1 // SPDX-License-Identifier: GPL-2.0-only
3 * VFIO: IOMMU DMA mapping support for Type1 IOMMU
5 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
6 * Author: Alex Williamson <alex.williamson@redhat.com>
8 * Derived from original vfio:
9 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
10 * Author: Tom Lyon, pugs@cisco.com
12 * We arbitrarily define a Type1 IOMMU as one matching the below code.
13 * It could be called the x86 IOMMU as it's designed for AMD-Vi & Intel
14 * VT-d, but that makes it harder to re-use as theoretically anyone
15 * implementing a similar IOMMU could make use of this. We expect the
16 * IOMMU to support the IOMMU API and have few to no restrictions around
17 * the IOVA range that can be mapped. The Type1 IOMMU is currently
18 * optimized for relatively static mappings of a userspace process with
19 * userspace pages pinned into memory. We also assume devices and IOMMU
20 * domains are PCI based as the IOMMU API is still centered around a
21 * device/bus interface rather than a group interface.
24 #include <linux/compat.h>
25 #include <linux/device.h>
27 #include <linux/highmem.h>
28 #include <linux/iommu.h>
29 #include <linux/module.h>
31 #include <linux/kthread.h>
32 #include <linux/rbtree.h>
33 #include <linux/sched/signal.h>
34 #include <linux/sched/mm.h>
35 #include <linux/slab.h>
36 #include <linux/uaccess.h>
37 #include <linux/vfio.h>
38 #include <linux/workqueue.h>
39 #include <linux/mdev.h>
40 #include <linux/notifier.h>
41 #include <linux/dma-iommu.h>
42 #include <linux/irqdomain.h>
44 #define DRIVER_VERSION "0.2"
45 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
46 #define DRIVER_DESC "Type1 IOMMU driver for VFIO"
48 static bool allow_unsafe_interrupts;
49 module_param_named(allow_unsafe_interrupts,
50 allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
51 MODULE_PARM_DESC(allow_unsafe_interrupts,
52 "Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
54 static bool disable_hugepages;
55 module_param_named(disable_hugepages,
56 disable_hugepages, bool, S_IRUGO | S_IWUSR);
57 MODULE_PARM_DESC(disable_hugepages,
58 "Disable VFIO IOMMU support for IOMMU hugepages.");
60 static unsigned int dma_entry_limit __read_mostly = U16_MAX;
61 module_param_named(dma_entry_limit, dma_entry_limit, uint, 0644);
62 MODULE_PARM_DESC(dma_entry_limit,
63 "Maximum number of user DMA mappings per container (65535).");
66 struct list_head domain_list;
67 struct list_head iova_list;
68 struct vfio_domain *external_domain; /* domain for external user */
70 struct rb_root dma_list;
71 struct blocking_notifier_head notifier;
72 unsigned int dma_avail;
73 unsigned int vaddr_invalid_count;
74 uint64_t pgsize_bitmap;
75 uint64_t num_non_pinned_groups;
76 wait_queue_head_t vaddr_wait;
79 bool dirty_page_tracking;
84 struct iommu_domain *domain;
85 struct list_head next;
86 struct list_head group_list;
87 int prot; /* IOMMU_CACHE */
88 bool fgsp; /* Fine-grained super pages */
93 dma_addr_t iova; /* Device address */
94 unsigned long vaddr; /* Process virtual addr */
95 size_t size; /* Map size (bytes) */
96 int prot; /* IOMMU_READ/WRITE */
98 bool lock_cap; /* capable(CAP_IPC_LOCK) */
100 struct task_struct *task;
101 struct rb_root pfn_list; /* Ex-user pinned pfn list */
102 unsigned long *bitmap;
106 struct page **pages; /* for pin_user_pages_remote */
107 struct page *fallback_page; /* if pages alloc fails */
108 int capacity; /* length of pages array */
109 int size; /* of batch currently */
110 int offset; /* of next entry in pages */
113 struct vfio_iommu_group {
114 struct iommu_group *iommu_group;
115 struct list_head next;
116 bool mdev_group; /* An mdev group */
117 bool pinned_page_dirty_scope;
121 struct list_head list;
127 * Guest RAM pinning working set or DMA target
131 dma_addr_t iova; /* Device address */
132 unsigned long pfn; /* Host pfn */
133 unsigned int ref_count;
136 struct vfio_regions {
137 struct list_head list;
143 #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \
144 (!list_empty(&iommu->domain_list))
146 #define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE)
149 * Input argument of number of bits to bitmap_set() is unsigned integer, which
150 * further casts to signed integer for unaligned multi-bit operation,
152 * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte,
153 * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page
156 #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX)
157 #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)
161 static int put_pfn(unsigned long pfn, int prot);
163 static struct vfio_iommu_group*
164 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
165 struct iommu_group *iommu_group);
168 * This code handles mapping and unmapping of user data buffers
169 * into DMA'ble space using the IOMMU
172 static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
173 dma_addr_t start, size_t size)
175 struct rb_node *node = iommu->dma_list.rb_node;
178 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
180 if (start + size <= dma->iova)
181 node = node->rb_left;
182 else if (start >= dma->iova + dma->size)
183 node = node->rb_right;
191 static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu,
192 dma_addr_t start, u64 size)
194 struct rb_node *res = NULL;
195 struct rb_node *node = iommu->dma_list.rb_node;
196 struct vfio_dma *dma_res = NULL;
199 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
201 if (start < dma->iova + dma->size) {
204 if (start >= dma->iova)
206 node = node->rb_left;
208 node = node->rb_right;
211 if (res && size && dma_res->iova >= start + size)
216 static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
218 struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
219 struct vfio_dma *dma;
223 dma = rb_entry(parent, struct vfio_dma, node);
225 if (new->iova + new->size <= dma->iova)
226 link = &(*link)->rb_left;
228 link = &(*link)->rb_right;
231 rb_link_node(&new->node, parent, link);
232 rb_insert_color(&new->node, &iommu->dma_list);
235 static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
237 rb_erase(&old->node, &iommu->dma_list);
241 static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize)
243 uint64_t npages = dma->size / pgsize;
245 if (npages > DIRTY_BITMAP_PAGES_MAX)
249 * Allocate extra 64 bits that are used to calculate shift required for
250 * bitmap_shift_left() to manipulate and club unaligned number of pages
251 * in adjacent vfio_dma ranges.
253 dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64),
261 static void vfio_dma_bitmap_free(struct vfio_dma *dma)
267 static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize)
270 unsigned long pgshift = __ffs(pgsize);
272 for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) {
273 struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node);
275 bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1);
279 static void vfio_iommu_populate_bitmap_full(struct vfio_iommu *iommu)
282 unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
284 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
285 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
287 bitmap_set(dma->bitmap, 0, dma->size >> pgshift);
291 static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize)
295 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
296 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
299 ret = vfio_dma_bitmap_alloc(dma, pgsize);
303 for (p = rb_prev(n); p; p = rb_prev(p)) {
304 struct vfio_dma *dma = rb_entry(n,
305 struct vfio_dma, node);
307 vfio_dma_bitmap_free(dma);
311 vfio_dma_populate_bitmap(dma, pgsize);
316 static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu)
320 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
321 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
323 vfio_dma_bitmap_free(dma);
328 * Helper Functions for host iova-pfn list
330 static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
332 struct vfio_pfn *vpfn;
333 struct rb_node *node = dma->pfn_list.rb_node;
336 vpfn = rb_entry(node, struct vfio_pfn, node);
338 if (iova < vpfn->iova)
339 node = node->rb_left;
340 else if (iova > vpfn->iova)
341 node = node->rb_right;
348 static void vfio_link_pfn(struct vfio_dma *dma,
349 struct vfio_pfn *new)
351 struct rb_node **link, *parent = NULL;
352 struct vfio_pfn *vpfn;
354 link = &dma->pfn_list.rb_node;
357 vpfn = rb_entry(parent, struct vfio_pfn, node);
359 if (new->iova < vpfn->iova)
360 link = &(*link)->rb_left;
362 link = &(*link)->rb_right;
365 rb_link_node(&new->node, parent, link);
366 rb_insert_color(&new->node, &dma->pfn_list);
369 static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
371 rb_erase(&old->node, &dma->pfn_list);
374 static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
377 struct vfio_pfn *vpfn;
379 vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
386 vfio_link_pfn(dma, vpfn);
390 static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
391 struct vfio_pfn *vpfn)
393 vfio_unlink_pfn(dma, vpfn);
397 static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
400 struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
407 static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
412 if (!vpfn->ref_count) {
413 ret = put_pfn(vpfn->pfn, dma->prot);
414 vfio_remove_from_pfn_list(dma, vpfn);
419 static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
421 struct mm_struct *mm;
427 mm = async ? get_task_mm(dma->task) : dma->task->mm;
429 return -ESRCH; /* process exited */
431 ret = mmap_write_lock_killable(mm);
433 ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task,
435 mmap_write_unlock(mm);
445 * Some mappings aren't backed by a struct page, for example an mmap'd
446 * MMIO range for our own or another device. These use a different
447 * pfn conversion and shouldn't be tracked as locked pages.
448 * For compound pages, any driver that sets the reserved bit in head
449 * page needs to set the reserved bit in all subpages to be safe.
