Merge tag 'hyperv-fixes-signed-20240303' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Merge commit. Changes below are compared with the first parent: 90d35da6.
Changes
11 files changed · +521 −126
| File | Status | Add | Del | Content |
|---|---|---|---|---|
| Documentation/virt/hyperv/index.rst | modified | +1 | −0 | View file |
| Documentation/virt/hyperv/vpci.rst | added | +316 | −0 | View file |
| arch/x86/hyperv/hv_vtl.c | modified | +7 | −0 | View file |
| arch/x86/hyperv/ivm.c | modified | +60 | −5 | View file |
| arch/x86/include/asm/set_memory.h | modified | +1 | −0 | View file |
| arch/x86/mm/pat/set_memory.c | modified | +14 | −10 | View file |
| drivers/hv/channel.c | modified | +70 | −106 | View file |
| drivers/hv/hv_util.c | modified | +30 | −1 | View file |
| drivers/hv/vmbus_drv.c | modified | +1 | −1 | View file |
| drivers/video/fbdev/hyperv_fb.c | modified | +0 | −2 | View file |
| include/linux/hyperv.h | modified | +21 | −1 | View file |
Only the first 600 diff lines are shown. Download the complete patch.
Documentation/virt/hyperv/index.rst
View filediff --git a/Documentation/virt/hyperv/index.rst b/Documentation/virt/hyperv/index.rst
index 4a7a1b7..de447e1 100644
--- a/Documentation/virt/hyperv/index.rst
+++ b/Documentation/virt/hyperv/index.rst
@@ -10,3 +10,4 @@ Hyper-V Enlightenments
overview
vmbus
clocks
+ vpci
Documentation/virt/hyperv/vpci.rst
View filediff --git a/Documentation/virt/hyperv/vpci.rst b/Documentation/virt/hyperv/vpci.rst
new file mode 100644
index 0000000..b65b212
--- /dev/null
+++ b/Documentation/virt/hyperv/vpci.rst
@@ -0,0 +1,316 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+PCI pass-thru devices
+=========================
+In a Hyper-V guest VM, PCI pass-thru devices (also called
+virtual PCI devices, or vPCI devices) are physical PCI devices
+that are mapped directly into the VM's physical address space.
+Guest device drivers can interact directly with the hardware
+without intermediation by the host hypervisor. This approach
+provides higher bandwidth access to the device with lower
+latency, compared with devices that are virtualized by the
+hypervisor. The device should appear to the guest just as it
+would when running on bare metal, so no changes are required
+to the Linux device drivers for the device.
+
+Hyper-V terminology for vPCI devices is "Discrete Device
+Assignment" (DDA). Public documentation for Hyper-V DDA is
+available here: `DDA`_
+
+.. _DDA: https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/plan/plan-for-deploying-devices-using-discrete-device-assignment
+
+DDA is typically used for storage controllers, such as NVMe,
+and for GPUs. A similar mechanism for NICs is called SR-IOV
+and produces the same benefits by allowing a guest device
+driver to interact directly with the hardware. See Hyper-V
+public documentation here: `SR-IOV`_
+
+.. _SR-IOV: https://learn.microsoft.com/en-us/windows-hardware/drivers/network/overview-of-single-root-i-o-virtualization--sr-iov-
+
+This discussion of vPCI devices includes DDA and SR-IOV
+devices.
