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1// SPDX-License-Identifier: GPL-2.0-only
2/******************************************************************************
3 * privcmd.c
4 *
5 * Interface to privileged domain-0 commands.
6 *
7 * Copyright (c) 2002-2004, K A Fraser, B Dragovic
8 */
9
10#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
11
12#include <linux/eventfd.h>
13#include <linux/file.h>
14#include <linux/kernel.h>
15#include <linux/kstrtox.h>
16#include <linux/module.h>
17#include <linux/mutex.h>
18#include <linux/poll.h>
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/srcu.h>
22#include <linux/string.h>
23#include <linux/workqueue.h>
24#include <linux/errno.h>
25#include <linux/mm.h>
26#include <linux/mman.h>
27#include <linux/uaccess.h>
28#include <linux/swap.h>
29#include <linux/highmem.h>
30#include <linux/pagemap.h>
31#include <linux/seq_file.h>
32#include <linux/miscdevice.h>
33#include <linux/moduleparam.h>
34#include <linux/notifier.h>
35#include <linux/security.h>
36#include <linux/virtio_mmio.h>
37#include <linux/wait.h>
38
39#include <asm/xen/hypervisor.h>
40#include <asm/xen/hypercall.h>
41
42#include <xen/xen.h>
43#include <xen/events.h>
44#include <xen/privcmd.h>
45#include <xen/interface/xen.h>
46#include <xen/interface/memory.h>
47#include <xen/interface/hvm/dm_op.h>
48#include <xen/interface/hvm/ioreq.h>
49#include <xen/features.h>
50#include <xen/page.h>
51#include <xen/xen-ops.h>
52#include <xen/balloon.h>
53#include <xen/xenbus.h>
54#ifdef CONFIG_XEN_ACPI
55#include <xen/acpi.h>
56#endif
57
58#include "privcmd.h"
59
60MODULE_DESCRIPTION("Xen hypercall passthrough driver");
61MODULE_LICENSE("GPL");
62
63#define PRIV_VMA_LOCKED ((void *)1)
64
65static unsigned int privcmd_dm_op_max_num = 16;
66module_param_named(dm_op_max_nr_bufs, privcmd_dm_op_max_num, uint, 0644);
67MODULE_PARM_DESC(dm_op_max_nr_bufs,
68 "Maximum number of buffers per dm_op hypercall");
69
70static unsigned int privcmd_dm_op_buf_max_size = 4096;
71module_param_named(dm_op_buf_max_size, privcmd_dm_op_buf_max_size, uint,
72 0644);
73MODULE_PARM_DESC(dm_op_buf_max_size,
74 "Maximum size of a dm_op hypercall buffer");
75
76static bool unrestricted;
77module_param(unrestricted, bool, 0);
78MODULE_PARM_DESC(unrestricted,
79 "Don't restrict hypercalls to target domain if running in a domU");
80
81struct privcmd_data {
82 domid_t domid;
83};
84
85/* DOMID_INVALID implies no restriction */
86static domid_t target_domain = DOMID_INVALID;
87static bool restrict_wait;
88static DECLARE_WAIT_QUEUE_HEAD(restrict_wait_wq);
89
90static int privcmd_vma_range_is_mapped(
91 struct vm_area_struct *vma,
92 unsigned long addr,
93 unsigned long nr_pages);
94
95static long privcmd_ioctl_hypercall(struct file *file, void __user *udata)
96{
97 struct privcmd_data *data = file->private_data;
98 struct privcmd_hypercall hypercall;
99 long ret;
100
101 /* Disallow arbitrary hypercalls if restricted */
102 if (data->domid != DOMID_INVALID)
103 return -EPERM;
104
105 if (copy_from_user(&hypercall, udata, sizeof(hypercall)))
106 return -EFAULT;
107
108 xen_preemptible_hcall_begin();
109 ret = privcmd_call(hypercall.op,
110 hypercall.arg[0], hypercall.arg[1],
111 hypercall.arg[2], hypercall.arg[3],
112 hypercall.arg[4]);
113 xen_preemptible_hcall_end();
114
115 return ret;
116}
117
118static void free_page_list(struct list_head *pages)
119{
120 struct page *p, *n;
121
122 list_for_each_entry_safe(p, n, pages, lru)
123 __free_page(p);
124
125 INIT_LIST_HEAD(pages);
126}
127
128/*
129 * Given an array of items in userspace, return a list of pages
130 * containing the data. If copying fails, either because of memory
131 * allocation failure or a problem reading user memory, return an
132 * error code; its up to the caller to dispose of any partial list.
133 */
134static int gather_array(struct list_head *pagelist,
135 unsigned nelem, size_t size,
136 const void __user *data)
137{
138 unsigned pageidx;
139 void *pagedata;
140 int ret;
141
142 if (size > PAGE_SIZE)
143 return 0;
144
145 pageidx = PAGE_SIZE;
146 pagedata = NULL; /* quiet, gcc */
147 while (nelem--) {
148 if (pageidx > PAGE_SIZE-size) {
149 struct page *page = alloc_page(GFP_KERNEL);
150
151 ret = -ENOMEM;
152 if (page == NULL)
153 goto fail;
154
155 pagedata = page_address(page);
156
157 list_add_tail(&page->lru, pagelist);
158 pageidx = 0;
159 }
160
161 ret = -EFAULT;
162 if (copy_from_user(pagedata + pageidx, data, size))
163 goto fail;
164
165 data += size;
166 pageidx += size;
167 }
168
169 ret = 0;
170
171fail:
172 return ret;
173}
174
175/*
176 * Call function "fn" on each element of the array fragmented
177 * over a list of pages.
178 */
179static int traverse_pages(unsigned nelem, size_t size,
180 struct list_head *pos,
181 int (*fn)(void *data, void *state),
182 void *state)
183{
184 void *pagedata;
185 unsigned pageidx;
186 int ret = 0;
187
188 BUG_ON(size > PAGE_SIZE);
189
190 pageidx = PAGE_SIZE;
191 pagedata = NULL; /* hush, gcc */
192
193 while (nelem--) {
194 if (pageidx > PAGE_SIZE-size) {
195 struct page *page;
196 pos = pos->next;
197 page = list_entry(pos, struct page, lru);
198 pagedata = page_address(page);
199 pageidx = 0;
200 }
201
202 ret = (*fn)(pagedata + pageidx, state);
203 if (ret)
204 break;
205 pageidx += size;
206 }
207
208 return ret;
209}
210
211/*
212 * Similar to traverse_pages, but use each page as a "block" of
213 * data to be processed as one unit.
