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/notifier.h>
40 #include <linux/dma-iommu.h>
41 #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;
69 struct rb_root dma_list;
70 struct blocking_notifier_head notifier;
71 unsigned int dma_avail;
72 unsigned int vaddr_invalid_count;
73 uint64_t pgsize_bitmap;
74 uint64_t num_non_pinned_groups;
75 wait_queue_head_t vaddr_wait;
78 bool dirty_page_tracking;
80 struct list_head emulated_iommu_groups;
84 struct iommu_domain *domain;
85 struct list_head next;
86 struct list_head group_list;
87 bool fgsp : 1; /* Fine-grained super pages */
88 bool enforce_cache_coherency : 1;
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 pinned_page_dirty_scope;
120 struct list_head list;
126 * Guest RAM pinning working set or DMA target
130 dma_addr_t iova; /* Device address */
131 unsigned long pfn; /* Host pfn */
132 unsigned int ref_count;
135 struct vfio_regions {
136 struct list_head list;
142 #define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE)
145 * Input argument of number of bits to bitmap_set() is unsigned integer, which
146 * further casts to signed integer for unaligned multi-bit operation,
148 * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte,
149 * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page
152 #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX)
153 #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)
157 static int put_pfn(unsigned long pfn, int prot);
159 static struct vfio_iommu_group*
160 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
161 struct iommu_group *iommu_group);
164 * This code handles mapping and unmapping of user data buffers
165 * into DMA'ble space using the IOMMU
168 static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
169 dma_addr_t start, size_t size)
171 struct rb_node *node = iommu->dma_list.rb_node;
174 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
176 if (start + size <= dma->iova)
177 node = node->rb_left;
178 else if (start >= dma->iova + dma->size)
179 node = node->rb_right;
187 static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu,
188 dma_addr_t start, u64 size)
190 struct rb_node *res = NULL;
191 struct rb_node *node = iommu->dma_list.rb_node;
192 struct vfio_dma *dma_res = NULL;
195 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
197 if (start < dma->iova + dma->size) {
200 if (start >= dma->iova)
202 node = node->rb_left;
204 node = node->rb_right;
207 if (res && size && dma_res->iova >= start + size)
212 static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
214 struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
215 struct vfio_dma *dma;
219 dma = rb_entry(parent, struct vfio_dma, node);
221 if (new->iova + new->size <= dma->iova)
222 link = &(*link)->rb_left;
224 link = &(*link)->rb_right;
227 rb_link_node(&new->node, parent, link);
228 rb_insert_color(&new->node, &iommu->dma_list);
231 static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
233 rb_erase(&old->node, &iommu->dma_list);
237 static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize)
239 uint64_t npages = dma->size / pgsize;
241 if (npages > DIRTY_BITMAP_PAGES_MAX)
245 * Allocate extra 64 bits that are used to calculate shift required for
246 * bitmap_shift_left() to manipulate and club unaligned number of pages
247 * in adjacent vfio_dma ranges.
249 dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64),
257 static void vfio_dma_bitmap_free(struct vfio_dma *dma)
263 static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize)
266 unsigned long pgshift = __ffs(pgsize);
268 for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) {
269 struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node);
271 bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1);
275 static void vfio_iommu_populate_bitmap_full(struct vfio_iommu *iommu)
278 unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
280 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
281 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
283 bitmap_set(dma->bitmap, 0, dma->size >> pgshift);
287 static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize)
291 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
292 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
295 ret = vfio_dma_bitmap_alloc(dma, pgsize);
299 for (p = rb_prev(n); p; p = rb_prev(p)) {
300 struct vfio_dma *dma = rb_entry(n,
301 struct vfio_dma, node);
303 vfio_dma_bitmap_free(dma);
307 vfio_dma_populate_bitmap(dma, pgsize);
312 static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu)
316 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
317 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
319 vfio_dma_bitmap_free(dma);
324 * Helper Functions for host iova-pfn list
326 static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
328 struct vfio_pfn *vpfn;
329 struct rb_node *node = dma->pfn_list.rb_node;
332 vpfn = rb_entry(node, struct vfio_pfn, node);
334 if (iova < vpfn->iova)
335 node = node->rb_left;
336 else if (iova > vpfn->iova)
337 node = node->rb_right;
344 static void vfio_link_pfn(struct vfio_dma *dma,
345 struct vfio_pfn *new)
347 struct rb_node **link, *parent = NULL;
348 struct vfio_pfn *vpfn;
350 link = &dma->pfn_list.rb_node;
353 vpfn = rb_entry(parent, struct vfio_pfn, node);
355 if (new->iova < vpfn->iova)
356 link = &(*link)->rb_left;
358 link = &(*link)->rb_right;
361 rb_link_node(&new->node, parent, link);
362 rb_insert_color(&new->node, &dma->pfn_list);
365 static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
367 rb_erase(&old->node, &dma->pfn_list);
370 static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
373 struct vfio_pfn *vpfn;
375 vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
382 vfio_link_pfn(dma, vpfn);
386 static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
387 struct vfio_pfn *vpfn)
389 vfio_unlink_pfn(dma, vpfn);
393 static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
396 struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
403 static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
408 if (!vpfn->ref_count) {
409 ret = put_pfn(vpfn->pfn, dma->prot);
410 vfio_remove_from_pfn_list(dma, vpfn);
415 static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
417 struct mm_struct *mm;
423 mm = async ? get_task_mm(dma->task) : dma->task->mm;
425 return -ESRCH; /* process exited */
427 ret = mmap_write_lock_killable(mm);
429 ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task,
431 mmap_write_unlock(mm);
441 * Some mappings aren't backed by a struct page, for example an mmap'd
442 * MMIO range for our own or another device. These use a different
443 * pfn conversion and shouldn't be tracked as locked pages.
444 * For compound pages, any driver that sets the reserved bit in head
445 * page needs to set the reserved bit in all subpages to be safe.
447 static bool is_invalid_reserved_pfn(unsigned long pfn)
450 return PageReserved(pfn_to_page(pfn));
455 static int put_pfn(unsigned long pfn, int prot)
457 if (!is_invalid_reserved_pfn(pfn)) {
458 struct page *page = pfn_to_page(pfn);
460 unpin_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE);
466 #define VFIO_BATCH_MAX_CAPACITY (PAGE_SIZE / sizeof(struct page *))
468 static void vfio_batch_init(struct vfio_batch *batch)
473 if (unlikely(disable_hugepages))
476 batch->pages = (struct page **) __get_free_page(GFP_KERNEL);
480 batch->capacity = VFIO_BATCH_MAX_CAPACITY;
484 batch->pages = &batch->fallback_page;
488 static void vfio_batch_unpin(struct vfio_batch *batch, struct vfio_dma *dma)
490 while (batch->size) {
491 unsigned long pfn = page_to_pfn(batch->pages[batch->offset]);
493 put_pfn(pfn, dma->prot);
499 static void vfio_batch_fini(struct vfio_batch *batch)
501 if (batch->capacity == VFIO_BATCH_MAX_CAPACITY)
502 free_page((unsigned long)batch->pages);
505 static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
506 unsigned long vaddr, unsigned long *pfn,
513 ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
515 bool unlocked = false;
517 ret = fixup_user_fault(mm, vaddr,
519 (write_fault ? FAULT_FLAG_WRITE : 0),
527 ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
532 if (write_fault && !pte_write(*ptep))
535 *pfn = pte_pfn(*ptep);
537 pte_unmap_unlock(ptep, ptl);
542 * Returns the positive number of pfns successfully obtained or a negative
545 static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
546 long npages, int prot, unsigned long *pfn,
549 struct vm_area_struct *vma;
550 unsigned int flags = 0;
553 if (prot & IOMMU_WRITE)
557 ret = pin_user_pages_remote(mm, vaddr, npages, flags | FOLL_LONGTERM,
560 *pfn = page_to_pfn(pages[0]);
564 vaddr = untagged_addr(vaddr);
567 vma = vma_lookup(mm, vaddr);
569 if (vma && vma->vm_flags & VM_PFNMAP) {
570 ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE);
575 if (is_invalid_reserved_pfn(*pfn))
582 mmap_read_unlock(mm);
586 static int vfio_wait(struct vfio_iommu *iommu)
590 prepare_to_wait(&iommu->vaddr_wait, &wait, TASK_KILLABLE);
591 mutex_unlock(&iommu->lock);
593 mutex_lock(&iommu->lock);
594 finish_wait(&iommu->vaddr_wait, &wait);
595 if (kthread_should_stop() || !iommu->container_open ||
596 fatal_signal_pending(current)) {
603 * Find dma struct and wait for its vaddr to be valid. iommu lock is dropped
604 * if the task waits, but is re-locked on return. Return result in *dma_p.