451 static bool is_invalid_reserved_pfn(unsigned long pfn)
454 return PageReserved(pfn_to_page(pfn));
459 static int put_pfn(unsigned long pfn, int prot)
461 if (!is_invalid_reserved_pfn(pfn)) {
462 struct page *page = pfn_to_page(pfn);
464 unpin_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE);
470 #define VFIO_BATCH_MAX_CAPACITY (PAGE_SIZE / sizeof(struct page *))
472 static void vfio_batch_init(struct vfio_batch *batch)
477 if (unlikely(disable_hugepages))
480 batch->pages = (struct page **) __get_free_page(GFP_KERNEL);
484 batch->capacity = VFIO_BATCH_MAX_CAPACITY;
488 batch->pages = &batch->fallback_page;
492 static void vfio_batch_unpin(struct vfio_batch *batch, struct vfio_dma *dma)
494 while (batch->size) {
495 unsigned long pfn = page_to_pfn(batch->pages[batch->offset]);
497 put_pfn(pfn, dma->prot);
503 static void vfio_batch_fini(struct vfio_batch *batch)
505 if (batch->capacity == VFIO_BATCH_MAX_CAPACITY)
506 free_page((unsigned long)batch->pages);
509 static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
510 unsigned long vaddr, unsigned long *pfn,
517 ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
519 bool unlocked = false;
521 ret = fixup_user_fault(mm, vaddr,
523 (write_fault ? FAULT_FLAG_WRITE : 0),
531 ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
536 if (write_fault && !pte_write(*ptep))
539 *pfn = pte_pfn(*ptep);
541 pte_unmap_unlock(ptep, ptl);
546 * Returns the positive number of pfns successfully obtained or a negative
549 static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
550 long npages, int prot, unsigned long *pfn,
553 struct vm_area_struct *vma;
554 unsigned int flags = 0;
557 if (prot & IOMMU_WRITE)
561 ret = pin_user_pages_remote(mm, vaddr, npages, flags | FOLL_LONGTERM,
564 *pfn = page_to_pfn(pages[0]);
568 vaddr = untagged_addr(vaddr);
571 vma = vma_lookup(mm, vaddr);
573 if (vma && vma->vm_flags & VM_PFNMAP) {
574 ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE);
579 if (is_invalid_reserved_pfn(*pfn))
586 mmap_read_unlock(mm);
590 static int vfio_wait(struct vfio_iommu *iommu)
594 prepare_to_wait(&iommu->vaddr_wait, &wait, TASK_KILLABLE);
595 mutex_unlock(&iommu->lock);
597 mutex_lock(&iommu->lock);
598 finish_wait(&iommu->vaddr_wait, &wait);
599 if (kthread_should_stop() || !iommu->container_open ||
600 fatal_signal_pending(current)) {
607 * Find dma struct and wait for its vaddr to be valid. iommu lock is dropped
608 * if the task waits, but is re-locked on return. Return result in *dma_p.
609 * Return 0 on success with no waiting, WAITED on success if waited, and -errno
612 static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
613 size_t size, struct vfio_dma **dma_p)
618 *dma_p = vfio_find_dma(iommu, start, size);
621 else if (!(*dma_p)->vaddr_invalid)
624 ret = vfio_wait(iommu);
631 * Wait for all vaddr in the dma_list to become valid. iommu lock is dropped
632 * if the task waits, but is re-locked on return. Return 0 on success with no
633 * waiting, WAITED on success if waited, and -errno on error.
635 static int vfio_wait_all_valid(struct vfio_iommu *iommu)
639 while (iommu->vaddr_invalid_count && ret >= 0)
640 ret = vfio_wait(iommu);
646 * Attempt to pin pages. We really don't want to track all the pfns and
647 * the iommu can only map chunks of consecutive pfns anyway, so get the
648 * first page and all consecutive pages with the same locking.
650 static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
651 long npage, unsigned long *pfn_base,
652 unsigned long limit, struct vfio_batch *batch)
655 struct mm_struct *mm = current->mm;
656 long ret, pinned = 0, lock_acct = 0;
658 dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
660 /* This code path is only user initiated */
665 /* Leftover pages in batch from an earlier call. */
666 *pfn_base = page_to_pfn(batch->pages[batch->offset]);
668 rsvd = is_invalid_reserved_pfn(*pfn_base);
675 /* Empty batch, so refill it. */
676 long req_pages = min_t(long, npage, batch->capacity);
678 ret = vaddr_get_pfns(mm, vaddr, req_pages, dma->prot,
688 rsvd = is_invalid_reserved_pfn(*pfn_base);
693 * pfn is preset for the first iteration of this inner loop and
694 * updated at the end to handle a VM_PFNMAP pfn. In that case,
695 * batch->pages isn't valid (there's no struct page), so allow
696 * batch->pages to be touched only when there's more than one
697 * pfn to check, which guarantees the pfns are from a
701 if (pfn != *pfn_base + pinned ||
702 rsvd != is_invalid_reserved_pfn(pfn))
706 * Reserved pages aren't counted against the user,
707 * externally pinned pages are already counted against
710 if (!rsvd && !vfio_find_vpfn(dma, iova)) {
711 if (!dma->lock_cap &&
712 mm->locked_vm + lock_acct + 1 > limit) {
713 pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
714 __func__, limit << PAGE_SHIFT);
731 pfn = page_to_pfn(batch->pages[batch->offset]);
734 if (unlikely(disable_hugepages))
739 ret = vfio_lock_acct(dma, lock_acct, false);
742 if (batch->size == 1 && !batch->offset) {
743 /* May be a VM_PFNMAP pfn, which the batch can't remember. */
744 put_pfn(pfn, dma->prot);
749 if (pinned && !rsvd) {
750 for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
751 put_pfn(pfn, dma->prot);
753 vfio_batch_unpin(batch, dma);
761 static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
762 unsigned long pfn, long npage,
765 long unlocked = 0, locked = 0;
768 for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
769 if (put_pfn(pfn++, dma->prot)) {
771 if (vfio_find_vpfn(dma, iova))
777 vfio_lock_acct(dma, locked - unlocked, true);
782 static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
783 unsigned long *pfn_base, bool do_accounting)
785 struct page *pages[1];
786 struct mm_struct *mm;
789 mm = get_task_mm(dma->task);
793 ret = vaddr_get_pfns(mm, vaddr, 1, dma->prot, pfn_base, pages);
799 if (do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
800 ret = vfio_lock_acct(dma, 1, true);
802 put_pfn(*pfn_base, dma->prot);
804 pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK "
805 "(%ld) exceeded\n", __func__,
806 dma->task->comm, task_pid_nr(dma->task),
807 task_rlimit(dma->task, RLIMIT_MEMLOCK));
816 static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
820 struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
825 unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
828 vfio_lock_acct(dma, -unlocked, true);
833 static int vfio_iommu_type1_pin_pages(void *iommu_data,
834 struct iommu_group *iommu_group,
835 unsigned long *user_pfn,
837 unsigned long *phys_pfn)
839 struct vfio_iommu *iommu = iommu_data;
840 struct vfio_iommu_group *group;
842 unsigned long remote_vaddr;
843 struct vfio_dma *dma;
847 if (!iommu || !user_pfn || !phys_pfn)
850 /* Supported for v2 version only */
854 mutex_lock(&iommu->lock);
857 * Wait for all necessary vaddr's to be valid so they can be used in
858 * the main loop without dropping the lock, to avoid racing vs unmap.
861 if (iommu->vaddr_invalid_count) {
862 for (i = 0; i < npage; i++) {
863 iova = user_pfn[i] << PAGE_SHIFT;
864 ret = vfio_find_dma_valid(iommu, iova, PAGE_SIZE, &dma);
872 /* Fail if notifier list is empty */
873 if (!iommu->notifier.head) {
879 * If iommu capable domain exist in the container then all pages are
880 * already pinned and accounted. Accounting should be done if there is no
881 * iommu capable domain in the container.
883 do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
885 for (i = 0; i < npage; i++) {
886 struct vfio_pfn *vpfn;
888 iova = user_pfn[i] << PAGE_SHIFT;
889 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
895 if ((dma->prot & prot) != prot) {
900 vpfn = vfio_iova_get_vfio_pfn(dma, iova);
902 phys_pfn[i] = vpfn->pfn;
906 remote_vaddr = dma->vaddr + (iova - dma->iova);
907 ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
912 ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
914 if (put_pfn(phys_pfn[i], dma->prot) && do_accounting)
915 vfio_lock_acct(dma, -1, true);
919 if (iommu->dirty_page_tracking) {
920 unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
923 * Bitmap populated with the smallest supported page
926 bitmap_set(dma->bitmap,
927 (iova - dma->iova) >> pgshift, 1);
932 group = vfio_iommu_find_iommu_group(iommu, iommu_group);
933 if (!group->pinned_page_dirty_scope) {
934 group->pinned_page_dirty_scope = true;
935 iommu->num_non_pinned_groups--;
942 for (j = 0; j < i; j++) {
945 iova = user_pfn[j] << PAGE_SHIFT;
946 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
947 vfio_unpin_page_external(dma, iova, do_accounting);
951 mutex_unlock(&iommu->lock);
955 static int vfio_iommu_type1_unpin_pages(void *iommu_data,
956 unsigned long *user_pfn,
959 struct vfio_iommu *iommu = iommu_data;
963 if (!iommu || !user_pfn || npage <= 0)
966 /* Supported for v2 version only */
970 mutex_lock(&iommu->lock);
972 do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
973 for (i = 0; i < npage; i++) {
974 struct vfio_dma *dma;
977 iova = user_pfn[i] << PAGE_SHIFT;
978 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
982 vfio_unpin_page_external(dma, iova, do_accounting);
985 mutex_unlock(&iommu->lock);
986 return i > 0 ? i : -EINVAL;
989 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
990 struct list_head *regions,
991 struct iommu_iotlb_gather *iotlb_gather)
994 struct vfio_regions *entry, *next;
996 iommu_iotlb_sync(domain->domain, iotlb_gather);
998 list_for_each_entry_safe(entry, next, regions, list) {
999 unlocked += vfio_unpin_pages_remote(dma,
1001 entry->phys >> PAGE_SHIFT,
1002 entry->len >> PAGE_SHIFT,
1004 list_del(&entry->list);
1014 * Generally, VFIO needs to unpin remote pages after each IOTLB flush.