214 */
215static int traverse_pages_block(unsigned nelem, size_t size,
216 struct list_head *pos,
217 int (*fn)(void *data, int nr, void *state),
218 void *state)
219{
220 void *pagedata;
221 int ret = 0;
222
223 BUG_ON(size > PAGE_SIZE);
224
225 while (nelem) {
226 int nr = (PAGE_SIZE/size);
227 struct page *page;
228 if (nr > nelem)
229 nr = nelem;
230 pos = pos->next;
231 page = list_entry(pos, struct page, lru);
232 pagedata = page_address(page);
233 ret = (*fn)(pagedata, nr, state);
234 if (ret)
235 break;
236 nelem -= nr;
237 }
238
239 return ret;
240}
241
242struct mmap_gfn_state {
243 unsigned long va;
244 struct vm_area_struct *vma;
245 domid_t domain;
246};
247
248static int mmap_gfn_range(void *data, void *state)
249{
250 struct privcmd_mmap_entry *msg = data;
251 struct mmap_gfn_state *st = state;
252 struct vm_area_struct *vma = st->vma;
253 int rc;
254
255 /* Do not allow range to wrap the address space. */
256 if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) ||
257 ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va))
258 return -EINVAL;
259
260 /* Range chunks must be contiguous in va space. */
261 if ((msg->va != st->va) ||
262 ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end))
263 return -EINVAL;
264
265 rc = xen_remap_domain_gfn_range(vma,
266 msg->va & PAGE_MASK,
267 msg->mfn, msg->npages,
268 vma->vm_page_prot,
269 st->domain, NULL);
270 if (rc < 0)
271 return rc;
272
273 st->va += msg->npages << PAGE_SHIFT;
274
275 return 0;
276}
277
278static long privcmd_ioctl_mmap(struct file *file, void __user *udata)
279{
280 struct privcmd_data *data = file->private_data;
281 struct privcmd_mmap mmapcmd;
282 struct mm_struct *mm = current->mm;
283 struct vm_area_struct *vma;
284 int rc;
285 LIST_HEAD(pagelist);
286 struct mmap_gfn_state state;
287
288 /* We only support privcmd_ioctl_mmap_batch for non-auto-translated. */
289 if (!xen_pv_domain())
290 return -ENOSYS;
291
292 if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
293 return -EFAULT;
294
295 /* If restriction is in place, check the domid matches */
296 if (data->domid != DOMID_INVALID && data->domid != mmapcmd.dom)
297 return -EPERM;
298
299 rc = gather_array(&pagelist,
300 mmapcmd.num, sizeof(struct privcmd_mmap_entry),
301 mmapcmd.entry);
302
303 if (rc || list_empty(&pagelist))
304 goto out;
305
306 mmap_write_lock(mm);
307
308 {
309 struct page *page = list_first_entry(&pagelist,
310 struct page, lru);
311 struct privcmd_mmap_entry *msg = page_address(page);
312
313 vma = vma_lookup(mm, msg->va);
314 rc = -EINVAL;
315
316 if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data)
317 goto out_up;
318 vma->vm_private_data = PRIV_VMA_LOCKED;
319 }
320
321 state.va = vma->vm_start;
322 state.vma = vma;
323 state.domain = mmapcmd.dom;
324
325 rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry),
326 &pagelist,
327 mmap_gfn_range, &state);
328
329
330out_up:
331 mmap_write_unlock(mm);
332
333out:
334 free_page_list(&pagelist);
335
336 return rc;
337}
338
339struct mmap_batch_state {
340 domid_t domain;
341 unsigned long va;
342 struct vm_area_struct *vma;
343 int index;
344 /* A tristate:
345 * 0 for no errors
346 * 1 if at least one error has happened (and no
347 * -ENOENT errors have happened)
348 * -ENOENT if at least 1 -ENOENT has happened.
349 */
350 int global_error;
351 int version;
352
353 /* User-space gfn array to store errors in the second pass for V1. */
354 xen_pfn_t __user *user_gfn;
355 /* User-space int array to store errors in the second pass for V2. */
356 int __user *user_err;
357};
358
359/* auto translated dom0 note: if domU being created is PV, then gfn is
360 * mfn(addr on bus). If it's auto xlated, then gfn is pfn (input to HAP).
361 */
362static int mmap_batch_fn(void *data, int nr, void *state)
363{
364 xen_pfn_t *gfnp = data;
365 struct mmap_batch_state *st = state;
366 struct vm_area_struct *vma = st->vma;
367 struct page **pages = vma->vm_private_data;
368 struct page **cur_pages = NULL;
369 int ret;
370
371 if (!xen_pv_domain())
372 cur_pages = &pages[st->index];
373
374 BUG_ON(nr < 0);
375 ret = xen_remap_domain_gfn_array(st->vma, st->va & PAGE_MASK, gfnp, nr,
376 (int *)gfnp, st->vma->vm_page_prot,
377 st->domain, cur_pages);
378
379 /* Adjust the global_error? */
380 if (ret != nr) {
381 if (ret == -ENOENT)
382 st->global_error = -ENOENT;
383 else {
384 /* Record that at least one error has happened. */
385 if (st->global_error == 0)
386 st->global_error = 1;
387 }
388 }
389 st->va += XEN_PAGE_SIZE * nr;
390 st->index += nr / XEN_PFN_PER_PAGE;
391
392 return 0;
393}
394
395static int mmap_return_error(int err, struct mmap_batch_state *st)
396{
397 int ret;
398
399 if (st->version == 1) {
400 if (err) {
401 xen_pfn_t gfn;
402
403 ret = get_user(gfn, st->user_gfn);
404 if (ret < 0)
405 return ret;
406 /*
407 * V1 encodes the error codes in the 32bit top
408 * nibble of the gfn (with its known
409 * limitations vis-a-vis 64 bit callers).
410 */
411 gfn |= (err == -ENOENT) ?
412 PRIVCMD_MMAPBATCH_PAGED_ERROR :
413 PRIVCMD_MMAPBATCH_MFN_ERROR;
414 return __put_user(gfn, st->user_gfn++);
415 } else
416 st->user_gfn++;
417 } else { /* st->version == 2 */
418 if (err)
419 return __put_user(err, st->user_err++);
420 else
421 st->user_err++;
422 }
423
424 return 0;
425}
426
427static int mmap_return_errors(void *data, int nr, void *state)
428{
429 struct mmap_batch_state *st = state;
430 int *errs = data;
431 int i;
432 int ret;
433
434 for (i = 0; i < nr; i++) {
435 ret = mmap_return_error(errs[i], st);
436 if (ret < 0)
437 return ret;
438 }
439 return 0;
440}
441
442/* Allocate pfns that are then mapped with gfns from foreign domid. Update
443 * the vma with the page info to use later.
444 * Returns: 0 if success, otherwise -errno
445 */
446static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs)
447{
448 int rc;
449 struct page **pages;
450
451 pages = kvzalloc_objs(pages[0], numpgs);
452 if (pages == NULL)
453 return -ENOMEM;
454
455 rc = xen_alloc_unpopulated_pages(numpgs, pages);
456 if (rc != 0) {
457 pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__,
458 numpgs, rc);
459 kvfree(pages);
460 return -ENOMEM;
461 }
462 BUG_ON(vma->vm_private_data != NULL);
463 vma->vm_private_data = pages;
464
465 return 0;
466}
467
468static const struct vm_operations_struct privcmd_vm_ops;
469
470static long privcmd_ioctl_mmap_batch(
471 struct file *file, void __user *udata, int version)
472{
473 struct privcmd_data *data = file->private_data;
474 int ret;
475 struct privcmd_mmapbatch_v2 m;
476 struct mm_struct *mm = current->mm;
477 struct vm_area_struct *vma;
478 unsigned long nr_pages;
479 LIST_HEAD(pagelist);
480 struct mmap_batch_state state;
481
482 switch (version) {
483 case 1:
484 if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch)))
485 return -EFAULT;
486 /* Returns per-frame error in m.arr. */
487 m.err = NULL;
488 if (!access_ok(m.arr, m.num * sizeof(*m.arr)))
489 return -EFAULT;
490 break;
491 case 2:
492 if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2)))
493 return -EFAULT;
494 /* Returns per-frame error code in m.err. */
495 if (!access_ok(m.err, m.num * (sizeof(*m.err))))
496 return -EFAULT;
497 break;
498 default:
499 return -EINVAL;
500 }
501
502 /* If restriction is in place, check the domid matches */
503 if (data->domid != DOMID_INVALID && data->domid != m.dom)
504 return -EPERM;
505
506 nr_pages = DIV_ROUND_UP(m.num, XEN_PFN_PER_PAGE);
507 if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
508 return -EINVAL;
509
510 ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr);
511
512 if (ret)
513 goto out;
514 if (list_empty(&pagelist)) {
515 ret = -EINVAL;
516 goto out;
517 }
518
519 if (version == 2) {
520 /* Zero error array now to only copy back actual errors. */
521 if (clear_user(m.err, sizeof(int) * m.num)) {
522 ret = -EFAULT;
523 goto out;
524 }
525 }
526
527 mmap_write_lock(mm);
528
529 vma = find_vma(mm, m.addr);
530 if (!vma ||
531 vma->vm_ops != &privcmd_vm_ops) {
532 ret = -EINVAL;
533 goto out_unlock;
534 }
535
536 /*
537 * Caller must either:
538 *
539 * Map the whole VMA range, which will also allocate all the
540 * pages required for the auto_translated_physmap case.