+
+Device Presentation
+-------------------
+Hyper-V provides full PCI functionality for a vPCI device when
+it is operating, so the Linux device driver for the device can
+be used unchanged, provided it uses the correct Linux kernel
+APIs for accessing PCI config space and for other integration
+with Linux. But the initial detection of the PCI device and
+its integration with the Linux PCI subsystem must use Hyper-V
+specific mechanisms. Consequently, vPCI devices on Hyper-V
+have a dual identity. They are initially presented to Linux
+guests as VMBus devices via the standard VMBus "offer"
+mechanism, so they have a VMBus identity and appear under
+/sys/bus/vmbus/devices. The VMBus vPCI driver in Linux at
+drivers/pci/controller/pci-hyperv.c handles a newly introduced
+vPCI device by fabricating a PCI bus topology and creating all
+the normal PCI device data structures in Linux that would
+exist if the PCI device were discovered via ACPI on a bare-
+metal system. Once those data structures are set up, the
+device also has a normal PCI identity in Linux, and the normal
+Linux device driver for the vPCI device can function as if it
+were running in Linux on bare-metal. Because vPCI devices are
+presented dynamically through the VMBus offer mechanism, they
+do not appear in the Linux guest's ACPI tables. vPCI devices
+may be added to a VM or removed from a VM at any time during
+the life of the VM, and not just during initial boot.
+
+With this approach, the vPCI device is a VMBus device and a
+PCI device at the same time. In response to the VMBus offer
+message, the hv_pci_probe() function runs and establishes a
+VMBus connection to the vPCI VSP on the Hyper-V host. That
+connection has a single VMBus channel. The channel is used to
+exchange messages with the vPCI VSP for the purpose of setting
+up and configuring the vPCI device in Linux. Once the device
+is fully configured in Linux as a PCI device, the VMBus
+channel is used only if Linux changes the vCPU to be interrupted
+in the guest, or if the vPCI device is removed from
+the VM while the VM is running. The ongoing operation of the
+device happens directly between the Linux device driver for
+the device and the hardware, with VMBus and the VMBus channel
+playing no role.
+
+PCI Device Setup
+----------------
+PCI device setup follows a sequence that Hyper-V originally
+created for Windows guests, and that can be ill-suited for
+Linux guests due to differences in the overall structure of
+the Linux PCI subsystem compared with Windows. Nonetheless,
+with a bit of hackery in the Hyper-V virtual PCI driver for
+Linux, the virtual PCI device is setup in Linux so that
+generic Linux PCI subsystem code and the Linux driver for the
+device "just work".
+
+Each vPCI device is set up in Linux to be in its own PCI
+domain with a host bridge. The PCI domainID is derived from
+bytes 4 and 5 of the instance GUID assigned to the VMBus vPCI
+device. The Hyper-V host does not guarantee that these bytes
+are unique, so hv_pci_probe() has an algorithm to resolve
+collisions. The collision resolution is intended to be stable
+across reboots of the same VM so that the PCI domainIDs don't
+change, as the domainID appears in the user space
+configuration of some devices.
+
+hv_pci_probe() allocates a guest MMIO range to be used as PCI
+config space for the device. This MMIO range is communicated
+to the Hyper-V host over the VMBus channel as part of telling
+the host that the device is ready to enter d0. See
+hv_pci_enter_d0(). When the guest subsequently accesses this
+MMIO range, the Hyper-V host intercepts the accesses and maps
+them to the physical device PCI config space.
+
+hv_pci_probe() also gets BAR information for the device from
+the Hyper-V host, and uses this information to allocate MMIO
+space for the BARs. That MMIO space is then setup to be
+associated with the host bridge so that it works when generic
+PCI subsystem code in Linux processes the BARs.
+
+Finally, hv_pci_probe() creates the root PCI bus. At this
+point the Hyper-V virtual PCI driver hackery is done, and the
+normal Linux PCI machinery for scanning the root bus works to
+detect the device, to perform driver matching, and to
+initialize the driver and device.
+
+PCI Device Removal
+------------------
+A Hyper-V host may initiate removal of a vPCI device from a
+guest VM at any time during the life of the VM. The removal
+is instigated by an admin action taken on the Hyper-V host and
+is not under the control of the guest OS.
