699	Specify a device address in the guest's physical address space where guests
3700	can access emulated or directly exposed devices, which the host kernel needs
3701	to know about. The id field is an architecture specific identifier for a
3702	specific device.
3703
3704	arm64 divides the id field into two parts, a device id and an
3705	address type id specific to the individual device::
3706
3707	bits: \| 63 ... 32 \| 31 ... 16 \| 15 ... 0 \|
3708	field: \| 0x00000000 \| device id \| addr type id \|
3709
3710	arm64 currently only require this when using the in-kernel GIC
3711	support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2
3712	as the device id. When setting the base address for the guest's
3713	mapping of the VGIC virtual CPU and distributor interface, the ioctl
3714	must be called after calling KVM_CREATE_IRQCHIP, but before calling
3715	KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the
3716	base addresses will return -EEXIST.
3717
3718	Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API
3719	should be used instead.
3720
3721
3722	4.86 KVM_PPC_RTAS_DEFINE_TOKEN
3723	------------------------------
3724
3725	:Capability: KVM_CAP_PPC_RTAS
3726	:Architectures: ppc
3727	:Type: vm ioctl
3728	:Parameters: struct kvm_rtas_token_args
3729	:Returns: 0 on success, -1 on error
3730
3731	Defines a token value for a RTAS (Run Time Abstraction Services)
3732	service in order to allow it to be handled in the kernel. The
3733	argument struct gives the name of the service, which must be the name
3734	of a service that has a kernel-side implementation. If the token
3735	value is non-zero, it will be associated with that service, and
3736	subsequent RTAS calls by the guest specifying that token will be
3737	handled by the kernel. If the token value is 0, then any token
3738	associated with the service will be forgotten, and subsequent RTAS
3739	calls by the guest for that service will be passed to userspace to be
3740	handled.
3741
3742	4.87 KVM_SET_GUEST_DEBUG
3743	------------------------
3744
3745	:Capability: KVM_CAP_SET_GUEST_DEBUG
3746	:Architectures: x86, s390, ppc, arm64
3747	:Type: vcpu ioctl
3748	:Parameters: struct kvm_guest_debug (in)
3749	:Returns: 0 on success; -1 on error
3750
3751	::
3752
3753	struct kvm_guest_debug {
3754	__u32 control;
3755	__u32 pad;
3756	struct kvm_guest_debug_arch arch;
3757	};
3758
3759	Set up the processor specific debug registers and configure vcpu for
3760	handling guest debug events. There are two parts to the structure, the
3761	first a control bitfield indicates the type of debug events to handle
3762	when running. Common control bits are:
3763
3764	- KVM_GUESTDBG_ENABLE: guest debugging is enabled
3765	- KVM_GUESTDBG_SINGLESTEP: the next run should single-step
3766
3767	The top 16 bits of the control field are architecture specific control
3768	flags which can include the following:
3769
3770	- KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64]
3771	- KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390]
3772	- KVM_GUESTDBG_USE_HW: using hardware debug events [arm64]
3773	- KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86]
3774	- KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86]
3775	- KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390]
3776	- KVM_GUESTDBG_BLOCKIRQ: avoid injecting interrupts/NMI/SMI [x86]
3777
3778	For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints
3779	are enabled in memory so we need to ensure breakpoint exceptions are
3780	correctly trapped and the KVM run loop exits at the breakpoint and not
3781	running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP
3782	we need to ensure the guest vCPUs architecture specific registers are
3783	updated to the correct (supplied) values.
3784
3785	The second part of the structure is architecture specific and
3786	typically contains a set of debug registers.
3787
3788	For arm64 the number of debug registers is implementation defined and
3789	can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and
3790	KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number
3791	indicating the number of supported registers.
3792
3793	For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether
3794	the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported.
3795
3796	Also when supported, KVM_CAP_SET_GUEST_DEBUG2 capability indicates the
3797	supported KVM_GUESTDBG_* bits in the control field.
3798
3799	When debug events exit the main run loop with the reason
3800	KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run
3801	structure containing architecture specific debug information.
3802
3803	4.88 KVM_GET_EMULATED_CPUID
3804	---------------------------
3805
3806	:Capability: KVM_CAP_EXT_EMUL_CPUID
3807	:Architectures: x86
3808	:Type: system ioctl
3809	:Parameters: struct kvm_cpuid2 (in/out)
3810	:Returns: 0 on success, -1 on error
3811
3812	::
3813
3814	struct kvm_cpuid2 {
3815	__u32 nent;
3816	__u32 flags;
3817	struct kvm_cpuid_entry2 entries[0];
3818	};
3819
3820	The member 'flags' is used for passing flags from userspace.
3821
3822	::
3823
3824	#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0)
3825	#define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */
3826	#define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */
3827
3828	struct kvm_cpuid_entry2 {
3829	__u32 function;
3830	__u32 index;
3831	__u32 flags;
3832	__u32 eax;
3833	__u32 ebx;
3834	__u32 ecx;
3835	__u32 edx;
3836	__u32 padding[3];
3837	};
3838
3839	This ioctl returns x86 cpuid features which are emulated by
3840	kvm.Userspace can use the information returned by this ioctl to query
3841	which features are emulated by kvm instead of being present natively.
3842
3843	Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2
3844	structure with the 'nent' field indicating the number of entries in
3845	the variable-size array 'entries'. If the number of entries is too low
3846	to describe the cpu capabilities, an error (E2BIG) is returned. If the
3847	number is too high, the 'nent' field is adjusted and an error (ENOMEM)
3848	is returned. If the number is just right, the 'nent' field is adjusted
3849	to the number of valid entries in the 'entries' array, which is then
3850	filled.
3851
3852	The entries returned are the set CPUID bits of the respective features
3853	which kvm emulates, as returned by the CPUID instruction, with unknown
3854	or unsupported feature bits cleared.
3855
3856	Features like x2apic, for example, may not be present in the host cpu
3857	but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be
3858	emulated efficiently and thus not included here.
3859
3860	The fields in each entry are defined as follows:
3861
3862	function:
3863	the eax value used to obtain the entry
3864	index:
3865	the ecx value used to obtain the entry (for entries that are
3866	affected by ecx)
3867	flags:
3868	an OR of zero or more of the following:
3869
3870	KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
3871	if the index field is valid
3872
3873	eax, ebx, ecx, edx:
3874
3875	the values returned by the cpuid instruction for
3876	this function/index combination
3877
3878	4.89 KVM_S390_MEM_OP
3879	--------------------
3880
3881	:Capability: KVM_CAP_S390_MEM_OP, KVM_CAP_S390_PROTECTED, KVM_CAP_S390_MEM_OP_EXTENSION
3882	:Architectures: s390
3883	:Type: vm ioctl, vcpu ioctl
3884	:Parameters: struct kvm_s390_mem_op (in)
3885	:Returns: = 0 on success,
3886	< 0 on generic error (e.g. -EFAULT or -ENOMEM),
3887	16 bit program exception code if the access causes such an exception
3888
3889	Read or write data from/to the VM's memory.
3890	The KVM_CAP_S390_MEM_OP_EXTENSION capability specifies what functionality is
3891	supported.
3892
3893	Parameters are specified via the following structure::
3894
3895	struct kvm_s390_mem_op {
3896	__u64 gaddr; /* the guest address */
3897	__u64 flags; /* flags */
3898	__u32 size; /* amount of bytes */
3899	__u32 op; /* type of operation */
3900	__u64 buf; /* buffer in userspace */
3901	union {
3902	struct {
3903	__u8 ar; /* the access register number */
3904	__u8 key; /* access key, ignored if flag unset */
3905	__u8 pad1[6]; /* ignored */
3906	__u64 old_addr; /* ignored if flag unset */
3907	};
3908	__u32 sida_offset; /* offset into the sida */
3909	__u8 reserved[32]; /* ignored */
3910	};
3911	};
3912
3913	The start address of the memory region has to be specified in the "gaddr"
3914	field, and the length of the region in the "size" field (which must not
3915	be 0). The maximum value for "size" can be obtained by checking the
3916	KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the
3917	userspace application where the read data should be written to for
3918	a read access, or where the data that should be written is stored for
3919	a write access. The "reserved" field is meant for future extensions.
3920	Reserved and unused values are ignored. Future extension that add members must
3921	introduce new flags.
3922
3923	The type of operation is specified in the "op" field. Flags modifying
3924	their behavior can be set in the "flags" field. Undefined flag bits must
3925	be set to 0.
3926
3927	Possible operations are:
3928	* ``KVM_S390_MEMOP_LOGICAL_READ``
3929	* ``KVM_S390_MEMOP_LOGICAL_WRITE``
3930	* ``KVM_S390_MEMOP_ABSOLUTE_READ``
3931	* ``KVM_S390_MEMOP_ABSOLUTE_WRITE``
3932	* ``KVM_S390_MEMOP_SIDA_READ``
3933	* ``KVM_S390_MEMOP_SIDA_WRITE``
3934	* ``KVM_S390_MEMOP_ABSOLUTE_CMPXCHG``
3935
3936	Logical read/write:
3937	^^^^^^^^^^^^^^^^^^^
3938
3939	Access logical memory, i.e. translate the given guest address to an absolute
3940	address given the state of the VCPU and use the absolute address as target of
3941	the access. "ar" designates the access register number to be used; the valid
3942	range is 0..15.
3943	Logical accesses are permitted for the VCPU ioctl only.
3944	Logical accesses are permitted for non-protected guests only.
3945
3946	Supported flags:
3947	* ``KVM_S390_MEMOP_F_CHECK_ONLY``
3948	* ``KVM_S390_MEMOP_F_INJECT_EXCEPTION``
3949	* ``KVM_S390_MEMOP_F_SKEY_PROTECTION``
3950
3951	The KVM_S390_MEMOP_F_CHECK_ONLY flag can be set to check whether the
3952	corresponding memory access would cause an access exception; however,
3953	no actual access to the data in memory at the destination is performed.
3954	In this case, "buf" is unused and can be NULL.
3955
3956	In case an access exception occurred during the access (or would occur
3957	in case of KVM_S390_MEMOP_F_CHECK_ONLY), the ioctl returns a positive
3958	error number indicating the type of exception. This exception is also
3959	raised directly at the corresponding VCPU if the flag
3960	KVM_S390_MEMOP_F_INJECT_EXCEPTION is set.
3961	On protection exceptions, unless specified otherwise, the injected
3962	translation-exception identifier (TEID) indicates suppression.
3963
3964	If the KVM_S390_MEMOP_F_SKEY_PROTECTION flag is set, storage key
3965	protection is also in effect and may cause exceptions if accesses are
3966	prohibited given the access key designated by "key"; the valid range is 0..15.
3967	KVM_S390_MEMOP_F_SKEY_PROTECTION is available if KVM_CAP_S390_MEM_OP_EXTENSION
3968	is > 0.
3969	Since the accessed memory may span multiple pages and those pages might have
3970	different storage keys, it is possible that a protection exception occurs
3971	after memory has been modified. In this case, if the exception is injected,
3972	the TEID does not indicate suppression.
3973
3974	Absolute read/write:
3975	^^^^^^^^^^^^^^^^^^^^
3976
3977	Access absolute memory. This operation is intended to be used with the
3978	KVM_S390_MEMOP_F_SKEY_PROTECTION flag, to allow accessing memory and performing
3979	the checks required for storage key protection as one operation (as opposed to
3980	user space getting the storage keys, performing the checks, and accessing
3981	memory thereafter, which could lead to a delay between check and access).
3982	Absolute accesses are permitted for the VM ioctl if KVM_CAP_S390_MEM_OP_EXTENSION
3983	has the KVM_S390_MEMOP_EXTENSION_CAP_BASE bit set.
3984	Currently absolute accesses are not permitted for VCPU ioctls.
3985	Absolute accesses are permitted for non-protected guests only.
3986
3987	Supported flags:
3988	* ``KVM_S390_MEMOP_F_CHECK_ONLY``
3989	* ``KVM_S390_MEMOP_F_SKEY_PROTECTION``
3990
3991	The semantics of the flags common with logical accesses are as for logical
3992	accesses.
3993
3994	Absolute cmpxchg:
3995	^^^^^^^^^^^^^^^^^
3996
3997	Perform cmpxchg on absolute guest memory. Intended for use with the
3998	KVM_S390_MEMOP_F_SKEY_PROTECTION flag.
3999	Instead of doing an unconditional write, the access occurs only if the target
4000	location contains the value pointed to by "old_addr".
4001	This is performed as an atomic cmpxchg with the length specified by the "size"
4002	parameter. "size" must be a power of two up to and including 16.
4003	If the exchange did not take place because the target value doesn't match the
4004	old value, the value "old_addr" points to is replaced by the target value.
4005	User space can tell if an exchange took place by checking if this replacement
4006	occurred. The cmpxchg op is permitted for the VM ioctl if
4007	KVM_CAP_S390_MEM_OP_EXTENSION has flag KVM_S390_MEMOP_EXTENSION_CAP_CMPXCHG set.
4008
4009	Supported flags:
4010	* ``KVM_S390_MEMOP_F_SKEY_PROTECTION``
4011
4012	SIDA read/write:
4013	^^^^^^^^^^^^^^^^
4014
4015	Access the secure instruction data area which contains memory operands necessary
4016	for instruction emulation for protected guests.
4017	SIDA accesses are available if the KVM_CAP_S390_PROTECTED capability is available.
4018	SIDA accesses are permitted for the VCPU ioctl only.
4019	SIDA accesses are permitted for protected guests only.
4020
4021	No flags are supported.
4022
4023	4.90 KVM_S390_GET_SKEYS
4024	-----------------------
4025
4026	:Capability: KVM_CAP_S390_SKEYS
4027	:Architectures: s390
4028	:Type: vm ioctl
4029	:Parameters: struct kvm_s390_skeys
4030	:Returns: 0 on success, KVM_S390_GET_SKEYS_NONE if guest is not using storage
4031	keys, negative value on error
4032
4033	This ioctl is used to get guest storage key values on the s390
4034	architecture. The ioctl takes parameters via the kvm_s390_skeys struct::
4035
4036	struct kvm_s390_skeys {
4037	__u64 start_gfn;
4038	__u64 count;
4039	__u64 skeydata_addr;
4040	__u32 flags;
4041	__u32 reserved[9];
4042	};
4043
4044	The start_gfn field is the number of the first guest frame whose storage keys
4045	you want to get.
4046
4047	The count field is the number of consecutive frames (starting from start_gfn)
4048	whose storage keys to get. The count field must be at least 1 and the maximum
4049	allowed value is defined as KVM_S390_SKEYS_MAX. Values outside this range
4050	will cause the ioctl to return -EINVAL.
4051
4052	The skeydata_addr field is the address to a buffer large enough to hold count
4053	bytes. This buffer will be filled with storage key data by the ioctl.
4054
4055	4.91 KVM_S390_SET_SKEYS
4056	-----------------------
4057
4058	:Capability: KVM_CAP_S390_SKEYS
4059	:Architectures: s390
4060	:Type: vm ioctl
4061	:Parameters: struct kvm_s390_skeys
4062	:Returns: 0 on success, negative value on error
4063
4064	This ioctl is used to set guest storage key values on the s390
4065	architecture. The ioctl takes parameters via the kvm_s390_skeys struct.
4066	See section on KVM_S390_GET_SKEYS for struct definition.
4067
4068	The start_gfn field is the number of the first guest frame whose storage keys
4069	you want to set.
4070
4071	The count field is the number of consecutive frames (starting from start_gfn)
4072	whose storage keys to get. The count field must be at least 1 and the maximum
4073	allowed value is defined as KVM_S390_SKEYS_MAX. Values outside this range
4074	will cause the ioctl to return -EINVAL.
4075
4076	The skeydata_addr field is the address to a buffer containing count bytes of
4077	storage keys. Each byte in the buffer will be set as the storage key for a
4078	single frame starting at start_gfn for count frames.
4079
4080	Note: If any architecturally invalid key value is found in the given data then
4081	the ioctl will return -EINVAL.
4082
4083	4.92 KVM_S390_IRQ
4084	-----------------
4085
4086	:Capability: KVM_CAP_S390_INJECT_IRQ
4087	:Architectures: s390
4088	:Type: vcpu ioctl
4089	:Parameters: struct kvm_s390_irq (in)
4090	:Returns: 0 on success, -1 on error
4091
4092	Errors:
4093
4094
4095	====== =================================================================
4096	EINVAL interrupt type is invalid
4097	type is KVM_S390_SIGP_STOP and flag parameter is invalid value,
4098	type is KVM_S390_INT_EXTERNAL_CALL and code is bigger
4099	than the maximum of VCPUs
4100	EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped,
4101	type is KVM_S390_SIGP_STOP and a stop irq is already pending,
4102	type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt
4103	is already pending
4104	====== =================================================================
4105
4106	Allows to inject an interrupt to the guest.
4107
4108	Using struct kvm_s390_irq as a parameter allows
4109	to inject additional payload which is not
4110	possible via KVM_S390_INTERRUPT.
4111
4112	Interrupt parameters are passed via kvm_s390_irq::
4113
4114	struct kvm_s390_irq {
4115	__u64 type;
4116	union {
4117	struct kvm_s390_io_info io;
4118	struct kvm_s390_ext_info ext;
4119	struct kvm_s390_pgm_info pgm;
4120	struct kvm_s390_emerg_info emerg;
4121	struct kvm_s390_extcall_info extcall;
4122	struct kvm_s390_prefix_info prefix;
4123	struct kvm_s390_stop_info stop;
4124	struct kvm_s390_mchk_info mchk;
4125	char reserved[64];
4126	} u;
4127	};
4128
4129	type can be one of the following:
4130
4131	- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop
4132	- KVM_S390_PROGRAM_INT - program check; parameters in .pgm
4133	- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix
4134	- KVM_S390_RESTART - restart; no parameters
4135	- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters
4136	- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters
4137	- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg
4138	- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall
4139	- KVM_S390_MCHK - machine check interrupt; parameters in .mchk
4140
4141	This is an asynchronous vcpu ioctl and can be invoked from any thread.
4142
4143	4.94 KVM_S390_GET_IRQ_STATE
4144	---------------------------
4145
4146	:Capability: KVM_CAP_S390_IRQ_STATE
4147	:Architectures: s390
4148	:Type: vcpu ioctl
4149	:Parameters: struct kvm_s390_irq_state (out)
4150	:Returns: >= number of bytes copied into buffer,
4151	-EINVAL if buffer size is 0,
4152	-ENOBUFS if buffer size is too small to fit all pending interrupts,
4153	-EFAULT if the buffer address was invalid
4154
4155	This ioctl allows userspace to retrieve the complete state of all currently
4156	pending interrupts in a single buffer. Use cases include migration
4157	and introspection. The parameter structure contains the address of a
4158	userspace buffer and its length::
4159
4160	struct kvm_s390_irq_state {
4161	__u64 buf;
4162	__u32 flags; /* will stay unused for compatibility reasons */
4163	__u32 len;
4164	__u32 reserved[4]; /* will stay unused for compatibility reasons */
4165	};
4166
4167	Userspace passes in the above struct and for each pending interrupt a
4168	struct kvm_s390_irq is copied to the provided buffer.
4169
4170	The structure contains a flags and a reserved field for future extensions. As
4171	the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and
4172	reserved, these fields can not be used in the future without breaking
4173	compatibility.
4174
4175	If -ENOBUFS is returned the buffer provided was too small and userspace
4176	may retry with a bigger buffer.
4177
4178	4.95 KVM_S390_SET_IRQ_STATE
4179	---------------------------
4180
4181	:Capability: KVM_CAP_S390_IRQ_STATE
4182	:Architectures: s390
4183	:Type: vcpu ioctl
4184	:Parameters: struct kvm_s390_irq_state (in)
4185	:Returns: 0 on success,
4186	-EFAULT if the buffer address was invalid,
4187	-EINVAL for an invalid buffer length (see below),
4188	-EBUSY if there were already interrupts pending,
4189	errors occurring when actually injecting the
4190	interrupt. See KVM_S390_IRQ.
4191
4192	This ioctl allows userspace to set the complete state of all cpu-local
4193	interrupts currently pending for the vcpu. It is intended for restoring
4194	interrupt state after a migration. The input parameter is a userspace buffer
4195	containing a struct kvm_s390_irq_state::
4196
4197	struct kvm_s390_irq_state {
4198	__u64 buf;
4199	__u32 flags; /* will stay unused for compatibility reasons */
4200	__u32 len;
4201	__u32 reserved[4]; /* will stay unused for compatibility reasons */
4202	};
4203
4204	The restrictions for flags and reserved apply as well.
4205	(see KVM_S390_GET_IRQ_STATE)
4206
4207	The userspace memory referenced by buf contains a struct kvm_s390_irq
4208	for each interrupt to be injected into the guest.
4209	If one of the interrupts could not be injected for some reason the
4210	ioctl aborts.
4211
4212	len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0
4213	and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq),
4214	which is the maximum number of possibly pending cpu-local interrupts.
4215
4216	4.96 KVM_SMI
4217	------------
4218
4219	:Capability: KVM_CAP_X86_SMM
4220	:Architectures: x86
4221	:Type: vcpu ioctl
4222	:Parameters: none
4223	:Returns: 0 on success, -1 on error
4224
4225	Queues an SMI on the thread's vcpu.
4226
4227	4.97 KVM_X86_SET_MSR_FILTER
4228	----------------------------
4229
4230	:Capability: KVM_CAP_X86_MSR_FILTER
4231	:Architectures: x86
4232	:Type: vm ioctl
4233	:Parameters: struct kvm_msr_filter
4234	:Returns: 0 on success, < 0 on error
4235
4236	::
4237
4238	struct kvm_msr_filter_range {
4239	#define KVM_MSR_FILTER_READ (1 << 0)
4240	#define KVM_MSR_FILTER_WRITE (1 << 1)
4241	__u32 flags;
4242	__u32 nmsrs; /* number of msrs in bitmap */
4243	__u32 base; /* MSR index the bitmap starts at */
4244	__u8 bitmap; / a 1 bit allows the operations in flags, 0 denies */
4245	};
4246
4247	#define KVM_MSR_FILTER_MAX_RANGES 16
4248	struct kvm_msr_filter {
4249	#define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0)
4250	#define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0)
4251	__u32 flags;
4252	struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES];
4253	};
4254
4255	flags values for ``struct kvm_msr_filter_range``:
4256
4257	``KVM_MSR_FILTER_READ``
4258
4259	Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap
4260	indicates that read accesses should be denied, while a 1 indicates that
4261	a read for a particular MSR should be allowed regardless of the default
4262	filter action.
4263
4264	``KVM_MSR_FILTER_WRITE``
4265
4266	Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap
4267	indicates that write accesses should be denied, while a 1 indicates that
4268	a write for a particular MSR should be allowed regardless of the default
4269	filter action.
4270
4271	flags values for ``struct kvm_msr_filter``:
4272
4273	``KVM_MSR_FILTER_DEFAULT_ALLOW``
4274
4275	If no filter range matches an MSR index that is getting accessed, KVM will
4276	allow accesses to all MSRs by default.
4277
4278	``KVM_MSR_FILTER_DEFAULT_DENY``
4279
4280	If no filter range matches an MSR index that is getting accessed, KVM will
4281	deny accesses to all MSRs by default.
4282
4283	This ioctl allows userspace to define up to 16 bitmaps of MSR ranges to deny
4284	guest MSR accesses that would normally be allowed by KVM. If an MSR is not
4285	covered by a specific range, the "default" filtering behavior applies. Each
4286	bitmap range covers MSRs from [base .. base+nmsrs).
4287
4288	If an MSR access is denied by userspace, the resulting KVM behavior depends on
4289	whether or not KVM_CAP_X86_USER_SPACE_MSR's KVM_MSR_EXIT_REASON_FILTER is
4290	enabled. If KVM_MSR_EXIT_REASON_FILTER is enabled, KVM will exit to userspace
4291	on denied accesses, i.e. userspace effectively intercepts the MSR access. If
4292	KVM_MSR_EXIT_REASON_FILTER is not enabled, KVM will inject a #GP into the guest
4293	on denied accesses. Note, if an MSR access is denied during emulation of MSR
4294	load/stores during VMX transitions, KVM ignores KVM_MSR_EXIT_REASON_FILTER.
4295	See the below warning for full details.
4296
4297	If an MSR access is allowed by userspace, KVM will emulate and/or virtualize
4298	the access in accordance with the vCPU model. Note, KVM may still ultimately
4299	inject a #GP if an access is allowed by userspace, e.g. if KVM doesn't support
4300	the MSR, or to follow architectural behavior for the MSR.
4301
4302	By default, KVM operates in KVM_MSR_FILTER_DEFAULT_ALLOW mode with no MSR range
4303	filters.
4304
4305	Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR
4306	filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes
4307	an error.
4308
4309	.. warning::
4310	MSR accesses that are side effects of instruction execution (emulated or
4311	native) are not filtered as hardware does not honor MSR bitmaps outside of
4312	RDMSR and WRMSR, and KVM mimics that behavior when emulating instructions
4313	to avoid pointless divergence from hardware. E.g. RDPID reads MSR_TSC_AUX,
4314	SYSENTER reads the SYSENTER MSRs, etc.
4315
4316	MSRs that are loaded/stored via dedicated VMCS fields are not filtered as
4317	part of VM-Enter/VM-Exit emulation.
4318
4319	MSRs that are loaded/store via VMX's load/store lists _are_ filtered as part
4320	of VM-Enter/VM-Exit emulation. If an MSR access is denied on VM-Enter, KVM
4321	synthesizes a consistency check VM-Exit(EXIT_REASON_MSR_LOAD_FAIL). If an
4322	MSR access is denied on VM-Exit, KVM synthesizes a VM-Abort. In short, KVM
4323	extends Intel's architectural list of MSRs that cannot be loaded/saved via
4324	the VM-Enter/VM-Exit MSR list. It is platform owner's responsibility to
4325	to communicate any such restrictions to their end users.
4326
4327	x2APIC MSR accesses cannot be filtered (KVM silently ignores filters that
4328	cover any x2APIC MSRs).
4329
4330	Note, invoking this ioctl while a vCPU is running is inherently racy. However,
4331	KVM does guarantee that vCPUs will see either the previous filter or the new
4332	filter, e.g. MSRs with identical settings in both the old and new filter will
4333	have deterministic behavior.
4334
4335	Similarly, if userspace wishes to intercept on denied accesses,
4336	KVM_MSR_EXIT_REASON_FILTER must be enabled before activating any filters, and
4337	left enabled until after all filters are deactivated. Failure to do so may
4338	result in KVM injecting a #GP instead of exiting to userspace.
4339
4340	4.98 KVM_CREATE_SPAPR_TCE_64
4341	----------------------------
4342
4343	:Capability: KVM_CAP_SPAPR_TCE_64
4344	:Architectures: powerpc
4345	:Type: vm ioctl
4346	:Parameters: struct kvm_create_spapr_tce_64 (in)
4347	:Returns: file descriptor for manipulating the created TCE table
4348
4349	This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit
4350	windows, described in 4.62 KVM_CREATE_SPAPR_TCE
4351
4352	This capability uses extended struct in ioctl interface::
4353
4354	/* for KVM_CAP_SPAPR_TCE_64 */
4355	struct kvm_create_spapr_tce_64 {
4356	__u64 liobn;
4357	__u32 page_shift;
4358	__u32 flags;
4359	__u64 offset; /* in pages */
4360	__u64 size; /* in pages */
4361	};
4362
4363	The aim of extension is to support an additional bigger DMA window with
4364	a variable page size.
4365	KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and
4366	a bus offset of the corresponding DMA window, @size and @offset are numbers
4367	of IOMMU pages.
4368
4369	@flags are not used at the moment.
4370
4371	The rest of functionality is identical to KVM_CREATE_SPAPR_TCE.
4372
4373	4.99 KVM_REINJECT_CONTROL
4374	-------------------------
4375
4376	:Capability: KVM_CAP_REINJECT_CONTROL
4377	:Architectures: x86
4378	:Type: vm ioctl
4379	:Parameters: struct kvm_reinject_control (in)
4380	:Returns: 0 on success,
4381	-EFAULT if struct kvm_reinject_control cannot be read,
4382	-ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier.
4383
4384	i8254 (PIT) has two modes, reinject and !reinject. The default is reinject,
4385	where KVM queues elapsed i8254 ticks and monitors completion of interrupt from
4386	vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its
4387	interrupt whenever there isn't a pending interrupt from i8254.
4388	!reinject mode injects an interrupt as soon as a tick arrives.
4389
4390	::
4391
4392	struct kvm_reinject_control {
4393	__u8 pit_reinject;
4394	__u8 reserved[31];
4395	};
4396
4397	pit_reinject = 0 (!reinject mode) is recommended, unless running an old
4398	operating system that uses the PIT for timing (e.g. Linux 2.4.x).
4399
4400	4.100 KVM_PPC_CONFIGURE_V3_MMU
4401	------------------------------
4402
4403	:Capability: KVM_CAP_PPC_MMU_RADIX or KVM_CAP_PPC_MMU_HASH_V3
4404	:Architectures: ppc
4405	:Type: vm ioctl
4406	:Parameters: struct kvm_ppc_mmuv3_cfg (in)
4407	:Returns: 0 on success,
4408	-EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read,
4409	-EINVAL if the configuration is invalid
4410
4411	This ioctl controls whether the guest will use radix or HPT (hashed
4412	page table) translation, and sets the pointer to the process table for
4413	the guest.
4414
4415	::
4416
4417	struct kvm_ppc_mmuv3_cfg {
4418	__u64 flags;
4419	__u64 process_table;
4420	};
4421
4422	There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and
4423	KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest
4424	to use radix tree translation, and if clear, to use HPT translation.
4425	KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest
4426	to be able to use the global TLB and SLB invalidation instructions;
4427	if clear, the guest may not use these instructions.
4428
4429	The process_table field specifies the address and size of the guest
4430	process table, which is in the guest's space. This field is formatted
4431	as the second doubleword of the partition table entry, as defined in
4432	the Power ISA V3.00, Book III section 5.7.6.1.