541 *
542 * Or
543 *
544 * Map unmapped holes left from a previous map attempt (e.g.,
545 * because those foreign frames were previously paged out).
546 */
547 if (vma->vm_private_data == NULL) {
548 if (m.addr != vma->vm_start ||
549 m.addr + (nr_pages << PAGE_SHIFT) != vma->vm_end) {
550 ret = -EINVAL;
551 goto out_unlock;
552 }
553 if (!xen_pv_domain()) {
554 ret = alloc_empty_pages(vma, nr_pages);
555 if (ret < 0)
556 goto out_unlock;
557 } else
558 vma->vm_private_data = PRIV_VMA_LOCKED;
559 } else {
560 if (m.addr < vma->vm_start ||
561 m.addr + (nr_pages << PAGE_SHIFT) > vma->vm_end) {
562 ret = -EINVAL;
563 goto out_unlock;
564 }
565 if (privcmd_vma_range_is_mapped(vma, m.addr, nr_pages)) {
566 ret = -EINVAL;
567 goto out_unlock;
568 }
569 }
570
571 state.domain = m.dom;
572 state.vma = vma;
573 state.va = m.addr;
574 state.index = 0;
575 state.global_error = 0;
576 state.version = version;
577
578 BUILD_BUG_ON(((PAGE_SIZE / sizeof(xen_pfn_t)) % XEN_PFN_PER_PAGE) != 0);
579 /* mmap_batch_fn guarantees ret == 0 */
580 BUG_ON(traverse_pages_block(m.num, sizeof(xen_pfn_t),
581 &pagelist, mmap_batch_fn, &state));
582
583 mmap_write_unlock(mm);
584
585 if (state.global_error) {
586 /* Write back errors in second pass. */
587 state.user_gfn = (xen_pfn_t *)m.arr;
588 state.user_err = m.err;
589 ret = traverse_pages_block(m.num, sizeof(xen_pfn_t),
590 &pagelist, mmap_return_errors, &state);
591 } else
592 ret = 0;
593
594 /* If we have not had any EFAULT-like global errors then set the global
595 * error to -ENOENT if necessary. */
596 if ((ret == 0) && (state.global_error == -ENOENT))
597 ret = -ENOENT;
598
599out:
600 free_page_list(&pagelist);
601 return ret;
602
603out_unlock:
604 mmap_write_unlock(mm);
605 goto out;
606}
607
608static int lock_pages(
609 struct privcmd_dm_op_buf kbufs[], unsigned int num,
610 struct page *pages[], unsigned int nr_pages, unsigned int *pinned)
611{
612 unsigned int i, off = 0;
613
614 for (i = 0; i < num; ) {
615 unsigned int requested;
616 int page_count;
617
618 requested = DIV_ROUND_UP(
619 offset_in_page(kbufs[i].uptr) + kbufs[i].size,
620 PAGE_SIZE) - off;
621 if (requested > nr_pages)
622 return -ENOSPC;
623
624 page_count = pin_user_pages_fast(
625 (unsigned long)kbufs[i].uptr + off * PAGE_SIZE,
626 requested, FOLL_WRITE, pages);
627 if (page_count <= 0)
628 return page_count ? : -EFAULT;
629
630 *pinned += page_count;
631 nr_pages -= page_count;
632 pages += page_count;
633
634 off = (requested == page_count) ? 0 : off + page_count;
635 i += !off;
636 }
637
638 return 0;
639}
640
641static void unlock_pages(struct page *pages[], unsigned int nr_pages)
642{
643 unpin_user_pages_dirty_lock(pages, nr_pages, true);
644}
645
646static long privcmd_ioctl_dm_op(struct file *file, void __user *udata)
647{
648 struct privcmd_data *data = file->private_data;
649 struct privcmd_dm_op kdata;
650 struct privcmd_dm_op_buf *kbufs;
651 unsigned int nr_pages = 0;
652 struct page **pages = NULL;
653 struct xen_dm_op_buf *xbufs = NULL;
654 unsigned int i;
655 long rc;
656 unsigned int pinned = 0;
657
658 if (copy_from_user(&kdata, udata, sizeof(kdata)))
659 return -EFAULT;
660
661 /* If restriction is in place, check the domid matches */
662 if (data->domid != DOMID_INVALID && data->domid != kdata.dom)
663 return -EPERM;
664
665 if (kdata.num == 0)
666 return 0;
667
668 if (kdata.num > privcmd_dm_op_max_num)
669 return -E2BIG;
670
671 kbufs = kzalloc_objs(*kbufs, kdata.num);
672 if (!kbufs)
673 return -ENOMEM;
674
675 if (copy_from_user(kbufs, kdata.ubufs,
676 sizeof(*kbufs) * kdata.num)) {
677 rc = -EFAULT;
678 goto out;
679 }
680
681 for (i = 0; i < kdata.num; i++) {
682 if (kbufs[i].size > privcmd_dm_op_buf_max_size) {
683 rc = -E2BIG;
684 goto out;
685 }
686
687 if (!access_ok(kbufs[i].uptr,
688 kbufs[i].size)) {
689 rc = -EFAULT;
690 goto out;
691 }
692
693 nr_pages += DIV_ROUND_UP(
694 offset_in_page(kbufs[i].uptr) + kbufs[i].size,
695 PAGE_SIZE);
696 }
697
698 pages = kzalloc_objs(*pages, nr_pages);
699 if (!pages) {
700 rc = -ENOMEM;
701 goto out;
702 }
703
704 xbufs = kzalloc_objs(*xbufs, kdata.num);
705 if (!xbufs) {
706 rc = -ENOMEM;
707 goto out;
708 }
709
710 rc = lock_pages(kbufs, kdata.num, pages, nr_pages, &pinned);
711 if (rc < 0)
712 goto out;
713
714 for (i = 0; i < kdata.num; i++) {
715 set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr);
716 xbufs[i].size = kbufs[i].size;
717 }
718
719 xen_preemptible_hcall_begin();
720 rc = HYPERVISOR_dm_op(kdata.dom, kdata.num, xbufs);
721 xen_preemptible_hcall_end();
722
723out:
724 unlock_pages(pages, pinned);
725 kfree(xbufs);
726 kfree(pages);
727 kfree(kbufs);
728
729 return rc;
730}
731
732static long privcmd_ioctl_restrict(struct file *file, void __user *udata)
733{
734 struct privcmd_data *data = file->private_data;
735 domid_t dom;
736
737 if (copy_from_user(&dom, udata, sizeof(dom)))
738 return -EFAULT;
739
740 /* Set restriction to the specified domain, or check it matches */
741 if (data->domid == DOMID_INVALID)
742 data->domid = dom;
743 else if (data->domid != dom)
744 return -EINVAL;
745
746 return 0;
747}
748
749static long privcmd_ioctl_mmap_resource(struct file *file,
750 struct privcmd_mmap_resource __user *udata)
751{
752 struct privcmd_data *data = file->private_data;
753 struct mm_struct *mm = current->mm;
754 struct vm_area_struct *vma;
755 struct privcmd_mmap_resource kdata;
756 xen_pfn_t *pfns = NULL;
757 struct xen_mem_acquire_resource xdata = { };
758 int rc;
759
760 if (copy_from_user(&kdata, udata, sizeof(kdata)))
761 return -EFAULT;
762
763 /* If restriction is in place, check the domid matches */
764 if (data->domid != DOMID_INVALID && data->domid != kdata.dom)
765 return -EPERM;
766
767 /* Both fields must be set or unset */
768 if (!!kdata.addr != !!kdata.num)
769 return -EINVAL;
770
771 xdata.domid = kdata.dom;
772 xdata.type = kdata.type;
773 xdata.id = kdata.id;
774