1015 * Therefore, when using IOTLB flush sync interface, VFIO need to keep track
1016 * of these regions (currently using a list).
1018 * This value specifies maximum number of regions for each IOTLB flush sync.
1020 #define VFIO_IOMMU_TLB_SYNC_MAX 512
1022 static size_t unmap_unpin_fast(struct vfio_domain *domain,
1023 struct vfio_dma *dma, dma_addr_t *iova,
1024 size_t len, phys_addr_t phys, long *unlocked,
1025 struct list_head *unmapped_list,
1027 struct iommu_iotlb_gather *iotlb_gather)
1029 size_t unmapped = 0;
1030 struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1033 unmapped = iommu_unmap_fast(domain->domain, *iova, len,
1039 entry->iova = *iova;
1041 entry->len = unmapped;
1042 list_add_tail(&entry->list, unmapped_list);
1050 * Sync if the number of fast-unmap regions hits the limit
1051 * or in case of errors.
1053 if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) {
1054 *unlocked += vfio_sync_unpin(dma, domain, unmapped_list,
1062 static size_t unmap_unpin_slow(struct vfio_domain *domain,
1063 struct vfio_dma *dma, dma_addr_t *iova,
1064 size_t len, phys_addr_t phys,
1067 size_t unmapped = iommu_unmap(domain->domain, *iova, len);
1070 *unlocked += vfio_unpin_pages_remote(dma, *iova,
1072 unmapped >> PAGE_SHIFT,
1080 static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
1083 dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
1084 struct vfio_domain *domain, *d;
1085 LIST_HEAD(unmapped_region_list);
1086 struct iommu_iotlb_gather iotlb_gather;
1087 int unmapped_region_cnt = 0;
1093 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
1097 * We use the IOMMU to track the physical addresses, otherwise we'd
1098 * need a much more complicated tracking system. Unfortunately that
1099 * means we need to use one of the iommu domains to figure out the
1100 * pfns to unpin. The rest need to be unmapped in advance so we have
1101 * no iommu translations remaining when the pages are unpinned.
1103 domain = d = list_first_entry(&iommu->domain_list,
1104 struct vfio_domain, next);
1106 list_for_each_entry_continue(d, &iommu->domain_list, next) {
1107 iommu_unmap(d->domain, dma->iova, dma->size);
1111 iommu_iotlb_gather_init(&iotlb_gather);
1112 while (iova < end) {
1113 size_t unmapped, len;
1114 phys_addr_t phys, next;
1116 phys = iommu_iova_to_phys(domain->domain, iova);
1117 if (WARN_ON(!phys)) {
1123 * To optimize for fewer iommu_unmap() calls, each of which
1124 * may require hardware cache flushing, try to find the
1125 * largest contiguous physical memory chunk to unmap.
1127 for (len = PAGE_SIZE;
1128 !domain->fgsp && iova + len < end; len += PAGE_SIZE) {
1129 next = iommu_iova_to_phys(domain->domain, iova + len);
1130 if (next != phys + len)
1135 * First, try to use fast unmap/unpin. In case of failure,
1136 * switch to slow unmap/unpin path.
1138 unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys,
1139 &unlocked, &unmapped_region_list,
1140 &unmapped_region_cnt,
1143 unmapped = unmap_unpin_slow(domain, dma, &iova, len,
1145 if (WARN_ON(!unmapped))
1150 dma->iommu_mapped = false;
1152 if (unmapped_region_cnt) {
1153 unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list,
1157 if (do_accounting) {
1158 vfio_lock_acct(dma, -unlocked, true);
1164 static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
1166 WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
1167 vfio_unmap_unpin(iommu, dma, true);
1168 vfio_unlink_dma(iommu, dma);
1169 put_task_struct(dma->task);
1170 vfio_dma_bitmap_free(dma);
1171 if (dma->vaddr_invalid) {
1172 iommu->vaddr_invalid_count--;
1173 wake_up_all(&iommu->vaddr_wait);
1179 static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu)
1181 struct vfio_domain *domain;
1183 iommu->pgsize_bitmap = ULONG_MAX;
1185 list_for_each_entry(domain, &iommu->domain_list, next)
1186 iommu->pgsize_bitmap &= domain->domain->pgsize_bitmap;
1189 * In case the IOMMU supports page sizes smaller than PAGE_SIZE
1190 * we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
1191 * That way the user will be able to map/unmap buffers whose size/
1192 * start address is aligned with PAGE_SIZE. Pinning code uses that
1193 * granularity while iommu driver can use the sub-PAGE_SIZE size
1194 * to map the buffer.
1196 if (iommu->pgsize_bitmap & ~PAGE_MASK) {
1197 iommu->pgsize_bitmap &= PAGE_MASK;
1198 iommu->pgsize_bitmap |= PAGE_SIZE;
1202 static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
1203 struct vfio_dma *dma, dma_addr_t base_iova,
1206 unsigned long pgshift = __ffs(pgsize);
1207 unsigned long nbits = dma->size >> pgshift;
1208 unsigned long bit_offset = (dma->iova - base_iova) >> pgshift;
1209 unsigned long copy_offset = bit_offset / BITS_PER_LONG;
1210 unsigned long shift = bit_offset % BITS_PER_LONG;
1211 unsigned long leftover;
1214 * mark all pages dirty if any IOMMU capable device is not able
1215 * to report dirty pages and all pages are pinned and mapped.
1217 if (iommu->num_non_pinned_groups && dma->iommu_mapped)
1218 bitmap_set(dma->bitmap, 0, nbits);
1221 bitmap_shift_left(dma->bitmap, dma->bitmap, shift,
1224 if (copy_from_user(&leftover,
1225 (void __user *)(bitmap + copy_offset),
1229 bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift);
1232 if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap,
1233 DIRTY_BITMAP_BYTES(nbits + shift)))
1239 static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
1240 dma_addr_t iova, size_t size, size_t pgsize)
1242 struct vfio_dma *dma;
1244 unsigned long pgshift = __ffs(pgsize);
1248 * GET_BITMAP request must fully cover vfio_dma mappings. Multiple
1249 * vfio_dma mappings may be clubbed by specifying large ranges, but
1250 * there must not be any previous mappings bisected by the range.
1251 * An error will be returned if these conditions are not met.
1253 dma = vfio_find_dma(iommu, iova, 1);
1254 if (dma && dma->iova != iova)
1257 dma = vfio_find_dma(iommu, iova + size - 1, 0);
1258 if (dma && dma->iova + dma->size != iova + size)
1261 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
1262 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1264 if (dma->iova < iova)
1267 if (dma->iova > iova + size - 1)
1270 ret = update_user_bitmap(bitmap, iommu, dma, iova, pgsize);
1275 * Re-populate bitmap to include all pinned pages which are
1276 * considered as dirty but exclude pages which are unpinned and
1277 * pages which are marked dirty by vfio_dma_rw()
1279 bitmap_clear(dma->bitmap, 0, dma->size >> pgshift);
1280 vfio_dma_populate_bitmap(dma, pgsize);
1285 static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size)
1287 if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) ||
1288 (bitmap_size < DIRTY_BITMAP_BYTES(npages)))
1294 static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
1295 struct vfio_iommu_type1_dma_unmap *unmap,
1296 struct vfio_bitmap *bitmap)
1298 struct vfio_dma *dma, *dma_last = NULL;
1299 size_t unmapped = 0, pgsize;
1300 int ret = -EINVAL, retries = 0;
1301 unsigned long pgshift;
1302 dma_addr_t iova = unmap->iova;
1303 u64 size = unmap->size;
1304 bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL;
1305 bool invalidate_vaddr = unmap->flags & VFIO_DMA_UNMAP_FLAG_VADDR;
1306 struct rb_node *n, *first_n;
1308 mutex_lock(&iommu->lock);
1310 pgshift = __ffs(iommu->pgsize_bitmap);
1311 pgsize = (size_t)1 << pgshift;
1313 if (iova & (pgsize - 1))
1320 } else if (!size || size & (pgsize - 1) ||
1321 iova + size - 1 < iova || size > SIZE_MAX) {
1325 /* When dirty tracking is enabled, allow only min supported pgsize */
1326 if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
1327 (!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) {
1331 WARN_ON((pgsize - 1) & PAGE_MASK);
1334 * vfio-iommu-type1 (v1) - User mappings were coalesced together to
1335 * avoid tracking individual mappings. This means that the granularity
1336 * of the original mapping was lost and the user was allowed to attempt
1337 * to unmap any range. Depending on the contiguousness of physical
1338 * memory and page sizes supported by the IOMMU, arbitrary unmaps may
1339 * or may not have worked. We only guaranteed unmap granularity
1340 * matching the original mapping; even though it was untracked here,
1341 * the original mappings are reflected in IOMMU mappings. This
1342 * resulted in a couple unusual behaviors. First, if a range is not
1343 * able to be unmapped, ex. a set of 4k pages that was mapped as a
1344 * 2M hugepage into the IOMMU, the unmap ioctl returns success but with
1345 * a zero sized unmap. Also, if an unmap request overlaps the first
1346 * address of a hugepage, the IOMMU will unmap the entire hugepage.