+
+A guest VM is notified of the removal by an unsolicited
+"Eject" message sent from the host to the guest over the VMBus
+channel associated with the vPCI device. Upon receipt of such
+a message, the Hyper-V virtual PCI driver in Linux
+asynchronously invokes Linux kernel PCI subsystem calls to
+shutdown and remove the device. When those calls are
+complete, an "Ejection Complete" message is sent back to
+Hyper-V over the VMBus channel indicating that the device has
+been removed. At this point, Hyper-V sends a VMBus rescind
+message to the Linux guest, which the VMBus driver in Linux
+processes by removing the VMBus identity for the device. Once
+that processing is complete, all vestiges of the device having
+been present are gone from the Linux kernel. The rescind
+message also indicates to the guest that Hyper-V has stopped
+providing support for the vPCI device in the guest. If the
+guest were to attempt to access that device's MMIO space, it
+would be an invalid reference. Hypercalls affecting the device
+return errors, and any further messages sent in the VMBus
+channel are ignored.
+
+After sending the Eject message, Hyper-V allows the guest VM
+60 seconds to cleanly shutdown the device and respond with
+Ejection Complete before sending the VMBus rescind
+message. If for any reason the Eject steps don't complete
+within the allowed 60 seconds, the Hyper-V host forcibly
+performs the rescind steps, which will likely result in
+cascading errors in the guest because the device is now no
+longer present from the guest standpoint and accessing the
+device MMIO space will fail.
+
+Because ejection is asynchronous and can happen at any point
+during the guest VM lifecycle, proper synchronization in the
+Hyper-V virtual PCI driver is very tricky. Ejection has been
+observed even before a newly offered vPCI device has been
+fully setup. The Hyper-V virtual PCI driver has been updated
+several times over the years to fix race conditions when
+ejections happen at inopportune times. Care must be taken when
+modifying this code to prevent re-introducing such problems.
+See comments in the code.
+
+Interrupt Assignment
+--------------------
+The Hyper-V virtual PCI driver supports vPCI devices using
+MSI, multi-MSI, or MSI-X. Assigning the guest vCPU that will
+receive the interrupt for a particular MSI or MSI-X message is
+complex because of the way the Linux setup of IRQs maps onto
+the Hyper-V interfaces. For the single-MSI and MSI-X cases,
+Linux calls hv_compse_msi_msg() twice, with the first call
+containing a dummy vCPU and the second call containing the
+real vCPU. Furthermore, hv_irq_unmask() is finally called
+(on x86) or the GICD registers are set (on arm64) to specify
+the real vCPU again. Each of these three calls interact
+with Hyper-V, which must decide which physical CPU should
+receive the interrupt before it is forwarded to the guest VM.
+Unfortunately, the Hyper-V decision-making process is a bit
+limited, and can result in concentrating the physical
+interrupts on a single CPU, causing a performance bottleneck.
+See details about how this is resolved in the extensive
+comment above the function hv_compose_msi_req_get_cpu().
+
+The Hyper-V virtual PCI driver implements the
+irq_chip.irq_compose_msi_msg function as hv_compose_msi_msg().
+Unfortunately, on Hyper-V the implementation requires sending
+a VMBus message to the Hyper-V host and awaiting an interrupt
+indicating receipt of a reply message. Since
+irq_chip.irq_compose_msi_msg can be called with IRQ locks
+held, it doesn't work to do the normal sleep until awakened by
+the interrupt. Instead hv_compose_msi_msg() must send the
+VMBus message, and then poll for the completion message. As
+further complexity, the vPCI device could be ejected/rescinded
+while the polling is in progress, so this scenario must be
+detected as well. See comments in the code regarding this
+very tricky area.
+
+Most of the code in the Hyper-V virtual PCI driver (pci-
+hyperv.c) applies to Hyper-V and Linux guests running on x86
+and on arm64 architectures. But there are differences in how
+interrupt assignments are managed. On x86, the Hyper-V
+virtual PCI driver in the guest must make a hypercall to tell
+Hyper-V which guest vCPU should be interrupted by each
+MSI/MSI-X interrupt, and the x86 interrupt vector number that
+the x86_vector IRQ domain has picked for the interrupt. This
+hypercall is made by hv_arch_irq_unmask(). On arm64, the
+Hyper-V virtual PCI driver manages the allocation of an SPI
+for each MSI/MSI-X interrupt. The Hyper-V virtual PCI driver
+stores the allocated SPI in the architectural GICD registers,
+which Hyper-V emulates, so no hypercall is necessary as with
+x86. Hyper-V does not support using LPIs for vPCI devices in
+arm64 guest VMs because it does not emulate a GICv3 ITS.