775 if (!kdata.addr && !kdata.num) {
776 /* Query the size of the resource. */
777 rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata);
778 if (rc)
779 return rc;
780 return __put_user(xdata.nr_frames, &udata->num);
781 }
782
783 mmap_write_lock(mm);
784
785 vma = find_vma(mm, kdata.addr);
786 if (!vma || vma->vm_ops != &privcmd_vm_ops) {
787 rc = -EINVAL;
788 goto out;
789 }
790
791 pfns = kzalloc_objs(*pfns, kdata.num, GFP_KERNEL | __GFP_NOWARN);
792 if (!pfns) {
793 rc = -ENOMEM;
794 goto out;
795 }
796
797 if (!xen_pv_domain()) {
798 unsigned int nr = DIV_ROUND_UP(kdata.num, XEN_PFN_PER_PAGE);
799 struct page **pages;
800 unsigned int i;
801
802 rc = alloc_empty_pages(vma, nr);
803 if (rc < 0)
804 goto out;
805
806 pages = vma->vm_private_data;
807
808 for (i = 0; i < kdata.num; i++) {
809 xen_pfn_t pfn =
810 page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]);
811
812 pfns[i] = pfn + (i % XEN_PFN_PER_PAGE);
813 }
814 } else
815 vma->vm_private_data = PRIV_VMA_LOCKED;
816
817 xdata.frame = kdata.idx;
818 xdata.nr_frames = kdata.num;
819 set_xen_guest_handle(xdata.frame_list, pfns);
820
821 xen_preemptible_hcall_begin();
822 rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata);
823 xen_preemptible_hcall_end();
824
825 if (rc)
826 goto out;
827
828 if (!xen_pv_domain()) {
829 rc = xen_remap_vma_range(vma, kdata.addr, kdata.num << PAGE_SHIFT);
830 } else {
831 unsigned int domid =
832 (xdata.flags & XENMEM_rsrc_acq_caller_owned) ?
833 DOMID_SELF : kdata.dom;
834 int num, *errs = (int *)pfns;
835
836 BUILD_BUG_ON(sizeof(*errs) > sizeof(*pfns));
837 num = xen_remap_domain_mfn_array(vma,
838 kdata.addr & PAGE_MASK,
839 pfns, kdata.num, errs,
840 vma->vm_page_prot,
841 domid);
842 if (num < 0)
843 rc = num;
844 else if (num != kdata.num) {
845 unsigned int i;
846
847 for (i = 0; i < num; i++) {
848 rc = errs[i];
849 if (rc < 0)
850 break;
851 }
852 } else
853 rc = 0;
854 }
855
856out:
857 mmap_write_unlock(mm);
858 kfree(pfns);
859
860 return rc;
861}
862
863static long privcmd_ioctl_pcidev_get_gsi(struct file *file, void __user *udata)
864{
865#if defined(CONFIG_XEN_ACPI)
866 int rc;
867 struct privcmd_pcidev_get_gsi kdata;
868
869 if (copy_from_user(&kdata, udata, sizeof(kdata)))
870 return -EFAULT;
871
872 rc = xen_acpi_get_gsi_from_sbdf(kdata.sbdf);
873 if (rc < 0)
874 return rc;
875
876 kdata.gsi = rc;
877 if (copy_to_user(udata, &kdata, sizeof(kdata)))
878 return -EFAULT;
879
880 return 0;
881#else
882 return -EINVAL;
883#endif
884}
885
886#ifdef CONFIG_XEN_PRIVCMD_EVENTFD
887/* Irqfd support */
888static struct workqueue_struct *irqfd_cleanup_wq;
889static DEFINE_SPINLOCK(irqfds_lock);
890DEFINE_STATIC_SRCU(irqfds_srcu);
891static LIST_HEAD(irqfds_list);
892
893struct privcmd_kernel_irqfd {
894 struct xen_dm_op_buf xbufs;
895 domid_t dom;
896 bool error;
897 struct eventfd_ctx *eventfd;
898 struct work_struct shutdown;
899 wait_queue_entry_t wait;
900 struct list_head list;
901 poll_table pt;
902};
903
904static void irqfd_deactivate(struct privcmd_kernel_irqfd *kirqfd)
905{
906 lockdep_assert_held(&irqfds_lock);
907
908 list_del_init(&kirqfd->list);
909 queue_work(irqfd_cleanup_wq, &kirqfd->shutdown);
910}
911
912static void irqfd_shutdown(struct work_struct *work)
913{
914 struct privcmd_kernel_irqfd *kirqfd =
915 container_of(work, struct privcmd_kernel_irqfd, shutdown);
916 u64 cnt;
917
918 /* Make sure irqfd has been initialized in assign path */
919 synchronize_srcu(&irqfds_srcu);
920
921 eventfd_ctx_remove_wait_queue(kirqfd->eventfd, &kirqfd->wait, &cnt);
922 eventfd_ctx_put(kirqfd->eventfd);
923 kfree(kirqfd);
924}
925
926static void irqfd_inject(struct privcmd_kernel_irqfd *kirqfd)
927{
928 u64 cnt;
929 long rc;
930
931 eventfd_ctx_do_read(kirqfd->eventfd, &cnt);
932
933 xen_preemptible_hcall_begin();
934 rc = HYPERVISOR_dm_op(kirqfd->dom, 1, &kirqfd->xbufs);
935 xen_preemptible_hcall_end();
936
937 /* Don't repeat the error message for consecutive failures */
938 if (rc && !kirqfd->error) {
939 pr_err("Failed to configure irq for guest domain: %d\n",
940 kirqfd->dom);
941 }
942
943 kirqfd->error = rc;
944}
945
946static int
947irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
948{
949 struct privcmd_kernel_irqfd *kirqfd =
950 container_of(wait, struct privcmd_kernel_irqfd, wait);
951 __poll_t flags = key_to_poll(key);
952
953 if (flags & EPOLLIN)
954 irqfd_inject(kirqfd);
955
956 if (flags & EPOLLHUP) {
957 unsigned long flags;
958
959 spin_lock_irqsave(&irqfds_lock, flags);
960 irqfd_deactivate(kirqfd);
961 spin_unlock_irqrestore(&irqfds_lock, flags);
962 }
963
964 return 0;
965}
966
967static void
968irqfd_poll_func(struct file *file, wait_queue_head_t *wqh, poll_table *pt)
969{
970 struct privcmd_kernel_irqfd *kirqfd =
971 container_of(pt, struct privcmd_kernel_irqfd, pt);
972
973 add_wait_queue_priority(wqh, &kirqfd->wait);
974}
975
976static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
977{
978 struct privcmd_kernel_irqfd *kirqfd, *tmp;
979 unsigned long flags;
980 __poll_t events;
981 void *dm_op;
982 int ret, idx;
983
984 CLASS(fd, f)(irqfd->fd);
985
986 kirqfd = kzalloc(sizeof(*kirqfd) + irqfd->size, GFP_KERNEL);
987 if (!kirqfd)
988 return -ENOMEM;
989 dm_op = kirqfd + 1;
990
991 if (copy_from_user(dm_op, u64_to_user_ptr(irqfd->dm_op), irqfd->size)) {
992 ret = -EFAULT;
993 goto error_kfree;
994 }
995
996 kirqfd->xbufs.size = irqfd->size;
997 set_xen_guest_handle(kirqfd->xbufs.h, dm_op);
998 kirqfd->dom = irqfd->dom;
999 INIT_WORK(&kirqfd->shutdown, irqfd_shutdown);
1000
1001 if (fd_empty(f)) {
1002 ret = -EBADF;
1003 goto error_kfree;
1004 }
1005
1006 kirqfd->eventfd = eventfd_ctx_fileget(fd_file(f));
1007 if (IS_ERR(kirqfd->eventfd)) {
1008 ret = PTR_ERR(kirqfd->eventfd);
1009 goto error_kfree;
1010 }
1011
1012 /*
1013 * Install our own custom wake-up handling so we are notified via a
1014 * callback whenever someone signals the underlying eventfd.