605 * Return 0 on success with no waiting, WAITED on success if waited, and -errno
608 static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
609 size_t size, struct vfio_dma **dma_p)
614 *dma_p = vfio_find_dma(iommu, start, size);
617 else if (!(*dma_p)->vaddr_invalid)
620 ret = vfio_wait(iommu);
621 } while (ret == WAITED);
627 * Wait for all vaddr in the dma_list to become valid. iommu lock is dropped
628 * if the task waits, but is re-locked on return. Return 0 on success with no
629 * waiting, WAITED on success if waited, and -errno on error.
631 static int vfio_wait_all_valid(struct vfio_iommu *iommu)
635 while (iommu->vaddr_invalid_count && ret >= 0)
636 ret = vfio_wait(iommu);
642 * Attempt to pin pages. We really don't want to track all the pfns and
643 * the iommu can only map chunks of consecutive pfns anyway, so get the
644 * first page and all consecutive pages with the same locking.
646 static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
647 long npage, unsigned long *pfn_base,
648 unsigned long limit, struct vfio_batch *batch)
651 struct mm_struct *mm = current->mm;
652 long ret, pinned = 0, lock_acct = 0;
654 dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
656 /* This code path is only user initiated */
661 /* Leftover pages in batch from an earlier call. */
662 *pfn_base = page_to_pfn(batch->pages[batch->offset]);
664 rsvd = is_invalid_reserved_pfn(*pfn_base);
671 /* Empty batch, so refill it. */
672 long req_pages = min_t(long, npage, batch->capacity);
674 ret = vaddr_get_pfns(mm, vaddr, req_pages, dma->prot,
684 rsvd = is_invalid_reserved_pfn(*pfn_base);
689 * pfn is preset for the first iteration of this inner loop and
690 * updated at the end to handle a VM_PFNMAP pfn. In that case,
691 * batch->pages isn't valid (there's no struct page), so allow
692 * batch->pages to be touched only when there's more than one
693 * pfn to check, which guarantees the pfns are from a
697 if (pfn != *pfn_base + pinned ||
698 rsvd != is_invalid_reserved_pfn(pfn))
702 * Reserved pages aren't counted against the user,
703 * externally pinned pages are already counted against
706 if (!rsvd && !vfio_find_vpfn(dma, iova)) {
707 if (!dma->lock_cap &&
708 mm->locked_vm + lock_acct + 1 > limit) {
709 pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
710 __func__, limit << PAGE_SHIFT);
727 pfn = page_to_pfn(batch->pages[batch->offset]);
730 if (unlikely(disable_hugepages))
735 ret = vfio_lock_acct(dma, lock_acct, false);
738 if (batch->size == 1 && !batch->offset) {
739 /* May be a VM_PFNMAP pfn, which the batch can't remember. */
740 put_pfn(pfn, dma->prot);
745 if (pinned && !rsvd) {
746 for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
747 put_pfn(pfn, dma->prot);
749 vfio_batch_unpin(batch, dma);
757 static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
758 unsigned long pfn, long npage,
761 long unlocked = 0, locked = 0;
764 for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
765 if (put_pfn(pfn++, dma->prot)) {
767 if (vfio_find_vpfn(dma, iova))
773 vfio_lock_acct(dma, locked - unlocked, true);
778 static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
779 unsigned long *pfn_base, bool do_accounting)
781 struct page *pages[1];
782 struct mm_struct *mm;
785 mm = get_task_mm(dma->task);
789 ret = vaddr_get_pfns(mm, vaddr, 1, dma->prot, pfn_base, pages);
795 if (do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
796 ret = vfio_lock_acct(dma, 1, true);
798 put_pfn(*pfn_base, dma->prot);
800 pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK "
801 "(%ld) exceeded\n", __func__,
802 dma->task->comm, task_pid_nr(dma->task),
803 task_rlimit(dma->task, RLIMIT_MEMLOCK));
812 static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
816 struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
821 unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
824 vfio_lock_acct(dma, -unlocked, true);
829 static int vfio_iommu_type1_pin_pages(void *iommu_data,
830 struct iommu_group *iommu_group,
831 unsigned long *user_pfn,
833 unsigned long *phys_pfn)
835 struct vfio_iommu *iommu = iommu_data;
836 struct vfio_iommu_group *group;
838 unsigned long remote_vaddr;
839 struct vfio_dma *dma;
843 if (!iommu || !user_pfn || !phys_pfn)
846 /* Supported for v2 version only */
850 mutex_lock(&iommu->lock);
853 * Wait for all necessary vaddr's to be valid so they can be used in
854 * the main loop without dropping the lock, to avoid racing vs unmap.
857 if (iommu->vaddr_invalid_count) {
858 for (i = 0; i < npage; i++) {
859 iova = user_pfn[i] << PAGE_SHIFT;
860 ret = vfio_find_dma_valid(iommu, iova, PAGE_SIZE, &dma);
868 /* Fail if notifier list is empty */
869 if (!iommu->notifier.head) {
875 * If iommu capable domain exist in the container then all pages are
876 * already pinned and accounted. Accounting should be done if there is no
877 * iommu capable domain in the container.
879 do_accounting = list_empty(&iommu->domain_list);
881 for (i = 0; i < npage; i++) {
882 struct vfio_pfn *vpfn;
884 iova = user_pfn[i] << PAGE_SHIFT;
885 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
891 if ((dma->prot & prot) != prot) {
896 vpfn = vfio_iova_get_vfio_pfn(dma, iova);
898 phys_pfn[i] = vpfn->pfn;
902 remote_vaddr = dma->vaddr + (iova - dma->iova);
903 ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
908 ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
910 if (put_pfn(phys_pfn[i], dma->prot) && do_accounting)
911 vfio_lock_acct(dma, -1, true);
915 if (iommu->dirty_page_tracking) {
916 unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
919 * Bitmap populated with the smallest supported page
922 bitmap_set(dma->bitmap,
923 (iova - dma->iova) >> pgshift, 1);
928 group = vfio_iommu_find_iommu_group(iommu, iommu_group);
929 if (!group->pinned_page_dirty_scope) {
930 group->pinned_page_dirty_scope = true;
931 iommu->num_non_pinned_groups--;
938 for (j = 0; j < i; j++) {
941 iova = user_pfn[j] << PAGE_SHIFT;
942 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
943 vfio_unpin_page_external(dma, iova, do_accounting);
947 mutex_unlock(&iommu->lock);
951 static int vfio_iommu_type1_unpin_pages(void *iommu_data,
952 unsigned long *user_pfn,
955 struct vfio_iommu *iommu = iommu_data;
959 if (!iommu || !user_pfn || npage <= 0)
962 /* Supported for v2 version only */
966 mutex_lock(&iommu->lock);
968 do_accounting = list_empty(&iommu->domain_list);
969 for (i = 0; i < npage; i++) {
970 struct vfio_dma *dma;
973 iova = user_pfn[i] << PAGE_SHIFT;
974 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
978 vfio_unpin_page_external(dma, iova, do_accounting);
981 mutex_unlock(&iommu->lock);
982 return i > 0 ? i : -EINVAL;
985 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
986 struct list_head *regions,
987 struct iommu_iotlb_gather *iotlb_gather)
990 struct vfio_regions *entry, *next;
992 iommu_iotlb_sync(domain->domain, iotlb_gather);
994 list_for_each_entry_safe(entry, next, regions, list) {
995 unlocked += vfio_unpin_pages_remote(dma,
997 entry->phys >> PAGE_SHIFT,
998 entry->len >> PAGE_SHIFT,
1000 list_del(&entry->list);
1010 * Generally, VFIO needs to unpin remote pages after each IOTLB flush.
1011 * Therefore, when using IOTLB flush sync interface, VFIO need to keep track
1012 * of these regions (currently using a list).
1014 * This value specifies maximum number of regions for each IOTLB flush sync.
1016 #define VFIO_IOMMU_TLB_SYNC_MAX 512
1018 static size_t unmap_unpin_fast(struct vfio_domain *domain,
1019 struct vfio_dma *dma, dma_addr_t *iova,
1020 size_t len, phys_addr_t phys, long *unlocked,
1021 struct list_head *unmapped_list,
1023 struct iommu_iotlb_gather *iotlb_gather)
1025 size_t unmapped = 0;
1026 struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1029 unmapped = iommu_unmap_fast(domain->domain, *iova, len,
1035 entry->iova = *iova;
1037 entry->len = unmapped;
1038 list_add_tail(&entry->list, unmapped_list);
1046 * Sync if the number of fast-unmap regions hits the limit
1047 * or in case of errors.