4433
4434	4.101 KVM_PPC_GET_RMMU_INFO
4435	---------------------------
4436
4437	:Capability: KVM_CAP_PPC_MMU_RADIX
4438	:Architectures: ppc
4439	:Type: vm ioctl
4440	:Parameters: struct kvm_ppc_rmmu_info (out)
4441	:Returns: 0 on success,
4442	-EFAULT if struct kvm_ppc_rmmu_info cannot be written,
4443	-EINVAL if no useful information can be returned
4444
4445	This ioctl returns a structure containing two things: (a) a list
4446	containing supported radix tree geometries, and (b) a list that maps
4447	page sizes to put in the "AP" (actual page size) field for the tlbie
4448	(TLB invalidate entry) instruction.
4449
4450	::
4451
4452	struct kvm_ppc_rmmu_info {
4453	struct kvm_ppc_radix_geom {
4454	__u8 page_shift;
4455	__u8 level_bits[4];
4456	__u8 pad[3];
4457	} geometries[8];
4458	__u32 ap_encodings[8];
4459	};
4460
4461	The geometries[] field gives up to 8 supported geometries for the
4462	radix page table, in terms of the log base 2 of the smallest page
4463	size, and the number of bits indexed at each level of the tree, from
4464	the PTE level up to the PGD level in that order. Any unused entries
4465	will have 0 in the page_shift field.
4466
4467	The ap_encodings gives the supported page sizes and their AP field
4468	encodings, encoded with the AP value in the top 3 bits and the log
4469	base 2 of the page size in the bottom 6 bits.
4470
4471	4.102 KVM_PPC_RESIZE_HPT_PREPARE
4472	--------------------------------
4473
4474	:Capability: KVM_CAP_SPAPR_RESIZE_HPT
4475	:Architectures: powerpc
4476	:Type: vm ioctl
4477	:Parameters: struct kvm_ppc_resize_hpt (in)
4478	:Returns: 0 on successful completion,
4479	>0 if a new HPT is being prepared, the value is an estimated
4480	number of milliseconds until preparation is complete,
4481	-EFAULT if struct kvm_reinject_control cannot be read,
4482	-EINVAL if the supplied shift or flags are invalid,
4483	-ENOMEM if unable to allocate the new HPT,
4484
4485	Used to implement the PAPR extension for runtime resizing of a guest's
4486	Hashed Page Table (HPT). Specifically this starts, stops or monitors
4487	the preparation of a new potential HPT for the guest, essentially
4488	implementing the H_RESIZE_HPT_PREPARE hypercall.
4489
4490	::
4491
4492	struct kvm_ppc_resize_hpt {
4493	__u64 flags;
4494	__u32 shift;
4495	__u32 pad;
4496	};
4497
4498	If called with shift > 0 when there is no pending HPT for the guest,
4499	this begins preparation of a new pending HPT of size 2^(shift) bytes.
4500	It then returns a positive integer with the estimated number of
4501	milliseconds until preparation is complete.
4502
4503	If called when there is a pending HPT whose size does not match that
4504	requested in the parameters, discards the existing pending HPT and
4505	creates a new one as above.
4506
4507	If called when there is a pending HPT of the size requested, will:
4508
4509	* If preparation of the pending HPT is already complete, return 0
4510	* If preparation of the pending HPT has failed, return an error
4511	code, then discard the pending HPT.
4512	* If preparation of the pending HPT is still in progress, return an
4513	estimated number of milliseconds until preparation is complete.
4514
4515	If called with shift == 0, discards any currently pending HPT and
4516	returns 0 (i.e. cancels any in-progress preparation).
4517
4518	flags is reserved for future expansion, currently setting any bits in
4519	flags will result in an -EINVAL.
4520
4521	Normally this will be called repeatedly with the same parameters until
4522	it returns <= 0. The first call will initiate preparation, subsequent
4523	ones will monitor preparation until it completes or fails.
4524
4525	4.103 KVM_PPC_RESIZE_HPT_COMMIT
4526	-------------------------------
4527
4528	:Capability: KVM_CAP_SPAPR_RESIZE_HPT
4529	:Architectures: powerpc
4530	:Type: vm ioctl
4531	:Parameters: struct kvm_ppc_resize_hpt (in)
4532	:Returns: 0 on successful completion,
4533	-EFAULT if struct kvm_reinject_control cannot be read,
4534	-EINVAL if the supplied shift or flags are invalid,
4535	-ENXIO is there is no pending HPT, or the pending HPT doesn't
4536	have the requested size,
4537	-EBUSY if the pending HPT is not fully prepared,
4538	-ENOSPC if there was a hash collision when moving existing
4539	HPT entries to the new HPT,
4540	-EIO on other error conditions
4541
4542	Used to implement the PAPR extension for runtime resizing of a guest's
4543	Hashed Page Table (HPT). Specifically this requests that the guest be
4544	transferred to working with the new HPT, essentially implementing the
4545	H_RESIZE_HPT_COMMIT hypercall.
4546
4547	::
4548
4549	struct kvm_ppc_resize_hpt {
4550	__u64 flags;
4551	__u32 shift;
4552	__u32 pad;
4553	};
4554
4555	This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has
4556	returned 0 with the same parameters. In other cases
4557	KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or
4558	-EBUSY, though others may be possible if the preparation was started,
4559	but failed).
4560
4561	This will have undefined effects on the guest if it has not already
4562	placed itself in a quiescent state where no vcpu will make MMU enabled
4563	memory accesses.
4564
4565	On successful completion, the pending HPT will become the guest's active
4566	HPT and the previous HPT will be discarded.
4567
4568	On failure, the guest will still be operating on its previous HPT.
4569
4570	4.104 KVM_X86_GET_MCE_CAP_SUPPORTED
4571	-----------------------------------
4572
4573	:Capability: KVM_CAP_MCE
4574	:Architectures: x86
4575	:Type: system ioctl
4576	:Parameters: u64 mce_cap (out)
4577	:Returns: 0 on success, -1 on error
4578
4579	Returns supported MCE capabilities. The u64 mce_cap parameter
4580	has the same format as the MSR_IA32_MCG_CAP register. Supported
4581	capabilities will have the corresponding bits set.
4582
4583	4.105 KVM_X86_SETUP_MCE
4584	-----------------------
4585
4586	:Capability: KVM_CAP_MCE
4587	:Architectures: x86
4588	:Type: vcpu ioctl
4589	:Parameters: u64 mcg_cap (in)
4590	:Returns: 0 on success,
4591	-EFAULT if u64 mcg_cap cannot be read,
4592	-EINVAL if the requested number of banks is invalid,
4593	-EINVAL if requested MCE capability is not supported.
4594
4595	Initializes MCE support for use. The u64 mcg_cap parameter
4596	has the same format as the MSR_IA32_MCG_CAP register and
4597	specifies which capabilities should be enabled. The maximum
4598	supported number of error-reporting banks can be retrieved when
4599	checking for KVM_CAP_MCE. The supported capabilities can be
4600	retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED.
4601
4602	4.106 KVM_X86_SET_MCE
4603	---------------------
4604
4605	:Capability: KVM_CAP_MCE
4606	:Architectures: x86
4607	:Type: vcpu ioctl
4608	:Parameters: struct kvm_x86_mce (in)
4609	:Returns: 0 on success,
4610	-EFAULT if struct kvm_x86_mce cannot be read,
4611	-EINVAL if the bank number is invalid,
4612	-EINVAL if VAL bit is not set in status field.
4613
4614	Inject a machine check error (MCE) into the guest. The input
4615	parameter is::
4616
4617	struct kvm_x86_mce {
4618	__u64 status;
4619	__u64 addr;
4620	__u64 misc;
4621	__u64 mcg_status;
4622	__u8 bank;
4623	__u8 pad1[7];
4624	__u64 pad2[3];
4625	};
4626
4627	If the MCE being reported is an uncorrected error, KVM will
4628	inject it as an MCE exception into the guest. If the guest
4629	MCG_STATUS register reports that an MCE is in progress, KVM
4630	causes an KVM_EXIT_SHUTDOWN vmexit.
4631
4632	Otherwise, if the MCE is a corrected error, KVM will just
4633	store it in the corresponding bank (provided this bank is
4634	not holding a previously reported uncorrected error).
4635
4636	4.107 KVM_S390_GET_CMMA_BITS
4637	----------------------------
4638
4639	:Capability: KVM_CAP_S390_CMMA_MIGRATION
4640	:Architectures: s390
4641	:Type: vm ioctl
4642	:Parameters: struct kvm_s390_cmma_log (in, out)
4643	:Returns: 0 on success, a negative value on error
4644
4645	Errors:
4646
4647	====== =============================================================
4648	ENOMEM not enough memory can be allocated to complete the task
4649	ENXIO if CMMA is not enabled
4650	EINVAL if KVM_S390_CMMA_PEEK is not set but migration mode was not enabled
4651	EINVAL if KVM_S390_CMMA_PEEK is not set but dirty tracking has been
4652	disabled (and thus migration mode was automatically disabled)
4653	EFAULT if the userspace address is invalid or if no page table is
4654	present for the addresses (e.g. when using hugepages).
4655	====== =============================================================
4656
4657	This ioctl is used to get the values of the CMMA bits on the s390
4658	architecture. It is meant to be used in two scenarios:
4659
4660	- During live migration to save the CMMA values. Live migration needs
4661	to be enabled via the KVM_REQ_START_MIGRATION VM property.
4662	- To non-destructively peek at the CMMA values, with the flag
4663	KVM_S390_CMMA_PEEK set.
4664
4665	The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired
4666	values are written to a buffer whose location is indicated via the "values"
4667	member in the kvm_s390_cmma_log struct. The values in the input struct are
4668	also updated as needed.
4669
4670	Each CMMA value takes up one byte.
4671
4672	::
4673
4674	struct kvm_s390_cmma_log {
4675	__u64 start_gfn;
4676	__u32 count;
4677	__u32 flags;
4678	union {
4679	__u64 remaining;
4680	__u64 mask;
4681	};
4682	__u64 values;
4683	};
4684
4685	start_gfn is the number of the first guest frame whose CMMA values are
4686	to be retrieved,
4687
4688	count is the length of the buffer in bytes,
4689
4690	values points to the buffer where the result will be written to.
4691
4692	If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be
4693	KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with
4694	other ioctls.
4695
4696	The result is written in the buffer pointed to by the field values, and
4697	the values of the input parameter are updated as follows.
4698
4699	Depending on the flags, different actions are performed. The only
4700	supported flag so far is KVM_S390_CMMA_PEEK.
4701
4702	The default behaviour if KVM_S390_CMMA_PEEK is not set is:
4703	start_gfn will indicate the first page frame whose CMMA bits were dirty.
4704	It is not necessarily the same as the one passed as input, as clean pages
4705	are skipped.
4706
4707	count will indicate the number of bytes actually written in the buffer.
4708	It can (and very often will) be smaller than the input value, since the
4709	buffer is only filled until 16 bytes of clean values are found (which
4710	are then not copied in the buffer). Since a CMMA migration block needs
4711	the base address and the length, for a total of 16 bytes, we will send
4712	back some clean data if there is some dirty data afterwards, as long as
4713	the size of the clean data does not exceed the size of the header. This
4714	allows to minimize the amount of data to be saved or transferred over
4715	the network at the expense of more roundtrips to userspace. The next
4716	invocation of the ioctl will skip over all the clean values, saving
4717	potentially more than just the 16 bytes we found.
4718
4719	If KVM_S390_CMMA_PEEK is set:
4720	the existing storage attributes are read even when not in migration
4721	mode, and no other action is performed;
4722
4723	the output start_gfn will be equal to the input start_gfn,
4724
4725	the output count will be equal to the input count, except if the end of
4726	memory has been reached.
4727
4728	In both cases:
4729	the field "remaining" will indicate the total number of dirty CMMA values
4730	still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is
4731	not enabled.
4732
4733	mask is unused.
4734
4735	values points to the userspace buffer where the result will be stored.
4736
4737	4.108 KVM_S390_SET_CMMA_BITS
4738	----------------------------
4739
4740	:Capability: KVM_CAP_S390_CMMA_MIGRATION
4741	:Architectures: s390
4742	:Type: vm ioctl
4743	:Parameters: struct kvm_s390_cmma_log (in)
4744	:Returns: 0 on success, a negative value on error
4745
4746	This ioctl is used to set the values of the CMMA bits on the s390
4747	architecture. It is meant to be used during live migration to restore
4748	the CMMA values, but there are no restrictions on its use.
4749	The ioctl takes parameters via the kvm_s390_cmma_values struct.
4750	Each CMMA value takes up one byte.
4751
4752	::
4753
4754	struct kvm_s390_cmma_log {
4755	__u64 start_gfn;
4756	__u32 count;
4757	__u32 flags;
4758	union {
4759	__u64 remaining;
4760	__u64 mask;
4761	};
4762	__u64 values;
4763	};
4764
4765	start_gfn indicates the starting guest frame number,
4766
4767	count indicates how many values are to be considered in the buffer,
4768
4769	flags is not used and must be 0.
4770
4771	mask indicates which PGSTE bits are to be considered.
4772
4773	remaining is not used.
4774
4775	values points to the buffer in userspace where to store the values.
4776
4777	This ioctl can fail with -ENOMEM if not enough memory can be allocated to
4778	complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if
4779	the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or
4780	if the flags field was not 0, with -EFAULT if the userspace address is
4781	invalid, if invalid pages are written to (e.g. after the end of memory)
4782	or if no page table is present for the addresses (e.g. when using
4783	hugepages).
4784
4785	4.109 KVM_PPC_GET_CPU_CHAR
4786	--------------------------
4787
4788	:Capability: KVM_CAP_PPC_GET_CPU_CHAR
4789	:Architectures: powerpc
4790	:Type: vm ioctl
4791	:Parameters: struct kvm_ppc_cpu_char (out)
4792	:Returns: 0 on successful completion,
4793	-EFAULT if struct kvm_ppc_cpu_char cannot be written
4794
4795	This ioctl gives userspace information about certain characteristics
4796	of the CPU relating to speculative execution of instructions and
4797	possible information leakage resulting from speculative execution (see
4798	CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is
4799	returned in struct kvm_ppc_cpu_char, which looks like this::
4800
4801	struct kvm_ppc_cpu_char {
4802	__u64 character; /* characteristics of the CPU */
4803	__u64 behaviour; /* recommended software behaviour */
4804	__u64 character_mask; /* valid bits in character */
4805	__u64 behaviour_mask; /* valid bits in behaviour */
4806	};
4807
4808	For extensibility, the character_mask and behaviour_mask fields
4809	indicate which bits of character and behaviour have been filled in by
4810	the kernel. If the set of defined bits is extended in future then
4811	userspace will be able to tell whether it is running on a kernel that
4812	knows about the new bits.
4813
4814	The character field describes attributes of the CPU which can help
4815	with preventing inadvertent information disclosure - specifically,
4816	whether there is an instruction to flash-invalidate the L1 data cache
4817	(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set
4818	to a mode where entries can only be used by the thread that created
4819	them, whether the bcctr[l] instruction prevents speculation, and
4820	whether a speculation barrier instruction (ori 31,31,0) is provided.
4821
4822	The behaviour field describes actions that software should take to
4823	prevent inadvertent information disclosure, and thus describes which
4824	vulnerabilities the hardware is subject to; specifically whether the
4825	L1 data cache should be flushed when returning to user mode from the
4826	kernel, and whether a speculation barrier should be placed between an
4827	array bounds check and the array access.
4828
4829	These fields use the same bit definitions as the new
4830	H_GET_CPU_CHARACTERISTICS hypercall.
4831
4832	4.110 KVM_MEMORY_ENCRYPT_OP
4833	---------------------------
4834
4835	:Capability: basic
4836	:Architectures: x86
4837	:Type: vm ioctl, vcpu ioctl
4838	:Parameters: an opaque platform specific structure (in/out)
4839	:Returns: 0 on success; -1 on error
4840
4841	If the platform supports creating encrypted VMs then this ioctl can be used
4842	for issuing platform-specific memory encryption commands to manage those
4843	encrypted VMs.
4844
4845	Currently, this ioctl is used for issuing both Secure Encrypted Virtualization
4846	(SEV) commands on AMD Processors and Trusted Domain Extensions (TDX) commands
4847	on Intel Processors. The detailed commands are defined in
4848	Documentation/virt/kvm/x86/amd-memory-encryption.rst and
4849	Documentation/virt/kvm/x86/intel-tdx.rst.
4850
4851	4.111 KVM_MEMORY_ENCRYPT_REG_REGION
4852	-----------------------------------
4853
4854	:Capability: basic
4855	:Architectures: x86
4856	:Type: system
4857	:Parameters: struct kvm_enc_region (in)
4858	:Returns: 0 on success; -1 on error
4859
4860	This ioctl can be used to register a guest memory region which may
4861	contain encrypted data (e.g. guest RAM, SMRAM etc).
4862
4863	It is used in the SEV-enabled guest. When encryption is enabled, a guest
4864	memory region may contain encrypted data. The SEV memory encryption
4865	engine uses a tweak such that two identical plaintext pages, each at
4866	different locations will have differing ciphertexts. So swapping or
4867	moving ciphertext of those pages will not result in plaintext being
4868	swapped. So relocating (or migrating) physical backing pages for the SEV
4869	guest will require some additional steps.
4870
4871	Note: The current SEV key management spec does not provide commands to
4872	swap or migrate (move) ciphertext pages. Hence, for now we pin the guest
4873	memory region registered with the ioctl.
4874
4875	4.112 KVM_MEMORY_ENCRYPT_UNREG_REGION
4876	-------------------------------------
4877
4878	:Capability: basic
4879	:Architectures: x86
4880	:Type: system
4881	:Parameters: struct kvm_enc_region (in)
4882	:Returns: 0 on success; -1 on error
4883
4884	This ioctl can be used to unregister the guest memory region registered
4885	with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above.
4886
4887	4.113 KVM_HYPERV_EVENTFD
4888	------------------------
4889
4890	:Capability: KVM_CAP_HYPERV_EVENTFD
4891	:Architectures: x86
4892	:Type: vm ioctl
4893	:Parameters: struct kvm_hyperv_eventfd (in)
4894
4895	This ioctl (un)registers an eventfd to receive notifications from the guest on
4896	the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without
4897	causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number
4898	(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit.
4899
4900	::
4901
4902	struct kvm_hyperv_eventfd {
4903	__u32 conn_id;
4904	__s32 fd;
4905	__u32 flags;
4906	__u32 padding[3];
4907	};
4908
4909	The conn_id field should fit within 24 bits::
4910
4911	#define KVM_HYPERV_CONN_ID_MASK 0x00ffffff
4912
4913	The acceptable values for the flags field are::
4914
4915	#define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0)
4916
4917	:Returns: 0 on success,
4918	-EINVAL if conn_id or flags is outside the allowed range,
4919	-ENOENT on deassign if the conn_id isn't registered,
4920	-EEXIST on assign if the conn_id is already registered
4921
4922	4.114 KVM_GET_NESTED_STATE
4923	--------------------------
4924
4925	:Capability: KVM_CAP_NESTED_STATE
4926	:Architectures: x86
4927	:Type: vcpu ioctl
4928	:Parameters: struct kvm_nested_state (in/out)
4929	:Returns: 0 on success, -1 on error
4930
4931	Errors:
4932
4933	===== =============================================================
4934	E2BIG the total state size exceeds the value of 'size' specified by
4935	the user; the size required will be written into size.
4936	===== =============================================================
4937
4938	::
4939
4940	struct kvm_nested_state {
4941	__u16 flags;
4942	__u16 format;
4943	__u32 size;
4944
4945	union {
4946	struct kvm_vmx_nested_state_hdr vmx;
4947	struct kvm_svm_nested_state_hdr svm;
4948
4949	/* Pad the header to 128 bytes. */
4950	__u8 pad[120];
4951	} hdr;
4952
4953	union {
4954	struct kvm_vmx_nested_state_data vmx[0];
4955	struct kvm_svm_nested_state_data svm[0];
4956	} data;
4957	};
4958
4959	#define KVM_STATE_NESTED_GUEST_MODE 0x00000001
4960	#define KVM_STATE_NESTED_RUN_PENDING 0x00000002
4961	#define KVM_STATE_NESTED_EVMCS 0x00000004
4962
4963	#define KVM_STATE_NESTED_FORMAT_VMX 0
4964	#define KVM_STATE_NESTED_FORMAT_SVM 1
4965
4966	#define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000
4967	#define KVM_STATE_NESTED_SVM_VMCB_SIZE 0x1000
4968
4969	#define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001
4970	#define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002
4971
4972	#define KVM_STATE_NESTED_GIF_SET 0x00000100
4973
4974	#define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001
4975
4976	struct kvm_vmx_nested_state_hdr {
4977	__u64 vmxon_pa;
4978	__u64 vmcs12_pa;
4979
4980	struct {
4981	__u16 flags;
4982	} smm;
4983
4984	__u32 flags;
4985	__u64 preemption_timer_deadline;
4986	};
4987
4988	struct kvm_svm_nested_state_hdr {
4989	__u64 vmcb_pa;
4990	__u64 gpat;
4991	};
4992
4993	struct kvm_vmx_nested_state_data {
4994	__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
4995	__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
4996	};
4997
4998	struct kvm_svm_nested_state_data {
4999	__u8 vmcb12[KVM_STATE_NESTED_SVM_VMCB_SIZE];
5000	};
5001
5002	This ioctl copies the vcpu's nested virtualization state from the kernel to
5003	userspace.
5004
5005	The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE
5006	to the KVM_CHECK_EXTENSION ioctl().
5007
5008	4.115 KVM_SET_NESTED_STATE
5009	--------------------------
5010
5011	:Capability: KVM_CAP_NESTED_STATE
5012	:Architectures: x86
5013	:Type: vcpu ioctl
5014	:Parameters: struct kvm_nested_state (in)
5015	:Returns: 0 on success, -1 on error
5016
5017	This copies the vcpu's kvm_nested_state struct from userspace to the kernel.
5018	For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.
5019
5020	4.116 KVM_(UN)REGISTER_COALESCED_MMIO
5021	-------------------------------------
5022
5023	:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio)
5024	KVM_CAP_COALESCED_PIO (for coalesced pio)
5025	:Architectures: all
5026	:Type: vm ioctl
5027	:Parameters: struct kvm_coalesced_mmio_zone
5028	:Returns: 0 on success, < 0 on error
5029
5030	Coalesced I/O is a performance optimization that defers hardware
5031	register write emulation so that userspace exits are avoided. It is
5032	typically used to reduce the overhead of emulating frequently accessed
5033	hardware registers.
5034
5035	When a hardware register is configured for coalesced I/O, write accesses
5036	do not exit to userspace and their value is recorded in a ring buffer
5037	that is shared between kernel and userspace.
5038
5039	Coalesced I/O is used if one or more write accesses to a hardware
5040	register can be deferred until a read or a write to another hardware
5041	register on the same device. This last access will cause a vmexit and
5042	userspace will process accesses from the ring buffer before emulating
5043	it. That will avoid exiting to userspace on repeated writes.
5044
5045	Coalesced pio is based on coalesced mmio. There is little difference
5046	between coalesced mmio and pio except that coalesced pio records accesses
5047	to I/O ports.
5048
5049	4.117 KVM_CLEAR_DIRTY_LOG
5050	-------------------------
5051
5052	:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
5053	:Architectures: x86, arm64, mips
5054	:Type: vm ioctl
5055	:Parameters: struct kvm_clear_dirty_log (in)
5056	:Returns: 0 on success, -1 on error
5057
5058	::
5059
5060	/* for KVM_CLEAR_DIRTY_LOG */
5061	struct kvm_clear_dirty_log {
5062	__u32 slot;
5063	__u32 num_pages;
5064	__u64 first_page;
5065	union {
5066	void __user dirty_bitmap; / one bit per page */
5067	__u64 padding;
5068	};
5069	};
5070
5071	The ioctl clears the dirty status of pages in a memory slot, according to
5072	the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap
5073	field. Bit 0 of the bitmap corresponds to page "first_page" in the
5074	memory slot, and num_pages is the size in bits of the input bitmap.
5075	first_page must be a multiple of 64; num_pages must also be a multiple of
5076	64 unless first_page + num_pages is the size of the memory slot. For each
5077	bit that is set in the input bitmap, the corresponding page is marked "clean"
5078	in KVM's dirty bitmap, and dirty tracking is re-enabled for that page
5079	(for example via write-protection, or by clearing the dirty bit in
5080	a page table entry).
5081
5082	If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies
5083	the address space for which you want to clear the dirty status. See
5084	KVM_SET_USER_MEMORY_REGION for details on the usage of slot field.
5085
5086	This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
5087	is enabled; for more information, see the description of the capability.
5088	However, it can always be used as long as KVM_CHECK_EXTENSION confirms
5089	that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present.
5090
5091	4.118 KVM_GET_SUPPORTED_HV_CPUID
5092	--------------------------------
5093
5094	:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system)
5095	:Architectures: x86
5096	:Type: system ioctl, vcpu ioctl
5097	:Parameters: struct kvm_cpuid2 (in/out)
5098	:Returns: 0 on success, -1 on error
5099
5100	::
5101
5102	struct kvm_cpuid2 {
5103	__u32 nent;
5104	__u32 padding;
5105	struct kvm_cpuid_entry2 entries[0];
5106	};
5107
5108	struct kvm_cpuid_entry2 {
5109	__u32 function;
5110	__u32 index;
5111	__u32 flags;
5112	__u32 eax;
5113	__u32 ebx;
5114	__u32 ecx;
5115	__u32 edx;
5116	__u32 padding[3];
5117	};
5118
5119	This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in
5120	KVM. Userspace can use the information returned by this ioctl to construct
5121	cpuid information presented to guests consuming Hyper-V enlightenments (e.g.
5122	Windows or Hyper-V guests).
5123
5124	CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level
5125	Functional Specification (TLFS). These leaves can't be obtained with
5126	KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature
5127	leaves (0x40000000, 0x40000001).
5128
5129	Currently, the following list of CPUID leaves are returned:
5130
5131	- HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS
5132	- HYPERV_CPUID_INTERFACE
5133	- HYPERV_CPUID_VERSION
5134	- HYPERV_CPUID_FEATURES
5135	- HYPERV_CPUID_ENLIGHTMENT_INFO
5136	- HYPERV_CPUID_IMPLEMENT_LIMITS
5137	- HYPERV_CPUID_NESTED_FEATURES
5138	- HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS
5139	- HYPERV_CPUID_SYNDBG_INTERFACE
5140	- HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
5141
5142	Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure
5143	with the 'nent' field indicating the number of entries in the variable-size
5144	array 'entries'. If the number of entries is too low to describe all Hyper-V
5145	feature leaves, an error (E2BIG) is returned. If the number is more or equal
5146	to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the
5147	number of valid entries in the 'entries' array, which is then filled.
5148
5149	'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved,
5150	userspace should not expect to get any particular value there.
5151
5152	Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike
5153	system ioctl which exposes all supported feature bits unconditionally, vcpu
5154	version has the following quirks:
5155
5156	- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED
5157	feature bit are only exposed when Enlightened VMCS was previously enabled
5158	on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS).
5159	- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC.
5160	(presumes KVM_CREATE_IRQCHIP has already been called).
5161
5162	4.119 KVM_ARM_VCPU_FINALIZE
5163	---------------------------
5164
5165	:Architectures: arm64
5166	:Type: vcpu ioctl
5167	:Parameters: int feature (in)
5168	:Returns: 0 on success, -1 on error
5169
5170	Errors:
5171
5172	====== ==============================================================
5173	EPERM feature not enabled, needs configuration, or already finalized
5174	EINVAL feature unknown or not present
5175	====== ==============================================================
5176
5177	Recognised values for feature:
5178
5179	===== ===========================================
5180	arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE)
5181	===== ===========================================
5182
5183	Finalizes the configuration of the specified vcpu feature.
5184
5185	The vcpu must already have been initialised, enabling the affected feature, by
5186	means of a successful :ref:`KVM_ARM_VCPU_INIT <KVM_ARM_VCPU_INIT>` call with the
5187	appropriate flag set in features[].
5188
5189	For affected vcpu features, this is a mandatory step that must be performed
5190	before the vcpu is fully usable.
5191
5192	Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be
5193	configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration
5194	that should be performed and how to do it are feature-dependent.
5195
5196	Other calls that depend on a particular feature being finalized, such as
5197	KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with
5198	-EPERM unless the feature has already been finalized by means of a
5199	KVM_ARM_VCPU_FINALIZE call.
5200
5201	See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization
5202	using this ioctl.
5203
5204	4.120 KVM_SET_PMU_EVENT_FILTER
5205	------------------------------
5206
5207	:Capability: KVM_CAP_PMU_EVENT_FILTER
5208	:Architectures: x86
5209	:Type: vm ioctl
5210	:Parameters: struct kvm_pmu_event_filter (in)
5211	:Returns: 0 on success, -1 on error
5212
5213	Errors:
5214
5215	====== ============================================================
5216	EFAULT args[0] cannot be accessed
5217	EINVAL args[0] contains invalid data in the filter or filter events
5218	E2BIG nevents is too large
5219	EBUSY not enough memory to allocate the filter
5220	====== ============================================================
5221
5222	::
5223
5224	struct kvm_pmu_event_filter {
5225	__u32 action;
5226	__u32 nevents;
5227	__u32 fixed_counter_bitmap;
5228	__u32 flags;
5229	__u32 pad[4];
5230	__u64 events[0];
5231	};
5232
5233	This ioctl restricts the set of PMU events the guest can program by limiting
5234	which event select and unit mask combinations are permitted.
5235
5236	The argument holds a list of filter events which will be allowed or denied.
5237
5238	Filter events only control general purpose counters; fixed purpose counters
5239	are controlled by the fixed_counter_bitmap.
5240
5241	Valid values for 'flags'::
5242
5243	``0``
5244
5245	To use this mode, clear the 'flags' field.
5246
5247	In this mode each event will contain an event select + unit mask.
5248
5249	When the guest attempts to program the PMU the guest's event select +
5250	unit mask is compared against the filter events to determine whether the
5251	guest should have access.
5252
5253	``KVM_PMU_EVENT_FLAG_MASKED_EVENTS``
5254	:Capability: KVM_CAP_PMU_EVENT_MASKED_EVENTS
5255
5256	In this mode each filter event will contain an event select, mask, match, and
5257	exclude value. To encode a masked event use::
5258
5259	KVM_PMU_ENCODE_MASKED_ENTRY()
5260
5261	An encoded event will follow this layout::
5262
5263	Bits Description
5264	---- -----------
5265	7:0 event select (low bits)
5266	15:8 umask match
5267	31:16 unused
5268	35:32 event select (high bits)
5269	36:54 unused
5270	55 exclude bit
5271	63:56 umask mask
5272
5273	When the guest attempts to program the PMU, these steps are followed in
5274	determining if the guest should have access:
5275
5276	1. Match the event select from the guest against the filter events.