1015 */
1016 init_waitqueue_func_entry(&kirqfd->wait, irqfd_wakeup);
1017 init_poll_funcptr(&kirqfd->pt, irqfd_poll_func);
1018
1019 spin_lock_irqsave(&irqfds_lock, flags);
1020
1021 list_for_each_entry(tmp, &irqfds_list, list) {
1022 if (kirqfd->eventfd == tmp->eventfd) {
1023 ret = -EBUSY;
1024 spin_unlock_irqrestore(&irqfds_lock, flags);
1025 goto error_eventfd;
1026 }
1027 }
1028
1029 idx = srcu_read_lock(&irqfds_srcu);
1030 list_add_tail(&kirqfd->list, &irqfds_list);
1031 spin_unlock_irqrestore(&irqfds_lock, flags);
1032
1033 /*
1034 * Check if there was an event already pending on the eventfd before we
1035 * registered, and trigger it as if we didn't miss it.
1036 */
1037 events = vfs_poll(fd_file(f), &kirqfd->pt);
1038 if (events & EPOLLIN)
1039 irqfd_inject(kirqfd);
1040
1041 srcu_read_unlock(&irqfds_srcu, idx);
1042 return 0;
1043
1044error_eventfd:
1045 eventfd_ctx_put(kirqfd->eventfd);
1046
1047error_kfree:
1048 kfree(kirqfd);
1049 return ret;
1050}
1051
1052static int privcmd_irqfd_deassign(struct privcmd_irqfd *irqfd)
1053{
1054 struct privcmd_kernel_irqfd *kirqfd;
1055 struct eventfd_ctx *eventfd;
1056 unsigned long flags;
1057
1058 eventfd = eventfd_ctx_fdget(irqfd->fd);
1059 if (IS_ERR(eventfd))
1060 return PTR_ERR(eventfd);
1061
1062 spin_lock_irqsave(&irqfds_lock, flags);
1063
1064 list_for_each_entry(kirqfd, &irqfds_list, list) {
1065 if (kirqfd->eventfd == eventfd) {
1066 irqfd_deactivate(kirqfd);
1067 break;
1068 }
1069 }
1070
1071 spin_unlock_irqrestore(&irqfds_lock, flags);
1072
1073 eventfd_ctx_put(eventfd);
1074
1075 /*
1076 * Block until we know all outstanding shutdown jobs have completed so
1077 * that we guarantee there will not be any more interrupts once this
1078 * deassign function returns.
1079 */
1080 flush_workqueue(irqfd_cleanup_wq);
1081
1082 return 0;
1083}
1084
1085static long privcmd_ioctl_irqfd(struct file *file, void __user *udata)
1086{
1087 struct privcmd_data *data = file->private_data;
1088 struct privcmd_irqfd irqfd;
1089
1090 if (copy_from_user(&irqfd, udata, sizeof(irqfd)))
1091 return -EFAULT;
1092
1093 /* No other flags should be set */
1094 if (irqfd.flags & ~PRIVCMD_IRQFD_FLAG_DEASSIGN)
1095 return -EINVAL;
1096
1097 /* If restriction is in place, check the domid matches */
1098 if (data->domid != DOMID_INVALID && data->domid != irqfd.dom)
1099 return -EPERM;
1100
1101 if (irqfd.flags & PRIVCMD_IRQFD_FLAG_DEASSIGN)
1102 return privcmd_irqfd_deassign(&irqfd);
1103
1104 return privcmd_irqfd_assign(&irqfd);
1105}
1106
1107static int privcmd_irqfd_init(void)
1108{
1109 irqfd_cleanup_wq = alloc_workqueue("privcmd-irqfd-cleanup", WQ_PERCPU,
1110 0);
1111 if (!irqfd_cleanup_wq)
1112 return -ENOMEM;
1113
1114 return 0;
1115}
1116
1117static void privcmd_irqfd_exit(void)
1118{
1119 struct privcmd_kernel_irqfd *kirqfd, *tmp;
1120 unsigned long flags;
1121
1122 spin_lock_irqsave(&irqfds_lock, flags);
1123
1124 list_for_each_entry_safe(kirqfd, tmp, &irqfds_list, list)
1125 irqfd_deactivate(kirqfd);
1126
1127 spin_unlock_irqrestore(&irqfds_lock, flags);
1128
1129 destroy_workqueue(irqfd_cleanup_wq);
1130}
1131
1132/* Ioeventfd Support */
1133#define QUEUE_NOTIFY_VQ_MASK 0xFFFF
1134
1135static DEFINE_MUTEX(ioreq_lock);
1136static LIST_HEAD(ioreq_list);
1137
1138/* per-eventfd structure */
1139struct privcmd_kernel_ioeventfd {
1140 struct eventfd_ctx *eventfd;
1141 struct list_head list;
1142 u64 addr;
1143 unsigned int addr_len;
1144 unsigned int vq;
1145};
1146
1147/* per-guest CPU / port structure */
1148struct ioreq_port {
1149 int vcpu;
1150 unsigned int port;
1151 struct privcmd_kernel_ioreq *kioreq;
1152};
1153
1154/* per-guest structure */
1155struct privcmd_kernel_ioreq {
1156 domid_t dom;
1157 unsigned int vcpus;
1158 u64 uioreq;
1159 struct ioreq *ioreq;
1160 spinlock_t lock; /* Protects ioeventfds list */
1161 struct list_head ioeventfds;
1162 struct list_head list;
1163 struct ioreq_port ports[] __counted_by(vcpus);
1164};
1165
1166static irqreturn_t ioeventfd_interrupt(int irq, void *dev_id)
1167{