1049 if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) {
1050 *unlocked += vfio_sync_unpin(dma, domain, unmapped_list,
1058 static size_t unmap_unpin_slow(struct vfio_domain *domain,
1059 struct vfio_dma *dma, dma_addr_t *iova,
1060 size_t len, phys_addr_t phys,
1063 size_t unmapped = iommu_unmap(domain->domain, *iova, len);
1066 *unlocked += vfio_unpin_pages_remote(dma, *iova,
1068 unmapped >> PAGE_SHIFT,
1076 static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
1079 dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
1080 struct vfio_domain *domain, *d;
1081 LIST_HEAD(unmapped_region_list);
1082 struct iommu_iotlb_gather iotlb_gather;
1083 int unmapped_region_cnt = 0;
1089 if (list_empty(&iommu->domain_list))
1093 * We use the IOMMU to track the physical addresses, otherwise we'd
1094 * need a much more complicated tracking system. Unfortunately that
1095 * means we need to use one of the iommu domains to figure out the
1096 * pfns to unpin. The rest need to be unmapped in advance so we have
1097 * no iommu translations remaining when the pages are unpinned.
1099 domain = d = list_first_entry(&iommu->domain_list,
1100 struct vfio_domain, next);
1102 list_for_each_entry_continue(d, &iommu->domain_list, next) {
1103 iommu_unmap(d->domain, dma->iova, dma->size);
1107 iommu_iotlb_gather_init(&iotlb_gather);
1108 while (iova < end) {
1109 size_t unmapped, len;
1110 phys_addr_t phys, next;
1112 phys = iommu_iova_to_phys(domain->domain, iova);
1113 if (WARN_ON(!phys)) {
1119 * To optimize for fewer iommu_unmap() calls, each of which
1120 * may require hardware cache flushing, try to find the
1121 * largest contiguous physical memory chunk to unmap.
1123 for (len = PAGE_SIZE;
1124 !domain->fgsp && iova + len < end; len += PAGE_SIZE) {
1125 next = iommu_iova_to_phys(domain->domain, iova + len);
1126 if (next != phys + len)
1131 * First, try to use fast unmap/unpin. In case of failure,
1132 * switch to slow unmap/unpin path.
1134 unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys,
1135 &unlocked, &unmapped_region_list,
1136 &unmapped_region_cnt,
1139 unmapped = unmap_unpin_slow(domain, dma, &iova, len,
1141 if (WARN_ON(!unmapped))
1146 dma->iommu_mapped = false;
1148 if (unmapped_region_cnt) {
1149 unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list,
1153 if (do_accounting) {
1154 vfio_lock_acct(dma, -unlocked, true);
1160 static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
1162 WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
1163 vfio_unmap_unpin(iommu, dma, true);
1164 vfio_unlink_dma(iommu, dma);
1165 put_task_struct(dma->task);
1166 vfio_dma_bitmap_free(dma);
1167 if (dma->vaddr_invalid) {
1168 iommu->vaddr_invalid_count--;
1169 wake_up_all(&iommu->vaddr_wait);
1175 static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu)
1177 struct vfio_domain *domain;
1179 iommu->pgsize_bitmap = ULONG_MAX;
1181 list_for_each_entry(domain, &iommu->domain_list, next)
1182 iommu->pgsize_bitmap &= domain->domain->pgsize_bitmap;
1185 * In case the IOMMU supports page sizes smaller than PAGE_SIZE
1186 * we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
1187 * That way the user will be able to map/unmap buffers whose size/
1188 * start address is aligned with PAGE_SIZE. Pinning code uses that
1189 * granularity while iommu driver can use the sub-PAGE_SIZE size
1190 * to map the buffer.
1192 if (iommu->pgsize_bitmap & ~PAGE_MASK) {
1193 iommu->pgsize_bitmap &= PAGE_MASK;
1194 iommu->pgsize_bitmap |= PAGE_SIZE;
1198 static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
1199 struct vfio_dma *dma, dma_addr_t base_iova,
1202 unsigned long pgshift = __ffs(pgsize);
1203 unsigned long nbits = dma->size >> pgshift;
1204 unsigned long bit_offset = (dma->iova - base_iova) >> pgshift;
1205 unsigned long copy_offset = bit_offset / BITS_PER_LONG;
1206 unsigned long shift = bit_offset % BITS_PER_LONG;
1207 unsigned long leftover;
1210 * mark all pages dirty if any IOMMU capable device is not able
1211 * to report dirty pages and all pages are pinned and mapped.
1213 if (iommu->num_non_pinned_groups && dma->iommu_mapped)
1214 bitmap_set(dma->bitmap, 0, nbits);
1217 bitmap_shift_left(dma->bitmap, dma->bitmap, shift,
1220 if (copy_from_user(&leftover,
1221 (void __user *)(bitmap + copy_offset),
1225 bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift);
1228 if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap,
1229 DIRTY_BITMAP_BYTES(nbits + shift)))
1235 static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
1236 dma_addr_t iova, size_t size, size_t pgsize)
1238 struct vfio_dma *dma;
1240 unsigned long pgshift = __ffs(pgsize);
1244 * GET_BITMAP request must fully cover vfio_dma mappings. Multiple
1245 * vfio_dma mappings may be clubbed by specifying large ranges, but
1246 * there must not be any previous mappings bisected by the range.
1247 * An error will be returned if these conditions are not met.
1249 dma = vfio_find_dma(iommu, iova, 1);
1250 if (dma && dma->iova != iova)
1253 dma = vfio_find_dma(iommu, iova + size - 1, 0);
1254 if (dma && dma->iova + dma->size != iova + size)
1257 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
1258 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1260 if (dma->iova < iova)
1263 if (dma->iova > iova + size - 1)
1266 ret = update_user_bitmap(bitmap, iommu, dma, iova, pgsize);
1271 * Re-populate bitmap to include all pinned pages which are
1272 * considered as dirty but exclude pages which are unpinned and
1273 * pages which are marked dirty by vfio_dma_rw()
1275 bitmap_clear(dma->bitmap, 0, dma->size >> pgshift);
1276 vfio_dma_populate_bitmap(dma, pgsize);
1281 static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size)
1283 if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) ||
1284 (bitmap_size < DIRTY_BITMAP_BYTES(npages)))
1290 static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
1291 struct vfio_iommu_type1_dma_unmap *unmap,
1292 struct vfio_bitmap *bitmap)
1294 struct vfio_dma *dma, *dma_last = NULL;
1295 size_t unmapped = 0, pgsize;
1296 int ret = -EINVAL, retries = 0;
1297 unsigned long pgshift;
1298 dma_addr_t iova = unmap->iova;
1299 u64 size = unmap->size;
1300 bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL;
1301 bool invalidate_vaddr = unmap->flags & VFIO_DMA_UNMAP_FLAG_VADDR;
1302 struct rb_node *n, *first_n;
1304 mutex_lock(&iommu->lock);
1306 pgshift = __ffs(iommu->pgsize_bitmap);
1307 pgsize = (size_t)1 << pgshift;
1309 if (iova & (pgsize - 1))
1316 } else if (!size || size & (pgsize - 1) ||
1317 iova + size - 1 < iova || size > SIZE_MAX) {
1321 /* When dirty tracking is enabled, allow only min supported pgsize */
1322 if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
1323 (!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) {
1327 WARN_ON((pgsize - 1) & PAGE_MASK);
1330 * vfio-iommu-type1 (v1) - User mappings were coalesced together to
1331 * avoid tracking individual mappings. This means that the granularity
1332 * of the original mapping was lost and the user was allowed to attempt
1333 * to unmap any range. Depending on the contiguousness of physical
1334 * memory and page sizes supported by the IOMMU, arbitrary unmaps may
1335 * or may not have worked. We only guaranteed unmap granularity
1336 * matching the original mapping; even though it was untracked here,
1337 * the original mappings are reflected in IOMMU mappings. This
1338 * resulted in a couple unusual behaviors. First, if a range is not
1339 * able to be unmapped, ex. a set of 4k pages that was mapped as a
1340 * 2M hugepage into the IOMMU, the unmap ioctl returns success but with
1341 * a zero sized unmap. Also, if an unmap request overlaps the first
1342 * address of a hugepage, the IOMMU will unmap the entire hugepage.
1343 * This also returns success and the returned unmap size reflects the
1344 * actual size unmapped.
1346 * We attempt to maintain compatibility with this "v1" interface, but
1347 * we take control out of the hands of the IOMMU. Therefore, an unmap
1348 * request offset from the beginning of the original mapping will
1349 * return success with zero sized unmap. And an unmap request covering
1350 * the first iova of mapping will unmap the entire range.
1352 * The v2 version of this interface intends to be more deterministic.