5277	2. If a match is found, match the guest's unit mask to the mask and match
5278	values of the included filter events.
5279	I.e. (unit mask & mask) == match && !exclude.
5280	3. If a match is found, match the guest's unit mask to the mask and match
5281	values of the excluded filter events.
5282	I.e. (unit mask & mask) == match && exclude.
5283	4.
5284	a. If an included match is found and an excluded match is not found, filter
5285	the event.
5286	b. For everything else, do not filter the event.
5287	5.
5288	a. If the event is filtered and it's an allow list, allow the guest to
5289	program the event.
5290	b. If the event is filtered and it's a deny list, do not allow the guest to
5291	program the event.
5292
5293	When setting a new pmu event filter, -EINVAL will be returned if any of the
5294	unused fields are set or if any of the high bits (35:32) in the event
5295	select are set when called on Intel.
5296
5297	Valid values for 'action'::
5298
5299	#define KVM_PMU_EVENT_ALLOW 0
5300	#define KVM_PMU_EVENT_DENY 1
5301
5302	Via this API, KVM userspace can also control the behavior of the VM's fixed
5303	counters (if any) by configuring the "action" and "fixed_counter_bitmap" fields.
5304
5305	Specifically, KVM follows the following pseudo-code when determining whether to
5306	allow the guest FixCtr[i] to count its pre-defined fixed event::
5307
5308	FixCtr[i]_is_allowed = (action == ALLOW) && (bitmap & BIT(i)) \|\|
5309	(action == DENY) && !(bitmap & BIT(i));
5310	FixCtr[i]_is_denied = !FixCtr[i]_is_allowed;
5311
5312	KVM always consumes fixed_counter_bitmap, it's userspace's responsibility to
5313	ensure fixed_counter_bitmap is set correctly, e.g. if userspace wants to define
5314	a filter that only affects general purpose counters.
5315
5316	Note, the "events" field also applies to fixed counters' hardcoded event_select
5317	and unit_mask values. "fixed_counter_bitmap" has higher priority than "events"
5318	if there is a contradiction between the two.
5319
5320	4.121 KVM_PPC_SVM_OFF
5321	---------------------
5322
5323	:Capability: basic
5324	:Architectures: powerpc
5325	:Type: vm ioctl
5326	:Parameters: none
5327	:Returns: 0 on successful completion,
5328
5329	Errors:
5330
5331	====== ================================================================
5332	EINVAL if ultravisor failed to terminate the secure guest
5333	ENOMEM if hypervisor failed to allocate new radix page tables for guest
5334	====== ================================================================
5335
5336	This ioctl is used to turn off the secure mode of the guest or transition
5337	the guest from secure mode to normal mode. This is invoked when the guest
5338	is reset. This has no effect if called for a normal guest.
5339
5340	This ioctl issues an ultravisor call to terminate the secure guest,
5341	unpins the VPA pages and releases all the device pages that are used to
5342	track the secure pages by hypervisor.
5343
5344	4.122 KVM_S390_NORMAL_RESET
5345	---------------------------
5346
5347	:Capability: KVM_CAP_S390_VCPU_RESETS
5348	:Architectures: s390
5349	:Type: vcpu ioctl
5350	:Parameters: none
5351	:Returns: 0
5352
5353	This ioctl resets VCPU registers and control structures according to
5354	the cpu reset definition in the POP (Principles Of Operation).
5355
5356	4.123 KVM_S390_INITIAL_RESET
5357	----------------------------
5358
5359	:Capability: basic
5360	:Architectures: s390
5361	:Type: vcpu ioctl
5362	:Parameters: none
5363	:Returns: 0
5364
5365	This ioctl resets VCPU registers and control structures according to
5366	the initial cpu reset definition in the POP. However, the cpu is not
5367	put into ESA mode. This reset is a superset of the normal reset.
5368
5369	4.124 KVM_S390_CLEAR_RESET
5370	--------------------------
5371
5372	:Capability: KVM_CAP_S390_VCPU_RESETS
5373	:Architectures: s390
5374	:Type: vcpu ioctl
5375	:Parameters: none
5376	:Returns: 0
5377
5378	This ioctl resets VCPU registers and control structures according to
5379	the clear cpu reset definition in the POP. However, the cpu is not put
5380	into ESA mode. This reset is a superset of the initial reset.
5381
5382
5383	4.125 KVM_S390_PV_COMMAND
5384	-------------------------
5385
5386	:Capability: KVM_CAP_S390_PROTECTED
5387	:Architectures: s390
5388	:Type: vm ioctl
5389	:Parameters: struct kvm_pv_cmd
5390	:Returns: 0 on success, < 0 on error
5391
5392	::
5393
5394	struct kvm_pv_cmd {
5395	__u32 cmd; /* Command to be executed */
5396	__u16 rc; /* Ultravisor return code */
5397	__u16 rrc; /* Ultravisor return reason code */
5398	__u64 data; /* Data or address */
5399	__u32 flags; /* flags for future extensions. Must be 0 for now */
5400	__u32 reserved[3];
5401	};
5402
5403	Ultravisor return codes
5404	The Ultravisor return (reason) codes are provided by the kernel if a
5405	Ultravisor call has been executed to achieve the results expected by
5406	the command. Therefore they are independent of the IOCTL return
5407	code. If KVM changes `rc`, its value will always be greater than 0
5408	hence setting it to 0 before issuing a PV command is advised to be
5409	able to detect a change of `rc`.
5410
5411	cmd values:
5412
5413	KVM_PV_ENABLE
5414	Allocate memory and register the VM with the Ultravisor, thereby
5415	donating memory to the Ultravisor that will become inaccessible to
5416	KVM. All existing CPUs are converted to protected ones. After this
5417	command has succeeded, any CPU added via hotplug will become
5418	protected during its creation as well.
5419
5420	Errors:
5421
5422	===== =============================
5423	EINTR an unmasked signal is pending
5424	===== =============================
5425
5426	KVM_PV_DISABLE
5427	Deregister the VM from the Ultravisor and reclaim the memory that had
5428	been donated to the Ultravisor, making it usable by the kernel again.
5429	All registered VCPUs are converted back to non-protected ones. If a
5430	previous protected VM had been prepared for asynchronous teardown with
5431	KVM_PV_ASYNC_CLEANUP_PREPARE and not subsequently torn down with
5432	KVM_PV_ASYNC_CLEANUP_PERFORM, it will be torn down in this call
5433	together with the current protected VM.
5434
5435	KVM_PV_VM_SET_SEC_PARMS
5436	Pass the image header from VM memory to the Ultravisor in
5437	preparation of image unpacking and verification.
5438
5439	KVM_PV_VM_UNPACK
5440	Unpack (protect and decrypt) a page of the encrypted boot image.
5441
5442	KVM_PV_VM_VERIFY
5443	Verify the integrity of the unpacked image. Only if this succeeds,
5444	KVM is allowed to start protected VCPUs.
5445
5446	KVM_PV_INFO
5447	:Capability: KVM_CAP_S390_PROTECTED_DUMP
5448
5449	Presents an API that provides Ultravisor related data to userspace
5450	via subcommands. len_max is the size of the user space buffer,
5451	len_written is KVM's indication of how much bytes of that buffer
5452	were actually written to. len_written can be used to determine the
5453	valid fields if more response fields are added in the future.
5454
5455	::
5456
5457	enum pv_cmd_info_id {
5458	KVM_PV_INFO_VM,
5459	KVM_PV_INFO_DUMP,
5460	};
5461
5462	struct kvm_s390_pv_info_header {
5463	__u32 id;
5464	__u32 len_max;
5465	__u32 len_written;
5466	__u32 reserved;
5467	};
5468
5469	struct kvm_s390_pv_info {
5470	struct kvm_s390_pv_info_header header;
5471	struct kvm_s390_pv_info_dump dump;
5472	struct kvm_s390_pv_info_vm vm;
5473	};
5474
5475	subcommands:
5476
5477	KVM_PV_INFO_VM
5478	This subcommand provides basic Ultravisor information for PV
5479	hosts. These values are likely also exported as files in the sysfs
5480	firmware UV query interface but they are more easily available to
5481	programs in this API.
5482
5483	The installed calls and feature_indication members provide the
5484	installed UV calls and the UV's other feature indications.
5485
5486	The max_* members provide information about the maximum number of PV
5487	vcpus, PV guests and PV guest memory size.
5488
5489	::
5490
5491	struct kvm_s390_pv_info_vm {
5492	__u64 inst_calls_list[4];
5493	__u64 max_cpus;
5494	__u64 max_guests;
5495	__u64 max_guest_addr;
5496	__u64 feature_indication;
5497	};
5498
5499
5500	KVM_PV_INFO_DUMP
5501	This subcommand provides information related to dumping PV guests.
5502
5503	::
5504
5505	struct kvm_s390_pv_info_dump {
5506	__u64 dump_cpu_buffer_len;
5507	__u64 dump_config_mem_buffer_per_1m;
5508	__u64 dump_config_finalize_len;
5509	};
5510
5511	KVM_PV_DUMP
5512	:Capability: KVM_CAP_S390_PROTECTED_DUMP
5513
5514	Presents an API that provides calls which facilitate dumping a
5515	protected VM.
5516
5517	::
5518
5519	struct kvm_s390_pv_dmp {
5520	__u64 subcmd;
5521	__u64 buff_addr;
5522	__u64 buff_len;
5523	__u64 gaddr; /* For dump storage state */
5524	};
5525
5526	subcommands:
5527
5528	KVM_PV_DUMP_INIT
5529	Initializes the dump process of a protected VM. If this call does
5530	not succeed all other subcommands will fail with -EINVAL. This
5531	subcommand will return -EINVAL if a dump process has not yet been
5532	completed.
5533
5534	Not all PV vms can be dumped, the owner needs to set `dump
5535	allowed` PCF bit 34 in the SE header to allow dumping.
5536
5537	KVM_PV_DUMP_CONFIG_STOR_STATE
5538	Stores `buff_len` bytes of tweak component values starting with
5539	the 1MB block specified by the absolute guest address
5540	(`gaddr`). `buff_len` needs to be `conf_dump_storage_state_len`
5541	aligned and at least >= the `conf_dump_storage_state_len` value
5542	provided by the dump uv_info data. buff_user might be written to
5543	even if an error rc is returned. For instance if we encounter a
5544	fault after writing the first page of data.
5545
5546	KVM_PV_DUMP_COMPLETE
5547	If the subcommand succeeds it completes the dump process and lets
5548	KVM_PV_DUMP_INIT be called again.
5549
5550	On success `conf_dump_finalize_len` bytes of completion data will be
5551	stored to the `buff_addr`. The completion data contains a key
5552	derivation seed, IV, tweak nonce and encryption keys as well as an
5553	authentication tag all of which are needed to decrypt the dump at a
5554	later time.
5555
5556	KVM_PV_ASYNC_CLEANUP_PREPARE
5557	:Capability: KVM_CAP_S390_PROTECTED_ASYNC_DISABLE
5558
5559	Prepare the current protected VM for asynchronous teardown. Most
5560	resources used by the current protected VM will be set aside for a
5561	subsequent asynchronous teardown. The current protected VM will then
5562	resume execution immediately as non-protected. There can be at most
5563	one protected VM prepared for asynchronous teardown at any time. If
5564	a protected VM had already been prepared for teardown without
5565	subsequently calling KVM_PV_ASYNC_CLEANUP_PERFORM, this call will
5566	fail. In that case, the userspace process should issue a normal
5567	KVM_PV_DISABLE. The resources set aside with this call will need to
5568	be cleaned up with a subsequent call to KVM_PV_ASYNC_CLEANUP_PERFORM
5569	or KVM_PV_DISABLE, otherwise they will be cleaned up when KVM
5570	terminates. KVM_PV_ASYNC_CLEANUP_PREPARE can be called again as soon
5571	as cleanup starts, i.e. before KVM_PV_ASYNC_CLEANUP_PERFORM finishes.
5572
5573	KVM_PV_ASYNC_CLEANUP_PERFORM
5574	:Capability: KVM_CAP_S390_PROTECTED_ASYNC_DISABLE
5575
5576	Tear down the protected VM previously prepared for teardown with
5577	KVM_PV_ASYNC_CLEANUP_PREPARE. The resources that had been set aside
5578	will be freed during the execution of this command. This PV command
5579	should ideally be issued by userspace from a separate thread. If a
5580	fatal signal is received (or the process terminates naturally), the
5581	command will terminate immediately without completing, and the normal
5582	KVM shutdown procedure will take care of cleaning up all remaining
5583	protected VMs, including the ones whose teardown was interrupted by
5584	process termination.
5585
5586	4.126 KVM_XEN_HVM_SET_ATTR
5587	--------------------------
5588
5589	:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
5590	:Architectures: x86
5591	:Type: vm ioctl
5592	:Parameters: struct kvm_xen_hvm_attr
5593	:Returns: 0 on success, < 0 on error
5594
5595	::
5596
5597	struct kvm_xen_hvm_attr {
5598	__u16 type;
5599	__u16 pad[3];
5600	union {
5601	__u8 long_mode;
5602	__u8 vector;
5603	__u8 runstate_update_flag;
5604	union {
5605	__u64 gfn;
5606	__u64 hva;
5607	} shared_info;
5608	struct {
5609	__u32 send_port;
5610	__u32 type; /* EVTCHNSTAT_ipi / EVTCHNSTAT_interdomain */
5611	__u32 flags;
5612	union {
5613	struct {
5614	__u32 port;
5615	__u32 vcpu;
5616	__u32 priority;
5617	} port;
5618	struct {
5619	__u32 port; /* Zero for eventfd */
5620	__s32 fd;
5621	} eventfd;
5622	__u32 padding[4];
5623	} deliver;
5624	} evtchn;
5625	__u32 xen_version;
5626	__u64 pad[8];
5627	} u;
5628	};
5629
5630	type values:
5631
5632	KVM_XEN_ATTR_TYPE_LONG_MODE
5633	Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This
5634	determines the layout of the shared_info page exposed to the VM.
5635
5636	KVM_XEN_ATTR_TYPE_SHARED_INFO
5637	Sets the guest physical frame number at which the Xen shared_info
5638	page resides. Note that although Xen places vcpu_info for the first
5639	32 vCPUs in the shared_info page, KVM does not automatically do so
5640	and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO or
5641	KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO_HVA be used explicitly even when
5642	the vcpu_info for a given vCPU resides at the "default" location
5643	in the shared_info page. This is because KVM may not be aware of
5644	the Xen CPU id which is used as the index into the vcpu_info[]
5645	array, so may know the correct default location.
5646
5647	Note that the shared_info page may be constantly written to by KVM;
5648	it contains the event channel bitmap used to deliver interrupts to
5649	a Xen guest, amongst other things. It is exempt from dirty tracking
5650	mechanisms — KVM will not explicitly mark the page as dirty each
5651	time an event channel interrupt is delivered to the guest! Thus,
5652	userspace should always assume that the designated GFN is dirty if
5653	any vCPU has been running or any event channel interrupts can be
5654	routed to the guest.
5655
5656	Setting the gfn to KVM_XEN_INVALID_GFN will disable the shared_info
5657	page.
5658
5659	KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA
5660	If the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA flag is also set in the
5661	Xen capabilities, then this attribute may be used to set the
5662	userspace address at which the shared_info page resides, which
5663	will always be fixed in the VMM regardless of where it is mapped
5664	in guest physical address space. This attribute should be used in
5665	preference to KVM_XEN_ATTR_TYPE_SHARED_INFO as it avoids
5666	unnecessary invalidation of an internal cache when the page is
5667	re-mapped in guest physical address space.
5668
5669	Setting the hva to zero will disable the shared_info page.
5670
5671	KVM_XEN_ATTR_TYPE_UPCALL_VECTOR
5672	Sets the exception vector used to deliver Xen event channel upcalls.
5673	This is the HVM-wide vector injected directly by the hypervisor
5674	(not through the local APIC), typically configured by a guest via
5675	HVM_PARAM_CALLBACK_IRQ. This can be disabled again (e.g. for guest
5676	SHUTDOWN_soft_reset) by setting it to zero.
5677
5678	KVM_XEN_ATTR_TYPE_EVTCHN
5679	This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
5680	support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It configures
5681	an outbound port number for interception of EVTCHNOP_send requests
5682	from the guest. A given sending port number may be directed back to
5683	a specified vCPU (by APIC ID) / port / priority on the guest, or to
5684	trigger events on an eventfd. The vCPU and priority can be changed
5685	by setting KVM_XEN_EVTCHN_UPDATE in a subsequent call, but other
5686	fields cannot change for a given sending port. A port mapping is
5687	removed by using KVM_XEN_EVTCHN_DEASSIGN in the flags field. Passing
5688	KVM_XEN_EVTCHN_RESET in the flags field removes all interception of
5689	outbound event channels. The values of the flags field are mutually
5690	exclusive and cannot be combined as a bitmask.
5691
5692	KVM_XEN_ATTR_TYPE_XEN_VERSION
5693	This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
5694	support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It configures
5695	the 32-bit version code returned to the guest when it invokes the
5696	XENVER_version call; typically (XEN_MAJOR << 16 \| XEN_MINOR). PV
5697	Xen guests will often use this to as a dummy hypercall to trigger
5698	event channel delivery, so responding within the kernel without
5699	exiting to userspace is beneficial.
5700
5701	KVM_XEN_ATTR_TYPE_RUNSTATE_UPDATE_FLAG
5702	This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
5703	support for KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG. It enables the
5704	XEN_RUNSTATE_UPDATE flag which allows guest vCPUs to safely read
5705	other vCPUs' vcpu_runstate_info. Xen guests enable this feature via
5706	the VMASST_TYPE_runstate_update_flag of the HYPERVISOR_vm_assist
5707	hypercall.
5708
5709	4.127 KVM_XEN_HVM_GET_ATTR
5710	--------------------------
5711
5712	:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
5713	:Architectures: x86
5714	:Type: vm ioctl
5715	:Parameters: struct kvm_xen_hvm_attr
5716	:Returns: 0 on success, < 0 on error
5717
5718	Allows Xen VM attributes to be read. For the structure and types,
5719	see KVM_XEN_HVM_SET_ATTR above. The KVM_XEN_ATTR_TYPE_EVTCHN
5720	attribute cannot be read.
5721
5722	4.128 KVM_XEN_VCPU_SET_ATTR
5723	---------------------------
5724
5725	:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
5726	:Architectures: x86
5727	:Type: vcpu ioctl
5728	:Parameters: struct kvm_xen_vcpu_attr
5729	:Returns: 0 on success, < 0 on error
5730
5731	::
5732
5733	struct kvm_xen_vcpu_attr {
5734	__u16 type;
5735	__u16 pad[3];
5736	union {
5737	__u64 gpa;
5738	__u64 pad[4];
5739	struct {
5740	__u64 state;
5741	__u64 state_entry_time;
5742	__u64 time_running;
5743	__u64 time_runnable;
5744	__u64 time_blocked;
5745	__u64 time_offline;
5746	} runstate;
5747	__u32 vcpu_id;
5748	struct {
5749	__u32 port;
5750	__u32 priority;
5751	__u64 expires_ns;
5752	} timer;
5753	__u8 vector;
5754	} u;
5755	};
5756
5757	type values:
5758
5759	KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO
5760	Sets the guest physical address of the vcpu_info for a given vCPU.
5761	As with the shared_info page for the VM, the corresponding page may be
5762	dirtied at any time if event channel interrupt delivery is enabled, so
5763	userspace should always assume that the page is dirty without relying
5764	on dirty logging. Setting the gpa to KVM_XEN_INVALID_GPA will disable
5765	the vcpu_info.
5766
5767	KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO_HVA
5768	If the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA flag is also set in the
5769	Xen capabilities, then this attribute may be used to set the
5770	userspace address of the vcpu_info for a given vCPU. It should
5771	only be used when the vcpu_info resides at the "default" location
5772	in the shared_info page. In this case it is safe to assume the
5773	userspace address will not change, because the shared_info page is
5774	an overlay on guest memory and remains at a fixed host address
5775	regardless of where it is mapped in guest physical address space
5776	and hence unnecessary invalidation of an internal cache may be
5777	avoided if the guest memory layout is modified.
5778	If the vcpu_info does not reside at the "default" location then
5779	it is not guaranteed to remain at the same host address and
5780	hence the aforementioned cache invalidation is required.
5781
5782	KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO
5783	Sets the guest physical address of an additional pvclock structure
5784	for a given vCPU. This is typically used for guest vsyscall support.
5785	Setting the gpa to KVM_XEN_INVALID_GPA will disable the structure.
5786
5787	KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR
5788	Sets the guest physical address of the vcpu_runstate_info for a given
5789	vCPU. This is how a Xen guest tracks CPU state such as steal time.
5790	Setting the gpa to KVM_XEN_INVALID_GPA will disable the runstate area.
5791
5792	KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT
5793	Sets the runstate (RUNSTATE_running/_runnable/_blocked/_offline) of
5794	the given vCPU from the .u.runstate.state member of the structure.
5795	KVM automatically accounts running and runnable time but blocked
5796	and offline states are only entered explicitly.
5797
5798	KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA
5799	Sets all fields of the vCPU runstate data from the .u.runstate member
5800	of the structure, including the current runstate. The state_entry_time
5801	must equal the sum of the other four times.
5802
5803	KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST
5804	This adds the contents of the .u.runstate members of the structure
5805	to the corresponding members of the given vCPU's runstate data, thus
5806	permitting atomic adjustments to the runstate times. The adjustment
5807	to the state_entry_time must equal the sum of the adjustments to the
5808	other four times. The state field must be set to -1, or to a valid
5809	runstate value (RUNSTATE_running, RUNSTATE_runnable, RUNSTATE_blocked
5810	or RUNSTATE_offline) to set the current accounted state as of the
5811	adjusted state_entry_time.
5812
5813	KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID
5814	This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
5815	support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It sets the Xen
5816	vCPU ID of the given vCPU, to allow timer-related VCPU operations to
5817	be intercepted by KVM.
5818
5819	KVM_XEN_VCPU_ATTR_TYPE_TIMER
5820	This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
5821	support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It sets the
5822	event channel port/priority for the VIRQ_TIMER of the vCPU, as well
5823	as allowing a pending timer to be saved/restored. Setting the timer
5824	port to zero disables kernel handling of the singleshot timer.
5825
5826	KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR
5827	This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
5828	support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It sets the
5829	per-vCPU local APIC upcall vector, configured by a Xen guest with
5830	the HVMOP_set_evtchn_upcall_vector hypercall. This is typically
5831	used by Windows guests, and is distinct from the HVM-wide upcall
5832	vector configured with HVM_PARAM_CALLBACK_IRQ. It is disabled by
5833	setting the vector to zero.
5834
5835
5836	4.129 KVM_XEN_VCPU_GET_ATTR
5837	---------------------------
5838
5839	:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
5840	:Architectures: x86
5841	:Type: vcpu ioctl
5842	:Parameters: struct kvm_xen_vcpu_attr
5843	:Returns: 0 on success, < 0 on error
5844
5845	Allows Xen vCPU attributes to be read. For the structure and types,
5846	see KVM_XEN_VCPU_SET_ATTR above.
5847
5848	The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used
5849	with the KVM_XEN_VCPU_GET_ATTR ioctl.
5850
5851	4.130 KVM_ARM_MTE_COPY_TAGS
5852	---------------------------
5853
5854	:Capability: KVM_CAP_ARM_MTE
5855	:Architectures: arm64
5856	:Type: vm ioctl
5857	:Parameters: struct kvm_arm_copy_mte_tags
5858	:Returns: number of bytes copied, < 0 on error (-EINVAL for incorrect
5859	arguments, -EFAULT if memory cannot be accessed).
5860
5861	::
5862
5863	struct kvm_arm_copy_mte_tags {
5864	__u64 guest_ipa;
5865	__u64 length;
5866	void __user *addr;
5867	__u64 flags;
5868	__u64 reserved[2];
5869	};
5870
5871	Copies Memory Tagging Extension (MTE) tags to/from guest tag memory. The
5872	``guest_ipa`` and ``length`` fields must be ``PAGE_SIZE`` aligned.
5873	``length`` must not be bigger than 2^31 - PAGE_SIZE bytes. The ``addr``
5874	field must point to a buffer which the tags will be copied to or from.
5875
5876	``flags`` specifies the direction of copy, either ``KVM_ARM_TAGS_TO_GUEST`` or
5877	``KVM_ARM_TAGS_FROM_GUEST``.
5878
5879	The size of the buffer to store the tags is ``(length / 16)`` bytes
5880	(granules in MTE are 16 bytes long). Each byte contains a single tag
5881	value. This matches the format of ``PTRACE_PEEKMTETAGS`` and
5882	``PTRACE_POKEMTETAGS``.
5883
5884	If an error occurs before any data is copied then a negative error code is
5885	returned. If some tags have been copied before an error occurs then the number
5886	of bytes successfully copied is returned. If the call completes successfully
5887	then ``length`` is returned.
5888
5889	4.131 KVM_GET_SREGS2
5890	--------------------
5891
5892	:Capability: KVM_CAP_SREGS2
5893	:Architectures: x86
5894	:Type: vcpu ioctl
5895	:Parameters: struct kvm_sregs2 (out)
5896	:Returns: 0 on success, -1 on error
5897
5898	Reads special registers from the vcpu.
5899	This ioctl (when supported) replaces the KVM_GET_SREGS.
5900
5901	::
5902
5903	struct kvm_sregs2 {
5904	/* out (KVM_GET_SREGS2) / in (KVM_SET_SREGS2) */
5905	struct kvm_segment cs, ds, es, fs, gs, ss;
5906	struct kvm_segment tr, ldt;
5907	struct kvm_dtable gdt, idt;
5908	__u64 cr0, cr2, cr3, cr4, cr8;
5909	__u64 efer;
5910	__u64 apic_base;
5911	__u64 flags;
5912	__u64 pdptrs[4];
5913	};
5914
5915	flags values for ``kvm_sregs2``:
5916
5917	``KVM_SREGS2_FLAGS_PDPTRS_VALID``
5918
5919	Indicates that the struct contains valid PDPTR values.
5920
5921
5922	4.132 KVM_SET_SREGS2
5923	--------------------
5924
5925	:Capability: KVM_CAP_SREGS2
5926	:Architectures: x86
5927	:Type: vcpu ioctl
5928	:Parameters: struct kvm_sregs2 (in)
5929	:Returns: 0 on success, -1 on error
5930
5931	Writes special registers into the vcpu.
5932	See KVM_GET_SREGS2 for the data structures.
5933	This ioctl (when supported) replaces the KVM_SET_SREGS.
5934
5935	4.133 KVM_GET_STATS_FD
5936	----------------------
5937
5938	:Capability: KVM_CAP_STATS_BINARY_FD
5939	:Architectures: all
5940	:Type: vm ioctl, vcpu ioctl
5941	:Parameters: none
5942	:Returns: statistics file descriptor on success, < 0 on error
5943
5944	Errors:
5945
5946	====== ======================================================
5947	ENOMEM if the fd could not be created due to lack of memory
5948	EMFILE if the number of opened files exceeds the limit
5949	====== ======================================================
5950
5951	The returned file descriptor can be used to read VM/vCPU statistics data in
5952	binary format. The data in the file descriptor consists of four blocks
5953	organized as follows:
5954
5955	+-------------+
5956	\| Header \|
5957	+-------------+
5958	\| id string \|
5959	+-------------+
5960	\| Descriptors \|
5961	+-------------+
5962	\| Stats Data \|
5963	+-------------+
5964
5965	Apart from the header starting at offset 0, please be aware that it is
5966	not guaranteed that the four blocks are adjacent or in the above order;
5967	the offsets of the id, descriptors and data blocks are found in the
5968	header. However, all four blocks are aligned to 64 bit offsets in the
5969	file and they do not overlap.
5970
5971	All blocks except the data block are immutable. Userspace can read them
5972	only one time after retrieving the file descriptor, and then use ``pread`` or
5973	``lseek`` to read the statistics repeatedly.
5974
5975	All data is in system endianness.
5976
5977	The format of the header is as follows::
5978
5979	struct kvm_stats_header {
5980	__u32 flags;
5981	__u32 name_size;
5982	__u32 num_desc;
5983	__u32 id_offset;
5984	__u32 desc_offset;
5985	__u32 data_offset;
5986	};
5987
5988	The ``flags`` field is not used at the moment. It is always read as 0.
5989
5990	The ``name_size`` field is the size (in byte) of the statistics name string
5991	(including trailing '\0') which is contained in the "id string" block and
5992	appended at the end of every descriptor.
5993
5994	The ``num_desc`` field is the number of descriptors that are included in the
5995	descriptor block. (The actual number of values in the data block may be
5996	larger, since each descriptor may comprise more than one value).
5997
5998	The ``id_offset`` field is the offset of the id string from the start of the
5999	file indicated by the file descriptor. It is a multiple of 8.
6000
6001	The ``desc_offset`` field is the offset of the Descriptors block from the start
6002	of the file indicated by the file descriptor. It is a multiple of 8.
6003
6004	The ``data_offset`` field is the offset of the Stats Data block from the start
6005	of the file indicated by the file descriptor. It is a multiple of 8.
6006
6007	The id string block contains a string which identifies the file descriptor on
6008	which KVM_GET_STATS_FD was invoked. The size of the block, including the
6009	trailing ``'\0'``, is indicated by the ``name_size`` field in the header.
6010
6011	The descriptors block is only needed to be read once for the lifetime of the
6012	file descriptor contains a sequence of ``struct kvm_stats_desc``, each followed
6013	by a string of size ``name_size``.