+
+The Hyper-V virtual PCI driver in Linux supports vPCI devices
+whose drivers create managed or unmanaged Linux IRQs. If the
+smp_affinity for an unmanaged IRQ is updated via the /proc/irq
+interface, the Hyper-V virtual PCI driver is called to tell
+the Hyper-V host to change the interrupt targeting and
+everything works properly. However, on x86 if the x86_vector
+IRQ domain needs to reassign an interrupt vector due to
+running out of vectors on a CPU, there's no path to inform the
+Hyper-V host of the change, and things break. Fortunately,
+guest VMs operate in a constrained device environment where
+using all the vectors on a CPU doesn't happen. Since such a
+problem is only a theoretical concern rather than a practical
+concern, it has been left unaddressed.
+
+DMA
+---
+By default, Hyper-V pins all guest VM memory in the host
+when the VM is created, and programs the physical IOMMU to
+allow the VM to have DMA access to all its memory. Hence
+it is safe to assign PCI devices to the VM, and allow the
+guest operating system to program the DMA transfers. The
+physical IOMMU prevents a malicious guest from initiating
+DMA to memory belonging to the host or to other VMs on the
+host. From the Linux guest standpoint, such DMA transfers
+are in "direct" mode since Hyper-V does not provide a virtual
+IOMMU in the guest.
+
+Hyper-V assumes that physical PCI devices always perform
+cache-coherent DMA. When running on x86, this behavior is
+required by the architecture. When running on arm64, the
+architecture allows for both cache-coherent and
+non-cache-coherent devices, with the behavior of each device
+specified in the ACPI DSDT. But when a PCI device is assigned
+to a guest VM, that device does not appear in the DSDT, so the
+Hyper-V VMBus driver propagates cache-coherency information
+from the VMBus node in the ACPI DSDT to all VMBus devices,
+including vPCI devices (since they have a dual identity as a VMBus
+device and as a PCI device). See vmbus_dma_configure().
+Current Hyper-V versions always indicate that the VMBus is
+cache coherent, so vPCI devices on arm64 always get marked as
+cache coherent and the CPU does not perform any sync
+operations as part of dma_map/unmap_*() calls.
+
+vPCI protocol versions
+----------------------
+As previously described, during vPCI device setup and teardown
+messages are passed over a VMBus channel between the Hyper-V
+host and the Hyper-v vPCI driver in the Linux guest. Some
+messages have been revised in newer versions of Hyper-V, so
+the guest and host must agree on the vPCI protocol version to
+be used. The version is negotiated when communication over
+the VMBus channel is first established. See
+hv_pci_protocol_negotiation(). Newer versions of the protocol
+extend support to VMs with more than 64 vCPUs, and provide
+additional information about the vPCI device, such as the
+guest virtual NUMA node to which it is most closely affined in
+the underlying hardware.
+
+Guest NUMA node affinity
+------------------------
+When the vPCI protocol version provides it, the guest NUMA
+node affinity of the vPCI device is stored as part of the Linux
+device information for subsequent use by the Linux driver. See
+hv_pci_assign_numa_node(). If the negotiated protocol version
+does not support the host providing NUMA affinity information,
+the Linux guest defaults the device NUMA node to 0. But even
+when the negotiated protocol version includes NUMA affinity
+information, the ability of the host to provide such
+information depends on certain host configuration options. If
+the guest receives NUMA node value "0", it could mean NUMA
+node 0, or it could mean "no information is available".
+Unfortunately it is not possible to distinguish the two cases
+from the guest side.
+
+PCI config space access in a CoCo VM
+------------------------------------
+Linux PCI device drivers access PCI config space using a
+standard set of functions provided by the Linux PCI subsystem.