1347 * This also returns success and the returned unmap size reflects the
1348 * actual size unmapped.
1350 * We attempt to maintain compatibility with this "v1" interface, but
1351 * we take control out of the hands of the IOMMU. Therefore, an unmap
1352 * request offset from the beginning of the original mapping will
1353 * return success with zero sized unmap. And an unmap request covering
1354 * the first iova of mapping will unmap the entire range.
1356 * The v2 version of this interface intends to be more deterministic.
1357 * Unmap requests must fully cover previous mappings. Multiple
1358 * mappings may still be unmaped by specifying large ranges, but there
1359 * must not be any previous mappings bisected by the range. An error
1360 * will be returned if these conditions are not met. The v2 interface
1361 * will only return success and a size of zero if there were no
1362 * mappings within the range.
1364 if (iommu->v2 && !unmap_all) {
1365 dma = vfio_find_dma(iommu, iova, 1);
1366 if (dma && dma->iova != iova)
1369 dma = vfio_find_dma(iommu, iova + size - 1, 0);
1370 if (dma && dma->iova + dma->size != iova + size)
1375 n = first_n = vfio_find_dma_first_node(iommu, iova, size);
1378 dma = rb_entry(n, struct vfio_dma, node);
1379 if (dma->iova >= iova + size)
1382 if (!iommu->v2 && iova > dma->iova)
1385 * Task with same address space who mapped this iova range is
1386 * allowed to unmap the iova range.
1388 if (dma->task->mm != current->mm)
1391 if (invalidate_vaddr) {
1392 if (dma->vaddr_invalid) {
1393 struct rb_node *last_n = n;
1395 for (n = first_n; n != last_n; n = rb_next(n)) {
1397 struct vfio_dma, node);
1398 dma->vaddr_invalid = false;
1399 iommu->vaddr_invalid_count--;
1405 dma->vaddr_invalid = true;
1406 iommu->vaddr_invalid_count++;
1407 unmapped += dma->size;
1412 if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
1413 struct vfio_iommu_type1_dma_unmap nb_unmap;
1415 if (dma_last == dma) {
1416 BUG_ON(++retries > 10);
1422 nb_unmap.iova = dma->iova;
1423 nb_unmap.size = dma->size;
1426 * Notify anyone (mdev vendor drivers) to invalidate and
1427 * unmap iovas within the range we're about to unmap.
1428 * Vendor drivers MUST unpin pages in response to an
1431 mutex_unlock(&iommu->lock);
1432 blocking_notifier_call_chain(&iommu->notifier,
1433 VFIO_IOMMU_NOTIFY_DMA_UNMAP,
1435 mutex_lock(&iommu->lock);
1439 if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
1440 ret = update_user_bitmap(bitmap->data, iommu, dma,
1446 unmapped += dma->size;
1448 vfio_remove_dma(iommu, dma);
1452 mutex_unlock(&iommu->lock);
1454 /* Report how much was unmapped */
1455 unmap->size = unmapped;
1460 static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
1461 unsigned long pfn, long npage, int prot)
1463 struct vfio_domain *d;
1466 list_for_each_entry(d, &iommu->domain_list, next) {
1467 ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
1468 npage << PAGE_SHIFT, prot | d->prot);
1478 list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
1479 iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
1486 static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
1489 dma_addr_t iova = dma->iova;
1490 unsigned long vaddr = dma->vaddr;
1491 struct vfio_batch batch;
1492 size_t size = map_size;
1494 unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1497 vfio_batch_init(&batch);
1500 /* Pin a contiguous chunk of memory */
1501 npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
1502 size >> PAGE_SHIFT, &pfn, limit,
1511 ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
1514 vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
1516 vfio_batch_unpin(&batch, dma);
1520 size -= npage << PAGE_SHIFT;
1521 dma->size += npage << PAGE_SHIFT;
1524 vfio_batch_fini(&batch);
1525 dma->iommu_mapped = true;
1528 vfio_remove_dma(iommu, dma);
1534 * Check dma map request is within a valid iova range
1536 static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu,
1537 dma_addr_t start, dma_addr_t end)
1539 struct list_head *iova = &iommu->iova_list;
1540 struct vfio_iova *node;
1542 list_for_each_entry(node, iova, list) {
1543 if (start >= node->start && end <= node->end)
1548 * Check for list_empty() as well since a container with
1549 * a single mdev device will have an empty list.
1551 return list_empty(iova);
1554 static int vfio_dma_do_map(struct vfio_iommu *iommu,
1555 struct vfio_iommu_type1_dma_map *map)
1557 bool set_vaddr = map->flags & VFIO_DMA_MAP_FLAG_VADDR;
1558 dma_addr_t iova = map->iova;
1559 unsigned long vaddr = map->vaddr;
1560 size_t size = map->size;
1561 int ret = 0, prot = 0;
1563 struct vfio_dma *dma;
1565 /* Verify that none of our __u64 fields overflow */
1566 if (map->size != size || map->vaddr != vaddr || map->iova != iova)
1569 /* READ/WRITE from device perspective */
1570 if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
1571 prot |= IOMMU_WRITE;
1572 if (map->flags & VFIO_DMA_MAP_FLAG_READ)
1575 if ((prot && set_vaddr) || (!prot && !set_vaddr))
1578 mutex_lock(&iommu->lock);
1580 pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
1582 WARN_ON((pgsize - 1) & PAGE_MASK);
1584 if (!size || (size | iova | vaddr) & (pgsize - 1)) {
1589 /* Don't allow IOVA or virtual address wrap */
1590 if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) {
1595 dma = vfio_find_dma(iommu, iova, size);
1599 } else if (!dma->vaddr_invalid || dma->iova != iova ||
1600 dma->size != size) {
1604 dma->vaddr_invalid = false;
1605 iommu->vaddr_invalid_count--;
1606 wake_up_all(&iommu->vaddr_wait);
1614 if (!iommu->dma_avail) {
1619 if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) {
1624 dma = kzalloc(sizeof(*dma), GFP_KERNEL);
1636 * We need to be able to both add to a task's locked memory and test
1637 * against the locked memory limit and we need to be able to do both
1638 * outside of this call path as pinning can be asynchronous via the
1639 * external interfaces for mdev devices. RLIMIT_MEMLOCK requires a
1640 * task_struct and VM locked pages requires an mm_struct, however
1641 * holding an indefinite mm reference is not recommended, therefore we
1642 * only hold a reference to a task. We could hold a reference to
1643 * current, however QEMU uses this call path through vCPU threads,
1644 * which can be killed resulting in a NULL mm and failure in the unmap
1645 * path when called via a different thread. Avoid this problem by
1646 * using the group_leader as threads within the same group require
1647 * both CLONE_THREAD and CLONE_VM and will therefore use the same
1650 * Previously we also used the task for testing CAP_IPC_LOCK at the
1651 * time of pinning and accounting, however has_capability() makes use
1652 * of real_cred, a copy-on-write field, so we can't guarantee that it
1653 * matches group_leader, or in fact that it might not change by the
1654 * time it's evaluated. If a process were to call MAP_DMA with
1655 * CAP_IPC_LOCK but later drop it, it doesn't make sense that they
1656 * possibly see different results for an iommu_mapped vfio_dma vs
1657 * externally mapped. Therefore track CAP_IPC_LOCK in vfio_dma at the
1658 * time of calling MAP_DMA.