1353 * Unmap requests must fully cover previous mappings. Multiple
1354 * mappings may still be unmaped by specifying large ranges, but there
1355 * must not be any previous mappings bisected by the range. An error
1356 * will be returned if these conditions are not met. The v2 interface
1357 * will only return success and a size of zero if there were no
1358 * mappings within the range.
1360 if (iommu->v2 && !unmap_all) {
1361 dma = vfio_find_dma(iommu, iova, 1);
1362 if (dma && dma->iova != iova)
1365 dma = vfio_find_dma(iommu, iova + size - 1, 0);
1366 if (dma && dma->iova + dma->size != iova + size)
1371 n = first_n = vfio_find_dma_first_node(iommu, iova, size);
1374 dma = rb_entry(n, struct vfio_dma, node);
1375 if (dma->iova >= iova + size)
1378 if (!iommu->v2 && iova > dma->iova)
1381 * Task with same address space who mapped this iova range is
1382 * allowed to unmap the iova range.
1384 if (dma->task->mm != current->mm)
1387 if (invalidate_vaddr) {
1388 if (dma->vaddr_invalid) {
1389 struct rb_node *last_n = n;
1391 for (n = first_n; n != last_n; n = rb_next(n)) {
1393 struct vfio_dma, node);
1394 dma->vaddr_invalid = false;
1395 iommu->vaddr_invalid_count--;
1401 dma->vaddr_invalid = true;
1402 iommu->vaddr_invalid_count++;
1403 unmapped += dma->size;
1408 if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
1409 struct vfio_iommu_type1_dma_unmap nb_unmap;
1411 if (dma_last == dma) {
1412 BUG_ON(++retries > 10);
1418 nb_unmap.iova = dma->iova;
1419 nb_unmap.size = dma->size;
1422 * Notify anyone (mdev vendor drivers) to invalidate and
1423 * unmap iovas within the range we're about to unmap.
1424 * Vendor drivers MUST unpin pages in response to an
1427 mutex_unlock(&iommu->lock);
1428 blocking_notifier_call_chain(&iommu->notifier,
1429 VFIO_IOMMU_NOTIFY_DMA_UNMAP,
1431 mutex_lock(&iommu->lock);
1435 if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
1436 ret = update_user_bitmap(bitmap->data, iommu, dma,
1442 unmapped += dma->size;
1444 vfio_remove_dma(iommu, dma);
1448 mutex_unlock(&iommu->lock);
1450 /* Report how much was unmapped */
1451 unmap->size = unmapped;
1456 static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
1457 unsigned long pfn, long npage, int prot)
1459 struct vfio_domain *d;
1462 list_for_each_entry(d, &iommu->domain_list, next) {
1463 ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
1464 npage << PAGE_SHIFT, prot | IOMMU_CACHE);
1474 list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
1475 iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
1482 static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
1485 dma_addr_t iova = dma->iova;
1486 unsigned long vaddr = dma->vaddr;
1487 struct vfio_batch batch;
1488 size_t size = map_size;
1490 unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1493 vfio_batch_init(&batch);
1496 /* Pin a contiguous chunk of memory */
1497 npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
1498 size >> PAGE_SHIFT, &pfn, limit,
1507 ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
1510 vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
1512 vfio_batch_unpin(&batch, dma);
1516 size -= npage << PAGE_SHIFT;
1517 dma->size += npage << PAGE_SHIFT;
1520 vfio_batch_fini(&batch);
1521 dma->iommu_mapped = true;
1524 vfio_remove_dma(iommu, dma);
1530 * Check dma map request is within a valid iova range
1532 static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu,
1533 dma_addr_t start, dma_addr_t end)
1535 struct list_head *iova = &iommu->iova_list;
1536 struct vfio_iova *node;
1538 list_for_each_entry(node, iova, list) {
1539 if (start >= node->start && end <= node->end)
1544 * Check for list_empty() as well since a container with
1545 * a single mdev device will have an empty list.
1547 return list_empty(iova);
1550 static int vfio_dma_do_map(struct vfio_iommu *iommu,
1551 struct vfio_iommu_type1_dma_map *map)
1553 bool set_vaddr = map->flags & VFIO_DMA_MAP_FLAG_VADDR;
1554 dma_addr_t iova = map->iova;
1555 unsigned long vaddr = map->vaddr;
1556 size_t size = map->size;
1557 int ret = 0, prot = 0;
1559 struct vfio_dma *dma;
1561 /* Verify that none of our __u64 fields overflow */
1562 if (map->size != size || map->vaddr != vaddr || map->iova != iova)
1565 /* READ/WRITE from device perspective */
1566 if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
1567 prot |= IOMMU_WRITE;
1568 if (map->flags & VFIO_DMA_MAP_FLAG_READ)
1571 if ((prot && set_vaddr) || (!prot && !set_vaddr))
1574 mutex_lock(&iommu->lock);
1576 pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
1578 WARN_ON((pgsize - 1) & PAGE_MASK);
1580 if (!size || (size | iova | vaddr) & (pgsize - 1)) {
1585 /* Don't allow IOVA or virtual address wrap */
1586 if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) {
1591 dma = vfio_find_dma(iommu, iova, size);
1595 } else if (!dma->vaddr_invalid || dma->iova != iova ||
1596 dma->size != size) {
1600 dma->vaddr_invalid = false;
1601 iommu->vaddr_invalid_count--;
1602 wake_up_all(&iommu->vaddr_wait);
1610 if (!iommu->dma_avail) {
1615 if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) {
1620 dma = kzalloc(sizeof(*dma), GFP_KERNEL);
1632 * We need to be able to both add to a task's locked memory and test
1633 * against the locked memory limit and we need to be able to do both
1634 * outside of this call path as pinning can be asynchronous via the
1635 * external interfaces for mdev devices. RLIMIT_MEMLOCK requires a
1636 * task_struct and VM locked pages requires an mm_struct, however
1637 * holding an indefinite mm reference is not recommended, therefore we
1638 * only hold a reference to a task. We could hold a reference to
1639 * current, however QEMU uses this call path through vCPU threads,
1640 * which can be killed resulting in a NULL mm and failure in the unmap
1641 * path when called via a different thread. Avoid this problem by
1642 * using the group_leader as threads within the same group require
1643 * both CLONE_THREAD and CLONE_VM and will therefore use the same
1646 * Previously we also used the task for testing CAP_IPC_LOCK at the
1647 * time of pinning and accounting, however has_capability() makes use
1648 * of real_cred, a copy-on-write field, so we can't guarantee that it
1649 * matches group_leader, or in fact that it might not change by the
1650 * time it's evaluated. If a process were to call MAP_DMA with
1651 * CAP_IPC_LOCK but later drop it, it doesn't make sense that they
1652 * possibly see different results for an iommu_mapped vfio_dma vs
1653 * externally mapped. Therefore track CAP_IPC_LOCK in vfio_dma at the
1654 * time of calling MAP_DMA.