+In Hyper-V guests these standard functions map to functions
+hv_pcifront_read_config() and hv_pcifront_write_config()
+in the Hyper-V virtual PCI driver. In normal VMs,
+these hv_pcifront_*() functions directly access the PCI config
+space, and the accesses trap to Hyper-V to be handled.
+But in CoCo VMs, memory encryption prevents Hyper-V
+from reading the guest instruction stream to emulate the
+access, so the hv_pcifront_*() functions must invoke
+hypercalls with explicit arguments describing the access to be
+made.
+
+Config Block back-channel
+-------------------------
+The Hyper-V host and Hyper-V virtual PCI driver in Linux
+together implement a non-standard back-channel communication
+path between the host and guest. The back-channel path uses
+messages sent over the VMBus channel associated with the vPCI
+device. The functions hyperv_read_cfg_blk() and
+hyperv_write_cfg_blk() are the primary interfaces provided to
+other parts of the Linux kernel. As of this writing, these
+interfaces are used only by the Mellanox mlx5 driver to pass
+diagnostic data to a Hyper-V host running in the Azure public
+cloud. The functions hyperv_read_cfg_blk() and
+hyperv_write_cfg_blk() are implemented in a separate module
+(pci-hyperv-intf.c, under CONFIG_PCI_HYPERV_INTERFACE) that
+effectively stubs them out when running in non-Hyper-V
+environments.
arch/x86/hyperv/hv_vtl.c
View filediff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index 96e6c51..cf1b78c 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -16,6 +16,11 @@
extern struct boot_params boot_params;
static struct real_mode_header hv_vtl_real_mode_header;
+static bool __init hv_vtl_msi_ext_dest_id(void)
+{
+ return true;
+}
+
void __init hv_vtl_init_platform(void)
{
pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
@@ -38,6 +43,8 @@ void __init hv_vtl_init_platform(void)
x86_platform.legacy.warm_reset = 0;
x86_platform.legacy.reserve_bios_regions = 0;
x86_platform.legacy.devices.pnpbios = 0;
+
+ x86_init.hyper.msi_ext_dest_id = hv_vtl_msi_ext_dest_id;
}
static inline u64 hv_vtl_system_desc_base(struct ldttss_desc *desc)
arch/x86/hyperv/ivm.c
View filediff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 7dcbf15..768d73d 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -15,6 +15,7 @@
#include <asm/io.h>
#include <asm/coco.h>
#include <asm/mem_encrypt.h>
+#include <asm/set_memory.h>
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#include <asm/mtrr.h>
@@ -503,6 +504,31 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
}
/*
+ * When transitioning memory between encrypted and decrypted, the caller
+ * of set_memory_encrypted() or set_memory_decrypted() is responsible for
+ * ensuring that the memory isn't in use and isn't referenced while the
+ * transition is in progress. The transition has multiple steps, and the
+ * memory is in an inconsistent state until all steps are complete. A
+ * reference while the state is inconsistent could result in an exception
+ * that can't be cleanly fixed up.
+ *
+ * But the Linux kernel load_unaligned_zeropad() mechanism could cause a
+ * stray reference that can't be prevented by the caller, so Linux has
+ * specific code to handle this case. But when the #VC and #VE exceptions
+ * routed to a paravisor, the specific code doesn't work. To avoid this
+ * problem, mark the pages as "not present" while the transition is in
+ * progress. If load_unaligned_zeropad() causes a stray reference, a normal
+ * page fault is generated instead of #VC or #VE, and the page-fault-based
+ * handlers for load_unaligned_zeropad() resolve the reference. When the
+ * transition is complete, hv_vtom_set_host_visibility() marks the pages
+ * as "present" again.
+ */
+static bool hv_vtom_clear_present(unsigned long kbuffer, int pagecount, bool enc)
+{
+ return !set_memory_np(kbuffer, pagecount);
+}
+
+/*
* hv_vtom_set_host_visibility - Set specified memory visible to host.