1660 get_task_struct(current->group_leader);
1661 dma->task = current->group_leader;
1662 dma->lock_cap = capable(CAP_IPC_LOCK);
1664 dma->pfn_list = RB_ROOT;
1666 /* Insert zero-sized and grow as we map chunks of it */
1667 vfio_link_dma(iommu, dma);
1669 /* Don't pin and map if container doesn't contain IOMMU capable domain*/
1670 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
1673 ret = vfio_pin_map_dma(iommu, dma, size);
1675 if (!ret && iommu->dirty_page_tracking) {
1676 ret = vfio_dma_bitmap_alloc(dma, pgsize);
1678 vfio_remove_dma(iommu, dma);
1682 mutex_unlock(&iommu->lock);
1686 static int vfio_bus_type(struct device *dev, void *data)
1688 struct bus_type **bus = data;
1690 if (*bus && *bus != dev->bus)
1698 static int vfio_iommu_replay(struct vfio_iommu *iommu,
1699 struct vfio_domain *domain)
1701 struct vfio_batch batch;
1702 struct vfio_domain *d = NULL;
1704 unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1707 ret = vfio_wait_all_valid(iommu);
1711 /* Arbitrarily pick the first domain in the list for lookups */
1712 if (!list_empty(&iommu->domain_list))
1713 d = list_first_entry(&iommu->domain_list,
1714 struct vfio_domain, next);
1716 vfio_batch_init(&batch);
1718 n = rb_first(&iommu->dma_list);
1720 for (; n; n = rb_next(n)) {
1721 struct vfio_dma *dma;
1724 dma = rb_entry(n, struct vfio_dma, node);
1727 while (iova < dma->iova + dma->size) {
1731 if (dma->iommu_mapped) {
1735 if (WARN_ON(!d)) { /* mapped w/o a domain?! */
1740 phys = iommu_iova_to_phys(d->domain, iova);
1742 if (WARN_ON(!phys)) {
1750 while (i < dma->iova + dma->size &&
1751 p == iommu_iova_to_phys(d->domain, i)) {
1758 unsigned long vaddr = dma->vaddr +
1760 size_t n = dma->iova + dma->size - iova;
1763 npage = vfio_pin_pages_remote(dma, vaddr,
1773 phys = pfn << PAGE_SHIFT;
1774 size = npage << PAGE_SHIFT;
1777 ret = iommu_map(domain->domain, iova, phys,
1778 size, dma->prot | domain->prot);
1780 if (!dma->iommu_mapped) {
1781 vfio_unpin_pages_remote(dma, iova,
1785 vfio_batch_unpin(&batch, dma);
1794 /* All dmas are now mapped, defer to second tree walk for unwind */
1795 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
1796 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1798 dma->iommu_mapped = true;
1801 vfio_batch_fini(&batch);
1805 for (; n; n = rb_prev(n)) {
1806 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1809 if (dma->iommu_mapped) {
1810 iommu_unmap(domain->domain, dma->iova, dma->size);
1815 while (iova < dma->iova + dma->size) {
1816 phys_addr_t phys, p;
1820 phys = iommu_iova_to_phys(domain->domain, iova);
1829 while (i < dma->iova + dma->size &&
1830 p == iommu_iova_to_phys(domain->domain, i)) {
1836 iommu_unmap(domain->domain, iova, size);
1837 vfio_unpin_pages_remote(dma, iova, phys >> PAGE_SHIFT,
1838 size >> PAGE_SHIFT, true);
1842 vfio_batch_fini(&batch);
1847 * We change our unmap behavior slightly depending on whether the IOMMU
1848 * supports fine-grained superpages. IOMMUs like AMD-Vi will use a superpage
1849 * for practically any contiguous power-of-two mapping we give it. This means
1850 * we don't need to look for contiguous chunks ourselves to make unmapping
1851 * more efficient. On IOMMUs with coarse-grained super pages, like Intel VT-d
1852 * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
1853 * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
1854 * hugetlbfs is in use.
1856 static void vfio_test_domain_fgsp(struct vfio_domain *domain)
1859 int ret, order = get_order(PAGE_SIZE * 2);
1861 pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
1865 ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
1866 IOMMU_READ | IOMMU_WRITE | domain->prot);
1868 size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
1870 if (unmapped == PAGE_SIZE)
1871 iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
1873 domain->fgsp = true;
1876 __free_pages(pages, order);
1879 static struct vfio_iommu_group *find_iommu_group(struct vfio_domain *domain,
1880 struct iommu_group *iommu_group)
1882 struct vfio_iommu_group *g;
1884 list_for_each_entry(g, &domain->group_list, next) {
1885 if (g->iommu_group == iommu_group)
1892 static struct vfio_iommu_group*
1893 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
1894 struct iommu_group *iommu_group)
1896 struct vfio_domain *domain;
1897 struct vfio_iommu_group *group = NULL;
1899 list_for_each_entry(domain, &iommu->domain_list, next) {
1900 group = find_iommu_group(domain, iommu_group);
1905 if (iommu->external_domain)
1906 group = find_iommu_group(iommu->external_domain, iommu_group);
1911 static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
1914 struct iommu_resv_region *region;
1917 list_for_each_entry(region, group_resv_regions, list) {
1919 * The presence of any 'real' MSI regions should take
1920 * precedence over the software-managed one if the
1921 * IOMMU driver happens to advertise both types.
1923 if (region->type == IOMMU_RESV_MSI) {
1928 if (region->type == IOMMU_RESV_SW_MSI) {
1929 *base = region->start;
1937 static int vfio_mdev_attach_domain(struct device *dev, void *data)
1939 struct mdev_device *mdev = to_mdev_device(dev);
1940 struct iommu_domain *domain = data;
1941 struct device *iommu_device;
1943 iommu_device = mdev_get_iommu_device(mdev);
1945 if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
1946 return iommu_aux_attach_device(domain, iommu_device);
1948 return iommu_attach_device(domain, iommu_device);
1954 static int vfio_mdev_detach_domain(struct device *dev, void *data)
1956 struct mdev_device *mdev = to_mdev_device(dev);
1957 struct iommu_domain *domain = data;
1958 struct device *iommu_device;
1960 iommu_device = mdev_get_iommu_device(mdev);
1962 if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
1963 iommu_aux_detach_device(domain, iommu_device);
1965 iommu_detach_device(domain, iommu_device);
1971 static int vfio_iommu_attach_group(struct vfio_domain *domain,
1972 struct vfio_iommu_group *group)
1974 if (group->mdev_group)
1975 return iommu_group_for_each_dev(group->iommu_group,
1977 vfio_mdev_attach_domain);
1979 return iommu_attach_group(domain->domain, group->iommu_group);
1982 static void vfio_iommu_detach_group(struct vfio_domain *domain,
1983 struct vfio_iommu_group *group)
1985 if (group->mdev_group)
1986 iommu_group_for_each_dev(group->iommu_group, domain->domain,
1987 vfio_mdev_detach_domain);
1989 iommu_detach_group(domain->domain, group->iommu_group);
1992 static bool vfio_bus_is_mdev(struct bus_type *bus)
1994 struct bus_type *mdev_bus;
1997 mdev_bus = symbol_get(mdev_bus_type);
1999 ret = (bus == mdev_bus);
2000 symbol_put(mdev_bus_type);
2006 static int vfio_mdev_iommu_device(struct device *dev, void *data)
2008 struct mdev_device *mdev = to_mdev_device(dev);
2009 struct device **old = data, *new;
2011 new = mdev_get_iommu_device(mdev);
2012 if (!new || (*old && *old != new))
2021 * This is a helper function to insert an address range to iova list.
2022 * The list is initially created with a single entry corresponding to
2023 * the IOMMU domain geometry to which the device group is attached.
2024 * The list aperture gets modified when a new domain is added to the
2025 * container if the new aperture doesn't conflict with the current one
2026 * or with any existing dma mappings. The list is also modified to
2027 * exclude any reserved regions associated with the device group.
2029 static int vfio_iommu_iova_insert(struct list_head *head,
2030 dma_addr_t start, dma_addr_t end)
2032 struct vfio_iova *region;
2034 region = kmalloc(sizeof(*region), GFP_KERNEL);
2038 INIT_LIST_HEAD(®ion->list);
2039 region->start = start;
2042 list_add_tail(®ion->list, head);
2047 * Check the new iommu aperture conflicts with existing aper or with any
2048 * existing dma mappings.
2050 static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu,
2051 dma_addr_t start, dma_addr_t end)
2053 struct vfio_iova *first, *last;
2054 struct list_head *iova = &iommu->iova_list;
2056 if (list_empty(iova))
2059 /* Disjoint sets, return conflict */
2060 first = list_first_entry(iova, struct vfio_iova, list);
2061 last = list_last_entry(iova, struct vfio_iova, list);
2062 if (start > last->end || end < first->start)
2065 /* Check for any existing dma mappings below the new start */
2066 if (start > first->start) {
2067 if (vfio_find_dma(iommu, first->start, start - first->start))
2071 /* Check for any existing dma mappings beyond the new end */
2072 if (end < last->end) {
2073 if (vfio_find_dma(iommu, end + 1, last->end - end))
2081 * Resize iommu iova aperture window. This is called only if the new
2082 * aperture has no conflict with existing aperture and dma mappings.
2084 static int vfio_iommu_aper_resize(struct list_head *iova,
2085 dma_addr_t start, dma_addr_t end)
2087 struct vfio_iova *node, *next;
2089 if (list_empty(iova))
2090 return vfio_iommu_iova_insert(iova, start, end);
2092 /* Adjust iova list start */
2093 list_for_each_entry_safe(node, next, iova, list) {
2094 if (start < node->start)
2096 if (start >= node->start && start < node->end) {
2097 node->start = start;
2100 /* Delete nodes before new start */
2101 list_del(&node->list);
2105 /* Adjust iova list end */
2106 list_for_each_entry_safe(node, next, iova, list) {
2107 if (end > node->end)
2109 if (end > node->start && end <= node->end) {
2113 /* Delete nodes after new end */
2114 list_del(&node->list);
2122 * Check reserved region conflicts with existing dma mappings
2124 static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
2125 struct list_head *resv_regions)
2127 struct iommu_resv_region *region;
2129 /* Check for conflict with existing dma mappings */
2130 list_for_each_entry(region, resv_regions, list) {
2131 if (region->type == IOMMU_RESV_DIRECT_RELAXABLE)
2134 if (vfio_find_dma(iommu, region->start, region->length))
2142 * Check iova region overlap with reserved regions and
2143 * exclude them from the iommu iova range
2145 static int vfio_iommu_resv_exclude(struct list_head *iova,
2146 struct list_head *resv_regions)
2148 struct iommu_resv_region *resv;
2149 struct vfio_iova *n, *next;
2151 list_for_each_entry(resv, resv_regions, list) {
2152 phys_addr_t start, end;
2154 if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE)
2157 start = resv->start;
2158 end = resv->start + resv->length - 1;
2160 list_for_each_entry_safe(n, next, iova, list) {
2164 if (start > n->end || end < n->start)
2167 * Insert a new node if current node overlaps with the
2168 * reserve region to exclude that from valid iova range.