1168 struct ioreq_port *port = dev_id;
1169 struct privcmd_kernel_ioreq *kioreq = port->kioreq;
1170 struct ioreq *ioreq = &kioreq->ioreq[port->vcpu];
1171 struct privcmd_kernel_ioeventfd *kioeventfd;
1172 bool matched = false;
1173
1174 if (ioreq->state != STATE_IOREQ_READY)
1175 return IRQ_NONE;
1176
1177 /* Xen publishes the request before changing its state to READY. */
1178 virt_rmb();
1179
1180 if (ioreq->type != IOREQ_TYPE_COPY || ioreq->dir != IOREQ_WRITE)
1181 return IRQ_NONE;
1182
1183 spin_lock(&kioreq->lock);
1184 list_for_each_entry(kioeventfd, &kioreq->ioeventfds, list) {
1185 if (ioreq->addr == kioeventfd->addr + VIRTIO_MMIO_QUEUE_NOTIFY &&
1186 ioreq->size == kioeventfd->addr_len &&
1187 (ioreq->data & QUEUE_NOTIFY_VQ_MASK) == kioeventfd->vq) {
1188 /* Finish reading the request before claiming it. */
1189 virt_mb();
1190 ioreq->state = STATE_IOREQ_INPROCESS;
1191 eventfd_signal(kioeventfd->eventfd);
1192 matched = true;
1193 break;
1194 }
1195 }
1196 spin_unlock(&kioreq->lock);
1197
1198 if (!matched)
1199 return IRQ_NONE;
1200
1201 /* Publish the response only after signaling the eventfd. */
1202 virt_wmb();
1203 ioreq->state = STATE_IORESP_READY;
1204 notify_remote_via_evtchn(port->port);
1205 return IRQ_HANDLED;
1206}
1207
1208static void ioreq_free(struct privcmd_kernel_ioreq *kioreq)
1209{
1210 struct ioreq_port *ports = kioreq->ports;
1211 int i;
1212
1213 lockdep_assert_held(&ioreq_lock);
1214
1215 list_del(&kioreq->list);
1216
1217 for (i = kioreq->vcpus - 1; i >= 0; i--)
1218 unbind_from_irqhandler(irq_from_evtchn(ports[i].port), &ports[i]);
1219
1220 kfree(kioreq);
1221}
1222
1223static
1224struct privcmd_kernel_ioreq *alloc_ioreq(struct privcmd_ioeventfd *ioeventfd)
1225{
1226 struct privcmd_kernel_ioreq *kioreq;
1227 struct mm_struct *mm = current->mm;
1228 struct vm_area_struct *vma;
1229 struct page **pages;
1230 unsigned int *ports;
1231 int ret, size, i;
1232
1233 lockdep_assert_held(&ioreq_lock);
1234
1235 size = struct_size(kioreq, ports, ioeventfd->vcpus);
1236 kioreq = kzalloc(size, GFP_KERNEL);
1237 if (!kioreq)
1238 return ERR_PTR(-ENOMEM);
1239
1240 kioreq->dom = ioeventfd->dom;
1241 kioreq->vcpus = ioeventfd->vcpus;
1242 kioreq->uioreq = ioeventfd->ioreq;
1243 spin_lock_init(&kioreq->lock);
1244 INIT_LIST_HEAD(&kioreq->ioeventfds);
1245
1246 /* The memory for ioreq server must have been mapped earlier */
1247 mmap_write_lock(mm);
1248 vma = find_vma(mm, (unsigned long)ioeventfd->ioreq);
1249 if (!vma) {
1250 pr_err("Failed to find vma for ioreq page!\n");
1251 mmap_write_unlock(mm);
1252 ret = -EFAULT;
1253 goto error_kfree;
1254 }
1255
1256 pages = vma->vm_private_data;
1257 kioreq->ioreq = (struct ioreq *)(page_to_virt(pages[0]));
1258 mmap_write_unlock(mm);
1259
1260 ports = memdup_array_user(u64_to_user_ptr(ioeventfd->ports),
1261 kioreq->vcpus, sizeof(*ports));
1262 if (IS_ERR(ports)) {
1263 ret = PTR_ERR(ports);
1264 goto error_kfree;
1265 }
1266
1267 for (i = 0; i < kioreq->vcpus; i++) {
1268 kioreq->ports[i].vcpu = i;
1269 kioreq->ports[i].port = ports[i];
1270 kioreq->ports[i].kioreq = kioreq;
1271
1272 ret = bind_evtchn_to_irqhandler_lateeoi(ports[i],
1273 ioeventfd_interrupt, IRQF_SHARED, "ioeventfd",
1274 &kioreq->ports[i]);
1275 if (ret < 0)
1276 goto error_unbind;
1277 }
1278
1279 kfree(ports);
1280
1281 list_add_tail(&kioreq->list, &ioreq_list);
1282
1283 return kioreq;
1284
1285error_unbind:
1286 while (--i >= 0)
1287 unbind_from_irqhandler(irq_from_evtchn(ports[i]), &kioreq->ports[i]);
1288
1289 kfree(ports);
1290error_kfree:
1291 kfree(kioreq);
1292 return ERR_PTR(ret);
1293}
1294
1295static struct privcmd_kernel_ioreq *
1296get_ioreq(struct privcmd_ioeventfd *ioeventfd, struct eventfd_ctx *eventfd)
1297{
1298 struct privcmd_kernel_ioreq *kioreq;
1299 unsigned long flags;
1300
1301 list_for_each_entry(kioreq, &ioreq_list, list) {
1302 struct privcmd_kernel_ioeventfd *kioeventfd;
1303
1304 /*
1305 * kioreq fields can be accessed here without a lock as they are
1306 * never updated after being added to the ioreq_list.