*
* In Isolation VM, all guest memory is encrypted from host and guest
@@ -515,16 +541,28 @@ static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bo
enum hv_mem_host_visibility visibility = enc ?
VMBUS_PAGE_NOT_VISIBLE : VMBUS_PAGE_VISIBLE_READ_WRITE;
u64 *pfn_array;
+ phys_addr_t paddr;
+ void *vaddr;
int ret = 0;
bool result = true;
int i, pfn;
pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
- if (!pfn_array)
- return false;
+ if (!pfn_array) {
+ result = false;
+ goto err_set_memory_p;
+ }
for (i = 0, pfn = 0; i < pagecount; i++) {
- pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE);
+ /*
+ * Use slow_virt_to_phys() because the PRESENT bit has been
+ * temporarily cleared in the PTEs. slow_virt_to_phys() works
+ * without the PRESENT bit while virt_to_hvpfn() or similar
+ * does not.
+ */
+ vaddr = (void *)kbuffer + (i * HV_HYP_PAGE_SIZE);
+ paddr = slow_virt_to_phys(vaddr);
+ pfn_array[pfn] = paddr >> HV_HYP_PAGE_SHIFT;
pfn++;
if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
@@ -538,14 +576,30 @@ static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bo
}
}
- err_free_pfn_array:
+err_free_pfn_array:
kfree(pfn_array);
+
+err_set_memory_p:
+ /*
+ * Set the PTE PRESENT bits again to revert what hv_vtom_clear_present()
+ * did. Do this even if there is an error earlier in this function in
+ * order to avoid leaving the memory range in a "broken" state. Setting
+ * the PRESENT bits shouldn't fail, but return an error if it does.
+ */
+ if (set_memory_p(kbuffer, pagecount))
+ result = false;
+
return result;
}
static bool hv_vtom_tlb_flush_required(bool private)
{
- return true;
+ /*
+ * Since hv_vtom_clear_present() marks the PTEs as "not present"
+ * and flushes the TLB, they can't be in the TLB. That makes the
+ * flush controlled by this function redundant, so return "false".
+ */
+ return false;
}
static bool hv_vtom_cache_flush_required(void)
@@ -608,6 +662,7 @@ void __init hv_vtom_init(void)
x86_platform.hyper.is_private_mmio = hv_is_private_mmio;
x86_platform.guest.enc_cache_flush_required = hv_vtom_cache_flush_required;
x86_platform.guest.enc_tlb_flush_required = hv_vtom_tlb_flush_required;
+ x86_platform.guest.enc_status_change_prepare = hv_vtom_clear_present;
x86_platform.guest.enc_status_change_finish = hv_vtom_set_host_visibility;
/* Set WB as the default cache mode. */
arch/x86/include/asm/set_memory.h
View filediff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index a5e8964..9aee318 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -47,6 +47,7 @@ int set_memory_uc(unsigned long addr, int numpages);
int set_memory_wc(unsigned long addr, int numpages);
int set_memory_wb(unsigned long addr, int numpages);
int set_memory_np(unsigned long addr, int numpages);
+int set_memory_p(unsigned long addr, int numpages);
int set_memory_4k(unsigned long addr, int numpages);
int set_memory_encrypted(unsigned long addr, int numpages);
int set_memory_decrypted(unsigned long addr, int numpages);
arch/x86/mm/pat/set_memory.c
View filediff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index e9b448d..1028804 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -755,10 +755,14 @@ pmd_t *lookup_pmd_address(unsigned long address)
* areas on 32-bit NUMA systems. The percpu areas can
* end up in this kind of memory, for instance.
*
- * This could be optimized, but it is only intended to be
- * used at initialization time, and keeping it
- * unoptimized should increase the testing coverage for
- * the more obscure platforms.
+ * Note that as long as the PTEs are well-formed with correct PFNs, this
+ * works without checking the PRESENT bit in the leaf PTE. This is unlike
+ * the similar vmalloc_to_page() and derivatives. Callers may depend on
+ * this behavior.