2169 * Note that, new node is inserted before the current
2170 * node and finally the current node is deleted keeping
2171 * the list updated and sorted.
2173 if (start > n->start)
2174 ret = vfio_iommu_iova_insert(&n->list, n->start,
2176 if (!ret && end < n->end)
2177 ret = vfio_iommu_iova_insert(&n->list, end + 1,
2187 if (list_empty(iova))
2193 static void vfio_iommu_resv_free(struct list_head *resv_regions)
2195 struct iommu_resv_region *n, *next;
2197 list_for_each_entry_safe(n, next, resv_regions, list) {
2203 static void vfio_iommu_iova_free(struct list_head *iova)
2205 struct vfio_iova *n, *next;
2207 list_for_each_entry_safe(n, next, iova, list) {
2213 static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu,
2214 struct list_head *iova_copy)
2216 struct list_head *iova = &iommu->iova_list;
2217 struct vfio_iova *n;
2220 list_for_each_entry(n, iova, list) {
2221 ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end);
2229 vfio_iommu_iova_free(iova_copy);
2233 static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu,
2234 struct list_head *iova_copy)
2236 struct list_head *iova = &iommu->iova_list;
2238 vfio_iommu_iova_free(iova);
2240 list_splice_tail(iova_copy, iova);
2243 static int vfio_iommu_type1_attach_group(void *iommu_data,
2244 struct iommu_group *iommu_group)
2246 struct vfio_iommu *iommu = iommu_data;
2247 struct vfio_iommu_group *group;
2248 struct vfio_domain *domain, *d;
2249 struct bus_type *bus = NULL;
2251 bool resv_msi, msi_remap;
2252 phys_addr_t resv_msi_base = 0;
2253 struct iommu_domain_geometry *geo;
2254 LIST_HEAD(iova_copy);
2255 LIST_HEAD(group_resv_regions);
2257 mutex_lock(&iommu->lock);
2259 /* Check for duplicates */
2260 if (vfio_iommu_find_iommu_group(iommu, iommu_group)) {
2261 mutex_unlock(&iommu->lock);
2265 group = kzalloc(sizeof(*group), GFP_KERNEL);
2266 domain = kzalloc(sizeof(*domain), GFP_KERNEL);
2267 if (!group || !domain) {
2272 group->iommu_group = iommu_group;
2274 /* Determine bus_type in order to allocate a domain */
2275 ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type);
2279 if (vfio_bus_is_mdev(bus)) {
2280 struct device *iommu_device = NULL;
2282 group->mdev_group = true;
2284 /* Determine the isolation type */
2285 ret = iommu_group_for_each_dev(iommu_group, &iommu_device,
2286 vfio_mdev_iommu_device);
2287 if (ret || !iommu_device) {
2288 if (!iommu->external_domain) {
2289 INIT_LIST_HEAD(&domain->group_list);
2290 iommu->external_domain = domain;
2291 vfio_update_pgsize_bitmap(iommu);
2296 list_add(&group->next,
2297 &iommu->external_domain->group_list);
2299 * Non-iommu backed group cannot dirty memory directly,
2300 * it can only use interfaces that provide dirty
2302 * The iommu scope can only be promoted with the
2303 * addition of a dirty tracking group.
2305 group->pinned_page_dirty_scope = true;
2306 mutex_unlock(&iommu->lock);
2311 bus = iommu_device->bus;
2314 domain->domain = iommu_domain_alloc(bus);
2315 if (!domain->domain) {
2320 if (iommu->nesting) {
2321 ret = iommu_enable_nesting(domain->domain);
2326 ret = vfio_iommu_attach_group(domain, group);
2330 /* Get aperture info */
2331 geo = &domain->domain->geometry;
2332 if (vfio_iommu_aper_conflict(iommu, geo->aperture_start,
2333 geo->aperture_end)) {
2338 ret = iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
2342 if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
2348 * We don't want to work on the original iova list as the list
2349 * gets modified and in case of failure we have to retain the
2350 * original list. Get a copy here.
2352 ret = vfio_iommu_iova_get_copy(iommu, &iova_copy);
2356 ret = vfio_iommu_aper_resize(&iova_copy, geo->aperture_start,
2361 ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
2365 resv_msi = vfio_iommu_has_sw_msi(&group_resv_regions, &resv_msi_base);
2367 INIT_LIST_HEAD(&domain->group_list);
2368 list_add(&group->next, &domain->group_list);
2370 msi_remap = irq_domain_check_msi_remap() ||
2371 iommu_capable(bus, IOMMU_CAP_INTR_REMAP);
2373 if (!allow_unsafe_interrupts && !msi_remap) {
2374 pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
2380 if (iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
2381 domain->prot |= IOMMU_CACHE;
2384 * Try to match an existing compatible domain. We don't want to
2385 * preclude an IOMMU driver supporting multiple bus_types and being
2386 * able to include different bus_types in the same IOMMU domain, so
2387 * we test whether the domains use the same iommu_ops rather than
2388 * testing if they're on the same bus_type.
2390 list_for_each_entry(d, &iommu->domain_list, next) {
2391 if (d->domain->ops == domain->domain->ops &&
2392 d->prot == domain->prot) {
2393 vfio_iommu_detach_group(domain, group);
2394 if (!vfio_iommu_attach_group(d, group)) {
2395 list_add(&group->next, &d->group_list);
2396 iommu_domain_free(domain->domain);
2401 ret = vfio_iommu_attach_group(domain, group);
2407 vfio_test_domain_fgsp(domain);
2409 /* replay mappings on new domains */
2410 ret = vfio_iommu_replay(iommu, domain);
2415 ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
2416 if (ret && ret != -ENODEV)
2420 list_add(&domain->next, &iommu->domain_list);
2421 vfio_update_pgsize_bitmap(iommu);
2423 /* Delete the old one and insert new iova list */
2424 vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2427 * An iommu backed group can dirty memory directly and therefore
2428 * demotes the iommu scope until it declares itself dirty tracking
2429 * capable via the page pinning interface.
2431 iommu->num_non_pinned_groups++;
2432 mutex_unlock(&iommu->lock);
2433 vfio_iommu_resv_free(&group_resv_regions);
2438 vfio_iommu_detach_group(domain, group);
2440 iommu_domain_free(domain->domain);
2441 vfio_iommu_iova_free(&iova_copy);
2442 vfio_iommu_resv_free(&group_resv_regions);
2446 mutex_unlock(&iommu->lock);
2450 static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
2452 struct rb_node *node;
2454 while ((node = rb_first(&iommu->dma_list)))
2455 vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
2458 static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
2460 struct rb_node *n, *p;
2462 n = rb_first(&iommu->dma_list);
2463 for (; n; n = rb_next(n)) {
2464 struct vfio_dma *dma;
2465 long locked = 0, unlocked = 0;
2467 dma = rb_entry(n, struct vfio_dma, node);
2468 unlocked += vfio_unmap_unpin(iommu, dma, false);
2469 p = rb_first(&dma->pfn_list);
2470 for (; p; p = rb_next(p)) {
2471 struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
2474 if (!is_invalid_reserved_pfn(vpfn->pfn))
2477 vfio_lock_acct(dma, locked - unlocked, true);
2482 * Called when a domain is removed in detach. It is possible that
2483 * the removed domain decided the iova aperture window. Modify the
2484 * iova aperture with the smallest window among existing domains.