6014	::
6015
6016	#define KVM_STATS_TYPE_SHIFT 0
6017	#define KVM_STATS_TYPE_MASK (0xF << KVM_STATS_TYPE_SHIFT)
6018	#define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
6019	#define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
6020	#define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
6021	#define KVM_STATS_TYPE_LINEAR_HIST (0x3 << KVM_STATS_TYPE_SHIFT)
6022	#define KVM_STATS_TYPE_LOG_HIST (0x4 << KVM_STATS_TYPE_SHIFT)
6023	#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_LOG_HIST
6024
6025	#define KVM_STATS_UNIT_SHIFT 4
6026	#define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
6027	#define KVM_STATS_UNIT_NONE (0x0 << KVM_STATS_UNIT_SHIFT)
6028	#define KVM_STATS_UNIT_BYTES (0x1 << KVM_STATS_UNIT_SHIFT)
6029	#define KVM_STATS_UNIT_SECONDS (0x2 << KVM_STATS_UNIT_SHIFT)
6030	#define KVM_STATS_UNIT_CYCLES (0x3 << KVM_STATS_UNIT_SHIFT)
6031	#define KVM_STATS_UNIT_BOOLEAN (0x4 << KVM_STATS_UNIT_SHIFT)
6032	#define KVM_STATS_UNIT_MAX KVM_STATS_UNIT_BOOLEAN
6033
6034	#define KVM_STATS_BASE_SHIFT 8
6035	#define KVM_STATS_BASE_MASK (0xF << KVM_STATS_BASE_SHIFT)
6036	#define KVM_STATS_BASE_POW10 (0x0 << KVM_STATS_BASE_SHIFT)
6037	#define KVM_STATS_BASE_POW2 (0x1 << KVM_STATS_BASE_SHIFT)
6038	#define KVM_STATS_BASE_MAX KVM_STATS_BASE_POW2
6039
6040	struct kvm_stats_desc {
6041	__u32 flags;
6042	__s16 exponent;
6043	__u16 size;
6044	__u32 offset;
6045	__u32 bucket_size;
6046	char name[];
6047	};
6048
6049	The ``flags`` field contains the type and unit of the statistics data described
6050	by this descriptor. Its endianness is CPU native.
6051	The following flags are supported:
6052
6053	Bits 0-3 of ``flags`` encode the type:
6054
6055	* ``KVM_STATS_TYPE_CUMULATIVE``
6056	The statistics reports a cumulative count. The value of data can only be increased.
6057	Most of the counters used in KVM are of this type.
6058	The corresponding ``size`` field for this type is always 1.
6059	All cumulative statistics data are read/write.
6060	* ``KVM_STATS_TYPE_INSTANT``
6061	The statistics reports an instantaneous value. Its value can be increased or
6062	decreased. This type is usually used as a measurement of some resources,
6063	like the number of dirty pages, the number of large pages, etc.
6064	All instant statistics are read only.
6065	The corresponding ``size`` field for this type is always 1.
6066	* ``KVM_STATS_TYPE_PEAK``
6067	The statistics data reports a peak value, for example the maximum number
6068	of items in a hash table bucket, the longest time waited and so on.
6069	The value of data can only be increased.
6070	The corresponding ``size`` field for this type is always 1.
6071	* ``KVM_STATS_TYPE_LINEAR_HIST``
6072	The statistic is reported as a linear histogram. The number of
6073	buckets is specified by the ``size`` field. The size of buckets is specified
6074	by the ``hist_param`` field. The range of the Nth bucket (1 <= N < ``size``)
6075	is [``hist_param``(N-1), ``hist_param``N), while the range of the last
6076	bucket is [``hist_param``*(``size``-1), +INF). (+INF means positive infinity
6077	value.)
6078	* ``KVM_STATS_TYPE_LOG_HIST``
6079	The statistic is reported as a logarithmic histogram. The number of
6080	buckets is specified by the ``size`` field. The range of the first bucket is
6081	[0, 1), while the range of the last bucket is [pow(2, ``size``-2), +INF).
6082	Otherwise, The Nth bucket (1 < N < ``size``) covers
6083	[pow(2, N-2), pow(2, N-1)).
6084
6085	Bits 4-7 of ``flags`` encode the unit:
6086
6087	* ``KVM_STATS_UNIT_NONE``
6088	There is no unit for the value of statistics data. This usually means that
6089	the value is a simple counter of an event.
6090	* ``KVM_STATS_UNIT_BYTES``
6091	It indicates that the statistics data is used to measure memory size, in the
6092	unit of Byte, KiByte, MiByte, GiByte, etc. The unit of the data is
6093	determined by the ``exponent`` field in the descriptor.
6094	* ``KVM_STATS_UNIT_SECONDS``
6095	It indicates that the statistics data is used to measure time or latency.
6096	* ``KVM_STATS_UNIT_CYCLES``
6097	It indicates that the statistics data is used to measure CPU clock cycles.
6098	* ``KVM_STATS_UNIT_BOOLEAN``
6099	It indicates that the statistic will always be either 0 or 1. Boolean
6100	statistics of "peak" type will never go back from 1 to 0. Boolean
6101	statistics can be linear histograms (with two buckets) but not logarithmic
6102	histograms.
6103
6104	Note that, in the case of histograms, the unit applies to the bucket
6105	ranges, while the bucket value indicates how many samples fell in the
6106	bucket's range.
6107
6108	Bits 8-11 of ``flags``, together with ``exponent``, encode the scale of the
6109	unit:
6110
6111	* ``KVM_STATS_BASE_POW10``
6112	The scale is based on power of 10. It is used for measurement of time and
6113	CPU clock cycles. For example, an exponent of -9 can be used with
6114	``KVM_STATS_UNIT_SECONDS`` to express that the unit is nanoseconds.
6115	* ``KVM_STATS_BASE_POW2``
6116	The scale is based on power of 2. It is used for measurement of memory size.
6117	For example, an exponent of 20 can be used with ``KVM_STATS_UNIT_BYTES`` to
6118	express that the unit is MiB.
6119
6120	The ``size`` field is the number of values of this statistics data. Its
6121	value is usually 1 for most of simple statistics. 1 means it contains an
6122	unsigned 64bit data.
6123
6124	The ``offset`` field is the offset from the start of Data Block to the start of
6125	the corresponding statistics data.
6126
6127	The ``bucket_size`` field is used as a parameter for histogram statistics data.
6128	It is only used by linear histogram statistics data, specifying the size of a
6129	bucket in the unit expressed by bits 4-11 of ``flags`` together with ``exponent``.
6130
6131	The ``name`` field is the name string of the statistics data. The name string
6132	starts at the end of ``struct kvm_stats_desc``. The maximum length including
6133	the trailing ``'\0'``, is indicated by ``name_size`` in the header.
6134
6135	The Stats Data block contains an array of 64-bit values in the same order
6136	as the descriptors in Descriptors block.
6137
6138	4.134 KVM_GET_XSAVE2
6139	--------------------
6140
6141	:Capability: KVM_CAP_XSAVE2
6142	:Architectures: x86
6143	:Type: vcpu ioctl
6144	:Parameters: struct kvm_xsave (out)
6145	:Returns: 0 on success, -1 on error
6146
6147
6148	::
6149
6150	struct kvm_xsave {
6151	__u32 region[1024];
6152	__u32 extra[0];
6153	};
6154
6155	This ioctl would copy current vcpu's xsave struct to the userspace. It
6156	copies as many bytes as are returned by KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2)
6157	when invoked on the vm file descriptor. The size value returned by
6158	KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2) will always be at least 4096.
6159	Currently, it is only greater than 4096 if a dynamic feature has been
6160	enabled with ``arch_prctl()``, but this may change in the future.
6161
6162	The offsets of the state save areas in struct kvm_xsave follow the contents
6163	of CPUID leaf 0xD on the host.
6164
6165	4.135 KVM_XEN_HVM_EVTCHN_SEND
6166	-----------------------------
6167
6168	:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_EVTCHN_SEND
6169	:Architectures: x86
6170	:Type: vm ioctl
6171	:Parameters: struct kvm_irq_routing_xen_evtchn
6172	:Returns: 0 on success, < 0 on error
6173
6174
6175	::
6176
6177	struct kvm_irq_routing_xen_evtchn {
6178	__u32 port;
6179	__u32 vcpu;
6180	__u32 priority;
6181	};
6182
6183	This ioctl injects an event channel interrupt directly to the guest vCPU.
6184
6185	4.136 KVM_S390_PV_CPU_COMMAND
6186	-----------------------------
6187
6188	:Capability: KVM_CAP_S390_PROTECTED_DUMP
6189	:Architectures: s390
6190	:Type: vcpu ioctl
6191	:Parameters: none
6192	:Returns: 0 on success, < 0 on error
6193
6194	This ioctl closely mirrors `KVM_S390_PV_COMMAND` but handles requests
6195	for vcpus. It re-uses the kvm_s390_pv_dmp struct and hence also shares
6196	the command ids.
6197
6198	command:
6199
6200	KVM_PV_DUMP
6201	Presents an API that provides calls which facilitate dumping a vcpu
6202	of a protected VM.
6203
6204	subcommand:
6205
6206	KVM_PV_DUMP_CPU
6207	Provides encrypted dump data like register values.
6208	The length of the returned data is provided by uv_info.guest_cpu_stor_len.
6209
6210	4.137 KVM_S390_ZPCI_OP
6211	----------------------
6212
6213	:Capability: KVM_CAP_S390_ZPCI_OP
6214	:Architectures: s390
6215	:Type: vm ioctl
6216	:Parameters: struct kvm_s390_zpci_op (in)
6217	:Returns: 0 on success, <0 on error
6218
6219	Used to manage hardware-assisted virtualization features for zPCI devices.
6220
6221	Parameters are specified via the following structure::
6222
6223	struct kvm_s390_zpci_op {
6224	/* in */
6225	__u32 fh; /* target device */
6226	__u8 op; /* operation to perform */
6227	__u8 pad[3];
6228	union {
6229	/* for KVM_S390_ZPCIOP_REG_AEN */
6230	struct {
6231	__u64 ibv; /* Guest addr of interrupt bit vector */
6232	__u64 sb; /* Guest addr of summary bit */
6233	__u32 flags;
6234	__u32 noi; /* Number of interrupts */
6235	__u8 isc; /* Guest interrupt subclass */
6236	__u8 sbo; /* Offset of guest summary bit vector */
6237	__u16 pad;
6238	} reg_aen;
6239	__u64 reserved[8];
6240	} u;
6241	};
6242
6243	The type of operation is specified in the "op" field.
6244	KVM_S390_ZPCIOP_REG_AEN is used to register the VM for adapter event
6245	notification interpretation, which will allow firmware delivery of adapter
6246	events directly to the vm, with KVM providing a backup delivery mechanism;
6247	KVM_S390_ZPCIOP_DEREG_AEN is used to subsequently disable interpretation of
6248	adapter event notifications.
6249
6250	The target zPCI function must also be specified via the "fh" field. For the
6251	KVM_S390_ZPCIOP_REG_AEN operation, additional information to establish firmware
6252	delivery must be provided via the "reg_aen" struct.
6253
6254	The "pad" and "reserved" fields may be used for future extensions and should be
6255	set to 0s by userspace.
6256
6257	4.138 KVM_ARM_SET_COUNTER_OFFSET
6258	--------------------------------
6259
6260	:Capability: KVM_CAP_COUNTER_OFFSET
6261	:Architectures: arm64
6262	:Type: vm ioctl
6263	:Parameters: struct kvm_arm_counter_offset (in)
6264	:Returns: 0 on success, < 0 on error
6265
6266	This capability indicates that userspace is able to apply a single VM-wide
6267	offset to both the virtual and physical counters as viewed by the guest
6268	using the KVM_ARM_SET_CNT_OFFSET ioctl and the following data structure:
6269
6270	::
6271
6272	struct kvm_arm_counter_offset {
6273	__u64 counter_offset;
6274	__u64 reserved;
6275	};
6276
6277	The offset describes a number of counter cycles that are subtracted from
6278	both virtual and physical counter views (similar to the effects of the
6279	CNTVOFF_EL2 and CNTPOFF_EL2 system registers, but only global). The offset
6280	always applies to all vcpus (already created or created after this ioctl)
6281	for this VM.
6282
6283	It is userspace's responsibility to compute the offset based, for example,
6284	on previous values of the guest counters.
6285
6286	Any value other than 0 for the "reserved" field may result in an error
6287	(-EINVAL) being returned. This ioctl can also return -EBUSY if any vcpu
6288	ioctl is issued concurrently.
6289
6290	Note that using this ioctl results in KVM ignoring subsequent userspace
6291	writes to the CNTVCT_EL0 and CNTPCT_EL0 registers using the SET_ONE_REG
6292	interface. No error will be returned, but the resulting offset will not be
6293	applied.
6294
6295	.. _KVM_ARM_GET_REG_WRITABLE_MASKS:
6296
6297	4.139 KVM_ARM_GET_REG_WRITABLE_MASKS
6298	------------------------------------
6299
6300	:Capability: KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES
6301	:Architectures: arm64
6302	:Type: vm ioctl
6303	:Parameters: struct reg_mask_range (in/out)
6304	:Returns: 0 on success, < 0 on error
6305
6306
6307	::
6308
6309	#define KVM_ARM_FEATURE_ID_RANGE 0
6310	#define KVM_ARM_FEATURE_ID_RANGE_SIZE (3 * 8 * 8)
6311
6312	struct reg_mask_range {
6313	__u64 addr; /* Pointer to mask array */
6314	__u32 range; /* Requested range */
6315	__u32 reserved[13];
6316	};
6317
6318	This ioctl copies the writable masks for a selected range of registers to
6319	userspace.
6320
6321	The ``addr`` field is a pointer to the destination array where KVM copies
6322	the writable masks.
6323
6324	The ``range`` field indicates the requested range of registers.
6325	``KVM_CHECK_EXTENSION`` for the ``KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES``
6326	capability returns the supported ranges, expressed as a set of flags. Each
6327	flag's bit index represents a possible value for the ``range`` field.
6328	All other values are reserved for future use and KVM may return an error.
6329
6330	The ``reserved[13]`` array is reserved for future use and should be 0, or
6331	KVM may return an error.
6332
6333	KVM_ARM_FEATURE_ID_RANGE (0)
6334	^^^^^^^^^^^^^^^^^^^^^^^^^^^^
6335
6336	The Feature ID range is defined as the AArch64 System register space with
6337	op0==3, op1=={0, 1, 3}, CRn==0, CRm=={0-7}, op2=={0-7}.
6338
6339	The mask returned array pointed to by ``addr`` is indexed by the macro
6340	``ARM64_FEATURE_ID_RANGE_IDX(op0, op1, crn, crm, op2)``, allowing userspace
6341	to know what fields can be changed for the system register described by
6342	``op0, op1, crn, crm, op2``. KVM rejects ID register values that describe a
6343	superset of the features supported by the system.
6344
6345	4.140 KVM_SET_USER_MEMORY_REGION2
6346	---------------------------------
6347
6348	:Capability: KVM_CAP_USER_MEMORY2
6349	:Architectures: all
6350	:Type: vm ioctl
6351	:Parameters: struct kvm_userspace_memory_region2 (in)
6352	:Returns: 0 on success, -1 on error
6353
6354	KVM_SET_USER_MEMORY_REGION2 is an extension to KVM_SET_USER_MEMORY_REGION that
6355	allows mapping guest_memfd memory into a guest. All fields shared with
6356	KVM_SET_USER_MEMORY_REGION identically. Userspace can set KVM_MEM_GUEST_MEMFD
6357	in flags to have KVM bind the memory region to a given guest_memfd range of
6358	[guest_memfd_offset, guest_memfd_offset + memory_size]. The target guest_memfd
6359	must point at a file created via KVM_CREATE_GUEST_MEMFD on the current VM, and
6360	the target range must not be bound to any other memory region. All standard
6361	bounds checks apply (use common sense).
6362
6363	::
6364
6365	struct kvm_userspace_memory_region2 {
6366	__u32 slot;
6367	__u32 flags;
6368	__u64 guest_phys_addr;
6369	__u64 memory_size; /* bytes */
6370	__u64 userspace_addr; /* start of the userspace allocated memory */
6371	__u64 guest_memfd_offset;
6372	__u32 guest_memfd;
6373	__u32 pad1;
6374	__u64 pad2[14];
6375	};
6376
6377	A KVM_MEM_GUEST_MEMFD region _must_ have a valid guest_memfd (private memory) and
6378	userspace_addr (shared memory). However, "valid" for userspace_addr simply
6379	means that the address itself must be a legal userspace address. The backing
6380	mapping for userspace_addr is not required to be valid/populated at the time of
6381	KVM_SET_USER_MEMORY_REGION2, e.g. shared memory can be lazily mapped/allocated
6382	on-demand.
6383
6384	When mapping a gfn into the guest, KVM selects shared vs. private, i.e consumes
6385	userspace_addr vs. guest_memfd, based on the gfn's KVM_MEMORY_ATTRIBUTE_PRIVATE
6386	state. At VM creation time, all memory is shared, i.e. the PRIVATE attribute
6387	is '0' for all gfns. Userspace can control whether memory is shared/private by
6388	toggling KVM_MEMORY_ATTRIBUTE_PRIVATE via KVM_SET_MEMORY_ATTRIBUTES as needed.
6389
6390	S390:
6391	^^^^^
6392
6393	Returns -EINVAL if the VM has the KVM_VM_S390_UCONTROL flag set.
6394	Returns -EINVAL if called on a protected VM.
6395
6396	4.141 KVM_SET_MEMORY_ATTRIBUTES
6397	-------------------------------
6398
6399	:Capability: KVM_CAP_MEMORY_ATTRIBUTES
6400	:Architectures: x86
6401	:Type: vm ioctl
6402	:Parameters: struct kvm_memory_attributes (in)
6403	:Returns: 0 on success, <0 on error
6404
6405	KVM_SET_MEMORY_ATTRIBUTES allows userspace to set memory attributes for a range
6406	of guest physical memory.
6407
6408	::
6409
6410	struct kvm_memory_attributes {
6411	__u64 address;
6412	__u64 size;
6413	__u64 attributes;
6414	__u64 flags;
6415	};
6416
6417	#define KVM_MEMORY_ATTRIBUTE_PRIVATE (1ULL << 3)
6418
6419	The address and size must be page aligned. The supported attributes can be
6420	retrieved via ioctl(KVM_CHECK_EXTENSION) on KVM_CAP_MEMORY_ATTRIBUTES. If
6421	executed on a VM, KVM_CAP_MEMORY_ATTRIBUTES precisely returns the attributes
6422	supported by that VM. If executed at system scope, KVM_CAP_MEMORY_ATTRIBUTES
6423	returns all attributes supported by KVM. The only attribute defined at this
6424	time is KVM_MEMORY_ATTRIBUTE_PRIVATE, which marks the associated gfn as being
6425	guest private memory.
6426
6427	Note, there is no "get" API. Userspace is responsible for explicitly tracking
6428	the state of a gfn/page as needed.
6429
6430	The "flags" field is reserved for future extensions and must be '0'.
6431
6432	4.142 KVM_CREATE_GUEST_MEMFD
6433	----------------------------
6434
6435	:Capability: KVM_CAP_GUEST_MEMFD
6436	:Architectures: none
6437	:Type: vm ioctl
6438	:Parameters: struct kvm_create_guest_memfd(in)
6439	:Returns: A file descriptor on success, <0 on error
6440
6441	KVM_CREATE_GUEST_MEMFD creates an anonymous file and returns a file descriptor
6442	that refers to it. guest_memfd files are roughly analogous to files created
6443	via memfd_create(), e.g. guest_memfd files live in RAM, have volatile storage,
6444	and are automatically released when the last reference is dropped. Unlike
6445	"regular" memfd_create() files, guest_memfd files are bound to their owning
6446	virtual machine (see below), cannot be mapped, read, or written by userspace,
6447	and cannot be resized (guest_memfd files do however support PUNCH_HOLE).
6448
6449	::
6450
6451	struct kvm_create_guest_memfd {
6452	__u64 size;
6453	__u64 flags;
6454	__u64 reserved[6];
6455	};
6456
6457	Conceptually, the inode backing a guest_memfd file represents physical memory,
6458	i.e. is coupled to the virtual machine as a thing, not to a "struct kvm". The
6459	file itself, which is bound to a "struct kvm", is that instance's view of the
6460	underlying memory, e.g. effectively provides the translation of guest addresses
6461	to host memory. This allows for use cases where multiple KVM structures are
6462	used to manage a single virtual machine, e.g. when performing intrahost
6463	migration of a virtual machine.
6464
6465	KVM currently only supports mapping guest_memfd via KVM_SET_USER_MEMORY_REGION2,
6466	and more specifically via the guest_memfd and guest_memfd_offset fields in
6467	"struct kvm_userspace_memory_region2", where guest_memfd_offset is the offset
6468	into the guest_memfd instance. For a given guest_memfd file, there can be at
6469	most one mapping per page, i.e. binding multiple memory regions to a single
6470	guest_memfd range is not allowed (any number of memory regions can be bound to
6471	a single guest_memfd file, but the bound ranges must not overlap).
6472
6473	The capability KVM_CAP_GUEST_MEMFD_FLAGS enumerates the `flags` that can be
6474	specified via KVM_CREATE_GUEST_MEMFD. Currently defined flags:
6475
6476	============================ ================================================
6477	GUEST_MEMFD_FLAG_MMAP Enable using mmap() on the guest_memfd file
6478	descriptor.
6479	GUEST_MEMFD_FLAG_INIT_SHARED Make all memory in the file shared during
6480	KVM_CREATE_GUEST_MEMFD (memory files created
6481	without INIT_SHARED will be marked private).
6482	Shared memory can be faulted into host userspace
6483	page tables. Private memory cannot.
6484	============================ ================================================
6485
6486	When the KVM MMU performs a PFN lookup to service a guest fault and the backing
6487	guest_memfd has the GUEST_MEMFD_FLAG_MMAP set, then the fault will always be
6488	consumed from guest_memfd, regardless of whether it is a shared or a private
6489	fault.
6490
6491	See KVM_SET_USER_MEMORY_REGION2 for additional details.
6492
6493	4.143 KVM_PRE_FAULT_MEMORY
6494	---------------------------
6495
6496	:Capability: KVM_CAP_PRE_FAULT_MEMORY
6497	:Architectures: none
6498	:Type: vcpu ioctl
6499	:Parameters: struct kvm_pre_fault_memory (in/out)
6500	:Returns: 0 if at least one page is processed, < 0 on error
6501
6502	Errors:
6503
6504	========== ===============================================================
6505	EINVAL The specified `gpa` and `size` were invalid (e.g. not
6506	page aligned, causes an overflow, or size is zero), or the VM
6507	is UCONTROL (s390).
6508	ENOENT The specified `gpa` is outside defined memslots.
6509	EINTR An unmasked signal is pending and no page was processed.
6510	EFAULT The parameter address was invalid.
6511	EOPNOTSUPP Mapping memory for a GPA is unsupported by the
6512	hypervisor, and/or for the current vCPU state/mode.
6513	EIO unexpected error conditions (also causes a WARN)
6514	========== ===============================================================
6515
6516	::
6517
6518	struct kvm_pre_fault_memory {
6519	/* in/out */
6520	__u64 gpa;
6521	__u64 size;
6522	/* in */
6523	__u64 flags;
6524	__u64 padding[5];
6525	};
6526
6527	KVM_PRE_FAULT_MEMORY populates KVM's stage-2 page tables used to map memory
6528	for the current vCPU state. KVM maps memory as if the vCPU generated a
6529	stage-2 read page fault, e.g. faults in memory as needed, but doesn't break
6530	CoW. On x86, KVM does not mark any newly created stage-2 PTE as Accessed.
6531
6532	In the case of confidential VM types where there is an initial set up of
6533	private guest memory before the guest is 'finalized'/measured, this ioctl
6534	should only be issued after completing all the necessary setup to put the
6535	guest into a 'finalized' state so that the above semantics can be reliably
6536	ensured.
6537
6538	In some cases, multiple vCPUs might share the page tables. In this
6539	case, the ioctl can be called in parallel.
6540
6541	When the ioctl returns, the input values are updated to point to the
6542	remaining range. If `size` > 0 on return, the caller can just issue
6543	the ioctl again with the same `struct kvm_map_memory` argument.
6544
6545	Shadow page tables cannot support this ioctl because they
6546	are indexed by virtual address or nested guest physical address.
6547	Calling this ioctl when the guest is using shadow page tables (for
6548	example because it is running a nested guest with nested page tables)
6549	will fail with `EOPNOTSUPP` even if `KVM_CHECK_EXTENSION` reports
6550	the capability to be present.
6551
6552	`flags` must currently be zero.
6553
6554	4.144 KVM_S390_KEYOP
6555	--------------------
6556
6557	:Capability: KVM_CAP_S390_KEYOP
6558	:Architectures: s390
6559	:Type: vm ioctl
6560	:Parameters: struct kvm_s390_keyop (in/out)
6561	:Returns: 0 in case of success, < 0 on error
6562
6563	The specified key operation is performed on the given guest address. The
6564	previous storage key (or the relevant part thereof) will be returned in
6565	`key`.
6566
6567	::
6568
6569	struct kvm_s390_keyop {
6570	__u64 guest_addr;
6571	__u8 key;
6572	__u8 operation;
6573	};
6574
6575	Currently supported values for ``operation``:
6576
6577	KVM_S390_KEYOP_ISKE
6578	Returns the storage key for the guest address ``guest_addr`` in ``key``.
6579
6580	KVM_S390_KEYOP_RRBE
6581	Resets the reference bit for the guest address ``guest_addr``, returning the
6582	R and C bits of the old storage key in ``key``; the remaining fields of
6583	the storage key will be set to 0.
6584
6585	KVM_S390_KEYOP_SSKE
6586	Sets the storage key for the guest address ``guest_addr`` to the key
6587	specified in ``key``, returning the previous value in ``key``.
6588
6589	4.145 KVM_PPC_GET_COMPAT_CAPS
6590	-----------------------------
6591	:Capability: KVM_CAP_PPC_COMPAT_CAPS
6592	:Architectures: powerpc
6593	:Type: vm ioctl
6594	:Parameters: struct kvm_ppc_compat_caps (in/out)
6595	:Returns: 0 on success, negative value on failure
6596
6597	Errors include:
6598
6599	======== ============================================================
6600	EFAULT if ``struct kvm_ppc_compat_caps`` cannot be read from or
6601	written to userspace
6602	EINVAL if the ``size`` field is smaller than
6603	``KVM_PPC_COMPAT_CAPS_SIZE_VER0``, if the ``flags`` field
6604	is non-zero, or if the backend fails to retrieve or map
6605	CPU compatibility capabilities
6606	E2BIG if ``size`` exceeds ``PAGE_SIZE`` (pathological input guard),
6607	or if ``size`` is larger than the kernel's struct size and
6608	the unknown trailing bytes are non-zero (new userspace on
6609	old kernel with non-default fields set); in the latter case
6610	the kernel writes back its own struct size into the ``size``
6611	field so userspace can retry with the correct size
6612	ENOTTY if the backend does not implement the ``get_compat_caps``
6613	operation (e.g., on non-HV KVM implementations where the
6614	required KVM operations are not available)
6615	======== ============================================================
6616
6617	IBM POWER system server-based processors provide a compatibility mode feature
6618	where an Nth generation processor can operate in modes consistent with earlier
6619	generations such as (N-1) and (N-2).
6620
6621	This ioctl provides userspace with information about the CPU compatibility modes
6622	supported by the current host processor for booting the nested KVM guests on
6623	KVM on PowerNV (nested API v1) and KVM on PowerVM (nested API v2) platforms.
6624
6625	::
6626
6627	struct kvm_ppc_compat_caps {
6628	__u64 size; /* Size of this structure */
6629	__u64 flags; /* Reserved for future use, must be 0 */
6630	__u64 compat_capabilities; /* Capabilities supported by the host */
6631	};
6632
6633	Before calling this ioctl, userspace must set the ``size`` field to
6634	``sizeof(struct kvm_ppc_compat_caps)`` and zero the ``flags`` field.
6635	The kernel rejects non-zero ``flags`` with ``-EINVAL`` to prevent
6636	uninitialized stack values from being silently accepted, keeping the
6637	field available for future use without ABI ambiguity.
6638
6639	The ioctl uses ``copy_struct_from_user()`` and ``copy_struct_to_user()``
6640	to support extensible versioning.
6641
6642	``KVM_PPC_COMPAT_CAPS_SIZE_VER0`` (24) is a frozen constant marking the
6643	size of the initial struct version.
6644
6645	The ``compat_capabilities`` bit field describes the processor compatibility
6646	modes supported by the host. The following bits indicate support for specific
6647	processor modes (using IBM's MSB-0 convention where bit 0 is the most
6648	significant bit):
6649
6650	- ``KVM_PPC_COMPAT_CAP_POWER9`` (bit 1) -- KVM guests can run in Power9 processor mode
6651	- ``KVM_PPC_COMPAT_CAP_POWER10`` (bit 2) -- KVM guests can run in Power10 processor mode
6652	- ``KVM_PPC_COMPAT_CAP_POWER11`` (bit 3) -- KVM guests can run in Power11 processor mode
6653
6654	.. note::
6655
6656	The bit numbering above uses IBM's MSB-0 convention (bit 0 is the most
6657	significant bit). In the actual implementation, these are defined as:
6658
6659	- ``KVM_PPC_COMPAT_CAP_POWER9`` = ``(1ULL << 62)``
6660	- ``KVM_PPC_COMPAT_CAP_POWER10`` = ``(1ULL << 61)``
6661	- ``KVM_PPC_COMPAT_CAP_POWER11`` = ``(1ULL << 60)``
6662
6663	Userspace should use the defined constants from ``<linux/kvm.h>`` rather
6664	than hardcoding bit positions.
6665
6666	.. _kvm_run:
6667
6668	5. The kvm_run structure
6669	========================
6670
6671	Application code obtains a pointer to the kvm_run structure by
6672	mmap()ing a vcpu fd. From that point, application code can control
6673	execution by changing fields in kvm_run prior to calling the KVM_RUN
6674	ioctl, and obtain information about the reason KVM_RUN returned by
6675	looking up structure members.
6676
6677	::
6678
6679	struct kvm_run {
6680	/* in */
6681	__u8 request_interrupt_window;
6682
6683	Request that KVM_RUN return when it becomes possible to inject external
6684	interrupts into the guest. Useful in conjunction with KVM_INTERRUPT.
6685
6686	::
6687
6688	__u8 immediate_exit;
6689
6690	This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN
6691	exits immediately, returning -EINTR. In the common scenario where a
6692	signal is used to "kick" a VCPU out of KVM_RUN, this field can be used
6693	to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability.