1307 */
1308 if (kioreq->uioreq != ioeventfd->ioreq) {
1309 continue;
1310 } else if (kioreq->dom != ioeventfd->dom ||
1311 kioreq->vcpus != ioeventfd->vcpus) {
1312 pr_err("Invalid ioeventfd configuration mismatch, dom (%u vs %u), vcpus (%u vs %u)\n",
1313 kioreq->dom, ioeventfd->dom, kioreq->vcpus,
1314 ioeventfd->vcpus);
1315 return ERR_PTR(-EINVAL);
1316 }
1317
1318 /* Look for a duplicate eventfd for the same guest */
1319 spin_lock_irqsave(&kioreq->lock, flags);
1320 list_for_each_entry(kioeventfd, &kioreq->ioeventfds, list) {
1321 if (eventfd == kioeventfd->eventfd) {
1322 spin_unlock_irqrestore(&kioreq->lock, flags);
1323 return ERR_PTR(-EBUSY);
1324 }
1325 }
1326 spin_unlock_irqrestore(&kioreq->lock, flags);
1327
1328 return kioreq;
1329 }
1330
1331 /* Matching kioreq isn't found, allocate a new one */
1332 return alloc_ioreq(ioeventfd);
1333}
1334
1335static void ioeventfd_free(struct privcmd_kernel_ioeventfd *kioeventfd)
1336{
1337 list_del(&kioeventfd->list);
1338 eventfd_ctx_put(kioeventfd->eventfd);
1339 kfree(kioeventfd);
1340}
1341
1342static int privcmd_ioeventfd_assign(struct privcmd_ioeventfd *ioeventfd)
1343{
1344 struct privcmd_kernel_ioeventfd *kioeventfd;
1345 struct privcmd_kernel_ioreq *kioreq;
1346 unsigned long flags;
1347 int ret;
1348
1349 /* Check for range overflow */
1350 if (ioeventfd->addr + ioeventfd->addr_len < ioeventfd->addr)
1351 return -EINVAL;
1352
1353 /* Vhost requires us to support length 1, 2, 4, and 8 */
1354 if (!(ioeventfd->addr_len == 1 || ioeventfd->addr_len == 2 ||
1355 ioeventfd->addr_len == 4 || ioeventfd->addr_len == 8))
1356 return -EINVAL;
1357
1358 /* 4096 vcpus limit enough ? */
1359 if (!ioeventfd->vcpus || ioeventfd->vcpus > 4096)
1360 return -EINVAL;
1361
1362 kioeventfd = kzalloc_obj(*kioeventfd);
1363 if (!kioeventfd)
1364 return -ENOMEM;
1365
1366 kioeventfd->eventfd = eventfd_ctx_fdget(ioeventfd->event_fd);
1367 if (IS_ERR(kioeventfd->eventfd)) {
1368 ret = PTR_ERR(kioeventfd->eventfd);
1369 goto error_kfree;
1370 }
1371
1372 kioeventfd->addr = ioeventfd->addr;
1373 kioeventfd->addr_len = ioeventfd->addr_len;
1374 kioeventfd->vq = ioeventfd->vq;
1375
1376 mutex_lock(&ioreq_lock);
1377 kioreq = get_ioreq(ioeventfd, kioeventfd->eventfd);
1378 if (IS_ERR(kioreq)) {
1379 mutex_unlock(&ioreq_lock);
1380 ret = PTR_ERR(kioreq);
1381 goto error_eventfd;
1382 }
1383
1384 spin_lock_irqsave(&kioreq->lock, flags);
1385 list_add_tail(&kioeventfd->list, &kioreq->ioeventfds);
1386 spin_unlock_irqrestore(&kioreq->lock, flags);
1387
1388 mutex_unlock(&ioreq_lock);
1389
1390 return 0;
1391
1392error_eventfd:
1393 eventfd_ctx_put(kioeventfd->eventfd);
1394
1395error_kfree:
1396 kfree(kioeventfd);
1397 return ret;
1398}
1399
1400static int privcmd_ioeventfd_deassign(struct privcmd_ioeventfd *ioeventfd)
1401{
1402 struct privcmd_kernel_ioreq *kioreq, *tkioreq;
1403 struct eventfd_ctx *eventfd;
1404 unsigned long flags;
1405 int ret = 0;
1406
1407 eventfd = eventfd_ctx_fdget(ioeventfd->event_fd);
1408 if (IS_ERR(eventfd))
1409 return PTR_ERR(eventfd);
1410
1411 mutex_lock(&ioreq_lock);
1412 list_for_each_entry_safe(kioreq, tkioreq, &ioreq_list, list) {
1413 struct privcmd_kernel_ioeventfd *kioeventfd, *tmp;
1414 /*
1415 * kioreq fields can be accessed here without a lock as they are
1416 * never updated after being added to the ioreq_list.
1417 */
1418 if (kioreq->dom != ioeventfd->dom ||
1419 kioreq->uioreq != ioeventfd->ioreq ||
1420 kioreq->vcpus != ioeventfd->vcpus)
1421 continue;
1422
1423 spin_lock_irqsave(&kioreq->lock, flags);
1424 list_for_each_entry_safe(kioeventfd, tmp, &kioreq->ioeventfds, list) {
1425 if (eventfd == kioeventfd->eventfd) {
1426 ioeventfd_free(kioeventfd);
1427 spin_unlock_irqrestore(&kioreq->lock, flags);
1428
1429 if (list_empty(&kioreq->ioeventfds))
1430 ioreq_free(kioreq);
1431 goto unlock;
1432 }
1433 }
1434 spin_unlock_irqrestore(&kioreq->lock, flags);
1435 break;
1436 }
1437
1438 pr_err("Ioeventfd isn't already assigned, dom: %u, addr: %llu\n",
1439 ioeventfd->dom, ioeventfd->addr);
1440 ret = -ENODEV;
1441
1442unlock:
1443 mutex_unlock(&ioreq_lock);
1444 eventfd_ctx_put(eventfd);
1445
1446 return ret;
1447}
1448
1449static long privcmd_ioctl_ioeventfd(struct file *file, void __user *udata)
1450{
1451 struct privcmd_data *data = file->private_data;
1452 struct privcmd_ioeventfd ioeventfd;
1453
1454 if (copy_from_user(&ioeventfd, udata, sizeof(ioeventfd)))
1455 return -EFAULT;
1456
1457 /* No other flags should be set */
1458 if (ioeventfd.flags & ~PRIVCMD_IOEVENTFD_FLAG_DEASSIGN)
1459 return -EINVAL;
1460
1461 /* If restriction is in place, check the domid matches */
1462 if (data->domid != DOMID_INVALID && data->domid != ioeventfd.dom)
1463 return -EPERM;
1464
1465 if (ioeventfd.flags & PRIVCMD_IOEVENTFD_FLAG_DEASSIGN)
1466 return privcmd_ioeventfd_deassign(&ioeventfd);
1467
1468 return privcmd_ioeventfd_assign(&ioeventfd);
1469}
1470
1471static void privcmd_ioeventfd_exit(void)
1472{
1473 struct privcmd_kernel_ioreq *kioreq, *tmp;
1474 unsigned long flags;
1475
1476 mutex_lock(&ioreq_lock);
1477 list_for_each_entry_safe(kioreq, tmp, &ioreq_list, list) {
1478 struct privcmd_kernel_ioeventfd *kioeventfd, *tmp;
1479
1480 spin_lock_irqsave(&kioreq->lock, flags);
1481 list_for_each_entry_safe(kioeventfd, tmp, &kioreq->ioeventfds, list)
1482 ioeventfd_free(kioeventfd);
1483 spin_unlock_irqrestore(&kioreq->lock, flags);
1484
1485 ioreq_free(kioreq);
1486 }
1487 mutex_unlock(&ioreq_lock);
1488}
1489#else
1490static inline long privcmd_ioctl_irqfd(struct file *file, void __user *udata)
1491{
1492 return -EOPNOTSUPP;
1493}
1494
1495static inline int privcmd_irqfd_init(void)
1496{
1497 return 0;
1498}
1499
1500static inline void privcmd_irqfd_exit(void)
1501{
1502}
1503
1504static inline long privcmd_ioctl_ioeventfd(struct file *file, void __user *udata)
1505{
1506 return -EOPNOTSUPP;
1507}
1508
1509static inline void privcmd_ioeventfd_exit(void)
1510{
1511}
1512#endif /* CONFIG_XEN_PRIVCMD_EVENTFD */
1513
1514static long privcmd_ioctl(struct file *file,
1515 unsigned int cmd, unsigned long data)
1516{
1517 int ret = -ENOTTY;
1518 void __user *udata = (void __user *) data;
1519
1520 switch (cmd) {
1521 case IOCTL_PRIVCMD_HYPERCALL:
1522 ret = privcmd_ioctl_hypercall(file, udata);
1523 break;
1524
1525 case IOCTL_PRIVCMD_MMAP:
1526 ret = privcmd_ioctl_mmap(file, udata);
1527 break;
1528
1529 case IOCTL_PRIVCMD_MMAPBATCH:
1530 ret = privcmd_ioctl_mmap_batch(file, udata, 1);
1531 break;
1532
1533 case IOCTL_PRIVCMD_MMAPBATCH_V2:
1534 ret = privcmd_ioctl_mmap_batch(file, udata, 2);
1535 break;
1536
1537 case IOCTL_PRIVCMD_DM_OP:
1538 ret = privcmd_ioctl_dm_op(file, udata);
1539 break;
1540
1541 case IOCTL_PRIVCMD_RESTRICT:
1542 ret = privcmd_ioctl_restrict(file, udata);
1543 break;
1544
1545 case IOCTL_PRIVCMD_MMAP_RESOURCE:
1546 ret = privcmd_ioctl_mmap_resource(file, udata);
1547 break;
1548
1549 case IOCTL_PRIVCMD_IRQFD:
1550 ret = privcmd_ioctl_irqfd(file, udata);
1551 break;
1552
1553 case IOCTL_PRIVCMD_IOEVENTFD:
1554 ret = privcmd_ioctl_ioeventfd(file, udata);
1555 break;
1556
1557 case IOCTL_PRIVCMD_PCIDEV_GET_GSI:
1558 ret = privcmd_ioctl_pcidev_get_gsi(file, udata);
1559 break;
1560
1561 default:
1562 break;
1563 }
1564
1565 return ret;
1566}
1567
1568static int privcmd_open(struct inode *ino, struct file *file)
1569{
1570 struct privcmd_data *data;
1571
1572 if (wait_event_interruptible(restrict_wait_wq, !restrict_wait) < 0)
1573 return -EINTR;
1574
1575 data = kzalloc_obj(*data);
1576 if (!data)
1577 return -ENOMEM;
1578
1579 data->domid = target_domain;
1580
1581 file->private_data = data;
1582 return 0;
1583}
1584
1585static int privcmd_release(struct inode *ino, struct file *file)
1586{
1587 struct privcmd_data *data = file->private_data;
1588
1589 kfree(data);
1590 return 0;
1591}
1592
1593static void privcmd_close(struct vm_area_struct *vma)
1594{
1595 struct page **pages = vma->vm_private_data;
1596 int numpgs = vma_pages(vma);
1597 int numgfns = (vma->vm_end - vma->vm_start) >> XEN_PAGE_SHIFT;
1598 int rc;
1599
1600 if (xen_pv_domain() || !numpgs || !pages)
1601 return;
1602
1603 rc = xen_unmap_domain_gfn_range(vma, numgfns, pages);
1604 if (rc == 0)
1605 xen_free_unpopulated_pages(numpgs, pages);
1606 else
1607 pr_crit("unable to unmap MFN range: leaking %d pages. rc=%d\n",
1608 numpgs, rc);
1609 kvfree(pages);
1610}
1611
1612static int privcmd_may_split(struct vm_area_struct *area, unsigned long addr)
1613{
1614 /* Forbid splitting, avoids double free via privcmd_close(). */
1615 return -EINVAL;
1616}
1617
1618static vm_fault_t privcmd_fault(struct vm_fault *vmf)
1619{
1620 printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
1621 vmf->vma, vmf->vma->vm_start, vmf->vma->vm_end,
1622 vmf->pgoff, (void *)vmf->address);
1623
1624 return VM_FAULT_SIGBUS;
1625}
1626
1627static const struct vm_operations_struct privcmd_vm_ops = {
1628 .close = privcmd_close,
1629 .may_split = privcmd_may_split,
1630 .fault = privcmd_fault
1631};
1632
1633static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
1634{
1635 /* DONTCOPY is essential for Xen because copy_page_range doesn't know
1636 * how to recreate these mappings */
1637 vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTCOPY |
1638 VM_DONTEXPAND | VM_DONTDUMP);
1639 vma->vm_ops = &privcmd_vm_ops;
1640 vma->vm_private_data = NULL;
1641
1642 return 0;
1643}
1644
1645/*
1646 * For MMAPBATCH*. This allows asserting the singleshot mapping
1647 * on a per pfn/pte basis. Mapping calls that fail with ENOENT
1648 * can be then retried until success.
1649 */
1650static int is_mapped_fn(pte_t *pte, unsigned long addr, void *data)
1651{
1652 return pte_none(ptep_get(pte)) ? 0 : -EBUSY;
1653}
1654
1655static int privcmd_vma_range_is_mapped(
1656 struct vm_area_struct *vma,
1657 unsigned long addr,
1658 unsigned long nr_pages)
1659{
1660 return apply_to_page_range(vma->vm_mm, addr, nr_pages << PAGE_SHIFT,
1661 is_mapped_fn, NULL) != 0;
1662}
1663
1664const struct file_operations xen_privcmd_fops = {
1665 .owner = THIS_MODULE,
1666 .unlocked_ioctl = privcmd_ioctl,
1667 .open = privcmd_open,
1668 .release = privcmd_release,
1669 .mmap = privcmd_mmap,
1670};
1671EXPORT_SYMBOL_GPL(xen_privcmd_fops);
1672
1673static struct miscdevice privcmd_dev = {
1674 .minor = MISC_DYNAMIC_MINOR,
1675 .name = "xen/privcmd",
1676 .fops = &xen_privcmd_fops,
1677};
1678
1679static int init_restrict(struct notifier_block *notifier,
1680 unsigned long event,
1681 void *data)
1682{
1683 char *target;
1684 unsigned int domid;
1685
1686 /* Default to an guaranteed unused domain-id. */
1687 target_domain = DOMID_IDLE;
1688
1689 target = xenbus_read(XBT_NIL, "target", "", NULL);
1690 if (IS_ERR(target) || kstrtouint(target, 10, &domid)) {
1691 pr_err("No target domain found, blocking all hypercalls\n");
1692 goto out;
1693 }
1694
1695 target_domain = domid;
1696
1697 out:
1698 if (!IS_ERR(target))
1699 kfree(target);
1700
1701 restrict_wait = false;
1702 wake_up_all(&restrict_wait_wq);
1703
1704 return NOTIFY_DONE;
1705}
1706
1707static struct notifier_block xenstore_notifier = {
1708 .notifier_call = init_restrict,
1709};
1710
1711static void __init restrict_driver(void)
1712{
1713 if (unrestricted) {
1714 if (security_locked_down(LOCKDOWN_XEN_USER_ACTIONS))
1715 pr_warn("Kernel is locked down, parameter \"unrestricted\" ignored\n");
1716 else
1717 return;
1718 }
1719
1720 restrict_wait = true;
1721
1722 register_xenstore_notifier(&xenstore_notifier);
1723}
1724
1725static int __init privcmd_init(void)
1726{
1727 int err;
1728
1729 if (!xen_domain())
1730 return -ENODEV;
1731
1732 if (!xen_initial_domain())
1733 restrict_driver();
1734
1735 err = misc_register(&privcmd_dev);
1736 if (err != 0) {
1737 pr_err("Could not register Xen privcmd device\n");
1738 return err;
1739 }
1740
1741 err = misc_register(&xen_privcmdbuf_dev);
1742 if (err != 0) {
1743 pr_err("Could not register Xen hypercall-buf device\n");
1744 goto err_privcmdbuf;
1745 }
1746
1747 err = privcmd_irqfd_init();
1748 if (err != 0) {
1749 pr_err("irqfd init failed\n");
1750 goto err_irqfd;
1751 }
1752
1753 return 0;
1754
1755err_irqfd:
1756 misc_deregister(&xen_privcmdbuf_dev);
1757err_privcmdbuf:
1758 misc_deregister(&privcmd_dev);
1759 return err;
1760}
1761
1762static void __exit privcmd_exit(void)
1763{
1764 if (!xen_initial_domain())
1765 unregister_xenstore_notifier(&xenstore_notifier);
1766
1767 privcmd_ioeventfd_exit();
1768 privcmd_irqfd_exit();
1769 misc_deregister(&privcmd_dev);
1770 misc_deregister(&xen_privcmdbuf_dev);
1771}
1772
1773module_init(privcmd_init);
1774module_exit(privcmd_exit);