+ *
+ * This could be optimized, but it is only used in paths that are not perf
+ * sensitive, and keeping it unoptimized should increase the testing coverage
+ * for the more obscure platforms.
*/
phys_addr_t slow_virt_to_phys(void *__virt_addr)
{
@@ -2041,17 +2045,12 @@ int set_mce_nospec(unsigned long pfn)
return rc;
}
-static int set_memory_p(unsigned long *addr, int numpages)
-{
- return change_page_attr_set(addr, numpages, __pgprot(_PAGE_PRESENT), 0);
-}
-
/* Restore full speculative operation to the pfn. */
int clear_mce_nospec(unsigned long pfn)
{
unsigned long addr = (unsigned long) pfn_to_kaddr(pfn);
- return set_memory_p(&addr, 1);
+ return set_memory_p(addr, 1);
}
EXPORT_SYMBOL_GPL(clear_mce_nospec);
#endif /* CONFIG_X86_64 */
@@ -2104,6 +2103,11 @@ int set_memory_np_noalias(unsigned long addr, int numpages)
CPA_NO_CHECK_ALIAS, NULL);
}
+int set_memory_p(unsigned long addr, int numpages)
+{
+ return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
+}
+
int set_memory_4k(unsigned long addr, int numpages)
{
return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
drivers/hv/channel.c
View filediff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 56f7e06..adbf674 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -322,125 +322,89 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
pagecount = hv_gpadl_size(type, size) >> HV_HYP_PAGE_SHIFT;
- /* do we need a gpadl body msg */
pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
sizeof(struct vmbus_channel_gpadl_header) -
sizeof(struct gpa_range);
+ pfncount = umin(pagecount, pfnsize / sizeof(u64));
+
+ msgsize = sizeof(struct vmbus_channel_msginfo) +
+ sizeof(struct vmbus_channel_gpadl_header) +
+ sizeof(struct gpa_range) + pfncount * sizeof(u64);
+ msgheader = kzalloc(msgsize, GFP_KERNEL);
+ if (!msgheader)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&msgheader->submsglist);
+ msgheader->msgsize = msgsize;
+
+ gpadl_header = (struct vmbus_channel_gpadl_header *)
+ msgheader->msg;
+ gpadl_header->rangecount = 1;
+ gpadl_header->range_buflen = sizeof(struct gpa_range) +
+ pagecount * sizeof(u64);
+ gpadl_header->range[0].byte_offset = 0;
+ gpadl_header->range[0].byte_count = hv_gpadl_size(type, size);
+ for (i = 0; i < pfncount; i++)
+ gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn(
+ type, kbuffer, size, send_offset, i);
+ *msginfo = msgheader;
+
+ pfnsum = pfncount;
+ pfnleft = pagecount - pfncount;
+
+ /* how many pfns can we fit in a body message */
+ pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
+ sizeof(struct vmbus_channel_gpadl_body);
pfncount = pfnsize / sizeof(u64);
- if (pagecount > pfncount) {
- /* we need a gpadl body */
- /* fill in the header */
+ /*
+ * If pfnleft is zero, everything fits in the header and no body
+ * messages are needed
+ */
+ while (pfnleft) {
+ pfncurr = umin(pfncount, pfnleft);
msgsize = sizeof(struct vmbus_channel_msginfo) +
- sizeof(struct vmbus_channel_gpadl_header) +
- sizeof(struct gpa_range) + pfncount * sizeof(u64);
- msgheader = kzalloc(msgsize, GFP_KERNEL);
- if (!msgheader)
- goto nomem;
-
- INIT_LIST_HEAD(&msgheader->submsglist);
This diff is incomplete. Download the complete patch.
drivers/hv/hv_util.c
View fileThis diff is incomplete. Download the complete patch.
drivers/hv/vmbus_drv.c
View fileThis diff is incomplete. Download the complete patch.
drivers/video/fbdev/hyperv_fb.c
View fileThis diff is incomplete. Download the complete patch.
include/linux/hyperv.h
View fileThis diff is incomplete. Download the complete patch.