6694	Rather than blocking the signal outside KVM_RUN, userspace can set up
6695	a signal handler that sets run->immediate_exit to a non-zero value.
6696
6697	This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available.
6698
6699	::
6700
6701	__u8 padding1[6];
6702
6703	/* out */
6704	__u32 exit_reason;
6705
6706	When KVM_RUN has returned successfully (return value 0), this informs
6707	application code why KVM_RUN has returned. Allowable values for this
6708	field are detailed below.
6709
6710	::
6711
6712	__u8 ready_for_interrupt_injection;
6713
6714	If request_interrupt_window has been specified, this field indicates
6715	an interrupt can be injected now with KVM_INTERRUPT.
6716
6717	::
6718
6719	__u8 if_flag;
6720
6721	The value of the current interrupt flag. Only valid if in-kernel
6722	local APIC is not used.
6723
6724	::
6725
6726	__u16 flags;
6727
6728	More architecture-specific flags detailing state of the VCPU that may
6729	affect the device's behavior. Current defined flags::
6730
6731	/* x86, set if the VCPU is in system management mode */
6732	#define KVM_RUN_X86_SMM (1 << 0)
6733	/* x86, set if bus lock detected in VM */
6734	#define KVM_RUN_X86_BUS_LOCK (1 << 1)
6735	/* x86, set if the VCPU is executing a nested (L2) guest */
6736	#define KVM_RUN_X86_GUEST_MODE (1 << 2)
6737
6738	/* arm64, set for KVM_EXIT_DEBUG */
6739	#define KVM_DEBUG_ARCH_HSR_HIGH_VALID (1 << 0)
6740
6741	::
6742
6743	/* in (pre_kvm_run), out (post_kvm_run) */
6744	__u64 cr8;
6745
6746	The value of the cr8 register. Only valid if in-kernel local APIC is
6747	not used. Both input and output.
6748
6749	::
6750
6751	__u64 apic_base;
6752
6753	The value of the APIC BASE msr. Only valid if in-kernel local
6754	APIC is not used. Both input and output.
6755
6756	::
6757
6758	union {
6759	/* KVM_EXIT_UNKNOWN */
6760	struct {
6761	__u64 hardware_exit_reason;
6762	} hw;
6763
6764	If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown
6765	reasons. Further architecture-specific information is available in
6766	hardware_exit_reason.
6767
6768	::
6769
6770	/* KVM_EXIT_FAIL_ENTRY */
6771	struct {
6772	__u64 hardware_entry_failure_reason;
6773	__u32 cpu; /* if KVM_LAST_CPU */
6774	} fail_entry;
6775
6776	If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due
6777	to unknown reasons. Further architecture-specific information is
6778	available in hardware_entry_failure_reason.
6779
6780	::
6781
6782	/* KVM_EXIT_EXCEPTION */
6783	struct {
6784	__u32 exception;
6785	__u32 error_code;
6786	} ex;
6787
6788	Unused.
6789
6790	::
6791
6792	/* KVM_EXIT_IO */
6793	struct {
6794	#define KVM_EXIT_IO_IN 0
6795	#define KVM_EXIT_IO_OUT 1
6796	__u8 direction;
6797	__u8 size; /* bytes */
6798	__u16 port;
6799	__u32 count;
6800	__u64 data_offset; /* relative to kvm_run start */
6801	} io;
6802
6803	If exit_reason is KVM_EXIT_IO, then the vcpu has
6804	executed a port I/O instruction which could not be satisfied by kvm.
6805	data_offset describes where the data is located (KVM_EXIT_IO_OUT) or
6806	where kvm expects application code to place the data for the next
6807	KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array.
6808
6809	::
6810
6811	/* KVM_EXIT_DEBUG */
6812	struct {
6813	struct kvm_debug_exit_arch arch;
6814	} debug;
6815
6816	If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event
6817	for which architecture specific information is returned.
6818
6819	::
6820
6821	/* KVM_EXIT_MMIO */
6822	struct {
6823	__u64 phys_addr;
6824	__u8 data[8];
6825	__u32 len;
6826	__u8 is_write;
6827	} mmio;
6828
6829	If exit_reason is KVM_EXIT_MMIO, then the vcpu has
6830	executed a memory-mapped I/O instruction which could not be satisfied
6831	by kvm. The 'data' member contains the written data if 'is_write' is
6832	true, and should be filled by application code otherwise.
6833
6834	The 'data' member contains, in its first 'len' bytes, the value as it would
6835	appear if the VCPU performed a load or store of the appropriate width directly
6836	to the byte array.
6837
6838	.. note::
6839
6840	For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN,
6841	KVM_EXIT_EPR, KVM_EXIT_HYPERCALL, KVM_EXIT_TDX,
6842	KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
6843	operations are complete (and guest state is consistent) only after userspace
6844	has re-entered the kernel with KVM_RUN. The kernel side will first finish
6845	incomplete operations and then check for pending signals.
6846
6847	The pending state of the operation is not preserved in state which is
6848	visible to userspace, thus userspace should ensure that the operation is
6849	completed before performing a live migration. Userspace can re-enter the
6850	guest with an unmasked signal pending or with the immediate_exit field set
6851	to complete pending operations without allowing any further instructions
6852	to be executed.
6853
6854	::
6855
6856	/* KVM_EXIT_HYPERCALL */
6857	struct {
6858	__u64 nr;
6859	__u64 args[6];
6860	__u64 ret;
6861	__u64 flags;
6862	} hypercall;
6863
6864
6865	It is strongly recommended that userspace use ``KVM_EXIT_IO`` (x86) or
6866	``KVM_EXIT_MMIO`` (all except s390) to implement functionality that
6867	requires a guest to interact with host userspace.
6868
6869	.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO.
6870
6871	For arm64:
6872	----------
6873
6874	SMCCC exits can be enabled depending on the configuration of the SMCCC
6875	filter. See the Documentation/virt/kvm/devices/vm.rst
6876	``KVM_ARM_SMCCC_FILTER`` for more details.
6877
6878	``nr`` contains the function ID of the guest's SMCCC call. Userspace is
6879	expected to use the ``KVM_GET_ONE_REG`` ioctl to retrieve the call
6880	parameters from the vCPU's GPRs.
6881
6882	Definition of ``flags``:
6883	- ``KVM_HYPERCALL_EXIT_SMC``: Indicates that the guest used the SMC
6884	conduit to initiate the SMCCC call. If this bit is 0 then the guest
6885	used the HVC conduit for the SMCCC call.
6886
6887	- ``KVM_HYPERCALL_EXIT_16BIT``: Indicates that the guest used a 16bit
6888	instruction to initiate the SMCCC call. If this bit is 0 then the
6889	guest used a 32bit instruction. An AArch64 guest always has this
6890	bit set to 0.
6891
6892	At the point of exit, PC points to the instruction immediately following
6893	the trapping instruction.
6894
6895	::
6896
6897	/* KVM_EXIT_TPR_ACCESS */
6898	struct {
6899	__u64 rip;
6900	__u32 is_write;
6901	__u32 pad;
6902	} tpr_access;
6903
6904	To be documented (KVM_TPR_ACCESS_REPORTING).
6905
6906	::
6907
6908	/* KVM_EXIT_S390_SIEIC */
6909	struct {
6910	__u8 icptcode;
6911	__u64 mask; /* psw upper half */
6912	__u64 addr; /* psw lower half */
6913	__u16 ipa;
6914	__u32 ipb;
6915	} s390_sieic;
6916
6917	s390 specific.
6918
6919	::
6920
6921	/* KVM_EXIT_S390_RESET */
6922	#define KVM_S390_RESET_POR 1
6923	#define KVM_S390_RESET_CLEAR 2
6924	#define KVM_S390_RESET_SUBSYSTEM 4
6925	#define KVM_S390_RESET_CPU_INIT 8
6926	#define KVM_S390_RESET_IPL 16
6927	__u64 s390_reset_flags;
6928
6929	s390 specific.
6930
6931	::
6932
6933	/* KVM_EXIT_S390_UCONTROL */
6934	struct {
6935	__u64 trans_exc_code;
6936	__u32 pgm_code;
6937	} s390_ucontrol;
6938
6939	s390 specific. A page fault has occurred for a user controlled virtual
6940	machine (KVM_VM_S390_UCONTROL) on its host page table that cannot be
6941	resolved by the kernel.
6942	The program code and the translation exception code that were placed
6943	in the cpu's lowcore are presented here as defined by the z Architecture
6944	Principles of Operation Book in the Chapter for Dynamic Address Translation
6945	(DAT)
6946
6947	::
6948
6949	/* KVM_EXIT_DCR */
6950	struct {
6951	__u32 dcrn;
6952	__u32 data;
6953	__u8 is_write;
6954	} dcr;
6955
6956	Deprecated - was used for 440 KVM.
6957
6958	::
6959
6960	/* KVM_EXIT_OSI */
6961	struct {
6962	__u64 gprs[32];
6963	} osi;
6964
6965	MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch
6966	hypercalls and exit with this exit struct that contains all the guest gprs.
6967
6968	If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall.
6969	Userspace can now handle the hypercall and when it's done modify the gprs as
6970	necessary. Upon guest entry all guest GPRs will then be replaced by the values
6971	in this struct.
6972
6973	::
6974
6975	/* KVM_EXIT_PAPR_HCALL */
6976	struct {
6977	__u64 nr;
6978	__u64 ret;
6979	__u64 args[9];
6980	} papr_hcall;
6981
6982	This is used on 64-bit PowerPC when emulating a pSeries partition,
6983	e.g. with the 'pseries' machine type in qemu. It occurs when the
6984	guest does a hypercall using the 'sc 1' instruction. The 'nr' field
6985	contains the hypercall number (from the guest R3), and 'args' contains
6986	the arguments (from the guest R4 - R12). Userspace should put the
6987	return code in 'ret' and any extra returned values in args[].
6988	The possible hypercalls are defined in the Power Architecture Platform
6989	Requirements (PAPR) document available from www.power.org (free
6990	developer registration required to access it).
6991
6992	::
6993
6994	/* KVM_EXIT_S390_TSCH */
6995	struct {
6996	__u16 subchannel_id;
6997	__u16 subchannel_nr;
6998	__u32 io_int_parm;
6999	__u32 io_int_word;
7000	__u32 ipb;
7001	__u8 dequeued;
7002	} s390_tsch;
7003
7004	s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled
7005	and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O
7006	interrupt for the target subchannel has been dequeued and subchannel_id,
7007	subchannel_nr, io_int_parm and io_int_word contain the parameters for that
7008	interrupt. ipb is needed for instruction parameter decoding.
7009
7010	::
7011
7012	/* KVM_EXIT_EPR */
7013	struct {
7014	__u32 epr;
7015	} epr;
7016
7017	On FSL BookE PowerPC chips, the interrupt controller has a fast patch
7018	interrupt acknowledge path to the core. When the core successfully
7019	delivers an interrupt, it automatically populates the EPR register with
7020	the interrupt vector number and acknowledges the interrupt inside
7021	the interrupt controller.
7022
7023	In case the interrupt controller lives in user space, we need to do
7024	the interrupt acknowledge cycle through it to fetch the next to be
7025	delivered interrupt vector using this exit.
7026
7027	It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an
7028	external interrupt has just been delivered into the guest. User space
7029	should put the acknowledged interrupt vector into the 'epr' field.
7030
7031	::
7032
7033	/* KVM_EXIT_SYSTEM_EVENT */
7034	struct {
7035	#define KVM_SYSTEM_EVENT_SHUTDOWN 1
7036	#define KVM_SYSTEM_EVENT_RESET 2
7037	#define KVM_SYSTEM_EVENT_CRASH 3
7038	#define KVM_SYSTEM_EVENT_WAKEUP 4
7039	#define KVM_SYSTEM_EVENT_SUSPEND 5
7040	#define KVM_SYSTEM_EVENT_SEV_TERM 6
7041	#define KVM_SYSTEM_EVENT_TDX_FATAL 7
7042	__u32 type;
7043	__u32 ndata;
7044	__u64 data[16];
7045	} system_event;
7046
7047	If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered
7048	a system-level event using some architecture specific mechanism (hypercall
7049	or some special instruction). In case of ARM64, this is triggered using
7050	HVC instruction based PSCI call from the vcpu.
7051
7052	The 'type' field describes the system-level event type.
7053	Valid values for 'type' are:
7054
7055	- KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the
7056	VM. Userspace is not obliged to honour this, and if it does honour
7057	this does not need to destroy the VM synchronously (ie it may call
7058	KVM_RUN again before shutdown finally occurs).
7059	- KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM.
7060	As with SHUTDOWN, userspace can choose to ignore the request, or
7061	to schedule the reset to occur in the future and may call KVM_RUN again.
7062	- KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest
7063	has requested a crash condition maintenance. Userspace can choose
7064	to ignore the request, or to gather VM memory core dump and/or
7065	reset/shutdown of the VM.
7066	- KVM_SYSTEM_EVENT_SEV_TERM -- an AMD SEV guest requested termination.
7067	The guest physical address of the guest's GHCB is stored in `data[0]`.
7068	- KVM_SYSTEM_EVENT_TDX_FATAL -- a TDX guest reported a fatal error state.
7069	KVM doesn't do any parsing or conversion, it just dumps 16 general-purpose
7070	registers to userspace, in ascending order of the 4-bit indices for x86-64
7071	general-purpose registers in instruction encoding, as defined in the Intel
7072	SDM.
7073	- KVM_SYSTEM_EVENT_WAKEUP -- the exiting vCPU is in a suspended state and
7074	KVM has recognized a wakeup event. Userspace may honor this event by
7075	marking the exiting vCPU as runnable, or deny it and call KVM_RUN again.
7076	- KVM_SYSTEM_EVENT_SUSPEND -- the guest has requested a suspension of
7077	the VM.
7078
7079	If KVM_CAP_SYSTEM_EVENT_DATA is present, the 'data' field can contain
7080	architecture specific information for the system-level event. Only
7081	the first `ndata` items (possibly zero) of the data array are valid.
7082
7083	- for arm64, data[0] is set to KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2 if
7084	the guest issued a SYSTEM_RESET2 call according to v1.1 of the PSCI
7085	specification.
7086
7087	- for arm64, data[0] is set to KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2
7088	if the guest issued a SYSTEM_OFF2 call according to v1.3 of the PSCI
7089	specification.
7090
7091	- for RISC-V, data[0] is set to the value of the second argument of the
7092	``sbi_system_reset`` call.
7093
7094	Previous versions of Linux defined a `flags` member in this struct. The
7095	field is now aliased to `data[0]`. Userspace can assume that it is only
7096	written if ndata is greater than 0.
7097
7098	For arm/arm64:
7099	--------------
7100
7101	KVM_SYSTEM_EVENT_SUSPEND exits are enabled with the
7102	KVM_CAP_ARM_SYSTEM_SUSPEND VM capability. If a guest invokes the PSCI
7103	SYSTEM_SUSPEND function, KVM will exit to userspace with this event
7104	type.
7105
7106	It is the sole responsibility of userspace to implement the PSCI
7107	SYSTEM_SUSPEND call according to ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND".
7108	KVM does not change the vCPU's state before exiting to userspace, so
7109	the call parameters are left in-place in the vCPU registers.
7110
7111	Userspace is _required_ to take action for such an exit. It must
7112	either:
7113
7114	- Honor the guest request to suspend the VM. Userspace can request
7115	in-kernel emulation of suspension by setting the calling vCPU's
7116	state to KVM_MP_STATE_SUSPENDED. Userspace must configure the vCPU's
7117	state according to the parameters passed to the PSCI function when
7118	the calling vCPU is resumed. See ARM DEN0022D.b 5.19.1 "Intended use"
7119	for details on the function parameters.
7120
7121	- Deny the guest request to suspend the VM. See ARM DEN0022D.b 5.19.2
7122	"Caller responsibilities" for possible return values.
7123
7124	Hibernation using the PSCI SYSTEM_OFF2 call is enabled when PSCI v1.3
7125	is enabled. If a guest invokes the PSCI SYSTEM_OFF2 function, KVM will
7126	exit to userspace with the KVM_SYSTEM_EVENT_SHUTDOWN event type and with
7127	data[0] set to KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2. The only
7128	supported hibernate type for the SYSTEM_OFF2 function is HIBERNATE_OFF.
7129
7130	::
7131
7132	/* KVM_EXIT_IOAPIC_EOI */
7133	struct {
7134	__u8 vector;
7135	} eoi;
7136
7137	Indicates that the VCPU's in-kernel local APIC received an EOI for a
7138	level-triggered IOAPIC interrupt. This exit only triggers when the
7139	IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled);
7140	the userspace IOAPIC should process the EOI and retrigger the interrupt if
7141	it is still asserted. Vector is the LAPIC interrupt vector for which the
7142	EOI was received.
7143
7144	::
7145
7146	struct kvm_hyperv_exit {
7147	#define KVM_EXIT_HYPERV_SYNIC 1
7148	#define KVM_EXIT_HYPERV_HCALL 2
7149	#define KVM_EXIT_HYPERV_SYNDBG 3
7150	__u32 type;
7151	__u32 pad1;
7152	union {
7153	struct {
7154	__u32 msr;
7155	__u32 pad2;
7156	__u64 control;
7157	__u64 evt_page;
7158	__u64 msg_page;
7159	} synic;
7160	struct {
7161	__u64 input;
7162	__u64 result;
7163	__u64 params[2];
7164	} hcall;
7165	struct {
7166	__u32 msr;
7167	__u32 pad2;
7168	__u64 control;
7169	__u64 status;
7170	__u64 send_page;
7171	__u64 recv_page;
7172	__u64 pending_page;
7173	} syndbg;
7174	} u;
7175	};
7176	/* KVM_EXIT_HYPERV */
7177	struct kvm_hyperv_exit hyperv;
7178
7179	Indicates that the VCPU exits into userspace to process some tasks
7180	related to Hyper-V emulation.
7181
7182	Valid values for 'type' are:
7183
7184	- KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about
7185
7186	Hyper-V SynIC state change. Notification is used to remap SynIC
7187	event/message pages and to enable/disable SynIC messages/events processing
7188	in userspace.
7189
7190	- KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about
7191
7192	Hyper-V Synthetic debugger state change. Notification is used to either update
7193	the pending_page location or to send a control command (send the buffer located
7194	in send_page or recv a buffer to recv_page).
7195
7196	::
7197
7198	/* KVM_EXIT_ARM_NISV / KVM_EXIT_ARM_LDST64B */
7199	struct {
7200	__u64 esr_iss;
7201	__u64 fault_ipa;
7202	} arm_nisv;
7203
7204	- KVM_EXIT_ARM_NISV:
7205
7206	Used on arm64 systems. If a guest accesses memory not in a memslot,
7207	KVM will typically return to userspace and ask it to do MMIO emulation on its
7208	behalf. However, for certain classes of instructions, no instruction decode
7209	(direction, length of memory access) is provided, and fetching and decoding
7210	the instruction from the VM is overly complicated to live in the kernel.
7211
7212	Historically, when this situation occurred, KVM would print a warning and kill
7213	the VM. KVM assumed that if the guest accessed non-memslot memory, it was
7214	trying to do I/O, which just couldn't be emulated, and the warning message was
7215	phrased accordingly. However, what happened more often was that a guest bug
7216	caused access outside the guest memory areas which should lead to a more
7217	meaningful warning message and an external abort in the guest, if the access
7218	did not fall within an I/O window.
7219
7220	Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable
7221	this capability at VM creation. Once this is done, these types of errors will
7222	instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from
7223	the ESR_EL2 in the esr_iss field, and the faulting IPA in the fault_ipa field.
7224	Userspace can either fix up the access if it's actually an I/O access by
7225	decoding the instruction from guest memory (if it's very brave) and continue
7226	executing the guest, or it can decide to suspend, dump, or restart the guest.
7227
7228	Note that KVM does not skip the faulting instruction as it does for
7229	KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state
7230	if it decides to decode and emulate the instruction.
7231
7232	This feature isn't available to protected VMs, as userspace does not
7233	have access to the state that is required to perform the emulation.
7234	Instead, a data abort exception is directly injected in the guest.
7235	Note that although KVM_CAP_ARM_NISV_TO_USER will be reported if
7236	queried outside of a protected VM context, the feature will not be
7237	exposed if queried on a protected VM file descriptor.
7238
7239	- KVM_EXIT_ARM_LDST64B:
7240
7241	Used on arm64 systems. When a guest using a LD64B, ST64B, ST64BV, ST64BV0,
7242	outside of a memslot, KVM will return to userspace with KVM_EXIT_ARM_LDST64B,
7243	exposing the relevant ESR_EL2 information and faulting IPA, similarly to
7244	KVM_EXIT_ARM_NISV.
7245
7246	Userspace is supposed to fully emulate the instructions, which includes:
7247
7248	- fetch of the operands for a store, including ACCDATA_EL1 in the case
7249	of a ST64BV0 instruction
7250	- deal with the endianness if the guest is big-endian
7251	- emulate the access, including the delivery of an exception if the
7252	access didn't succeed
7253	- provide a return value in the case of ST64BV/ST64BV0
7254	- return the data in the case of a load
7255	- increment PC if the instruction was successfully executed
7256
7257	Note that there is no expectation of performance for this emulation, as it
7258	involves a large number of interaction with the guest state. It is, however,
7259	expected that the instruction's semantics are preserved, specially the
7260	single-copy atomicity property of the 64 byte access.
7261
7262	This exit reason must be handled if userspace sets ID_AA64ISAR1_EL1.LS64 to a
7263	non-zero value, indicating that FEAT_LS64* is enabled.
7264
7265	::
7266
7267	/* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */
7268	struct {
7269	__u8 error; /* user -> kernel */
7270	__u8 pad[7];
7271	__u32 reason; /* kernel -> user */
7272	__u32 index; /* kernel -> user */
7273	__u64 data; /* kernel <-> user */
7274	} msr;
7275
7276	Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is
7277	enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code
7278	may instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR
7279	exit for writes.
7280
7281	The "reason" field specifies why the MSR interception occurred. Userspace will
7282	only receive MSR exits when a particular reason was requested during through
7283	ENABLE_CAP. Currently valid exit reasons are:
7284
7285	============================ ========================================
7286	KVM_MSR_EXIT_REASON_UNKNOWN access to MSR that is unknown to KVM
7287	KVM_MSR_EXIT_REASON_INVAL access to invalid MSRs or reserved bits
7288	KVM_MSR_EXIT_REASON_FILTER access blocked by KVM_X86_SET_MSR_FILTER
7289	============================ ========================================
7290
7291	For KVM_EXIT_X86_RDMSR, the "index" field tells userspace which MSR the guest
7292	wants to read. To respond to this request with a successful read, userspace
7293	writes the respective data into the "data" field and must continue guest
7294	execution to ensure the read data is transferred into guest register state.
7295
7296	If the RDMSR request was unsuccessful, userspace indicates that with a "1" in
7297	the "error" field. This will inject a #GP into the guest when the VCPU is
7298	executed again.
7299
7300	For KVM_EXIT_X86_WRMSR, the "index" field tells userspace which MSR the guest
7301	wants to write. Once finished processing the event, userspace must continue
7302	vCPU execution. If the MSR write was unsuccessful, userspace also sets the
7303	"error" field to "1".
7304
7305	See KVM_X86_SET_MSR_FILTER for details on the interaction with MSR filtering.
7306
7307	::
7308
7309
7310	struct kvm_xen_exit {
7311	#define KVM_EXIT_XEN_HCALL 1
7312	__u32 type;
7313	union {
7314	struct {
7315	__u32 longmode;
7316	__u32 cpl;
7317	__u64 input;
7318	__u64 result;
7319	__u64 params[6];
7320	} hcall;
7321	} u;
7322	};
7323	/* KVM_EXIT_XEN */
7324	struct kvm_hyperv_exit xen;
7325
7326	Indicates that the VCPU exits into userspace to process some tasks
7327	related to Xen emulation.
7328
7329	Valid values for 'type' are:
7330
7331	- KVM_EXIT_XEN_HCALL -- synchronously notify user-space about Xen hypercall.
7332	Userspace is expected to place the hypercall result into the appropriate
7333	field before invoking KVM_RUN again.
7334
7335	::
7336
7337	/* KVM_EXIT_RISCV_SBI */
7338	struct {
7339	unsigned long extension_id;
7340	unsigned long function_id;
7341	unsigned long args[6];
7342	unsigned long ret[2];
7343	} riscv_sbi;
7344
7345	If exit reason is KVM_EXIT_RISCV_SBI then it indicates that the VCPU has
7346	done a SBI call which is not handled by KVM RISC-V kernel module. The details
7347	of the SBI call are available in 'riscv_sbi' member of kvm_run structure. The
7348	'extension_id' field of 'riscv_sbi' represents SBI extension ID whereas the
7349	'function_id' field represents function ID of given SBI extension. The 'args'
7350	array field of 'riscv_sbi' represents parameters for the SBI call and 'ret'
7351	array field represents return values. The userspace should update the return
7352	values of SBI call before resuming the VCPU. For more details on RISC-V SBI
7353	spec refer, https://github.com/riscv/riscv-sbi-doc.
7354
7355	::
7356
7357	/* KVM_EXIT_MEMORY_FAULT */
7358	struct {
7359	#define KVM_MEMORY_EXIT_FLAG_PRIVATE (1ULL << 3)
7360	__u64 flags;
7361	__u64 gpa;
7362	__u64 size;
7363	} memory_fault;
7364
7365	KVM_EXIT_MEMORY_FAULT indicates the vCPU has encountered a memory fault that
7366	could not be resolved by KVM. The 'gpa' and 'size' (in bytes) describe the
7367	guest physical address range [gpa, gpa + size) of the fault. The 'flags' field
7368	describes properties of the faulting access that are likely pertinent:
7369
7370	- KVM_MEMORY_EXIT_FLAG_PRIVATE - When set, indicates the memory fault occurred
7371	on a private memory access. When clear, indicates the fault occurred on a
7372	shared access.
7373
7374	Note! KVM_EXIT_MEMORY_FAULT is unique among all KVM exit reasons in that it
7375	accompanies a return code of '-1', not '0'! errno will always be set to EFAULT
7376	or EHWPOISON when KVM exits with KVM_EXIT_MEMORY_FAULT, userspace should assume
7377	kvm_run.exit_reason is stale/undefined for all other error numbers.
7378
7379	::
7380
7381	/* KVM_EXIT_NOTIFY */
7382	struct {
7383	#define KVM_NOTIFY_CONTEXT_INVALID (1 << 0)
7384	__u32 flags;
7385	} notify;
7386
7387	Used on x86 systems. When the VM capability KVM_CAP_X86_NOTIFY_VMEXIT is
7388	enabled, a VM exit generated if no event window occurs in VM non-root mode
7389	for a specified amount of time. Once KVM_X86_NOTIFY_VMEXIT_USER is set when
7390	enabling the cap, it would exit to userspace with the exit reason
7391	KVM_EXIT_NOTIFY for further handling. The "flags" field contains more
7392	detailed info.
7393
7394	The valid value for 'flags' is:
7395
7396	- KVM_NOTIFY_CONTEXT_INVALID -- the VM context is corrupted and not valid
7397	in VMCS. It would run into unknown result if resume the target VM.
7398
7399	::
7400
7401	/* KVM_EXIT_TDX */
7402	struct {
7403	__u64 flags;
7404	__u64 nr;
7405	union {
7406	struct {
7407	u64 ret;
7408	u64 data[5];
7409	} unknown;
7410	struct {
7411	u64 ret;
7412	u64 gpa;
7413	u64 size;
7414	} get_quote;
7415	struct {
7416	u64 ret;
7417	u64 leaf;
7418	u64 r11, r12, r13, r14;
7419	} get_tdvmcall_info;
7420	struct {
7421	u64 ret;
7422	u64 vector;
7423	} setup_event_notify;
7424	};
7425	} tdx;
7426
7427	Process a TDVMCALL from the guest. KVM forwards select TDVMCALL based
7428	on the Guest-Hypervisor Communication Interface (GHCI) specification;
7429	KVM bridges these requests to the userspace VMM with minimal changes,
7430	placing the inputs in the union and copying them back to the guest
7431	on re-entry.
7432
7433	Flags are currently always zero, whereas ``nr`` contains the TDVMCALL
7434	number from register R11. The remaining field of the union provide the
7435	inputs and outputs of the TDVMCALL. Currently the following values of
7436	``nr`` are defined:
7437
7438	* ``TDVMCALL_GET_QUOTE``: the guest has requested to generate a TD-Quote
7439	signed by a service hosting TD-Quoting Enclave operating on the host.
7440	Parameters and return value are in the ``get_quote`` field of the union.
7441	The ``gpa`` field and ``size`` specify the guest physical address
7442	(without the shared bit set) and the size of a shared-memory buffer, in
7443	which the TDX guest passes a TD Report. The ``ret`` field represents
7444	the return value of the GetQuote request. When the request has been
7445	queued successfully, the TDX guest can poll the status field in the
7446	shared-memory area to check whether the Quote generation is completed or
7447	not. When completed, the generated Quote is returned via the same buffer.
7448
7449	* ``TDVMCALL_GET_TD_VM_CALL_INFO``: the guest has requested the support
7450	status of TDVMCALLs. The output values for the given leaf should be
7451	placed in fields from ``r11`` to ``r14`` of the ``get_tdvmcall_info``
7452	field of the union.
7453
7454	* ``TDVMCALL_SETUP_EVENT_NOTIFY_INTERRUPT``: the guest has requested to
7455	set up a notification interrupt for vector ``vector``.
7456
7457	KVM may add support for more values in the future that may cause a userspace
7458	exit, even without calls to ``KVM_ENABLE_CAP`` or similar. In this case,
7459	it will enter with output fields already valid; in the common case, the
7460	``unknown.ret`` field of the union will be ``TDVMCALL_STATUS_SUBFUNC_UNSUPPORTED``.
7461	Userspace need not do anything if it does not wish to support a TDVMCALL.
7462
7463	::
7464
7465	/* KVM_EXIT_ARM_SEA */
7466	struct {
7467	#define KVM_EXIT_ARM_SEA_FLAG_GPA_VALID (1ULL << 0)
7468	__u64 flags;
7469	__u64 esr;
7470	__u64 gva;
7471	__u64 gpa;
7472	} arm_sea;
7473
7474	Used on arm64 systems. When the VM capability ``KVM_CAP_ARM_SEA_TO_USER`` is
7475	enabled, a KVM exits to userspace if a guest access causes a synchronous
7476	external abort (SEA) and the host APEI fails to handle the SEA.