1656 get_task_struct(current->group_leader);
1657 dma->task = current->group_leader;
1658 dma->lock_cap = capable(CAP_IPC_LOCK);
1660 dma->pfn_list = RB_ROOT;
1662 /* Insert zero-sized and grow as we map chunks of it */
1663 vfio_link_dma(iommu, dma);
1665 /* Don't pin and map if container doesn't contain IOMMU capable domain*/
1666 if (list_empty(&iommu->domain_list))
1669 ret = vfio_pin_map_dma(iommu, dma, size);
1671 if (!ret && iommu->dirty_page_tracking) {
1672 ret = vfio_dma_bitmap_alloc(dma, pgsize);
1674 vfio_remove_dma(iommu, dma);
1678 mutex_unlock(&iommu->lock);
1682 static int vfio_bus_type(struct device *dev, void *data)
1684 struct bus_type **bus = data;
1686 if (*bus && *bus != dev->bus)
1694 static int vfio_iommu_replay(struct vfio_iommu *iommu,
1695 struct vfio_domain *domain)
1697 struct vfio_batch batch;
1698 struct vfio_domain *d = NULL;
1700 unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1703 ret = vfio_wait_all_valid(iommu);
1707 /* Arbitrarily pick the first domain in the list for lookups */
1708 if (!list_empty(&iommu->domain_list))
1709 d = list_first_entry(&iommu->domain_list,
1710 struct vfio_domain, next);
1712 vfio_batch_init(&batch);
1714 n = rb_first(&iommu->dma_list);
1716 for (; n; n = rb_next(n)) {
1717 struct vfio_dma *dma;
1720 dma = rb_entry(n, struct vfio_dma, node);
1723 while (iova < dma->iova + dma->size) {
1727 if (dma->iommu_mapped) {
1731 if (WARN_ON(!d)) { /* mapped w/o a domain?! */
1736 phys = iommu_iova_to_phys(d->domain, iova);
1738 if (WARN_ON(!phys)) {
1746 while (i < dma->iova + dma->size &&
1747 p == iommu_iova_to_phys(d->domain, i)) {
1754 unsigned long vaddr = dma->vaddr +
1756 size_t n = dma->iova + dma->size - iova;
1759 npage = vfio_pin_pages_remote(dma, vaddr,
1769 phys = pfn << PAGE_SHIFT;
1770 size = npage << PAGE_SHIFT;
1773 ret = iommu_map(domain->domain, iova, phys,
1774 size, dma->prot | IOMMU_CACHE);
1776 if (!dma->iommu_mapped) {
1777 vfio_unpin_pages_remote(dma, iova,
1781 vfio_batch_unpin(&batch, dma);
1790 /* All dmas are now mapped, defer to second tree walk for unwind */
1791 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
1792 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1794 dma->iommu_mapped = true;
1797 vfio_batch_fini(&batch);
1801 for (; n; n = rb_prev(n)) {
1802 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1805 if (dma->iommu_mapped) {
1806 iommu_unmap(domain->domain, dma->iova, dma->size);
1811 while (iova < dma->iova + dma->size) {
1812 phys_addr_t phys, p;
1816 phys = iommu_iova_to_phys(domain->domain, iova);
1825 while (i < dma->iova + dma->size &&
1826 p == iommu_iova_to_phys(domain->domain, i)) {
1832 iommu_unmap(domain->domain, iova, size);
1833 vfio_unpin_pages_remote(dma, iova, phys >> PAGE_SHIFT,
1834 size >> PAGE_SHIFT, true);
1838 vfio_batch_fini(&batch);
1843 * We change our unmap behavior slightly depending on whether the IOMMU
1844 * supports fine-grained superpages. IOMMUs like AMD-Vi will use a superpage
1845 * for practically any contiguous power-of-two mapping we give it. This means
1846 * we don't need to look for contiguous chunks ourselves to make unmapping
1847 * more efficient. On IOMMUs with coarse-grained super pages, like Intel VT-d
1848 * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
1849 * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
1850 * hugetlbfs is in use.
1852 static void vfio_test_domain_fgsp(struct vfio_domain *domain)
1855 int ret, order = get_order(PAGE_SIZE * 2);
1857 pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
1861 ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
1862 IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE);
1864 size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
1866 if (unmapped == PAGE_SIZE)
1867 iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
1869 domain->fgsp = true;
1872 __free_pages(pages, order);
1875 static struct vfio_iommu_group *find_iommu_group(struct vfio_domain *domain,
1876 struct iommu_group *iommu_group)
1878 struct vfio_iommu_group *g;
1880 list_for_each_entry(g, &domain->group_list, next) {
1881 if (g->iommu_group == iommu_group)
1888 static struct vfio_iommu_group*
1889 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
1890 struct iommu_group *iommu_group)
1892 struct vfio_iommu_group *group;
1893 struct vfio_domain *domain;
1895 list_for_each_entry(domain, &iommu->domain_list, next) {
1896 group = find_iommu_group(domain, iommu_group);
1901 list_for_each_entry(group, &iommu->emulated_iommu_groups, next)
1902 if (group->iommu_group == iommu_group)
1907 static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
1910 struct iommu_resv_region *region;
1913 list_for_each_entry(region, group_resv_regions, list) {
1915 * The presence of any 'real' MSI regions should take
1916 * precedence over the software-managed one if the
1917 * IOMMU driver happens to advertise both types.
1919 if (region->type == IOMMU_RESV_MSI) {
1924 if (region->type == IOMMU_RESV_SW_MSI) {
1925 *base = region->start;
1934 * This is a helper function to insert an address range to iova list.
1935 * The list is initially created with a single entry corresponding to
1936 * the IOMMU domain geometry to which the device group is attached.
1937 * The list aperture gets modified when a new domain is added to the
1938 * container if the new aperture doesn't conflict with the current one
1939 * or with any existing dma mappings. The list is also modified to
1940 * exclude any reserved regions associated with the device group.
1942 static int vfio_iommu_iova_insert(struct list_head *head,
1943 dma_addr_t start, dma_addr_t end)
1945 struct vfio_iova *region;
1947 region = kmalloc(sizeof(*region), GFP_KERNEL);
1951 INIT_LIST_HEAD(®ion->list);
1952 region->start = start;
1955 list_add_tail(®ion->list, head);
1960 * Check the new iommu aperture conflicts with existing aper or with any
1961 * existing dma mappings.
1963 static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu,
1964 dma_addr_t start, dma_addr_t end)
1966 struct vfio_iova *first, *last;
1967 struct list_head *iova = &iommu->iova_list;
1969 if (list_empty(iova))
1972 /* Disjoint sets, return conflict */
1973 first = list_first_entry(iova, struct vfio_iova, list);
1974 last = list_last_entry(iova, struct vfio_iova, list);
1975 if (start > last->end || end < first->start)
1978 /* Check for any existing dma mappings below the new start */
1979 if (start > first->start) {
1980 if (vfio_find_dma(iommu, first->start, start - first->start))
1984 /* Check for any existing dma mappings beyond the new end */
1985 if (end < last->end) {
1986 if (vfio_find_dma(iommu, end + 1, last->end - end))
1994 * Resize iommu iova aperture window. This is called only if the new
1995 * aperture has no conflict with existing aperture and dma mappings.
1997 static int vfio_iommu_aper_resize(struct list_head *iova,
1998 dma_addr_t start, dma_addr_t end)
2000 struct vfio_iova *node, *next;
2002 if (list_empty(iova))
2003 return vfio_iommu_iova_insert(iova, start, end);
2005 /* Adjust iova list start */
2006 list_for_each_entry_safe(node, next, iova, list) {
2007 if (start < node->start)
2009 if (start >= node->start && start < node->end) {
2010 node->start = start;
2013 /* Delete nodes before new start */
2014 list_del(&node->list);
2018 /* Adjust iova list end */
2019 list_for_each_entry_safe(node, next, iova, list) {
2020 if (end > node->end)
2022 if (end > node->start && end <= node->end) {
2026 /* Delete nodes after new end */
2027 list_del(&node->list);
2035 * Check reserved region conflicts with existing dma mappings
2037 static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
2038 struct list_head *resv_regions)
2040 struct iommu_resv_region *region;
2042 /* Check for conflict with existing dma mappings */
2043 list_for_each_entry(region, resv_regions, list) {
2044 if (region->type == IOMMU_RESV_DIRECT_RELAXABLE)
2047 if (vfio_find_dma(iommu, region->start, region->length))
2055 * Check iova region overlap with reserved regions and
2056 * exclude them from the iommu iova range
2058 static int vfio_iommu_resv_exclude(struct list_head *iova,
2059 struct list_head *resv_regions)
2061 struct iommu_resv_region *resv;
2062 struct vfio_iova *n, *next;
2064 list_for_each_entry(resv, resv_regions, list) {
2065 phys_addr_t start, end;
2067 if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE)
2070 start = resv->start;
2071 end = resv->start + resv->length - 1;
2073 list_for_each_entry_safe(n, next, iova, list) {
2077 if (start > n->end || end < n->start)
2080 * Insert a new node if current node overlaps with the
2081 * reserve region to exclude that from valid iova range.
2082 * Note that, new node is inserted before the current
2083 * node and finally the current node is deleted keeping
2084 * the list updated and sorted.
2086 if (start > n->start)
2087 ret = vfio_iommu_iova_insert(&n->list, n->start,
2089 if (!ret && end < n->end)
2090 ret = vfio_iommu_iova_insert(&n->list, end + 1,
2100 if (list_empty(iova))
2106 static void vfio_iommu_resv_free(struct list_head *resv_regions)
2108 struct iommu_resv_region *n, *next;
2110 list_for_each_entry_safe(n, next, resv_regions, list) {
2116 static void vfio_iommu_iova_free(struct list_head *iova)
2118 struct vfio_iova *n, *next;
2120 list_for_each_entry_safe(n, next, iova, list) {
2126 static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu,
2127 struct list_head *iova_copy)
2129 struct list_head *iova = &iommu->iova_list;
2130 struct vfio_iova *n;
2133 list_for_each_entry(n, iova, list) {
2134 ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end);
2142 vfio_iommu_iova_free(iova_copy);
2146 static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu,
2147 struct list_head *iova_copy)
2149 struct list_head *iova = &iommu->iova_list;
2151 vfio_iommu_iova_free(iova);
2153 list_splice_tail(iova_copy, iova);
2156 static int vfio_iommu_type1_attach_group(void *iommu_data,
2157 struct iommu_group *iommu_group, enum vfio_group_type type)
2159 struct vfio_iommu *iommu = iommu_data;
2160 struct vfio_iommu_group *group;
2161 struct vfio_domain *domain, *d;
2162 struct bus_type *bus = NULL;
2163 bool resv_msi, msi_remap;
2164 phys_addr_t resv_msi_base = 0;
2165 struct iommu_domain_geometry *geo;
2166 LIST_HEAD(iova_copy);
2167 LIST_HEAD(group_resv_regions);
2170 mutex_lock(&iommu->lock);
2172 /* Check for duplicates */
2173 if (vfio_iommu_find_iommu_group(iommu, iommu_group))
2177 group = kzalloc(sizeof(*group), GFP_KERNEL);
2180 group->iommu_group = iommu_group;
2182 if (type == VFIO_EMULATED_IOMMU) {
2183 list_add(&group->next, &iommu->emulated_iommu_groups);
2185 * An emulated IOMMU group cannot dirty memory directly, it can
2186 * only use interfaces that provide dirty tracking.