2486 static void vfio_iommu_aper_expand(struct vfio_iommu *iommu,
2487 struct list_head *iova_copy)
2489 struct vfio_domain *domain;
2490 struct vfio_iova *node;
2491 dma_addr_t start = 0;
2492 dma_addr_t end = (dma_addr_t)~0;
2494 if (list_empty(iova_copy))
2497 list_for_each_entry(domain, &iommu->domain_list, next) {
2498 struct iommu_domain_geometry *geo = &domain->domain->geometry;
2500 if (geo->aperture_start > start)
2501 start = geo->aperture_start;
2502 if (geo->aperture_end < end)
2503 end = geo->aperture_end;
2506 /* Modify aperture limits. The new aper is either same or bigger */
2507 node = list_first_entry(iova_copy, struct vfio_iova, list);
2508 node->start = start;
2509 node = list_last_entry(iova_copy, struct vfio_iova, list);
2514 * Called when a group is detached. The reserved regions for that
2515 * group can be part of valid iova now. But since reserved regions
2516 * may be duplicated among groups, populate the iova valid regions
2519 static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu,
2520 struct list_head *iova_copy)
2522 struct vfio_domain *d;
2523 struct vfio_iommu_group *g;
2524 struct vfio_iova *node;
2525 dma_addr_t start, end;
2526 LIST_HEAD(resv_regions);
2529 if (list_empty(iova_copy))
2532 list_for_each_entry(d, &iommu->domain_list, next) {
2533 list_for_each_entry(g, &d->group_list, next) {
2534 ret = iommu_get_group_resv_regions(g->iommu_group,
2541 node = list_first_entry(iova_copy, struct vfio_iova, list);
2542 start = node->start;
2543 node = list_last_entry(iova_copy, struct vfio_iova, list);
2546 /* purge the iova list and create new one */
2547 vfio_iommu_iova_free(iova_copy);
2549 ret = vfio_iommu_aper_resize(iova_copy, start, end);
2553 /* Exclude current reserved regions from iova ranges */
2554 ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions);
2556 vfio_iommu_resv_free(&resv_regions);
2560 static void vfio_iommu_type1_detach_group(void *iommu_data,
2561 struct iommu_group *iommu_group)
2563 struct vfio_iommu *iommu = iommu_data;
2564 struct vfio_domain *domain;
2565 struct vfio_iommu_group *group;
2566 bool update_dirty_scope = false;
2567 LIST_HEAD(iova_copy);
2569 mutex_lock(&iommu->lock);
2571 if (iommu->external_domain) {
2572 group = find_iommu_group(iommu->external_domain, iommu_group);
2574 update_dirty_scope = !group->pinned_page_dirty_scope;
2575 list_del(&group->next);
2578 if (list_empty(&iommu->external_domain->group_list)) {
2579 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) {
2580 WARN_ON(iommu->notifier.head);
2581 vfio_iommu_unmap_unpin_all(iommu);
2584 kfree(iommu->external_domain);
2585 iommu->external_domain = NULL;
2587 goto detach_group_done;
2592 * Get a copy of iova list. This will be used to update
2593 * and to replace the current one later. Please note that
2594 * we will leave the original list as it is if update fails.
2596 vfio_iommu_iova_get_copy(iommu, &iova_copy);
2598 list_for_each_entry(domain, &iommu->domain_list, next) {
2599 group = find_iommu_group(domain, iommu_group);
2603 vfio_iommu_detach_group(domain, group);
2604 update_dirty_scope = !group->pinned_page_dirty_scope;
2605 list_del(&group->next);
2608 * Group ownership provides privilege, if the group list is
2609 * empty, the domain goes away. If it's the last domain with
2610 * iommu and external domain doesn't exist, then all the
2611 * mappings go away too. If it's the last domain with iommu and
2612 * external domain exist, update accounting
2614 if (list_empty(&domain->group_list)) {
2615 if (list_is_singular(&iommu->domain_list)) {
2616 if (!iommu->external_domain) {
2617 WARN_ON(iommu->notifier.head);
2618 vfio_iommu_unmap_unpin_all(iommu);
2620 vfio_iommu_unmap_unpin_reaccount(iommu);
2623 iommu_domain_free(domain->domain);
2624 list_del(&domain->next);
2626 vfio_iommu_aper_expand(iommu, &iova_copy);
2627 vfio_update_pgsize_bitmap(iommu);
2632 if (!vfio_iommu_resv_refresh(iommu, &iova_copy))
2633 vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2635 vfio_iommu_iova_free(&iova_copy);
2639 * Removal of a group without dirty tracking may allow the iommu scope
2642 if (update_dirty_scope) {
2643 iommu->num_non_pinned_groups--;
2644 if (iommu->dirty_page_tracking)
2645 vfio_iommu_populate_bitmap_full(iommu);
2647 mutex_unlock(&iommu->lock);
2650 static void *vfio_iommu_type1_open(unsigned long arg)
2652 struct vfio_iommu *iommu;
2654 iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
2656 return ERR_PTR(-ENOMEM);
2659 case VFIO_TYPE1_IOMMU:
2661 case VFIO_TYPE1_NESTING_IOMMU:
2662 iommu->nesting = true;
2664 case VFIO_TYPE1v2_IOMMU:
2669 return ERR_PTR(-EINVAL);
2672 INIT_LIST_HEAD(&iommu->domain_list);
2673 INIT_LIST_HEAD(&iommu->iova_list);
2674 iommu->dma_list = RB_ROOT;
2675 iommu->dma_avail = dma_entry_limit;
2676 iommu->container_open = true;
2677 mutex_init(&iommu->lock);
2678 BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
2679 init_waitqueue_head(&iommu->vaddr_wait);
2684 static void vfio_release_domain(struct vfio_domain *domain, bool external)
2686 struct vfio_iommu_group *group, *group_tmp;
2688 list_for_each_entry_safe(group, group_tmp,
2689 &domain->group_list, next) {
2691 vfio_iommu_detach_group(domain, group);
2692 list_del(&group->next);
2697 iommu_domain_free(domain->domain);
2700 static void vfio_iommu_type1_release(void *iommu_data)
2702 struct vfio_iommu *iommu = iommu_data;
2703 struct vfio_domain *domain, *domain_tmp;
2705 if (iommu->external_domain) {
2706 vfio_release_domain(iommu->external_domain, true);
2707 kfree(iommu->external_domain);
2710 vfio_iommu_unmap_unpin_all(iommu);
2712 list_for_each_entry_safe(domain, domain_tmp,
2713 &iommu->domain_list, next) {
2714 vfio_release_domain(domain, false);
2715 list_del(&domain->next);
2719 vfio_iommu_iova_free(&iommu->iova_list);
2724 static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
2726 struct vfio_domain *domain;
2729 mutex_lock(&iommu->lock);
2730 list_for_each_entry(domain, &iommu->domain_list, next) {
2731 if (!(domain->prot & IOMMU_CACHE)) {
2736 mutex_unlock(&iommu->lock);
2741 static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
2745 case VFIO_TYPE1_IOMMU:
2746 case VFIO_TYPE1v2_IOMMU:
2747 case VFIO_TYPE1_NESTING_IOMMU:
2748 case VFIO_UNMAP_ALL:
2749 case VFIO_UPDATE_VADDR:
2751 case VFIO_DMA_CC_IOMMU:
2754 return vfio_domains_have_iommu_cache(iommu);
2760 static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
2761 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
2764 struct vfio_info_cap_header *header;
2765 struct vfio_iommu_type1_info_cap_iova_range *iova_cap;
2767 header = vfio_info_cap_add(caps, size,
2768 VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);
2770 return PTR_ERR(header);
2772 iova_cap = container_of(header,
2773 struct vfio_iommu_type1_info_cap_iova_range,
2775 iova_cap->nr_iovas = cap_iovas->nr_iovas;
2776 memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges,
2777 cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges));
2781 static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,
2782 struct vfio_info_cap *caps)
2784 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas;
2785 struct vfio_iova *iova;
2787 int iovas = 0, i = 0, ret;
2789 list_for_each_entry(iova, &iommu->iova_list, list)
2794 * Return 0 as a container with a single mdev device
2795 * will have an empty list
2800 size = struct_size(cap_iovas, iova_ranges, iovas);
2802 cap_iovas = kzalloc(size, GFP_KERNEL);
2806 cap_iovas->nr_iovas = iovas;
2808 list_for_each_entry(iova, &iommu->iova_list, list) {
2809 cap_iovas->iova_ranges[i].start = iova->start;
2810 cap_iovas->iova_ranges[i].end = iova->end;
2814 ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size);
2820 static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
2821 struct vfio_info_cap *caps)
2823 struct vfio_iommu_type1_info_cap_migration cap_mig;
2825 cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
2826 cap_mig.header.version = 1;
2829 /* support minimum pgsize */
2830 cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap);
2831 cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX;
2833 return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
2836 static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu,
2837 struct vfio_info_cap *caps)
2839 struct vfio_iommu_type1_info_dma_avail cap_dma_avail;
2841 cap_dma_avail.header.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL;
2842 cap_dma_avail.header.version = 1;
2844 cap_dma_avail.avail = iommu->dma_avail;
2846 return vfio_info_add_capability(caps, &cap_dma_avail.header,
2847 sizeof(cap_dma_avail));
2850 static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
2853 struct vfio_iommu_type1_info info;
2854 unsigned long minsz;
2855 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
2856 unsigned long capsz;
2859 minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
2861 /* For backward compatibility, cannot require this */
2862 capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
2864 if (copy_from_user(&info, (void __user *)arg, minsz))
2867 if (info.argsz < minsz)
2870 if (info.argsz >= capsz) {
2872 info.cap_offset = 0; /* output, no-recopy necessary */
2875 mutex_lock(&iommu->lock);
2876 info.flags = VFIO_IOMMU_INFO_PGSIZES;
2878 info.iova_pgsizes = iommu->pgsize_bitmap;
2880 ret = vfio_iommu_migration_build_caps(iommu, &caps);
2883 ret = vfio_iommu_dma_avail_build_caps(iommu, &caps);
2886 ret = vfio_iommu_iova_build_caps(iommu, &caps);
2888 mutex_unlock(&iommu->lock);
2894 info.flags |= VFIO_IOMMU_INFO_CAPS;
2896 if (info.argsz < sizeof(info) + caps.size) {
2897 info.argsz = sizeof(info) + caps.size;
2899 vfio_info_cap_shift(&caps, sizeof(info));
2900 if (copy_to_user((void __user *)arg +
2901 sizeof(info), caps.buf,
2906 info.cap_offset = sizeof(info);
2912 return copy_to_user((void __user *)arg, &info, minsz) ?