7477
7478	``esr`` is set to a sanitized value of ESR_EL2 from the exception taken to KVM,
7479	consisting of the following fields:
7480
7481	- ``ESR_EL2.EC``
7482	- ``ESR_EL2.IL``
7483	- ``ESR_EL2.FnV``
7484	- ``ESR_EL2.EA``
7485	- ``ESR_EL2.CM``
7486	- ``ESR_EL2.WNR``
7487	- ``ESR_EL2.FSC``
7488	- ``ESR_EL2.SET`` (when FEAT_RAS is implemented for the VM)
7489
7490	``gva`` is set to the value of FAR_EL2 from the exception taken to KVM when
7491	``ESR_EL2.FnV == 0``. Otherwise, the value of ``gva`` is unknown.
7492
7493	``gpa`` is set to the faulting IPA from the exception taken to KVM when
7494	the ``KVM_EXIT_ARM_SEA_FLAG_GPA_VALID`` flag is set. Otherwise, the value of
7495	``gpa`` is unknown.
7496
7497	::
7498
7499	/* Fix the size of the union. */
7500	char padding[256];
7501	};
7502
7503	/*
7504	* shared registers between kvm and userspace.
7505	* kvm_valid_regs specifies the register classes set by the host
7506	* kvm_dirty_regs specified the register classes dirtied by userspace
7507	* struct kvm_sync_regs is architecture specific, as well as the
7508	* bits for kvm_valid_regs and kvm_dirty_regs
7509	*/
7510	__u64 kvm_valid_regs;
7511	__u64 kvm_dirty_regs;
7512	union {
7513	struct kvm_sync_regs regs;
7514	char padding[SYNC_REGS_SIZE_BYTES];
7515	} s;
7516
7517	If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access
7518	certain guest registers without having to call SET/GET_*REGS. Thus we can
7519	avoid some system call overhead if userspace has to handle the exit.
7520	Userspace can query the validity of the structure by checking
7521	kvm_valid_regs for specific bits. These bits are architecture specific
7522	and usually define the validity of a groups of registers. (e.g. one bit
7523	for general purpose registers)
7524
7525	Please note that the kernel is allowed to use the kvm_run structure as the
7526	primary storage for certain register types. Therefore, the kernel may use the
7527	values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set.
7528
7529	::
7530
7531	/* KVM_EXIT_SNP_REQ_CERTS */
7532	struct kvm_exit_snp_req_certs {
7533	__u64 gpa;
7534	__u64 npages;
7535	__u64 ret;
7536	};
7537
7538	KVM_EXIT_SNP_REQ_CERTS indicates an SEV-SNP guest with certificate-fetching
7539	enabled (see KVM_SEV_SNP_ENABLE_REQ_CERTS) has generated an Extended Guest
7540	Request NAE #VMGEXIT (SNP_GUEST_REQUEST) with message type MSG_REPORT_REQ,
7541	i.e. has requested an attestation report from firmware, and would like the
7542	certificate data corresponding to the attestation report signature to be
7543	provided by the hypervisor as part of the request.
7544
7545	To allow for userspace to provide the certificate, the 'gpa' and 'npages'
7546	are forwarded verbatim from the guest request (the RAX and RBX GHCB fields
7547	respectively). 'ret' is not an "output" from KVM, and is always '0' on
7548	exit. KVM verifies the 'gpa' is 4KiB aligned prior to exiting to userspace,
7549	but otherwise the information from the guest isn't validated.
7550
7551	Upon the next KVM_RUN, e.g. after userspace has serviced the request (or not),
7552	KVM will complete the #VMGEXIT, using the 'ret' field to determine whether to
7553	signal success or failure to the guest, and on failure, what reason code will
7554	be communicated via SW_EXITINFO2. If 'ret' is set to an unsupported value (see
7555	the table below), KVM_RUN will fail with -EINVAL. For a 'ret' of 'ENOSPC', KVM
7556	also consumes the 'npages' field, i.e. userspace can use the field to inform
7557	the guest of the number of pages needed to hold all the certificate data.
7558
7559	The supported 'ret' values and their respective SW_EXITINFO2 encodings:
7560
7561	====== =============================================================
7562	0 0x0, i.e. success. KVM will emit an SNP_GUEST_REQUEST command
7563	to SNP firmware.
7564	ENOSPC 0x0000000100000000, i.e. not enough guest pages to hold the
7565	certificate table and certificate data. KVM will also set the
7566	RBX field in the GHBC to 'npages'.
7567	EAGAIN 0x0000000200000000, i.e. the host is busy and the guest should
7568	retry the request.
7569	EIO 0xffffffff00000000, for all other errors (this return code is
7570	a KVM-defined hypervisor value, as allowed by the GHCB)
7571	====== =============================================================
7572
7573
7574	.. _cap_enable:
7575
7576	6. Capabilities that can be enabled on vCPUs
7577	============================================
7578
7579	There are certain capabilities that change the behavior of the virtual CPU or
7580	the virtual machine when enabled. To enable them, please see
7581	:ref:`KVM_ENABLE_CAP`.
7582
7583	Below you can find a list of capabilities and what their effect on the vCPU or
7584	the virtual machine is when enabling them.
7585
7586	The following information is provided along with the description:
7587
7588	Architectures:
7589	which instruction set architectures provide this ioctl.
7590	x86 includes both i386 and x86_64.
7591
7592	Target:
7593	whether this is a per-vcpu or per-vm capability.
7594
7595	Parameters:
7596	what parameters are accepted by the capability.
7597
7598	Returns:
7599	the return value. General error numbers (EBADF, ENOMEM, EINVAL)
7600	are not detailed, but errors with specific meanings are.
7601
7602
7603	6.1 KVM_CAP_PPC_OSI
7604	-------------------
7605
7606	:Architectures: ppc
7607	:Target: vcpu
7608	:Parameters: none
7609	:Returns: 0 on success; -1 on error
7610
7611	This capability enables interception of OSI hypercalls that otherwise would
7612	be treated as normal system calls to be injected into the guest. OSI hypercalls
7613	were invented by Mac-on-Linux to have a standardized communication mechanism
7614	between the guest and the host.
7615
7616	When this capability is enabled, KVM_EXIT_OSI can occur.
7617
7618
7619	6.2 KVM_CAP_PPC_PAPR
7620	--------------------
7621
7622	:Architectures: ppc
7623	:Target: vcpu
7624	:Parameters: none
7625	:Returns: 0 on success; -1 on error
7626
7627	This capability enables interception of PAPR hypercalls. PAPR hypercalls are
7628	done using the hypercall instruction "sc 1".
7629
7630	It also sets the guest privilege level to "supervisor" mode. Usually the guest
7631	runs in "hypervisor" privilege mode with a few missing features.
7632
7633	In addition to the above, it changes the semantics of SDR1. In this mode, the
7634	HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the
7635	HTAB invisible to the guest.
7636
7637	When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur.
7638
7639
7640	6.3 KVM_CAP_SW_TLB
7641	------------------
7642
7643	:Architectures: ppc
7644	:Target: vcpu
7645	:Parameters: args[0] is the address of a struct kvm_config_tlb
7646	:Returns: 0 on success; -1 on error
7647
7648	::
7649
7650	struct kvm_config_tlb {
7651	__u64 params;
7652	__u64 array;
7653	__u32 mmu_type;
7654	__u32 array_len;
7655	};
7656
7657	Configures the virtual CPU's TLB array, establishing a shared memory area
7658	between userspace and KVM. The "params" and "array" fields are userspace
7659	addresses of mmu-type-specific data structures. The "array_len" field is an
7660	safety mechanism, and should be set to the size in bytes of the memory that
7661	userspace has reserved for the array. It must be at least the size dictated
7662	by "mmu_type" and "params".
7663
7664	While KVM_RUN is active, the shared region is under control of KVM. Its
7665	contents are undefined, and any modification by userspace results in
7666	boundedly undefined behavior.
7667
7668	On return from KVM_RUN, the shared region will reflect the current state of
7669	the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB
7670	to tell KVM which entries have been changed, prior to calling KVM_RUN again
7671	on this vcpu.
7672
7673	For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV:
7674
7675	- The "params" field is of type "struct kvm_book3e_206_tlb_params".
7676	- The "array" field points to an array of type "struct
7677	kvm_book3e_206_tlb_entry".
7678	- The array consists of all entries in the first TLB, followed by all
7679	entries in the second TLB.
7680	- Within a TLB, entries are ordered first by increasing set number. Within a
7681	set, entries are ordered by way (increasing ESEL).
7682	- The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1)
7683	where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value.
7684	- The tsize field of mas1 shall be set to 4K on TLB0, even though the
7685	hardware ignores this value for TLB0.
7686
7687	6.4 KVM_CAP_S390_CSS_SUPPORT
7688	----------------------------
7689
7690	:Architectures: s390
7691	:Target: vcpu
7692	:Parameters: none
7693	:Returns: 0 on success; -1 on error
7694
7695	This capability enables support for handling of channel I/O instructions.
7696
7697	TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are
7698	handled in-kernel, while the other I/O instructions are passed to userspace.
7699
7700	When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST
7701	SUBCHANNEL intercepts.
7702
7703	Note that even though this capability is enabled per-vcpu, the complete
7704	virtual machine is affected.
7705
7706	6.5 KVM_CAP_PPC_EPR
7707	-------------------
7708
7709	:Architectures: ppc
7710	:Target: vcpu
7711	:Parameters: args[0] defines whether the proxy facility is active
7712	:Returns: 0 on success; -1 on error
7713
7714	This capability enables or disables the delivery of interrupts through the
7715	external proxy facility.
7716
7717	When enabled (args[0] != 0), every time the guest gets an external interrupt
7718	delivered, it automatically exits into user space with a KVM_EXIT_EPR exit
7719	to receive the topmost interrupt vector.
7720
7721	When disabled (args[0] == 0), behavior is as if this facility is unsupported.
7722
7723	When this capability is enabled, KVM_EXIT_EPR can occur.
7724
7725	6.6 KVM_CAP_IRQ_MPIC
7726	--------------------
7727
7728	:Architectures: ppc
7729	:Parameters: args[0] is the MPIC device fd;
7730	args[1] is the MPIC CPU number for this vcpu
7731
7732	This capability connects the vcpu to an in-kernel MPIC device.
7733
7734	6.7 KVM_CAP_IRQ_XICS
7735	--------------------
7736
7737	:Architectures: ppc
7738	:Target: vcpu
7739	:Parameters: args[0] is the XICS device fd;
7740	args[1] is the XICS CPU number (server ID) for this vcpu
7741
7742	This capability connects the vcpu to an in-kernel XICS device.
7743
7744	6.8 KVM_CAP_S390_IRQCHIP
7745	------------------------
7746
7747	:Architectures: s390
7748	:Target: vm
7749	:Parameters: none
7750
7751	This capability enables the in-kernel irqchip for s390. Please refer to
7752	"4.24 KVM_CREATE_IRQCHIP" for details.
7753
7754	6.9 KVM_CAP_MIPS_FPU
7755	--------------------
7756
7757	:Architectures: mips
7758	:Target: vcpu
7759	:Parameters: args[0] is reserved for future use (should be 0).
7760
7761	This capability allows the use of the host Floating Point Unit by the guest. It
7762	allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is
7763	done the ``KVM_REG_MIPS_FPR_`` and ``KVM_REG_MIPS_FCR_`` registers can be
7764	accessed (depending on the current guest FPU register mode), and the Status.FR,
7765	Config5.FRE bits are accessible via the KVM API and also from the guest,
7766	depending on them being supported by the FPU.
7767
7768	6.10 KVM_CAP_MIPS_MSA
7769	---------------------
7770
7771	:Architectures: mips
7772	:Target: vcpu
7773	:Parameters: args[0] is reserved for future use (should be 0).
7774
7775	This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest.
7776	It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest.
7777	Once this is done the ``KVM_REG_MIPS_VEC_`` and ``KVM_REG_MIPS_MSA_``
7778	registers can be accessed, and the Config5.MSAEn bit is accessible via the
7779	KVM API and also from the guest.
7780
7781	6.74 KVM_CAP_SYNC_REGS
7782	----------------------
7783
7784	:Architectures: s390, x86
7785	:Target: s390: always enabled, x86: vcpu
7786	:Parameters: none
7787	:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register
7788	sets are supported
7789	(bitfields defined in arch/x86/include/uapi/asm/kvm.h).
7790
7791	As described above in the kvm_sync_regs struct info in section :ref:`kvm_run`,
7792	KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers
7793	without having to call SET/GET_*REGS". This reduces overhead by eliminating
7794	repeated ioctl calls for setting and/or getting register values. This is
7795	particularly important when userspace is making synchronous guest state
7796	modifications, e.g. when emulating and/or intercepting instructions in
7797	userspace.
7798
7799	For s390 specifics, please refer to the source code.
7800
7801	For x86:
7802
7803	- the register sets to be copied out to kvm_run are selectable
7804	by userspace (rather that all sets being copied out for every exit).
7805	- vcpu_events are available in addition to regs and sregs.
7806
7807	For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to
7808	function as an input bit-array field set by userspace to indicate the
7809	specific register sets to be copied out on the next exit.
7810
7811	To indicate when userspace has modified values that should be copied into
7812	the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set.
7813	This is done using the same bitflags as for the 'kvm_valid_regs' field.
7814	If the dirty bit is not set, then the register set values will not be copied
7815	into the vCPU even if they've been modified.
7816
7817	Unused bitfields in the bitarrays must be set to zero.
7818
7819	::
7820
7821	struct kvm_sync_regs {
7822	struct kvm_regs regs;
7823	struct kvm_sregs sregs;
7824	struct kvm_vcpu_events events;
7825	};
7826
7827	6.75 KVM_CAP_PPC_IRQ_XIVE
7828	-------------------------
7829
7830	:Architectures: ppc
7831	:Target: vcpu
7832	:Parameters: args[0] is the XIVE device fd;
7833	args[1] is the XIVE CPU number (server ID) for this vcpu
7834
7835	This capability connects the vcpu to an in-kernel XIVE device.
7836
7837	6.76 KVM_CAP_HYPERV_SYNIC
7838	-------------------------
7839
7840	:Architectures: x86
7841	:Target: vcpu
7842
7843	This capability, if KVM_CHECK_EXTENSION indicates that it is
7844	available, means that the kernel has an implementation of the
7845	Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is
7846	used to support Windows Hyper-V based guest paravirt drivers(VMBus).
7847
7848	In order to use SynIC, it has to be activated by setting this
7849	capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this
7850	will disable the use of APIC hardware virtualization even if supported
7851	by the CPU, as it's incompatible with SynIC auto-EOI behavior.
7852
7853	6.77 KVM_CAP_HYPERV_SYNIC2
7854	--------------------------
7855
7856	:Architectures: x86
7857	:Target: vcpu
7858
7859	This capability enables a newer version of Hyper-V Synthetic interrupt
7860	controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM
7861	doesn't clear SynIC message and event flags pages when they are enabled by
7862	writing to the respective MSRs.
7863
7864	6.78 KVM_CAP_HYPERV_DIRECT_TLBFLUSH
7865	-----------------------------------
7866
7867	:Architectures: x86
7868	:Target: vcpu
7869
7870	This capability indicates that KVM running on top of Hyper-V hypervisor
7871	enables Direct TLB flush for its guests meaning that TLB flush
7872	hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM.
7873	Due to the different ABI for hypercall parameters between Hyper-V and
7874	KVM, enabling this capability effectively disables all hypercall
7875	handling by KVM (as some KVM hypercall may be mistakenly treated as TLB
7876	flush hypercalls by Hyper-V) so userspace should disable KVM identification
7877	in CPUID and only exposes Hyper-V identification. In this case, guest
7878	thinks it's running on Hyper-V and only use Hyper-V hypercalls.
7879
7880	6.79 KVM_CAP_HYPERV_ENFORCE_CPUID
7881	---------------------------------
7882
7883	:Architectures: x86
7884	:Target: vcpu
7885
7886	When enabled, KVM will disable emulated Hyper-V features provided to the
7887	guest according to the bits Hyper-V CPUID feature leaves. Otherwise, all
7888	currently implemented Hyper-V features are provided unconditionally when
7889	Hyper-V identification is set in the HYPERV_CPUID_INTERFACE (0x40000001)
7890	leaf.
7891
7892	6.80 KVM_CAP_ENFORCE_PV_FEATURE_CPUID
7893	-------------------------------------
7894
7895	:Architectures: x86
7896	:Target: vcpu
7897
7898	When enabled, KVM will disable paravirtual features provided to the
7899	guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf
7900	(0x40000001). Otherwise, a guest may use the paravirtual features
7901	regardless of what has actually been exposed through the CPUID leaf.
7902
7903	.. _KVM_CAP_DIRTY_LOG_RING:
7904
7905
7906	.. _cap_enable_vm:
7907
7908	7. Capabilities that can be enabled on VMs
7909	==========================================
7910
7911	There are certain capabilities that change the behavior of the virtual
7912	machine when enabled. To enable them, please see section
7913	:ref:`KVM_ENABLE_CAP`. Below you can find a list of capabilities and
7914	what their effect on the VM is when enabling them.
7915
7916	The following information is provided along with the description:
7917
7918	Architectures:
7919	which instruction set architectures provide this ioctl.
7920	x86 includes both i386 and x86_64.
7921
7922	Parameters:
7923	what parameters are accepted by the capability.
7924
7925	Returns:
7926	the return value. General error numbers (EBADF, ENOMEM, EINVAL)
7927	are not detailed, but errors with specific meanings are.
7928
7929
7930	7.1 KVM_CAP_PPC_ENABLE_HCALL
7931	----------------------------
7932
7933	:Architectures: ppc
7934	:Parameters: args[0] is the sPAPR hcall number;
7935	args[1] is 0 to disable, 1 to enable in-kernel handling
7936
7937	This capability controls whether individual sPAPR hypercalls (hcalls)
7938	get handled by the kernel or not. Enabling or disabling in-kernel
7939	handling of an hcall is effective across the VM. On creation, an
7940	initial set of hcalls are enabled for in-kernel handling, which
7941	consists of those hcalls for which in-kernel handlers were implemented
7942	before this capability was implemented. If disabled, the kernel will
7943	not to attempt to handle the hcall, but will always exit to userspace
7944	to handle it. Note that it may not make sense to enable some and
7945	disable others of a group of related hcalls, but KVM does not prevent
7946	userspace from doing that.
7947
7948	If the hcall number specified is not one that has an in-kernel
7949	implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL
7950	error.
7951
7952	7.2 KVM_CAP_S390_USER_SIGP
7953	--------------------------
7954
7955	:Architectures: s390
7956	:Parameters: none
7957
7958	This capability controls which SIGP orders will be handled completely in user
7959	space. With this capability enabled, all fast orders will be handled completely
7960	in the kernel:
7961
7962	- SENSE
7963	- SENSE RUNNING
7964	- EXTERNAL CALL
7965	- EMERGENCY SIGNAL
7966	- CONDITIONAL EMERGENCY SIGNAL
7967
7968	All other orders will be handled completely in user space.
7969
7970	Only privileged operation exceptions will be checked for in the kernel (or even
7971	in the hardware prior to interception). If this capability is not enabled, the
7972	old way of handling SIGP orders is used (partially in kernel and user space).
7973
7974	7.3 KVM_CAP_S390_VECTOR_REGISTERS
7975	---------------------------------
7976
7977	:Architectures: s390
7978	:Parameters: none
7979	:Returns: 0 on success, negative value on error
7980
7981	Allows use of the vector registers introduced with z13 processor, and
7982	provides for the synchronization between host and user space. Will
7983	return -EINVAL if the machine does not support vectors.
7984
7985	7.4 KVM_CAP_S390_USER_STSI
7986	--------------------------
7987
7988	:Architectures: s390
7989	:Parameters: none
7990
7991	This capability allows post-handlers for the STSI instruction. After
7992	initial handling in the kernel, KVM exits to user space with
7993	KVM_EXIT_S390_STSI to allow user space to insert further data.
7994
7995	Before exiting to userspace, kvm handlers should fill in s390_stsi field of
7996	vcpu->run::
7997
7998	struct {
7999	__u64 addr;
8000	__u8 ar;
8001	__u8 reserved;
8002	__u8 fc;
8003	__u8 sel1;
8004	__u16 sel2;
8005	} s390_stsi;
8006
8007	@addr - guest address of STSI SYSIB
8008	@fc - function code
8009	@sel1 - selector 1
8010	@sel2 - selector 2
8011	@ar - access register number
8012
8013	KVM handlers should exit to userspace with rc = -EREMOTE.
8014
8015	7.5 KVM_CAP_SPLIT_IRQCHIP
8016	-------------------------
8017
8018	:Architectures: x86
8019	:Parameters: args[0] - number of routes reserved for userspace IOAPICs
8020	:Returns: 0 on success, -1 on error
8021
8022	Create a local apic for each processor in the kernel. This can be used
8023	instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the
8024	IOAPIC and PIC (and also the PIT, even though this has to be enabled
8025	separately).
8026
8027	This capability also enables in kernel routing of interrupt requests;
8028	when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are
8029	used in the IRQ routing table. The first args[0] MSI routes are reserved
8030	for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes,
8031	a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace.
8032
8033	As with ``KVM_CREATE_IRQCHIP``, subsequent vcpu creation may install a private
8034	memory slot at the APIC base address (0xfee00000) that must not overlap user
8035	memory regions. See ``KVM_CREATE_IRQCHIP`` for details.
8036
8037	Fails if VCPU has already been created, or if the irqchip is already in the
8038	kernel (i.e. KVM_CREATE_IRQCHIP has already been called).
8039
8040	7.6 KVM_CAP_S390_RI
8041	-------------------
8042
8043	:Architectures: s390
8044	:Parameters: none
8045
8046	Allows use of runtime-instrumentation introduced with zEC12 processor.
8047	Will return -EINVAL if the machine does not support runtime-instrumentation.
8048	Will return -EBUSY if a VCPU has already been created.
8049
8050	7.7 KVM_CAP_X2APIC_API
8051	----------------------
8052
8053	:Architectures: x86
8054	:Parameters: args[0] - features that should be enabled
8055	:Returns: 0 on success, -EINVAL when args[0] contains invalid features
8056
8057	Valid feature flags in args[0] are::
8058
8059	#define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0)
8060	#define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1)
8061	#define KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST (1ULL << 2)
8062	#define KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST (1ULL << 3)
8063
8064	Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of
8065	KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC,
8066	allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their
8067	respective sections.
8068
8069	KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work
8070	in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff
8071	as a broadcast even in x2APIC mode in order to support physical x2APIC
8072	without interrupt remapping. This is undesirable in logical mode,
8073	where 0xff represents CPUs 0-7 in cluster 0.
8074
8075	Setting KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST instructs KVM to enable
8076	Suppress EOI Broadcasts. KVM will advertise support for Suppress EOI
8077	Broadcast to the guest and suppress LAPIC EOI broadcasts when the guest
8078	sets the Suppress EOI Broadcast bit in the SPIV register. This flag is
8079	supported only when using a split IRQCHIP.
8080
8081	Setting KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST disables support for
8082	Suppress EOI Broadcasts entirely, i.e. instructs KVM to NOT advertise
8083	support to the guest.
8084
8085	Modern VMMs should either enable KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST
8086	or KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST. If not, legacy quirky
8087	behavior will be used by KVM: in split IRQCHIP mode, KVM will advertise
8088	support for Suppress EOI Broadcasts but not actually suppress EOI
8089	broadcasts; for in-kernel IRQCHIP mode, KVM will not advertise support for
8090	Suppress EOI Broadcasts.
8091
8092	Setting both KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST and
8093	KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST will fail with an EINVAL error,
8094	as will setting KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST without a split
8095	IRCHIP.
8096
8097	7.8 KVM_CAP_S390_USER_INSTR0
8098	----------------------------
8099
8100	:Architectures: s390
8101	:Parameters: none
8102
8103	With this capability enabled, the illegal instruction 0x0000 (2 bytes) will
8104	be intercepted and forwarded to user space. User space can use this
8105	mechanism e.g. to realize 2-byte software breakpoints. The kernel will
8106	not inject an operating exception for these instructions, user space has
8107	to take care of that.
8108
8109	This capability can be enabled dynamically even if VCPUs were already
8110	created and are running.
8111
8112	7.9 KVM_CAP_S390_GS
8113	-------------------
8114
8115	:Architectures: s390
8116	:Parameters: none
8117	:Returns: 0 on success; -EINVAL if the machine does not support
8118	guarded storage; -EBUSY if a VCPU has already been created.
8119
8120	Allows use of guarded storage for the KVM guest.
8121
8122	7.10 KVM_CAP_S390_AIS
8123	---------------------
8124
8125	:Architectures: s390
8126	:Parameters: none
8127
8128	Allow use of adapter-interruption suppression.
8129	:Returns: 0 on success; -EBUSY if a VCPU has already been created.
8130
8131	7.11 KVM_CAP_PPC_SMT
8132	--------------------
8133
8134	:Architectures: ppc
8135	:Parameters: vsmt_mode, flags
8136
8137	Enabling this capability on a VM provides userspace with a way to set
8138	the desired virtual SMT mode (i.e. the number of virtual CPUs per
8139	virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2
8140	between 1 and 8. On POWER8, vsmt_mode must also be no greater than
8141	the number of threads per subcore for the host. Currently flags must
8142	be 0. A successful call to enable this capability will result in
8143	vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is
8144	subsequently queried for the VM. This capability is only supported by
8145	HV KVM, and can only be set before any VCPUs have been created.
8146	The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT
8147	modes are available.
8148
8149	7.12 KVM_CAP_PPC_FWNMI
8150	----------------------
8151
8152	:Architectures: ppc
8153	:Parameters: none
8154
8155	With this capability a machine check exception in the guest address
8156	space will cause KVM to exit the guest with NMI exit reason. This
8157	enables QEMU to build error log and branch to guest kernel registered
8158	machine check handling routine. Without this capability KVM will
8159	branch to guests' 0x200 interrupt vector.
8160
8161	7.13 KVM_CAP_X86_DISABLE_EXITS
8162	------------------------------
8163
8164	:Architectures: x86
8165	:Parameters: args[0] defines which exits are disabled
8166	:Returns: 0 on success, -EINVAL when args[0] contains invalid exits
8167	or if any vCPUs have already been created
8168
8169	Valid bits in args[0] are::
8170
8171	#define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0)
8172	#define KVM_X86_DISABLE_EXITS_HLT (1 << 1)
8173	#define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2)
8174	#define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3)
8175	#define KVM_X86_DISABLE_EXITS_APERFMPERF (1 << 4)
8176
8177	Enabling this capability on a VM provides userspace with a way to no
8178	longer intercept some instructions for improved latency in some
8179	workloads, and is suggested when vCPUs are associated to dedicated
8180	physical CPUs. More bits can be added in the future; userspace can
8181	just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable
8182	all such vmexits.
8183
8184	Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits.
8185
8186	Virtualizing the ``IA32_APERF`` and ``IA32_MPERF`` MSRs requires more
8187	than just disabling APERF/MPERF exits. While both Intel and AMD
8188	document strict usage conditions for these MSRs--emphasizing that only
8189	the ratio of their deltas over a time interval (T0 to T1) is
8190	architecturally defined--simply passing through the MSRs can still
8191	produce an incorrect ratio.
8192
8193	This erroneous ratio can occur if, between T0 and T1:
8194
8195	1. The vCPU thread migrates between logical processors.
8196	2. Live migration or suspend/resume operations take place.
8197	3. Another task shares the vCPU's logical processor.
8198	4. C-states lower than C0 are emulated (e.g., via HLT interception).
8199	5. The guest TSC frequency doesn't match the host TSC frequency.
8200
8201	Due to these complexities, KVM does not automatically associate this
8202	passthrough capability with the guest CPUID bit,
8203	``CPUID.6:ECX.APERFMPERF[bit 0]``. Userspace VMMs that deem this
8204	mechanism adequate for virtualizing the ``IA32_APERF`` and
8205	``IA32_MPERF`` MSRs must set the guest CPUID bit explicitly.
8206
8207
8208	7.14 KVM_CAP_S390_HPAGE_1M
8209	--------------------------
8210
8211	:Architectures: s390
8212	:Parameters: none
8213	:Returns: 0 on success, -EINVAL if hpage module parameter was not set
8214	or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL
8215	flag set
8216
8217	With this capability the KVM support for memory backing with 1m pages
8218	through hugetlbfs can be enabled for a VM. After the capability is
8219	enabled, cmma can't be enabled anymore and pfmfi and the storage key
8220	interpretation are disabled. If cmma has already been enabled or the
8221	hpage module parameter is not set to 1, -EINVAL is returned.
8222
8223	While it is generally possible to create a huge page backed VM without
8224	this capability, the VM will not be able to run.
8225
8226	7.15 KVM_CAP_MSR_PLATFORM_INFO
8227	------------------------------
8228
8229	:Architectures: x86
8230	:Parameters: args[0] whether feature should be enabled or not
8231
8232	With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise,
8233	a #GP would be raised when the guest tries to access. Currently, this
8234	capability does not enable write permissions of this MSR for the guest.
8235
8236	7.16 KVM_CAP_PPC_NESTED_HV
8237	--------------------------
8238
8239	:Architectures: ppc
8240	:Parameters: none
8241	:Returns: 0 on success, -EINVAL when the implementation doesn't support
8242	nested-HV virtualization.
8243
8244	HV-KVM on POWER9 and later systems allows for "nested-HV"
8245	virtualization, which provides a way for a guest VM to run guests that
8246	can run using the CPU's supervisor mode (privileged non-hypervisor
8247	state). Enabling this capability on a VM depends on the CPU having
8248	the necessary functionality and on the facility being enabled with a
8249	kvm-hv module parameter.