2187 * The iommu scope can only be promoted with the addition of a
2188 * dirty tracking group.
2190 group->pinned_page_dirty_scope = true;
2195 /* Determine bus_type in order to allocate a domain */
2196 ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type);
2198 goto out_free_group;
2201 domain = kzalloc(sizeof(*domain), GFP_KERNEL);
2203 goto out_free_group;
2206 domain->domain = iommu_domain_alloc(bus);
2207 if (!domain->domain)
2208 goto out_free_domain;
2210 if (iommu->nesting) {
2211 ret = iommu_enable_nesting(domain->domain);
2216 ret = iommu_attach_group(domain->domain, group->iommu_group);
2220 /* Get aperture info */
2221 geo = &domain->domain->geometry;
2222 if (vfio_iommu_aper_conflict(iommu, geo->aperture_start,
2223 geo->aperture_end)) {
2228 ret = iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
2232 if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
2238 * We don't want to work on the original iova list as the list
2239 * gets modified and in case of failure we have to retain the
2240 * original list. Get a copy here.
2242 ret = vfio_iommu_iova_get_copy(iommu, &iova_copy);
2246 ret = vfio_iommu_aper_resize(&iova_copy, geo->aperture_start,
2251 ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
2255 resv_msi = vfio_iommu_has_sw_msi(&group_resv_regions, &resv_msi_base);
2257 INIT_LIST_HEAD(&domain->group_list);
2258 list_add(&group->next, &domain->group_list);
2260 msi_remap = irq_domain_check_msi_remap() ||
2261 iommu_capable(bus, IOMMU_CAP_INTR_REMAP);
2263 if (!allow_unsafe_interrupts && !msi_remap) {
2264 pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
2271 * If the IOMMU can block non-coherent operations (ie PCIe TLPs with
2272 * no-snoop set) then VFIO always turns this feature on because on Intel
2273 * platforms it optimizes KVM to disable wbinvd emulation.
2275 if (domain->domain->ops->enforce_cache_coherency)
2276 domain->enforce_cache_coherency =
2277 domain->domain->ops->enforce_cache_coherency(
2281 * Try to match an existing compatible domain. We don't want to
2282 * preclude an IOMMU driver supporting multiple bus_types and being
2283 * able to include different bus_types in the same IOMMU domain, so
2284 * we test whether the domains use the same iommu_ops rather than
2285 * testing if they're on the same bus_type.
2287 list_for_each_entry(d, &iommu->domain_list, next) {
2288 if (d->domain->ops == domain->domain->ops &&
2289 d->enforce_cache_coherency ==
2290 domain->enforce_cache_coherency) {
2291 iommu_detach_group(domain->domain, group->iommu_group);
2292 if (!iommu_attach_group(d->domain,
2293 group->iommu_group)) {
2294 list_add(&group->next, &d->group_list);
2295 iommu_domain_free(domain->domain);
2300 ret = iommu_attach_group(domain->domain,
2301 group->iommu_group);
2307 vfio_test_domain_fgsp(domain);
2309 /* replay mappings on new domains */
2310 ret = vfio_iommu_replay(iommu, domain);
2315 ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
2316 if (ret && ret != -ENODEV)
2320 list_add(&domain->next, &iommu->domain_list);
2321 vfio_update_pgsize_bitmap(iommu);
2323 /* Delete the old one and insert new iova list */
2324 vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2327 * An iommu backed group can dirty memory directly and therefore
2328 * demotes the iommu scope until it declares itself dirty tracking
2329 * capable via the page pinning interface.
2331 iommu->num_non_pinned_groups++;
2332 mutex_unlock(&iommu->lock);
2333 vfio_iommu_resv_free(&group_resv_regions);
2338 iommu_detach_group(domain->domain, group->iommu_group);
2340 iommu_domain_free(domain->domain);
2341 vfio_iommu_iova_free(&iova_copy);
2342 vfio_iommu_resv_free(&group_resv_regions);
2348 mutex_unlock(&iommu->lock);
2352 static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
2354 struct rb_node *node;
2356 while ((node = rb_first(&iommu->dma_list)))
2357 vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
2360 static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
2362 struct rb_node *n, *p;
2364 n = rb_first(&iommu->dma_list);
2365 for (; n; n = rb_next(n)) {
2366 struct vfio_dma *dma;
2367 long locked = 0, unlocked = 0;
2369 dma = rb_entry(n, struct vfio_dma, node);
2370 unlocked += vfio_unmap_unpin(iommu, dma, false);
2371 p = rb_first(&dma->pfn_list);
2372 for (; p; p = rb_next(p)) {
2373 struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
2376 if (!is_invalid_reserved_pfn(vpfn->pfn))
2379 vfio_lock_acct(dma, locked - unlocked, true);
2384 * Called when a domain is removed in detach. It is possible that
2385 * the removed domain decided the iova aperture window. Modify the
2386 * iova aperture with the smallest window among existing domains.
2388 static void vfio_iommu_aper_expand(struct vfio_iommu *iommu,
2389 struct list_head *iova_copy)
2391 struct vfio_domain *domain;
2392 struct vfio_iova *node;
2393 dma_addr_t start = 0;
2394 dma_addr_t end = (dma_addr_t)~0;
2396 if (list_empty(iova_copy))
2399 list_for_each_entry(domain, &iommu->domain_list, next) {
2400 struct iommu_domain_geometry *geo = &domain->domain->geometry;
2402 if (geo->aperture_start > start)
2403 start = geo->aperture_start;
2404 if (geo->aperture_end < end)
2405 end = geo->aperture_end;
2408 /* Modify aperture limits. The new aper is either same or bigger */
2409 node = list_first_entry(iova_copy, struct vfio_iova, list);
2410 node->start = start;
2411 node = list_last_entry(iova_copy, struct vfio_iova, list);
2416 * Called when a group is detached. The reserved regions for that
2417 * group can be part of valid iova now. But since reserved regions
2418 * may be duplicated among groups, populate the iova valid regions
2421 static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu,
2422 struct list_head *iova_copy)
2424 struct vfio_domain *d;
2425 struct vfio_iommu_group *g;
2426 struct vfio_iova *node;
2427 dma_addr_t start, end;
2428 LIST_HEAD(resv_regions);
2431 if (list_empty(iova_copy))
2434 list_for_each_entry(d, &iommu->domain_list, next) {
2435 list_for_each_entry(g, &d->group_list, next) {
2436 ret = iommu_get_group_resv_regions(g->iommu_group,
2443 node = list_first_entry(iova_copy, struct vfio_iova, list);
2444 start = node->start;
2445 node = list_last_entry(iova_copy, struct vfio_iova, list);
2448 /* purge the iova list and create new one */
2449 vfio_iommu_iova_free(iova_copy);
2451 ret = vfio_iommu_aper_resize(iova_copy, start, end);
2455 /* Exclude current reserved regions from iova ranges */
2456 ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions);
2458 vfio_iommu_resv_free(&resv_regions);
2462 static void vfio_iommu_type1_detach_group(void *iommu_data,
2463 struct iommu_group *iommu_group)
2465 struct vfio_iommu *iommu = iommu_data;
2466 struct vfio_domain *domain;
2467 struct vfio_iommu_group *group;
2468 bool update_dirty_scope = false;
2469 LIST_HEAD(iova_copy);
2471 mutex_lock(&iommu->lock);
2472 list_for_each_entry(group, &iommu->emulated_iommu_groups, next) {
2473 if (group->iommu_group != iommu_group)
2475 update_dirty_scope = !group->pinned_page_dirty_scope;
2476 list_del(&group->next);
2479 if (list_empty(&iommu->emulated_iommu_groups) &&
2480 list_empty(&iommu->domain_list)) {
2481 WARN_ON(iommu->notifier.head);
2482 vfio_iommu_unmap_unpin_all(iommu);
2484 goto detach_group_done;
2488 * Get a copy of iova list. This will be used to update
2489 * and to replace the current one later. Please note that
2490 * we will leave the original list as it is if update fails.