2916 static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu,
2919 struct vfio_iommu_type1_dma_map map;
2920 unsigned long minsz;
2921 uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE |
2922 VFIO_DMA_MAP_FLAG_VADDR;
2924 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
2926 if (copy_from_user(&map, (void __user *)arg, minsz))
2929 if (map.argsz < minsz || map.flags & ~mask)
2932 return vfio_dma_do_map(iommu, &map);
2935 static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
2938 struct vfio_iommu_type1_dma_unmap unmap;
2939 struct vfio_bitmap bitmap = { 0 };
2940 uint32_t mask = VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP |
2941 VFIO_DMA_UNMAP_FLAG_VADDR |
2942 VFIO_DMA_UNMAP_FLAG_ALL;
2943 unsigned long minsz;
2946 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
2948 if (copy_from_user(&unmap, (void __user *)arg, minsz))
2951 if (unmap.argsz < minsz || unmap.flags & ~mask)
2954 if ((unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
2955 (unmap.flags & (VFIO_DMA_UNMAP_FLAG_ALL |
2956 VFIO_DMA_UNMAP_FLAG_VADDR)))
2959 if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
2960 unsigned long pgshift;
2962 if (unmap.argsz < (minsz + sizeof(bitmap)))
2965 if (copy_from_user(&bitmap,
2966 (void __user *)(arg + minsz),
2970 if (!access_ok((void __user *)bitmap.data, bitmap.size))
2973 pgshift = __ffs(bitmap.pgsize);
2974 ret = verify_bitmap_size(unmap.size >> pgshift,
2980 ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
2984 return copy_to_user((void __user *)arg, &unmap, minsz) ?
2988 static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
2991 struct vfio_iommu_type1_dirty_bitmap dirty;
2992 uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
2993 VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
2994 VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
2995 unsigned long minsz;
3001 minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags);
3003 if (copy_from_user(&dirty, (void __user *)arg, minsz))
3006 if (dirty.argsz < minsz || dirty.flags & ~mask)
3009 /* only one flag should be set at a time */
3010 if (__ffs(dirty.flags) != __fls(dirty.flags))
3013 if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) {
3016 mutex_lock(&iommu->lock);
3017 pgsize = 1 << __ffs(iommu->pgsize_bitmap);
3018 if (!iommu->dirty_page_tracking) {
3019 ret = vfio_dma_bitmap_alloc_all(iommu, pgsize);
3021 iommu->dirty_page_tracking = true;
3023 mutex_unlock(&iommu->lock);
3025 } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) {
3026 mutex_lock(&iommu->lock);
3027 if (iommu->dirty_page_tracking) {
3028 iommu->dirty_page_tracking = false;
3029 vfio_dma_bitmap_free_all(iommu);
3031 mutex_unlock(&iommu->lock);
3033 } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
3034 struct vfio_iommu_type1_dirty_bitmap_get range;
3035 unsigned long pgshift;
3036 size_t data_size = dirty.argsz - minsz;
3037 size_t iommu_pgsize;
3039 if (!data_size || data_size < sizeof(range))
3042 if (copy_from_user(&range, (void __user *)(arg + minsz),
3046 if (range.iova + range.size < range.iova)
3048 if (!access_ok((void __user *)range.bitmap.data,
3052 pgshift = __ffs(range.bitmap.pgsize);
3053 ret = verify_bitmap_size(range.size >> pgshift,
3058 mutex_lock(&iommu->lock);
3060 iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
3062 /* allow only smallest supported pgsize */
3063 if (range.bitmap.pgsize != iommu_pgsize) {
3067 if (range.iova & (iommu_pgsize - 1)) {
3071 if (!range.size || range.size & (iommu_pgsize - 1)) {
3076 if (iommu->dirty_page_tracking)
3077 ret = vfio_iova_dirty_bitmap(range.bitmap.data,
3080 range.bitmap.pgsize);
3084 mutex_unlock(&iommu->lock);
3092 static long vfio_iommu_type1_ioctl(void *iommu_data,
3093 unsigned int cmd, unsigned long arg)
3095 struct vfio_iommu *iommu = iommu_data;
3098 case VFIO_CHECK_EXTENSION:
3099 return vfio_iommu_type1_check_extension(iommu, arg);
3100 case VFIO_IOMMU_GET_INFO:
3101 return vfio_iommu_type1_get_info(iommu, arg);
3102 case VFIO_IOMMU_MAP_DMA:
3103 return vfio_iommu_type1_map_dma(iommu, arg);
3104 case VFIO_IOMMU_UNMAP_DMA:
3105 return vfio_iommu_type1_unmap_dma(iommu, arg);
3106 case VFIO_IOMMU_DIRTY_PAGES:
3107 return vfio_iommu_type1_dirty_pages(iommu, arg);
3113 static int vfio_iommu_type1_register_notifier(void *iommu_data,
3114 unsigned long *events,
3115 struct notifier_block *nb)
3117 struct vfio_iommu *iommu = iommu_data;
3119 /* clear known events */
3120 *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;
3122 /* refuse to register if still events remaining */
3126 return blocking_notifier_chain_register(&iommu->notifier, nb);
3129 static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
3130 struct notifier_block *nb)
3132 struct vfio_iommu *iommu = iommu_data;
3134 return blocking_notifier_chain_unregister(&iommu->notifier, nb);
3137 static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
3138 dma_addr_t user_iova, void *data,
3139 size_t count, bool write,
3142 struct mm_struct *mm;
3143 unsigned long vaddr;
3144 struct vfio_dma *dma;
3145 bool kthread = current->mm == NULL;
3151 ret = vfio_find_dma_valid(iommu, user_iova, 1, &dma);
3155 if ((write && !(dma->prot & IOMMU_WRITE)) ||
3156 !(dma->prot & IOMMU_READ))
3159 mm = get_task_mm(dma->task);
3166 else if (current->mm != mm)
3169 offset = user_iova - dma->iova;
3171 if (count > dma->size - offset)
3172 count = dma->size - offset;
3174 vaddr = dma->vaddr + offset;
3177 *copied = copy_to_user((void __user *)vaddr, data,
3179 if (*copied && iommu->dirty_page_tracking) {
3180 unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
3182 * Bitmap populated with the smallest supported page
3185 bitmap_set(dma->bitmap, offset >> pgshift,
3186 ((offset + *copied - 1) >> pgshift) -
3187 (offset >> pgshift) + 1);
3190 *copied = copy_from_user(data, (void __user *)vaddr,
3193 kthread_unuse_mm(mm);
3196 return *copied ? 0 : -EFAULT;
3199 static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova,
3200 void *data, size_t count, bool write)
3202 struct vfio_iommu *iommu = iommu_data;
3206 mutex_lock(&iommu->lock);
3208 ret = vfio_iommu_type1_dma_rw_chunk(iommu, user_iova, data,
3209 count, write, &done);
3218 mutex_unlock(&iommu->lock);
3222 static struct iommu_domain *
3223 vfio_iommu_type1_group_iommu_domain(void *iommu_data,
3224 struct iommu_group *iommu_group)
3226 struct iommu_domain *domain = ERR_PTR(-ENODEV);
3227 struct vfio_iommu *iommu = iommu_data;
3228 struct vfio_domain *d;
3230 if (!iommu || !iommu_group)
3231 return ERR_PTR(-EINVAL);
3233 mutex_lock(&iommu->lock);
3234 list_for_each_entry(d, &iommu->domain_list, next) {
3235 if (find_iommu_group(d, iommu_group)) {
3240 mutex_unlock(&iommu->lock);
3245 static void vfio_iommu_type1_notify(void *iommu_data,
3246 enum vfio_iommu_notify_type event)
3248 struct vfio_iommu *iommu = iommu_data;
3250 if (event != VFIO_IOMMU_CONTAINER_CLOSE)
3252 mutex_lock(&iommu->lock);
3253 iommu->container_open = false;
3254 mutex_unlock(&iommu->lock);
3255 wake_up_all(&iommu->vaddr_wait);
3258 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
3259 .name = "vfio-iommu-type1",
3260 .owner = THIS_MODULE,
3261 .open = vfio_iommu_type1_open,
3262 .release = vfio_iommu_type1_release,
3263 .ioctl = vfio_iommu_type1_ioctl,
3264 .attach_group = vfio_iommu_type1_attach_group,
3265 .detach_group = vfio_iommu_type1_detach_group,
3266 .pin_pages = vfio_iommu_type1_pin_pages,
3267 .unpin_pages = vfio_iommu_type1_unpin_pages,
3268 .register_notifier = vfio_iommu_type1_register_notifier,
3269 .unregister_notifier = vfio_iommu_type1_unregister_notifier,
3270 .dma_rw = vfio_iommu_type1_dma_rw,
3271 .group_iommu_domain = vfio_iommu_type1_group_iommu_domain,
3272 .notify = vfio_iommu_type1_notify,
3275 static int __init vfio_iommu_type1_init(void)
3277 return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
3280 static void __exit vfio_iommu_type1_cleanup(void)
3282 vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1);
3285 module_init(vfio_iommu_type1_init);
3286 module_exit(vfio_iommu_type1_cleanup);
3288 MODULE_VERSION(DRIVER_VERSION);
3289 MODULE_LICENSE("GPL v2");
3290 MODULE_AUTHOR(DRIVER_AUTHOR);
3291 MODULE_DESCRIPTION(DRIVER_DESC);