8250
8251	7.17 KVM_CAP_EXCEPTION_PAYLOAD
8252	------------------------------
8253
8254	:Architectures: x86
8255	:Parameters: args[0] whether feature should be enabled or not
8256
8257	With this capability enabled, CR2 will not be modified prior to the
8258	emulated VM-exit when L1 intercepts a #PF exception that occurs in
8259	L2. Similarly, for kvm-intel only, DR6 will not be modified prior to
8260	the emulated VM-exit when L1 intercepts a #DB exception that occurs in
8261	L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or
8262	#DB) exception for L2, exception.has_payload will be set and the
8263	faulting address (or the new DR6 bits*) will be reported in the
8264	exception_payload field. Similarly, when userspace injects a #PF (or
8265	#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set
8266	exception.has_payload and to put the faulting address - or the new DR6
8267	bits\ [#]_ - in the exception_payload field.
8268
8269	This capability also enables exception.pending in struct
8270	kvm_vcpu_events, which allows userspace to distinguish between pending
8271	and injected exceptions.
8272
8273
8274	.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception
8275	will clear DR6.RTM.
8276
8277	7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
8278	--------------------------------------
8279
8280	:Architectures: x86, arm64, mips
8281	:Parameters: args[0] whether feature should be enabled or not
8282
8283	Valid flags are::
8284
8285	#define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0)
8286	#define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1)
8287
8288	With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not
8289	automatically clear and write-protect all pages that are returned as dirty.
8290	Rather, userspace will have to do this operation separately using
8291	KVM_CLEAR_DIRTY_LOG.
8292
8293	At the cost of a slightly more complicated operation, this provides better
8294	scalability and responsiveness for two reasons. First,
8295	KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather
8296	than requiring to sync a full memslot; this ensures that KVM does not
8297	take spinlocks for an extended period of time. Second, in some cases a
8298	large amount of time can pass between a call to KVM_GET_DIRTY_LOG and
8299	userspace actually using the data in the page. Pages can be modified
8300	during this time, which is inefficient for both the guest and userspace:
8301	the guest will incur a higher penalty due to write protection faults,
8302	while userspace can see false reports of dirty pages. Manual reprotection
8303	helps reducing this time, improving guest performance and reducing the
8304	number of dirty log false positives.
8305
8306	With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap
8307	will be initialized to 1 when created. This also improves performance because
8308	dirty logging can be enabled gradually in small chunks on the first call
8309	to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on
8310	KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on
8311	x86, arm64 and riscv for now).
8312
8313	KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name
8314	KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make
8315	it hard or impossible to use it correctly. The availability of
8316	KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed.
8317	Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT.
8318
8319	7.19 KVM_CAP_PPC_SECURE_GUEST
8320	------------------------------
8321
8322	:Architectures: ppc
8323
8324	This capability indicates that KVM is running on a host that has
8325	ultravisor firmware and thus can support a secure guest. On such a
8326	system, a guest can ask the ultravisor to make it a secure guest,
8327	one whose memory is inaccessible to the host except for pages which
8328	are explicitly requested to be shared with the host. The ultravisor
8329	notifies KVM when a guest requests to become a secure guest, and KVM
8330	has the opportunity to veto the transition.
8331
8332	If present, this capability can be enabled for a VM, meaning that KVM
8333	will allow the transition to secure guest mode. Otherwise KVM will
8334	veto the transition.
8335
8336	7.20 KVM_CAP_HALT_POLL
8337	----------------------
8338
8339	:Architectures: all
8340	:Target: VM
8341	:Parameters: args[0] is the maximum poll time in nanoseconds
8342	:Returns: 0 on success; -1 on error
8343
8344	KVM_CAP_HALT_POLL overrides the kvm.halt_poll_ns module parameter to set the
8345	maximum halt-polling time for all vCPUs in the target VM. This capability can
8346	be invoked at any time and any number of times to dynamically change the
8347	maximum halt-polling time.
8348
8349	See Documentation/virt/kvm/halt-polling.rst for more information on halt
8350	polling.
8351
8352	7.21 KVM_CAP_X86_USER_SPACE_MSR
8353	-------------------------------
8354
8355	:Architectures: x86
8356	:Target: VM
8357	:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report
8358	:Returns: 0 on success; -1 on error
8359
8360	This capability allows userspace to intercept RDMSR and WRMSR instructions if
8361	access to an MSR is denied. By default, KVM injects #GP on denied accesses.
8362
8363	When a guest requests to read or write an MSR, KVM may not implement all MSRs
8364	that are relevant to a respective system. It also does not differentiate by
8365	CPU type.
8366
8367	To allow more fine grained control over MSR handling, userspace may enable
8368	this capability. With it enabled, MSR accesses that match the mask specified in
8369	args[0] and would trigger a #GP inside the guest will instead trigger
8370	KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications. Userspace
8371	can then implement model specific MSR handling and/or user notifications
8372	to inform a user that an MSR was not emulated/virtualized by KVM.
8373
8374	The valid mask flags are:
8375
8376	============================ ===============================================
8377	KVM_MSR_EXIT_REASON_UNKNOWN intercept accesses to unknown (to KVM) MSRs
8378	KVM_MSR_EXIT_REASON_INVAL intercept accesses that are architecturally
8379	invalid according to the vCPU model and/or mode
8380	KVM_MSR_EXIT_REASON_FILTER intercept accesses that are denied by userspace
8381	via KVM_X86_SET_MSR_FILTER
8382	============================ ===============================================
8383
8384	7.22 KVM_CAP_X86_BUS_LOCK_EXIT
8385	-------------------------------
8386
8387	:Architectures: x86
8388	:Target: VM
8389	:Parameters: args[0] defines the policy used when bus locks detected in guest
8390	:Returns: 0 on success, -EINVAL when args[0] contains invalid bits
8391
8392	Valid bits in args[0] are::
8393
8394	#define KVM_BUS_LOCK_DETECTION_OFF (1 << 0)
8395	#define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1)
8396
8397	Enabling this capability on a VM provides userspace with a way to select a
8398	policy to handle the bus locks detected in guest. Userspace can obtain the
8399	supported modes from the result of KVM_CHECK_EXTENSION and define it through
8400	the KVM_ENABLE_CAP. The supported modes are mutually-exclusive.
8401
8402	This capability allows userspace to force VM exits on bus locks detected in the
8403	guest, irrespective whether or not the host has enabled split-lock detection
8404	(which triggers an #AC exception that KVM intercepts). This capability is
8405	intended to mitigate attacks where a malicious/buggy guest can exploit bus
8406	locks to degrade the performance of the whole system.
8407
8408	If KVM_BUS_LOCK_DETECTION_OFF is set, KVM doesn't force guest bus locks to VM
8409	exit, although the host kernel's split-lock #AC detection still applies, if
8410	enabled.
8411
8412	If KVM_BUS_LOCK_DETECTION_EXIT is set, KVM enables a CPU feature that ensures
8413	bus locks in the guest trigger a VM exit, and KVM exits to userspace for all
8414	such VM exits, e.g. to allow userspace to throttle the offending guest and/or
8415	apply some other policy-based mitigation. When exiting to userspace, KVM sets
8416	KVM_RUN_X86_BUS_LOCK in vcpu-run->flags, and conditionally sets the exit_reason
8417	to KVM_EXIT_X86_BUS_LOCK.
8418
8419	Due to differences in the underlying hardware implementation, the vCPU's RIP at
8420	the time of exit diverges between Intel and AMD. On Intel hosts, RIP points at
8421	the next instruction, i.e. the exit is trap-like. On AMD hosts, RIP points at
8422	the offending instruction, i.e. the exit is fault-like.
8423
8424	Note! Detected bus locks may be coincident with other exits to userspace, i.e.
8425	KVM_RUN_X86_BUS_LOCK should be checked regardless of the primary exit reason if
8426	userspace wants to take action on all detected bus locks.
8427
8428	7.23 KVM_CAP_PPC_DAWR1
8429	----------------------
8430
8431	:Architectures: ppc
8432	:Parameters: none
8433	:Returns: 0 on success, -EINVAL when CPU doesn't support 2nd DAWR
8434
8435	This capability can be used to check / enable 2nd DAWR feature provided
8436	by POWER10 processor.
8437
8438
8439	7.24 KVM_CAP_VM_COPY_ENC_CONTEXT_FROM
8440	-------------------------------------
8441
8442	:Architectures: x86 SEV enabled
8443	:Type: vm
8444	:Parameters: args[0] is the fd of the source vm
8445	:Returns: 0 on success; ENOTTY on error
8446
8447	This capability enables userspace to copy encryption context from the vm
8448	indicated by the fd to the vm this is called on.
8449
8450	This is intended to support in-guest workloads scheduled by the host. This
8451	allows the in-guest workload to maintain its own NPTs and keeps the two vms
8452	from accidentally clobbering each other with interrupts and the like (separate
8453	APIC/MSRs/etc).
8454
8455	7.25 KVM_CAP_SGX_ATTRIBUTE
8456	--------------------------
8457
8458	:Architectures: x86
8459	:Target: VM
8460	:Parameters: args[0] is a file handle of a SGX attribute file in securityfs
8461	:Returns: 0 on success, -EINVAL if the file handle is invalid or if a requested
8462	attribute is not supported by KVM.
8463
8464	KVM_CAP_SGX_ATTRIBUTE enables a userspace VMM to grant a VM access to one or
8465	more privileged enclave attributes. args[0] must hold a file handle to a valid
8466	SGX attribute file corresponding to an attribute that is supported/restricted
8467	by KVM (currently only PROVISIONKEY).
8468
8469	The SGX subsystem restricts access to a subset of enclave attributes to provide
8470	additional security for an uncompromised kernel, e.g. use of the PROVISIONKEY
8471	is restricted to deter malware from using the PROVISIONKEY to obtain a stable
8472	system fingerprint. To prevent userspace from circumventing such restrictions
8473	by running an enclave in a VM, KVM prevents access to privileged attributes by
8474	default.
8475
8476	See Documentation/arch/x86/sgx.rst for more details.
8477
8478	7.27 KVM_CAP_EXIT_ON_EMULATION_FAILURE
8479	--------------------------------------
8480
8481	:Architectures: x86
8482	:Parameters: args[0] whether the feature should be enabled or not
8483
8484	When this capability is enabled, an emulation failure will result in an exit
8485	to userspace with KVM_INTERNAL_ERROR (except when the emulator was invoked
8486	to handle a VMware backdoor instruction). Furthermore, KVM will now provide up
8487	to 15 instruction bytes for any exit to userspace resulting from an emulation
8488	failure. When these exits to userspace occur use the emulation_failure struct
8489	instead of the internal struct. They both have the same layout, but the
8490	emulation_failure struct matches the content better. It also explicitly
8491	defines the 'flags' field which is used to describe the fields in the struct
8492	that are valid (ie: if KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES is
8493	set in the 'flags' field then both 'insn_size' and 'insn_bytes' have valid data
8494	in them.)
8495
8496	7.28 KVM_CAP_ARM_MTE
8497	--------------------
8498
8499	:Architectures: arm64
8500	:Parameters: none
8501
8502	This capability indicates that KVM (and the hardware) supports exposing the
8503	Memory Tagging Extensions (MTE) to the guest. It must also be enabled by the
8504	VMM before creating any VCPUs to allow the guest access. Note that MTE is only
8505	available to a guest running in AArch64 mode and enabling this capability will
8506	cause attempts to create AArch32 VCPUs to fail.
8507
8508	When enabled the guest is able to access tags associated with any memory given
8509	to the guest. KVM will ensure that the tags are maintained during swap or
8510	hibernation of the host; however the VMM needs to manually save/restore the
8511	tags as appropriate if the VM is migrated.
8512
8513	When this capability is enabled all memory in memslots must be mapped as
8514	``MAP_ANONYMOUS`` or with a RAM-based file mapping (``tmpfs``, ``memfd``),
8515	attempts to create a memslot with an invalid mmap will result in an
8516	-EINVAL return.
8517
8518	``guest_memfd``, even though it is an anonymous file, is not supported with MTE.
8519	Attempting to create a memslot backed by ``guest_memfd`` when the MTE capability
8520	is enabled, or attempting to enable the MTE capability after
8521	``guest_memfd``-backed memslots have been created, will result in an -EINVAL
8522	return.
8523
8524	When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to
8525	perform a bulk copy of tags to/from the guest.
8526
8527	7.29 KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
8528	-------------------------------------
8529
8530	:Architectures: x86 SEV enabled
8531	:Type: vm
8532	:Parameters: args[0] is the fd of the source vm
8533	:Returns: 0 on success
8534
8535	This capability enables userspace to migrate the encryption context from the VM
8536	indicated by the fd to the VM this is called on.
8537
8538	This is intended to support intra-host migration of VMs between userspace VMMs,
8539	upgrading the VMM process without interrupting the guest.
8540
8541	7.31 KVM_CAP_DISABLE_QUIRKS2
8542	----------------------------
8543
8544	:Parameters: args[0] - set of KVM quirks to disable
8545	:Architectures: x86
8546	:Type: vm
8547
8548	This capability, if enabled, will cause KVM to disable some behavior
8549	quirks.
8550
8551	Calling KVM_CHECK_EXTENSION for this capability returns a bitmask of
8552	quirks that can be disabled in KVM.
8553
8554	The argument to KVM_ENABLE_CAP for this capability is a bitmask of
8555	quirks to disable, and must be a subset of the bitmask returned by
8556	KVM_CHECK_EXTENSION.
8557
8558	The valid bits in cap.args[0] are:
8559
8560	======================================== ================================================
8561	KVM_X86_QUIRK_LINT0_REENABLED By default, the reset value for the LVT
8562	LINT0 register is 0x700 (APIC_MODE_EXTINT).
8563	When this quirk is disabled, the reset value
8564	is 0x10000 (APIC_LVT_MASKED).
8565
8566	KVM_X86_QUIRK_CD_NW_CLEARED By default, KVM clears CR0.CD and CR0.NW on
8567	AMD CPUs to workaround buggy guest firmware
8568	that runs in perpetuity with CR0.CD, i.e.
8569	with caches in "no fill" mode.
8570
8571	When this quirk is disabled, KVM does not
8572	change the value of CR0.CD and CR0.NW.
8573
8574	KVM_X86_QUIRK_LAPIC_MMIO_HOLE By default, the MMIO LAPIC interface is
8575	available even when configured for x2APIC
8576	mode. When this quirk is disabled, KVM
8577	disables the MMIO LAPIC interface if the
8578	LAPIC is in x2APIC mode.
8579
8580	KVM_X86_QUIRK_OUT_7E_INC_RIP By default, KVM pre-increments %rip before
8581	exiting to userspace for an OUT instruction
8582	to port 0x7e. When this quirk is disabled,
8583	KVM does not pre-increment %rip before
8584	exiting to userspace.
8585
8586	KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT When this quirk is disabled, KVM sets
8587	CPUID.01H:ECX[bit 3] (MONITOR/MWAIT) if
8588	IA32_MISC_ENABLE[bit 18] (MWAIT) is set.
8589	Additionally, when this quirk is disabled,
8590	KVM clears CPUID.01H:ECX[bit 3] if
8591	IA32_MISC_ENABLE[bit 18] is cleared.
8592
8593	KVM_X86_QUIRK_FIX_HYPERCALL_INSN By default, KVM rewrites guest
8594	VMMCALL/VMCALL instructions to match the
8595	vendor's hypercall instruction for the
8596	system. When this quirk is disabled, KVM
8597	will no longer rewrite invalid guest
8598	hypercall instructions. Executing the
8599	incorrect hypercall instruction will
8600	generate a #UD within the guest.
8601
8602	KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS By default, KVM emulates MONITOR/MWAIT (if
8603	they are intercepted) as NOPs regardless of
8604	whether or not MONITOR/MWAIT are supported
8605	according to guest CPUID. When this quirk
8606	is disabled and KVM_X86_DISABLE_EXITS_MWAIT
8607	is not set (MONITOR/MWAIT are intercepted),
8608	KVM will inject a #UD on MONITOR/MWAIT if
8609	they're unsupported per guest CPUID. Note,
8610	KVM will modify MONITOR/MWAIT support in
8611	guest CPUID on writes to MISC_ENABLE if
8612	KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT is
8613	disabled.
8614
8615	KVM_X86_QUIRK_SLOT_ZAP_ALL By default, for KVM_X86_DEFAULT_VM VMs, KVM
8616	invalidates all SPTEs in all memslots and
8617	address spaces when a memslot is deleted or
8618	moved. When this quirk is disabled (or the
8619	VM type isn't KVM_X86_DEFAULT_VM), KVM only
8620	ensures the backing memory of the deleted
8621	or moved memslot isn't reachable, i.e KVM
8622	_may_ invalidate only SPTEs related to the
8623	memslot.
8624
8625	KVM_X86_QUIRK_STUFF_FEATURE_MSRS By default, at vCPU creation, KVM sets the
8626	vCPU's MSR_IA32_PERF_CAPABILITIES (0x345),
8627	MSR_IA32_ARCH_CAPABILITIES (0x10a),
8628	MSR_PLATFORM_INFO (0xce), and all VMX MSRs
8629	(0x480..0x492) to the maximal capabilities
8630	supported by KVM. KVM also sets
8631	MSR_IA32_UCODE_REV (0x8b) to an arbitrary
8632	value (which is different for Intel vs.
8633	AMD). Lastly, when guest CPUID is set (by
8634	userspace), KVM modifies select VMX MSR
8635	fields to force consistency between guest
8636	CPUID and L2's effective ISA. When this
8637	quirk is disabled, KVM zeroes the vCPU's MSR
8638	values (with two exceptions, see below),
8639	i.e. treats the feature MSRs like CPUID
8640	leaves and gives userspace full control of
8641	the vCPU model definition. This quirk does
8642	not affect VMX MSRs CR0/CR4_FIXED1 (0x487
8643	and 0x489), as KVM does now allow them to
8644	be set by userspace (KVM sets them based on
8645	guest CPUID, for safety purposes).
8646
8647	KVM_X86_QUIRK_IGNORE_GUEST_PAT By default, on Intel platforms, KVM ignores
8648	guest PAT and forces the effective memory
8649	type to WB in EPT. The quirk is not available
8650	on Intel platforms which are incapable of
8651	safely honoring guest PAT (i.e., without CPU
8652	self-snoop, KVM always ignores guest PAT and
8653	forces effective memory type to WB). It is
8654	also ignored on AMD platforms or, on Intel,
8655	when a VM has non-coherent DMA devices
8656	assigned; KVM always honors guest PAT in
8657	such case. The quirk is needed to avoid
8658	slowdowns on certain Intel Xeon platforms
8659	(e.g. ICX, SPR) where self-snoop feature is
8660	supported but UC is slow enough to cause
8661	issues with some older guests that use
8662	UC instead of WC to map the video RAM.
8663	Userspace can disable the quirk to honor
8664	guest PAT if it knows that there is no such
8665	guest software, for example if it does not
8666	expose a bochs graphics device (which is
8667	known to have had a buggy driver).
8668
8669	KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM By default, KVM relaxes the consistency
8670	check for GUEST_IA32_DEBUGCTL in vmcs12
8671	to allow FREEZE_IN_SMM to be set. When
8672	this quirk is disabled, KVM requires this
8673	bit to be cleared. Note that the vmcs02
8674	bit is still completely controlled by the
8675	host, regardless of the quirk setting.
8676
8677	KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT By default, KVM for nested SVM guests
8678	shares the IA32_PAT MSR between L1 and
8679	L2. This is legacy behavior and does
8680	not match the AMD architecture
8681	specification. When this quirk is
8682	disabled and nested paging (NPT) is
8683	enabled for L2, KVM correctly
8684	virtualizes a separate guest PAT
8685	register for L2, using the g_pat
8686	field in the VMCB. When NPT is
8687	disabled for L2, L1 and L2 continue
8688	to share the IA32_PAT MSR regardless
8689	of the quirk setting.
8690	======================================== ================================================
8691
8692	7.32 KVM_CAP_MAX_VCPU_ID
8693	------------------------
8694
8695	:Architectures: x86
8696	:Target: VM
8697	:Parameters: args[0] - maximum APIC ID value set for current VM
8698	:Returns: 0 on success, -EINVAL if args[0] is beyond KVM_MAX_VCPU_IDS
8699	supported in KVM or if it has been set.
8700
8701	This capability allows userspace to specify maximum possible APIC ID
8702	assigned for current VM session prior to the creation of vCPUs, saving
8703	memory for data structures indexed by the APIC ID. Userspace is able
8704	to calculate the limit to APIC ID values from designated
8705	CPU topology.
8706
8707	The value can be changed only until KVM_ENABLE_CAP is set to a nonzero
8708	value or until a vCPU is created. Upon creation of the first vCPU,
8709	if the value was set to zero or KVM_ENABLE_CAP was not invoked, KVM
8710	uses the return value of KVM_CHECK_EXTENSION(KVM_CAP_MAX_VCPU_ID) as
8711	the maximum APIC ID.
8712
8713	7.33 KVM_CAP_X86_NOTIFY_VMEXIT
8714	------------------------------
8715
8716	:Architectures: x86
8717	:Target: VM
8718	:Parameters: args[0] is the value of notify window as well as some flags
8719	:Returns: 0 on success, -EINVAL if args[0] contains invalid flags or notify
8720	VM exit is unsupported.
8721
8722	Bits 63:32 of args[0] are used for notify window.
8723	Bits 31:0 of args[0] are for some flags. Valid bits are::
8724
8725	#define KVM_X86_NOTIFY_VMEXIT_ENABLED (1 << 0)
8726	#define KVM_X86_NOTIFY_VMEXIT_USER (1 << 1)
8727
8728	This capability allows userspace to configure the notify VM exit on/off
8729	in per-VM scope during VM creation. Notify VM exit is disabled by default.
8730	When userspace sets KVM_X86_NOTIFY_VMEXIT_ENABLED bit in args[0], VMM will
8731	enable this feature with the notify window provided, which will generate
8732	a VM exit if no event window occurs in VM non-root mode for a specified of
8733	time (notify window).
8734
8735	If KVM_X86_NOTIFY_VMEXIT_USER is set in args[0], upon notify VM exits happen,
8736	KVM would exit to userspace for handling.
8737
8738	This capability is aimed to mitigate the threat that malicious VMs can
8739	cause CPU stuck (due to event windows don't open up) and make the CPU
8740	unavailable to host or other VMs.
8741
8742	7.35 KVM_CAP_X86_APIC_BUS_CYCLES_NS
8743	-----------------------------------
8744
8745	:Architectures: x86
8746	:Target: VM
8747	:Parameters: args[0] is the desired APIC bus clock rate, in nanoseconds
8748	:Returns: 0 on success, -EINVAL if args[0] contains an invalid value for the
8749	frequency or if any vCPUs have been created, -ENXIO if a virtual
8750	local APIC has not been created using KVM_CREATE_IRQCHIP.
8751
8752	This capability sets the VM's APIC bus clock frequency, used by KVM's in-kernel
8753	virtual APIC when emulating APIC timers. KVM's default value can be retrieved
8754	by KVM_CHECK_EXTENSION.
8755
8756	Note: Userspace is responsible for correctly configuring CPUID 0x15, a.k.a. the
8757	core crystal clock frequency, if a non-zero CPUID 0x15 is exposed to the guest.
8758
8759	7.36 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL
8760	----------------------------------------------------------
8761
8762	:Architectures: x86, arm64, riscv
8763	:Type: vm
8764	:Parameters: args[0] - size of the dirty log ring
8765
8766	KVM is capable of tracking dirty memory using ring buffers that are
8767	mmapped into userspace; there is one dirty ring per vcpu.
8768
8769	The dirty ring is available to userspace as an array of
8770	``struct kvm_dirty_gfn``. Each dirty entry is defined as::
8771
8772	struct kvm_dirty_gfn {
8773	__u32 flags;
8774	__u32 slot; /* as_id \| slot_id */
8775	__u64 offset;
8776	};
8777
8778	The following values are defined for the flags field to define the
8779	current state of the entry::
8780
8781	#define KVM_DIRTY_GFN_F_DIRTY BIT(0)
8782	#define KVM_DIRTY_GFN_F_RESET BIT(1)
8783	#define KVM_DIRTY_GFN_F_MASK 0x3
8784
8785	Userspace should call KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM
8786	ioctl to enable this capability for the new guest and set the size of
8787	the rings. Enabling the capability is only allowed before creating any
8788	vCPU, and the size of the ring must be a power of two. The larger the
8789	ring buffer, the less likely the ring is full and the VM is forced to
8790	exit to userspace. The optimal size depends on the workload, but it is
8791	recommended that it be at least 64 KiB (4096 entries).
8792
8793	Just like for dirty page bitmaps, the buffer tracks writes to
8794	all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was
8795	set in KVM_SET_USER_MEMORY_REGION. Once a memory region is registered
8796	with the flag set, userspace can start harvesting dirty pages from the
8797	ring buffer.
8798
8799	An entry in the ring buffer can be unused (flag bits ``00``),
8800	dirty (flag bits ``01``) or harvested (flag bits ``1X``). The
8801	state machine for the entry is as follows::
8802
8803	dirtied harvested reset
8804	00 -----------> 01 -------------> 1X -------+
8805	^ \|
8806	\| \|
8807	+------------------------------------------+
8808
8809	To harvest the dirty pages, userspace accesses the mmapped ring buffer
8810	to read the dirty GFNs. If the flags has the DIRTY bit set (at this stage
8811	the RESET bit must be cleared), then it means this GFN is a dirty GFN.
8812	The userspace should harvest this GFN and mark the flags from state
8813	``01b`` to ``1Xb`` (bit 0 will be ignored by KVM, but bit 1 must be set
8814	to show that this GFN is harvested and waiting for a reset), and move
8815	on to the next GFN. The userspace should continue to do this until the
8816	flags of a GFN have the DIRTY bit cleared, meaning that it has harvested
8817	all the dirty GFNs that were available.
8818
8819	Note that on weakly ordered architectures, userspace accesses to the
8820	ring buffer (and more specifically the 'flags' field) must be ordered,
8821	using load-acquire/store-release accessors when available, or any
8822	other memory barrier that will ensure this ordering.
8823
8824	It's not necessary for userspace to harvest the all dirty GFNs at once.
8825	However it must collect the dirty GFNs in sequence, i.e., the userspace
8826	program cannot skip one dirty GFN to collect the one next to it.
8827
8828	After processing one or more entries in the ring buffer, userspace
8829	calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about
8830	it, so that the kernel will reprotect those collected GFNs.
8831	Therefore, the ioctl must be called before reading the content of
8832	the dirty pages.
8833
8834	The dirty ring can get full. When it happens, the KVM_RUN of the
8835	vcpu will return with exit reason KVM_EXIT_DIRTY_RING_FULL.
8836
8837	The dirty ring interface has a major difference comparing to the
8838	KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from
8839	userspace, it's still possible that the kernel has not yet flushed the
8840	processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the
8841	flushing is done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one
8842	needs to kick the vcpu out of KVM_RUN using a signal. The resulting
8843	vmexit ensures that all dirty GFNs are flushed to the dirty rings.
8844
8845	NOTE: KVM_CAP_DIRTY_LOG_RING_ACQ_REL is the only capability that
8846	should be exposed by weakly ordered architecture, in order to indicate
8847	the additional memory ordering requirements imposed on userspace when
8848	reading the state of an entry and mutating it from DIRTY to HARVESTED.
8849	Architecture with TSO-like ordering (such as x86) are allowed to
8850	expose both KVM_CAP_DIRTY_LOG_RING and KVM_CAP_DIRTY_LOG_RING_ACQ_REL
8851	to userspace.
8852
8853	After enabling the dirty rings, the userspace needs to detect the
8854	capability of KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP to see whether the
8855	ring structures can be backed by per-slot bitmaps. With this capability
8856	advertised, it means the architecture can dirty guest pages without
8857	vcpu/ring context, so that some of the dirty information will still be
8858	maintained in the bitmap structure. KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP
8859	can't be enabled if the capability of KVM_CAP_DIRTY_LOG_RING_ACQ_REL
8860	hasn't been enabled, or any memslot has been existing.
8861
8862	Note that the bitmap here is only a backup of the ring structure. The
8863	use of the ring and bitmap combination is only beneficial if there is
8864	only a very small amount of memory that is dirtied out of vcpu/ring
8865	context. Otherwise, the stand-alone per-slot bitmap mechanism needs to
8866	be considered.
8867
8868	To collect dirty bits in the backup bitmap, userspace can use the same
8869	KVM_GET_DIRTY_LOG ioctl. KVM_CLEAR_DIRTY_LOG isn't needed as long as all
8870	the generation of the dirty bits is done in a single pass. Collecting
8871	the dirty bitmap should be the very last thing that the VMM does before
8872	considering the state as complete. VMM needs to ensure that the dirty
8873	state is final and avoid missing dirty pages from another ioctl ordered
8874	after the bitmap collection.
8875
8876	NOTE: Multiple examples of using the backup bitmap: (1) save vgic/its
8877	tables through command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} on
8878	KVM device "kvm-arm-vgic-its". (2) restore vgic/its tables through
8879	command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM device
8880	"kvm-arm-vgic-its". VGICv3 LPI pending status is restored. (3) save
8881	vgic3 pending table through KVM_DEV_ARM_VGIC_{GRP_CTRL, SAVE_PENDING_TABLES}
8882	command on KVM device "kvm-arm-vgic-v3".
8883
8884	7.37 KVM_CAP_PMU_CAPABILITY
8885	---------------------------
8886
8887	:Architectures: x86
8888	:Type: vm
8889	:Parameters: arg[0] is bitmask of PMU virtualization capabilities.
8890	:Returns: 0 on success, -EINVAL when arg[0] contains invalid bits
8891
8892	This capability alters PMU virtualization in KVM.
8893
8894	Calling KVM_CHECK_EXTENSION for this capability returns a bitmask of
8895	PMU virtualization capabilities that can be adjusted on a VM.
8896
8897	The argument to KVM_ENABLE_CAP is also a bitmask and selects specific
8898	PMU virtualization capabilities to be applied to the VM. This can
8899	only be invoked on a VM prior to the creation of VCPUs.
8900
8901	At this time, KVM_PMU_CAP_DISABLE is the only capability. Setting
8902	this capability will disable PMU virtualization for that VM. Usermode
8903	should adjust CPUID leaf 0xA to reflect that the PMU is disabled.
8904
8905	7.38 KVM_CAP_VM_DISABLE_NX_HUGE_PAGES
8906	-------------------------------------
8907
8908	:Architectures: x86
8909	:Type: vm
8910	:Parameters: arg[0] must be 0.