2492 vfio_iommu_iova_get_copy(iommu, &iova_copy);
2494 list_for_each_entry(domain, &iommu->domain_list, next) {
2495 group = find_iommu_group(domain, iommu_group);
2499 iommu_detach_group(domain->domain, group->iommu_group);
2500 update_dirty_scope = !group->pinned_page_dirty_scope;
2501 list_del(&group->next);
2504 * Group ownership provides privilege, if the group list is
2505 * empty, the domain goes away. If it's the last domain with
2506 * iommu and external domain doesn't exist, then all the
2507 * mappings go away too. If it's the last domain with iommu and
2508 * external domain exist, update accounting
2510 if (list_empty(&domain->group_list)) {
2511 if (list_is_singular(&iommu->domain_list)) {
2512 if (list_empty(&iommu->emulated_iommu_groups)) {
2513 WARN_ON(iommu->notifier.head);
2514 vfio_iommu_unmap_unpin_all(iommu);
2516 vfio_iommu_unmap_unpin_reaccount(iommu);
2519 iommu_domain_free(domain->domain);
2520 list_del(&domain->next);
2522 vfio_iommu_aper_expand(iommu, &iova_copy);
2523 vfio_update_pgsize_bitmap(iommu);
2528 if (!vfio_iommu_resv_refresh(iommu, &iova_copy))
2529 vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2531 vfio_iommu_iova_free(&iova_copy);
2535 * Removal of a group without dirty tracking may allow the iommu scope
2538 if (update_dirty_scope) {
2539 iommu->num_non_pinned_groups--;
2540 if (iommu->dirty_page_tracking)
2541 vfio_iommu_populate_bitmap_full(iommu);
2543 mutex_unlock(&iommu->lock);
2546 static void *vfio_iommu_type1_open(unsigned long arg)
2548 struct vfio_iommu *iommu;
2550 iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
2552 return ERR_PTR(-ENOMEM);
2555 case VFIO_TYPE1_IOMMU:
2557 case VFIO_TYPE1_NESTING_IOMMU:
2558 iommu->nesting = true;
2560 case VFIO_TYPE1v2_IOMMU:
2565 return ERR_PTR(-EINVAL);
2568 INIT_LIST_HEAD(&iommu->domain_list);
2569 INIT_LIST_HEAD(&iommu->iova_list);
2570 iommu->dma_list = RB_ROOT;
2571 iommu->dma_avail = dma_entry_limit;
2572 iommu->container_open = true;
2573 mutex_init(&iommu->lock);
2574 BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
2575 init_waitqueue_head(&iommu->vaddr_wait);
2576 iommu->pgsize_bitmap = PAGE_MASK;
2577 INIT_LIST_HEAD(&iommu->emulated_iommu_groups);
2582 static void vfio_release_domain(struct vfio_domain *domain)
2584 struct vfio_iommu_group *group, *group_tmp;
2586 list_for_each_entry_safe(group, group_tmp,
2587 &domain->group_list, next) {
2588 iommu_detach_group(domain->domain, group->iommu_group);
2589 list_del(&group->next);
2593 iommu_domain_free(domain->domain);
2596 static void vfio_iommu_type1_release(void *iommu_data)
2598 struct vfio_iommu *iommu = iommu_data;
2599 struct vfio_domain *domain, *domain_tmp;
2600 struct vfio_iommu_group *group, *next_group;
2602 list_for_each_entry_safe(group, next_group,
2603 &iommu->emulated_iommu_groups, next) {
2604 list_del(&group->next);
2608 vfio_iommu_unmap_unpin_all(iommu);
2610 list_for_each_entry_safe(domain, domain_tmp,
2611 &iommu->domain_list, next) {
2612 vfio_release_domain(domain);
2613 list_del(&domain->next);
2617 vfio_iommu_iova_free(&iommu->iova_list);
2622 static int vfio_domains_have_enforce_cache_coherency(struct vfio_iommu *iommu)
2624 struct vfio_domain *domain;
2627 mutex_lock(&iommu->lock);
2628 list_for_each_entry(domain, &iommu->domain_list, next) {
2629 if (!(domain->enforce_cache_coherency)) {
2634 mutex_unlock(&iommu->lock);
2639 static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
2643 case VFIO_TYPE1_IOMMU:
2644 case VFIO_TYPE1v2_IOMMU:
2645 case VFIO_TYPE1_NESTING_IOMMU:
2646 case VFIO_UNMAP_ALL:
2647 case VFIO_UPDATE_VADDR:
2649 case VFIO_DMA_CC_IOMMU:
2652 return vfio_domains_have_enforce_cache_coherency(iommu);
2658 static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
2659 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
2662 struct vfio_info_cap_header *header;
2663 struct vfio_iommu_type1_info_cap_iova_range *iova_cap;
2665 header = vfio_info_cap_add(caps, size,
2666 VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);
2668 return PTR_ERR(header);
2670 iova_cap = container_of(header,
2671 struct vfio_iommu_type1_info_cap_iova_range,
2673 iova_cap->nr_iovas = cap_iovas->nr_iovas;
2674 memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges,
2675 cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges));
2679 static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,
2680 struct vfio_info_cap *caps)
2682 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas;
2683 struct vfio_iova *iova;
2685 int iovas = 0, i = 0, ret;
2687 list_for_each_entry(iova, &iommu->iova_list, list)
2692 * Return 0 as a container with a single mdev device
2693 * will have an empty list
2698 size = struct_size(cap_iovas, iova_ranges, iovas);
2700 cap_iovas = kzalloc(size, GFP_KERNEL);
2704 cap_iovas->nr_iovas = iovas;
2706 list_for_each_entry(iova, &iommu->iova_list, list) {
2707 cap_iovas->iova_ranges[i].start = iova->start;
2708 cap_iovas->iova_ranges[i].end = iova->end;
2712 ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size);
2718 static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
2719 struct vfio_info_cap *caps)
2721 struct vfio_iommu_type1_info_cap_migration cap_mig;
2723 cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
2724 cap_mig.header.version = 1;
2727 /* support minimum pgsize */
2728 cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap);
2729 cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX;
2731 return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
2734 static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu,
2735 struct vfio_info_cap *caps)
2737 struct vfio_iommu_type1_info_dma_avail cap_dma_avail;
2739 cap_dma_avail.header.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL;
2740 cap_dma_avail.header.version = 1;
2742 cap_dma_avail.avail = iommu->dma_avail;
2744 return vfio_info_add_capability(caps, &cap_dma_avail.header,
2745 sizeof(cap_dma_avail));
2748 static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
2751 struct vfio_iommu_type1_info info;
2752 unsigned long minsz;
2753 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
2754 unsigned long capsz;
2757 minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
2759 /* For backward compatibility, cannot require this */
2760 capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
2762 if (copy_from_user(&info, (void __user *)arg, minsz))
2765 if (info.argsz < minsz)
2768 if (info.argsz >= capsz) {
2770 info.cap_offset = 0; /* output, no-recopy necessary */
2773 mutex_lock(&iommu->lock);
2774 info.flags = VFIO_IOMMU_INFO_PGSIZES;
2776 info.iova_pgsizes = iommu->pgsize_bitmap;
2778 ret = vfio_iommu_migration_build_caps(iommu, &caps);
2781 ret = vfio_iommu_dma_avail_build_caps(iommu, &caps);
2784 ret = vfio_iommu_iova_build_caps(iommu, &caps);
2786 mutex_unlock(&iommu->lock);
2792 info.flags |= VFIO_IOMMU_INFO_CAPS;
2794 if (info.argsz < sizeof(info) + caps.size) {
2795 info.argsz = sizeof(info) + caps.size;
2797 vfio_info_cap_shift(&caps, sizeof(info));
2798 if (copy_to_user((void __user *)arg +
2799 sizeof(info), caps.buf,
2804 info.cap_offset = sizeof(info);
2810 return copy_to_user((void __user *)arg, &info, minsz) ?