8911	:Returns: 0 on success, -EPERM if the userspace process does not
8912	have CAP_SYS_BOOT, -EINVAL if args[0] is not 0 or any vCPUs have been
8913	created.
8914
8915	This capability disables the NX huge pages mitigation for iTLB MULTIHIT.
8916
8917	The capability has no effect if the nx_huge_pages module parameter is not set.
8918
8919	This capability may only be set before any vCPUs are created.
8920
8921	7.39 KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
8922	---------------------------------------
8923
8924	:Architectures: arm64
8925	:Type: vm
8926	:Parameters: arg[0] is the new split chunk size.
8927	:Returns: 0 on success, -EINVAL if any memslot was already created.
8928
8929	This capability sets the chunk size used in Eager Page Splitting.
8930
8931	Eager Page Splitting improves the performance of dirty-logging (used
8932	in live migrations) when guest memory is backed by huge-pages. It
8933	avoids splitting huge-pages (into PAGE_SIZE pages) on fault, by doing
8934	it eagerly when enabling dirty logging (with the
8935	KVM_MEM_LOG_DIRTY_PAGES flag for a memory region), or when using
8936	KVM_CLEAR_DIRTY_LOG.
8937
8938	The chunk size specifies how many pages to break at a time, using a
8939	single allocation for each chunk. Bigger the chunk size, more pages
8940	need to be allocated ahead of time.
8941
8942	The chunk size needs to be a valid block size. The list of acceptable
8943	block sizes is exposed in KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES as a
8944	64-bit bitmap (each bit describing a block size). The default value is
8945	0, to disable the eager page splitting.
8946
8947	7.40 KVM_CAP_EXIT_HYPERCALL
8948	---------------------------
8949
8950	:Architectures: x86
8951	:Type: vm
8952
8953	This capability, if enabled, will cause KVM to exit to userspace
8954	with KVM_EXIT_HYPERCALL exit reason to process some hypercalls.
8955	Userspace may fail the hypercall by setting hypercall.ret to EINVAL
8956	or may request the hypercall to be retried the next time the guest run
8957	by setting hypercall.ret to EAGAIN.
8958
8959	Calling KVM_CHECK_EXTENSION for this capability will return a bitmask
8960	of hypercalls that can be configured to exit to userspace.
8961	Right now, the only such hypercall is KVM_HC_MAP_GPA_RANGE.
8962
8963	The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset
8964	of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace
8965	the hypercalls whose corresponding bit is in the argument, and return
8966	ENOSYS for the others.
8967
8968	7.41 KVM_CAP_ARM_SYSTEM_SUSPEND
8969	-------------------------------
8970
8971	:Architectures: arm64
8972	:Type: vm
8973
8974	When enabled, KVM will exit to userspace with KVM_EXIT_SYSTEM_EVENT of
8975	type KVM_SYSTEM_EVENT_SUSPEND to process the guest suspend request.
8976
8977	7.42 KVM_CAP_ARM_WRITABLE_IMP_ID_REGS
8978	-------------------------------------
8979
8980	:Architectures: arm64
8981	:Target: VM
8982	:Parameters: None
8983	:Returns: 0 on success, -EINVAL if vCPUs have been created before enabling this
8984	capability.
8985
8986	This capability changes the behavior of the registers that identify a PE
8987	implementation of the Arm architecture: MIDR_EL1, REVIDR_EL1, and AIDR_EL1.
8988	By default, these registers are visible to userspace but treated as invariant.
8989
8990	When this capability is enabled, KVM allows userspace to change the
8991	aforementioned registers before the first KVM_RUN. These registers are VM
8992	scoped, meaning that the same set of values are presented on all vCPUs in a
8993	given VM.
8994
8995	7.43 KVM_CAP_RISCV_MP_STATE_RESET
8996	---------------------------------
8997
8998	:Architectures: riscv
8999	:Type: VM
9000	:Parameters: None
9001	:Returns: 0 on success, -EINVAL if arg[0] is not zero
9002
9003	When this capability is enabled, KVM resets the VCPU when setting
9004	MP_STATE_INIT_RECEIVED through IOCTL. The original MP_STATE is preserved.
9005
9006	7.44 KVM_CAP_ARM_CACHEABLE_PFNMAP_SUPPORTED
9007	-------------------------------------------
9008
9009	:Architectures: arm64
9010	:Target: VM
9011	:Parameters: None
9012
9013	This capability indicate to the userspace whether a PFNMAP memory region
9014	can be safely mapped as cacheable. This relies on the presence of
9015	force write back (FWB) feature support on the hardware.
9016
9017	7.45 KVM_CAP_ARM_SEA_TO_USER
9018	----------------------------
9019
9020	:Architecture: arm64
9021	:Target: VM
9022	:Parameters: none
9023	:Returns: 0 on success, -EINVAL if unsupported.
9024
9025	When this capability is enabled, KVM may exit to userspace for SEAs taken to
9026	EL2 resulting from a guest access. See ``KVM_EXIT_ARM_SEA`` for more
9027	information.
9028
9029	7.46 KVM_CAP_S390_USER_OPEREXEC
9030	-------------------------------
9031
9032	:Architectures: s390
9033	:Parameters: none
9034
9035	When this capability is enabled KVM forwards all operation exceptions
9036	that it doesn't handle itself to user space. This also includes the
9037	0x0000 instructions managed by KVM_CAP_S390_USER_INSTR0. This is
9038	helpful if user space wants to emulate instructions which are not
9039	(yet) implemented in hardware.
9040
9041	This capability can be enabled dynamically even if VCPUs were already
9042	created and are running.
9043
9044	7.47 KVM_CAP_S390_HPAGE_2G
9045	--------------------------
9046
9047	:Architectures: s390
9048	:Parameters: none
9049	:Returns: 0 on success; -EINVAL if hpage_2g module parameter was not set,
9050	cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL
9051	flag set; -EBUSY if vCPUs were already created for the VM.
9052
9053	With this capability the KVM support for memory backing with 2g pages
9054	through hugetlbfs can be enabled for a VM. After the capability is
9055	enabled, cmma can't be enabled anymore and pfmfi and the storage key
9056	interpretation are disabled. If cmma has already been enabled or the
9057	hpage_2g module parameter is not set to 1, -EINVAL is returned.
9058
9059	8. Other capabilities.
9060	======================
9061
9062	This section lists capabilities that give information about other
9063	features of the KVM implementation.
9064
9065	8.1 KVM_CAP_PPC_HWRNG
9066	---------------------
9067
9068	:Architectures: ppc
9069
9070	This capability, if KVM_CHECK_EXTENSION indicates that it is
9071	available, means that the kernel has an implementation of the
9072	H_RANDOM hypercall backed by a hardware random-number generator.
9073	If present, the kernel H_RANDOM handler can be enabled for guest use
9074	with the KVM_CAP_PPC_ENABLE_HCALL capability.
9075
9076	8.3 KVM_CAP_PPC_MMU_RADIX
9077	-------------------------
9078
9079	:Architectures: ppc
9080
9081	This capability, if KVM_CHECK_EXTENSION indicates that it is
9082	available, means that the kernel can support guests using the
9083	radix MMU defined in Power ISA V3.00 (as implemented in the POWER9
9084	processor).
9085
9086	8.4 KVM_CAP_PPC_MMU_HASH_V3
9087	---------------------------
9088
9089	:Architectures: ppc
9090
9091	This capability, if KVM_CHECK_EXTENSION indicates that it is
9092	available, means that the kernel can support guests using the
9093	hashed page table MMU defined in Power ISA V3.00 (as implemented in
9094	the POWER9 processor), including in-memory segment tables.
9095
9096	8.5 KVM_CAP_MIPS_VZ
9097	-------------------
9098
9099	:Architectures: mips
9100
9101	This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that
9102	it is available, means that full hardware assisted virtualization capabilities
9103	of the hardware are available for use through KVM. An appropriate
9104	KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which
9105	utilises it.
9106
9107	If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is
9108	available, it means that the VM is using full hardware assisted virtualization
9109	capabilities of the hardware. This is useful to check after creating a VM with
9110	KVM_VM_MIPS_DEFAULT.
9111
9112	The value returned by KVM_CHECK_EXTENSION should be compared against known
9113	values (see below). All other values are reserved. This is to allow for the
9114	possibility of other hardware assisted virtualization implementations which
9115	may be incompatible with the MIPS VZ ASE.
9116
9117	== ==========================================================================
9118	0 The trap & emulate implementation is in use to run guest code in user
9119	mode. Guest virtual memory segments are rearranged to fit the guest in the
9120	user mode address space.
9121
9122	1 The MIPS VZ ASE is in use, providing full hardware assisted
9123	virtualization, including standard guest virtual memory segments.
9124	== ==========================================================================
9125
9126	8.7 KVM_CAP_MIPS_64BIT
9127	----------------------
9128
9129	:Architectures: mips
9130
9131	This capability indicates the supported architecture type of the guest, i.e. the
9132	supported register and address width.
9133
9134	The values returned when this capability is checked by KVM_CHECK_EXTENSION on a
9135	kvm VM handle correspond roughly to the CP0_Config.AT register field, and should
9136	be checked specifically against known values (see below). All other values are
9137	reserved.
9138
9139	== ========================================================================
9140	0 MIPS32 or microMIPS32.
9141	Both registers and addresses are 32-bits wide.
9142	It will only be possible to run 32-bit guest code.
9143
9144	1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments.
9145	Registers are 64-bits wide, but addresses are 32-bits wide.
9146	64-bit guest code may run but cannot access MIPS64 memory segments.
9147	It will also be possible to run 32-bit guest code.
9148
9149	2 MIPS64 or microMIPS64 with access to all address segments.
9150	Both registers and addresses are 64-bits wide.
9151	It will be possible to run 64-bit or 32-bit guest code.
9152	== ========================================================================
9153
9154	8.9 KVM_CAP_ARM_USER_IRQ
9155	------------------------
9156
9157	:Architectures: arm64
9158
9159	This capability, if KVM_CHECK_EXTENSION indicates that it is available, means
9160	that if userspace creates a VM without an in-kernel interrupt controller, it
9161	will be notified of changes to the output level of in-kernel emulated devices,
9162	which can generate virtual interrupts, presented to the VM.
9163	For such VMs, on every return to userspace, the kernel
9164	updates the vcpu's run->s.regs.device_irq_level field to represent the actual
9165	output level of the device.
9166
9167	Whenever kvm detects a change in the device output level, kvm guarantees at
9168	least one return to userspace before running the VM. This exit could either
9169	be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way,
9170	userspace can always sample the device output level and re-compute the state of
9171	the userspace interrupt controller. Userspace should always check the state
9172	of run->s.regs.device_irq_level on every kvm exit.
9173	The value in run->s.regs.device_irq_level can represent both level and edge
9174	triggered interrupt signals, depending on the device. Edge triggered interrupt
9175	signals will exit to userspace with the bit in run->s.regs.device_irq_level
9176	set exactly once per edge signal.
9177
9178	The field run->s.regs.device_irq_level is available independent of
9179	run->kvm_valid_regs or run->kvm_dirty_regs bits.
9180
9181	If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a
9182	number larger than 0 indicating the version of this capability is implemented
9183	and thereby which bits in run->s.regs.device_irq_level can signal values.
9184
9185	Currently the following bits are defined for the device_irq_level bitmap::
9186
9187	KVM_CAP_ARM_USER_IRQ >= 1:
9188
9189	KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer
9190	KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer
9191	KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal
9192
9193	Future versions of kvm may implement additional events. These will get
9194	indicated by returning a higher number from KVM_CHECK_EXTENSION and will be
9195	listed above.
9196
9197	8.10 KVM_CAP_PPC_SMT_POSSIBLE
9198	-----------------------------
9199
9200	:Architectures: ppc
9201
9202	Querying this capability returns a bitmap indicating the possible
9203	virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N
9204	(counting from the right) is set, then a virtual SMT mode of 2^N is
9205	available.
9206
9207	8.12 KVM_CAP_HYPERV_VP_INDEX
9208	----------------------------
9209
9210	:Architectures: x86
9211
9212	This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its
9213	value is used to denote the target vcpu for a SynIC interrupt. For
9214	compatibility, KVM initializes this msr to KVM's internal vcpu index. When this
9215	capability is absent, userspace can still query this msr's value.
9216
9217	8.13 KVM_CAP_S390_AIS_MIGRATION
9218	-------------------------------
9219
9220	:Architectures: s390
9221
9222	This capability indicates if the flic device will be able to get/set the
9223	AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows
9224	to discover this without having to create a flic device.
9225
9226	8.14 KVM_CAP_S390_PSW
9227	---------------------
9228
9229	:Architectures: s390
9230
9231	This capability indicates that the PSW is exposed via the kvm_run structure.
9232
9233	8.15 KVM_CAP_S390_GMAP
9234	----------------------
9235
9236	:Architectures: s390
9237
9238	This capability indicates that the user space memory used as guest mapping can
9239	be anywhere in the user memory address space, as long as the memory slots are
9240	aligned and sized to a segment (1MB) boundary.
9241
9242	8.16 KVM_CAP_S390_COW
9243	---------------------
9244
9245	:Architectures: s390
9246
9247	This capability indicates that the user space memory used as guest mapping can
9248	use copy-on-write semantics as well as dirty pages tracking via read-only page
9249	tables.
9250
9251	8.17 KVM_CAP_S390_BPB
9252	---------------------
9253
9254	:Architectures: s390
9255
9256	This capability indicates that kvm will implement the interfaces to handle
9257	reset, migration and nested KVM for branch prediction blocking. The stfle
9258	facility 82 should not be provided to the guest without this capability.
9259
9260	8.18 KVM_CAP_HYPERV_TLBFLUSH
9261	----------------------------
9262
9263	:Architectures: x86
9264
9265	This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
9266	hypercalls:
9267	HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
9268	HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
9269
9270	8.19 KVM_CAP_ARM_INJECT_SERROR_ESR
9271	----------------------------------
9272
9273	:Architectures: arm64
9274
9275	This capability indicates that userspace can specify (via the
9276	KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
9277	takes a virtual SError interrupt exception.
9278	If KVM advertises this capability, userspace can only specify the ISS field for
9279	the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
9280	CPU when the exception is taken. If this virtual SError is taken to EL1 using
9281	AArch64, this value will be reported in the ISS field of ESR_ELx.
9282
9283	See KVM_CAP_VCPU_EVENTS for more details.
9284
9285	8.20 KVM_CAP_HYPERV_SEND_IPI
9286	----------------------------
9287
9288	:Architectures: x86
9289
9290	This capability indicates that KVM supports paravirtualized Hyper-V IPI send
9291	hypercalls:
9292	HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx.
9293
9294	8.22 KVM_CAP_S390_VCPU_RESETS
9295	-----------------------------
9296
9297	:Architectures: s390
9298
9299	This capability indicates that the KVM_S390_NORMAL_RESET and
9300	KVM_S390_CLEAR_RESET ioctls are available.
9301
9302	8.23 KVM_CAP_S390_PROTECTED
9303	---------------------------
9304
9305	:Architectures: s390
9306
9307	This capability indicates that the Ultravisor has been initialized and
9308	KVM can therefore start protected VMs.
9309	This capability governs the KVM_S390_PV_COMMAND ioctl and the
9310	KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected
9311	guests when the state change is invalid.
9312
9313	8.24 KVM_CAP_STEAL_TIME
9314	-----------------------
9315
9316	:Architectures: arm64, x86
9317
9318	This capability indicates that KVM supports steal time accounting.
9319	When steal time accounting is supported it may be enabled with
9320	architecture-specific interfaces. This capability and the architecture-
9321	specific interfaces must be consistent, i.e. if one says the feature
9322	is supported, than the other should as well and vice versa. For arm64
9323	see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL".
9324	For x86 see Documentation/virt/kvm/x86/msr.rst "MSR_KVM_STEAL_TIME".
9325
9326	8.25 KVM_CAP_S390_DIAG318
9327	-------------------------
9328
9329	:Architectures: s390
9330
9331	This capability enables a guest to set information about its control program
9332	(i.e. guest kernel type and version). The information is helpful during
9333	system/firmware service events, providing additional data about the guest
9334	environments running on the machine.
9335
9336	The information is associated with the DIAGNOSE 0x318 instruction, which sets
9337	an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and
9338	a 7-byte Control Program Version Code (CPVC). The CPNC determines what
9339	environment the control program is running in (e.g. Linux, z/VM...), and the
9340	CPVC is used for information specific to OS (e.g. Linux version, Linux
9341	distribution...)
9342
9343	If this capability is available, then the CPNC and CPVC can be synchronized
9344	between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318).
9345
9346	8.26 KVM_CAP_X86_USER_SPACE_MSR
9347	-------------------------------
9348
9349	:Architectures: x86
9350
9351	This capability indicates that KVM supports deflection of MSR reads and
9352	writes to user space. It can be enabled on a VM level. If enabled, MSR
9353	accesses that would usually trigger a #GP by KVM into the guest will
9354	instead get bounced to user space through the KVM_EXIT_X86_RDMSR and
9355	KVM_EXIT_X86_WRMSR exit notifications.
9356
9357	8.27 KVM_CAP_X86_MSR_FILTER
9358	---------------------------
9359
9360	:Architectures: x86
9361
9362	This capability indicates that KVM supports that accesses to user defined MSRs
9363	may be rejected. With this capability exposed, KVM exports new VM ioctl
9364	KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR
9365	ranges that KVM should deny access to.
9366
9367	In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to
9368	trap and emulate MSRs that are outside of the scope of KVM as well as
9369	limit the attack surface on KVM's MSR emulation code.
9370
9371	8.30 KVM_CAP_XEN_HVM
9372	--------------------
9373
9374	:Architectures: x86
9375
9376	This capability indicates the features that Xen supports for hosting Xen
9377	PVHVM guests. Valid flags are::
9378
9379	#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0)
9380	#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
9381	#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
9382	#define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 3)
9383	#define KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL (1 << 4)
9384	#define KVM_XEN_HVM_CONFIG_EVTCHN_SEND (1 << 5)
9385	#define KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG (1 << 6)
9386	#define KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE (1 << 7)
9387
9388	The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
9389	ioctl is available, for the guest to set its hypercall page.
9390
9391	If KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL is also set, the same flag may also be
9392	provided in the flags to KVM_XEN_HVM_CONFIG, without providing hypercall page
9393	contents, to request that KVM generate hypercall page content automatically
9394	and also enable interception of guest hypercalls with KVM_EXIT_XEN.
9395
9396	The KVM_XEN_HVM_CONFIG_SHARED_INFO flag indicates the availability of the
9397	KVM_XEN_HVM_SET_ATTR, KVM_XEN_HVM_GET_ATTR, KVM_XEN_VCPU_SET_ATTR and
9398	KVM_XEN_VCPU_GET_ATTR ioctls, as well as the delivery of exception vectors
9399	for event channel upcalls when the evtchn_upcall_pending field of a vcpu's
9400	vcpu_info is set.
9401
9402	The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related
9403	features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are
9404	supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls.
9405
9406	The KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL flag indicates that IRQ routing entries
9407	of the type KVM_IRQ_ROUTING_XEN_EVTCHN are supported, with the priority
9408	field set to indicate 2 level event channel delivery.
9409
9410	The KVM_XEN_HVM_CONFIG_EVTCHN_SEND flag indicates that KVM supports
9411	injecting event channel events directly into the guest with the
9412	KVM_XEN_HVM_EVTCHN_SEND ioctl. It also indicates support for the
9413	KVM_XEN_ATTR_TYPE_EVTCHN/XEN_VERSION HVM attributes and the
9414	KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID/TIMER/UPCALL_VECTOR vCPU attributes.
9415	related to event channel delivery, timers, and the XENVER_version
9416	interception.
9417
9418	The KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG flag indicates that KVM supports
9419	the KVM_XEN_ATTR_TYPE_RUNSTATE_UPDATE_FLAG attribute in the KVM_XEN_SET_ATTR
9420	and KVM_XEN_GET_ATTR ioctls. This controls whether KVM will set the
9421	XEN_RUNSTATE_UPDATE flag in guest memory mapped vcpu_runstate_info during
9422	updates of the runstate information. Note that versions of KVM which support
9423	the RUNSTATE feature above, but not the RUNSTATE_UPDATE_FLAG feature, will
9424	always set the XEN_RUNSTATE_UPDATE flag when updating the guest structure,
9425	which is perhaps counterintuitive. When this flag is advertised, KVM will
9426	behave more correctly, not using the XEN_RUNSTATE_UPDATE flag until/unless
9427	specifically enabled (by the guest making the hypercall, causing the VMM
9428	to enable the KVM_XEN_ATTR_TYPE_RUNSTATE_UPDATE_FLAG attribute).
9429
9430	The KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE flag indicates that KVM supports
9431	clearing the PVCLOCK_TSC_STABLE_BIT flag in Xen pvclock sources. This will be
9432	done when the KVM_CAP_XEN_HVM ioctl sets the
9433	KVM_XEN_HVM_CONFIG_PVCLOCK_TSC_UNSTABLE flag.
9434
9435	8.31 KVM_CAP_SPAPR_MULTITCE
9436	---------------------------
9437
9438	:Architectures: ppc
9439	:Type: vm
9440
9441	This capability means the kernel is capable of handling hypercalls
9442	H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user
9443	space. This significantly accelerates DMA operations for PPC KVM guests.
9444	User space should expect that its handlers for these hypercalls
9445	are not going to be called if user space previously registered LIOBN
9446	in KVM (via KVM_CREATE_SPAPR_TCE or similar calls).
9447
9448	In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest,
9449	user space might have to advertise it for the guest. For example,
9450	IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is
9451	present in the "ibm,hypertas-functions" device-tree property.
9452
9453	The hypercalls mentioned above may or may not be processed successfully
9454	in the kernel based fast path. If they can not be handled by the kernel,
9455	they will get passed on to user space. So user space still has to have
9456	an implementation for these despite the in kernel acceleration.
9457
9458	This capability is always enabled.
9459
9460	8.32 KVM_CAP_PTP_KVM
9461	--------------------
9462
9463	:Architectures: arm64
9464
9465	This capability indicates that the KVM virtual PTP service is
9466	supported in the host. A VMM can check whether the service is
9467	available to the guest on migration.
9468
9469	8.37 KVM_CAP_S390_PROTECTED_DUMP
9470	--------------------------------
9471
9472	:Architectures: s390
9473	:Type: vm
9474
9475	This capability indicates that KVM and the Ultravisor support dumping
9476	PV guests. The `KVM_PV_DUMP` command is available for the
9477	`KVM_S390_PV_COMMAND` ioctl and the `KVM_PV_INFO` command provides
9478	dump related UV data. Also the vcpu ioctl `KVM_S390_PV_CPU_COMMAND` is
9479	available and supports the `KVM_PV_DUMP_CPU` subcommand.
9480
9481	8.39 KVM_CAP_S390_CPU_TOPOLOGY
9482	------------------------------
9483
9484	:Architectures: s390
9485	:Type: vm
9486
9487	This capability indicates that KVM will provide the S390 CPU Topology
9488	facility which consist of the interpretation of the PTF instruction for
9489	the function code 2 along with interception and forwarding of both the
9490	PTF instruction with function codes 0 or 1 and the STSI(15,1,x)
9491	instruction to the userland hypervisor.
9492
9493	The stfle facility 11, CPU Topology facility, should not be indicated
9494	to the guest without this capability.
9495
9496	When this capability is present, KVM provides a new attribute group
9497	on vm fd, KVM_S390_VM_CPU_TOPOLOGY.
9498	This new attribute allows to get, set or clear the Modified Change
9499	Topology Report (MTCR) bit of the SCA through the kvm_device_attr
9500	structure.
9501
9502	When getting the Modified Change Topology Report value, the attr->addr
9503	must point to a byte where the value will be stored or retrieved from.
9504
9505	8.41 KVM_CAP_VM_TYPES
9506	---------------------
9507
9508	:Architectures: x86
9509	:Type: system ioctl
9510
9511	This capability returns a bitmap of support VM types. The 1-setting of bit @n
9512	means the VM type with value @n is supported. Possible values of @n are::
9513
9514	#define KVM_X86_DEFAULT_VM 0
9515	#define KVM_X86_SW_PROTECTED_VM 1
9516	#define KVM_X86_SEV_VM 2
9517	#define KVM_X86_SEV_ES_VM 3
9518	#define KVM_X86_SNP_VM 4
9519	#define KVM_X86_TDX_VM 5
9520
9521	Note, KVM_X86_SW_PROTECTED_VM is currently only for development and testing.
9522	Do not use KVM_X86_SW_PROTECTED_VM for "real" VMs, and especially not in
9523	production. The behavior and effective ABI for software-protected VMs is
9524	unstable.
9525
9526	8.42 KVM_CAP_PPC_RPT_INVALIDATE
9527	-------------------------------
9528
9529	:Architectures: ppc
9530
9531	This capability indicates that the kernel is capable of handling
9532	H_RPT_INVALIDATE hcall.
9533
9534	In order to enable the use of H_RPT_INVALIDATE in the guest,
9535	user space might have to advertise it for the guest. For example,
9536	IBM pSeries (sPAPR) guest starts using it if "hcall-rpt-invalidate" is
9537	present in the "ibm,hypertas-functions" device-tree property.
9538
9539	This capability is enabled for hypervisors on platforms like POWER9
9540	that support radix MMU.
9541
9542	8.43 KVM_CAP_PPC_AIL_MODE_3
9543	---------------------------
9544
9545	:Architectures: ppc
9546
9547	This capability indicates that the kernel supports the mode 3 setting for the
9548	"Address Translation Mode on Interrupt" aka "Alternate Interrupt Location"
9549	resource that is controlled with the H_SET_MODE hypercall.
9550
9551	This capability allows a guest kernel to use a better-performance mode for
9552	handling interrupts and system calls.
9553
9554	8.44 KVM_CAP_MEMORY_FAULT_INFO
9555	------------------------------
9556
9557	:Architectures: x86
9558
9559	The presence of this capability indicates that KVM_RUN will fill
9560	kvm_run.memory_fault if KVM cannot resolve a guest page fault VM-Exit, e.g. if
9561	there is a valid memslot but no backing VMA for the corresponding host virtual
9562	address.
9563
9564	The information in kvm_run.memory_fault is valid if and only if KVM_RUN returns
9565	an error with errno=EFAULT or errno=EHWPOISON and kvm_run.exit_reason is set
9566	to KVM_EXIT_MEMORY_FAULT.
9567
9568	Note: Userspaces which attempt to resolve memory faults so that they can retry
9569	KVM_RUN are encouraged to guard against repeatedly receiving the same
9570	error/annotated fault.
9571
9572	See KVM_EXIT_MEMORY_FAULT for more information.
9573
9574	8.45 KVM_CAP_X86_GUEST_MODE
9575	---------------------------
9576
9577	:Architectures: x86
9578
9579	The presence of this capability indicates that KVM_RUN will update the
9580	KVM_RUN_X86_GUEST_MODE bit in kvm_run.flags to indicate whether the
9581	vCPU was executing nested guest code when it exited.
9582
9583	8.46 KVM_CAP_S390_KEYOP
9584	-----------------------
9585
9586	:Architectures: s390
9587
9588	The presence of this capability indicates that the KVM_S390_KEYOP ioctl is
9589	available.
9590
9591	KVM exits with the register state of either the L1 or L2 guest
9592	depending on which executed at the time of an exit. Userspace must
9593	take care to differentiate between these cases.
9594
9595	8.47 KVM_CAP_S390_VSIE_ESAMODE
9596	------------------------------
9597
9598	:Architectures: s390
9599
9600	The presence of this capability indicates that the nested KVM guest can
9601	start in ESA mode.
9602
9603	9. Known KVM API problems
9604	=========================
9605
9606	In some cases, KVM's API has some inconsistencies or common pitfalls
9607	that userspace need to be aware of. This section details some of
9608	these issues.
9609
9610	Most of them are architecture specific, so the section is split by
9611	architecture.
9612
9613	9.1. x86
9614	--------
9615
9616	``KVM_GET_SUPPORTED_CPUID`` issues
9617	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
9618
9619	In general, ``KVM_GET_SUPPORTED_CPUID`` is designed so that it is possible
9620	to take its result and pass it directly to ``KVM_SET_CPUID2``. This section
9621	documents some cases in which that requires some care.
9622
9623	Local APIC features
9624	~~~~~~~~~~~~~~~~~~~
9625
9626	CPU[EAX=1]:ECX[21] (X2APIC) is reported by ``KVM_GET_SUPPORTED_CPUID``,
9627	but it can only be enabled if ``KVM_CREATE_IRQCHIP`` or
9628	``KVM_ENABLE_CAP(KVM_CAP_IRQCHIP_SPLIT)`` are used to enable in-kernel emulation of
9629	the local APIC.
9630
9631	The same is true for the ``KVM_FEATURE_PV_UNHALT`` paravirtualized feature.
9632
9633	On older versions of Linux, CPU[EAX=1]:ECX[24] (TSC_DEADLINE) is not reported by
9634	``KVM_GET_SUPPORTED_CPUID``, but it can be enabled if ``KVM_CAP_TSC_DEADLINE_TIMER``
9635	is present and the kernel has enabled in-kernel emulation of the local APIC.
9636	On newer versions, ``KVM_GET_SUPPORTED_CPUID`` does report the bit as available.
9637
9638	CPU topology
9639	~~~~~~~~~~~~
9640
9641	Several CPUID values include topology information for the host CPU:
9642	0x0b and 0x1f for Intel systems, 0x8000001e for AMD systems. Different
9643	versions of KVM return different values for this information and userspace
9644	should not rely on it. Currently they return all zeroes.
9645
9646	If userspace wishes to set up a guest topology, it should be careful that
9647	the values of these three leaves differ for each CPU. In particular,
9648	the APIC ID is found in EDX for all subleaves of 0x0b and 0x1f, and in EAX
9649	for 0x8000001e; the latter also encodes the core id and node id in bits
9650	7:0 of EBX and ECX respectively.
9651
9652	Obsolete ioctls and capabilities
9653	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
9654
9655	KVM_CAP_DISABLE_QUIRKS does not let userspace know which quirks are actually
9656	available. Use ``KVM_CHECK_EXTENSION(KVM_CAP_DISABLE_QUIRKS2)`` instead if
9657	available.
9658
9659	Ordering of KVM_GET_/KVM_SET_ ioctls
9660	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
9661
9662	TBD