2814 static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu,
2817 struct vfio_iommu_type1_dma_map map;
2818 unsigned long minsz;
2819 uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE |
2820 VFIO_DMA_MAP_FLAG_VADDR;
2822 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
2824 if (copy_from_user(&map, (void __user *)arg, minsz))
2827 if (map.argsz < minsz || map.flags & ~mask)
2830 return vfio_dma_do_map(iommu, &map);
2833 static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
2836 struct vfio_iommu_type1_dma_unmap unmap;
2837 struct vfio_bitmap bitmap = { 0 };
2838 uint32_t mask = VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP |
2839 VFIO_DMA_UNMAP_FLAG_VADDR |
2840 VFIO_DMA_UNMAP_FLAG_ALL;
2841 unsigned long minsz;
2844 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
2846 if (copy_from_user(&unmap, (void __user *)arg, minsz))
2849 if (unmap.argsz < minsz || unmap.flags & ~mask)
2852 if ((unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
2853 (unmap.flags & (VFIO_DMA_UNMAP_FLAG_ALL |
2854 VFIO_DMA_UNMAP_FLAG_VADDR)))
2857 if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
2858 unsigned long pgshift;
2860 if (unmap.argsz < (minsz + sizeof(bitmap)))
2863 if (copy_from_user(&bitmap,
2864 (void __user *)(arg + minsz),
2868 if (!access_ok((void __user *)bitmap.data, bitmap.size))
2871 pgshift = __ffs(bitmap.pgsize);
2872 ret = verify_bitmap_size(unmap.size >> pgshift,
2878 ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
2882 return copy_to_user((void __user *)arg, &unmap, minsz) ?
2886 static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
2889 struct vfio_iommu_type1_dirty_bitmap dirty;
2890 uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
2891 VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
2892 VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
2893 unsigned long minsz;
2899 minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags);
2901 if (copy_from_user(&dirty, (void __user *)arg, minsz))
2904 if (dirty.argsz < minsz || dirty.flags & ~mask)
2907 /* only one flag should be set at a time */
2908 if (__ffs(dirty.flags) != __fls(dirty.flags))
2911 if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) {
2914 mutex_lock(&iommu->lock);
2915 pgsize = 1 << __ffs(iommu->pgsize_bitmap);
2916 if (!iommu->dirty_page_tracking) {
2917 ret = vfio_dma_bitmap_alloc_all(iommu, pgsize);
2919 iommu->dirty_page_tracking = true;
2921 mutex_unlock(&iommu->lock);
2923 } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) {
2924 mutex_lock(&iommu->lock);
2925 if (iommu->dirty_page_tracking) {
2926 iommu->dirty_page_tracking = false;
2927 vfio_dma_bitmap_free_all(iommu);
2929 mutex_unlock(&iommu->lock);
2931 } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
2932 struct vfio_iommu_type1_dirty_bitmap_get range;
2933 unsigned long pgshift;
2934 size_t data_size = dirty.argsz - minsz;
2935 size_t iommu_pgsize;
2937 if (!data_size || data_size < sizeof(range))
2940 if (copy_from_user(&range, (void __user *)(arg + minsz),
2944 if (range.iova + range.size < range.iova)
2946 if (!access_ok((void __user *)range.bitmap.data,
2950 pgshift = __ffs(range.bitmap.pgsize);
2951 ret = verify_bitmap_size(range.size >> pgshift,
2956 mutex_lock(&iommu->lock);
2958 iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
2960 /* allow only smallest supported pgsize */
2961 if (range.bitmap.pgsize != iommu_pgsize) {
2965 if (range.iova & (iommu_pgsize - 1)) {
2969 if (!range.size || range.size & (iommu_pgsize - 1)) {
2974 if (iommu->dirty_page_tracking)
2975 ret = vfio_iova_dirty_bitmap(range.bitmap.data,
2978 range.bitmap.pgsize);
2982 mutex_unlock(&iommu->lock);
2990 static long vfio_iommu_type1_ioctl(void *iommu_data,
2991 unsigned int cmd, unsigned long arg)
2993 struct vfio_iommu *iommu = iommu_data;
2996 case VFIO_CHECK_EXTENSION:
2997 return vfio_iommu_type1_check_extension(iommu, arg);
2998 case VFIO_IOMMU_GET_INFO:
2999 return vfio_iommu_type1_get_info(iommu, arg);
3000 case VFIO_IOMMU_MAP_DMA:
3001 return vfio_iommu_type1_map_dma(iommu, arg);
3002 case VFIO_IOMMU_UNMAP_DMA:
3003 return vfio_iommu_type1_unmap_dma(iommu, arg);
3004 case VFIO_IOMMU_DIRTY_PAGES:
3005 return vfio_iommu_type1_dirty_pages(iommu, arg);
3011 static int vfio_iommu_type1_register_notifier(void *iommu_data,
3012 unsigned long *events,
3013 struct notifier_block *nb)
3015 struct vfio_iommu *iommu = iommu_data;
3017 /* clear known events */
3018 *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;
3020 /* refuse to register if still events remaining */
3024 return blocking_notifier_chain_register(&iommu->notifier, nb);
3027 static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
3028 struct notifier_block *nb)
3030 struct vfio_iommu *iommu = iommu_data;
3032 return blocking_notifier_chain_unregister(&iommu->notifier, nb);
3035 static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
3036 dma_addr_t user_iova, void *data,
3037 size_t count, bool write,
3040 struct mm_struct *mm;
3041 unsigned long vaddr;
3042 struct vfio_dma *dma;
3043 bool kthread = current->mm == NULL;
3049 ret = vfio_find_dma_valid(iommu, user_iova, 1, &dma);
3053 if ((write && !(dma->prot & IOMMU_WRITE)) ||
3054 !(dma->prot & IOMMU_READ))
3057 mm = get_task_mm(dma->task);
3064 else if (current->mm != mm)
3067 offset = user_iova - dma->iova;
3069 if (count > dma->size - offset)
3070 count = dma->size - offset;
3072 vaddr = dma->vaddr + offset;
3075 *copied = copy_to_user((void __user *)vaddr, data,
3077 if (*copied && iommu->dirty_page_tracking) {
3078 unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
3080 * Bitmap populated with the smallest supported page
3083 bitmap_set(dma->bitmap, offset >> pgshift,
3084 ((offset + *copied - 1) >> pgshift) -
3085 (offset >> pgshift) + 1);
3088 *copied = copy_from_user(data, (void __user *)vaddr,
3091 kthread_unuse_mm(mm);
3094 return *copied ? 0 : -EFAULT;
3097 static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova,
3098 void *data, size_t count, bool write)
3100 struct vfio_iommu *iommu = iommu_data;
3104 mutex_lock(&iommu->lock);
3106 ret = vfio_iommu_type1_dma_rw_chunk(iommu, user_iova, data,
3107 count, write, &done);
3116 mutex_unlock(&iommu->lock);
3120 static struct iommu_domain *
3121 vfio_iommu_type1_group_iommu_domain(void *iommu_data,
3122 struct iommu_group *iommu_group)
3124 struct iommu_domain *domain = ERR_PTR(-ENODEV);
3125 struct vfio_iommu *iommu = iommu_data;
3126 struct vfio_domain *d;
3128 if (!iommu || !iommu_group)
3129 return ERR_PTR(-EINVAL);
3131 mutex_lock(&iommu->lock);
3132 list_for_each_entry(d, &iommu->domain_list, next) {
3133 if (find_iommu_group(d, iommu_group)) {
3138 mutex_unlock(&iommu->lock);
3143 static void vfio_iommu_type1_notify(void *iommu_data,
3144 enum vfio_iommu_notify_type event)
3146 struct vfio_iommu *iommu = iommu_data;
3148 if (event != VFIO_IOMMU_CONTAINER_CLOSE)
3150 mutex_lock(&iommu->lock);
3151 iommu->container_open = false;
3152 mutex_unlock(&iommu->lock);
3153 wake_up_all(&iommu->vaddr_wait);
3156 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
3157 .name = "vfio-iommu-type1",
3158 .owner = THIS_MODULE,
3159 .open = vfio_iommu_type1_open,
3160 .release = vfio_iommu_type1_release,
3161 .ioctl = vfio_iommu_type1_ioctl,
3162 .attach_group = vfio_iommu_type1_attach_group,
3163 .detach_group = vfio_iommu_type1_detach_group,
3164 .pin_pages = vfio_iommu_type1_pin_pages,
3165 .unpin_pages = vfio_iommu_type1_unpin_pages,
3166 .register_notifier = vfio_iommu_type1_register_notifier,
3167 .unregister_notifier = vfio_iommu_type1_unregister_notifier,
3168 .dma_rw = vfio_iommu_type1_dma_rw,
3169 .group_iommu_domain = vfio_iommu_type1_group_iommu_domain,
3170 .notify = vfio_iommu_type1_notify,
3173 static int __init vfio_iommu_type1_init(void)
3175 return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
3178 static void __exit vfio_iommu_type1_cleanup(void)
3180 vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1);
3183 module_init(vfio_iommu_type1_init);
3184 module_exit(vfio_iommu_type1_cleanup);
3186 MODULE_VERSION(DRIVER_VERSION);
3187 MODULE_LICENSE("GPL v2");
3188 MODULE_AUTHOR(DRIVER_AUTHOR);
3189 MODULE_DESCRIPTION(DRIVER_DESC);