drivers/vfio/vfio_iommu

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This source file includes following definitions.
vfio_find_dma
vfio_link_dma
vfio_unlink_dma
vfio_find_vpfn
vfio_link_pfn
vfio_unlink_pfn
vfio_add_to_pfn_list
vfio_remove_from_pfn_list
vfio_iova_get_vfio_pfn
vfio_iova_put_vfio_pfn
vfio_lock_acct
is_invalid_reserved_pfn
put_pfn
vaddr_get_pfn
vfio_pin_pages_remote
vfio_unpin_pages_remote
vfio_pin_page_external
vfio_unpin_page_external
vfio_iommu_type1_pin_pages
vfio_iommu_type1_unpin_pages
vfio_sync_unpin
unmap_unpin_fast
unmap_unpin_slow
vfio_unmap_unpin
vfio_remove_dma
vfio_pgsize_bitmap
vfio_dma_do_unmap
vfio_iommu_map
vfio_pin_map_dma
vfio_iommu_iova_dma_valid
vfio_dma_do_map
vfio_bus_type
vfio_iommu_replay
vfio_test_domain_fgsp
find_iommu_group
vfio_iommu_has_sw_msi
vfio_mdev_get_iommu_device
vfio_mdev_attach_domain
vfio_mdev_detach_domain
vfio_iommu_attach_group
vfio_iommu_detach_group
vfio_bus_is_mdev
vfio_mdev_iommu_device
vfio_iommu_iova_insert
vfio_iommu_aper_conflict
vfio_iommu_aper_resize
vfio_iommu_resv_conflict
vfio_iommu_resv_exclude
vfio_iommu_resv_free
vfio_iommu_iova_free
vfio_iommu_iova_get_copy
vfio_iommu_iova_insert_copy
vfio_iommu_type1_attach_group
vfio_iommu_unmap_unpin_all
vfio_iommu_unmap_unpin_reaccount
vfio_sanity_check_pfn_list
vfio_iommu_aper_expand
vfio_iommu_resv_refresh
vfio_iommu_type1_detach_group
vfio_iommu_type1_open
vfio_release_domain
vfio_iommu_type1_release
vfio_domains_have_iommu_cache
vfio_iommu_iova_add_cap
vfio_iommu_iova_build_caps
vfio_iommu_type1_ioctl
vfio_iommu_type1_register_notifier
vfio_iommu_type1_unregister_notifier
vfio_iommu_type1_init
vfio_iommu_type1_cleanup
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VFIO: IOMMU DMA mapping support for Type1 IOMMU
   4  *
   5  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   6  *     Author: Alex Williamson <alex.williamson@redhat.com>
   7  *
   8  * Derived from original vfio:
   9  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
  10  * Author: Tom Lyon, pugs@cisco.com
  11  *
  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  * userpsace 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.
  22  */
  23 
  24 #include <linux/compat.h>
  25 #include <linux/device.h>
  26 #include <linux/fs.h>
  27 #include <linux/iommu.h>
  28 #include <linux/module.h>
  29 #include <linux/mm.h>
  30 #include <linux/rbtree.h>
  31 #include <linux/sched/signal.h>
  32 #include <linux/sched/mm.h>
  33 #include <linux/slab.h>
  34 #include <linux/uaccess.h>
  35 #include <linux/vfio.h>
  36 #include <linux/workqueue.h>
  37 #include <linux/mdev.h>
  38 #include <linux/notifier.h>
  39 #include <linux/dma-iommu.h>
  40 #include <linux/irqdomain.h>
  41 
  42 #define DRIVER_VERSION  "0.2"
  43 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
  44 #define DRIVER_DESC     "Type1 IOMMU driver for VFIO"
  45 
  46 static bool allow_unsafe_interrupts;
  47 module_param_named(allow_unsafe_interrupts,
  48                    allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
  49 MODULE_PARM_DESC(allow_unsafe_interrupts,
  50                  "Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
  51 
  52 static bool disable_hugepages;
  53 module_param_named(disable_hugepages,
  54                    disable_hugepages, bool, S_IRUGO | S_IWUSR);
  55 MODULE_PARM_DESC(disable_hugepages,
  56                  "Disable VFIO IOMMU support for IOMMU hugepages.");
  57 
  58 static unsigned int dma_entry_limit __read_mostly = U16_MAX;
  59 module_param_named(dma_entry_limit, dma_entry_limit, uint, 0644);
  60 MODULE_PARM_DESC(dma_entry_limit,
  61                  "Maximum number of user DMA mappings per container (65535).");
  62 
  63 struct vfio_iommu {
  64         struct list_head        domain_list;
  65         struct list_head        iova_list;
  66         struct vfio_domain      *external_domain; /* domain for external user */
  67         struct mutex            lock;
  68         struct rb_root          dma_list;
  69         struct blocking_notifier_head notifier;
  70         unsigned int            dma_avail;
  71         bool                    v2;
  72         bool                    nesting;
  73 };
  74 
  75 struct vfio_domain {
  76         struct iommu_domain     *domain;
  77         struct list_head        next;
  78         struct list_head        group_list;
  79         int                     prot;           /* IOMMU_CACHE */
  80         bool                    fgsp;           /* Fine-grained super pages */
  81 };
  82 
  83 struct vfio_dma {
  84         struct rb_node          node;
  85         dma_addr_t              iova;           /* Device address */
  86         unsigned long           vaddr;          /* Process virtual addr */
  87         size_t                  size;           /* Map size (bytes) */
  88         int                     prot;           /* IOMMU_READ/WRITE */
  89         bool                    iommu_mapped;
  90         bool                    lock_cap;       /* capable(CAP_IPC_LOCK) */
  91         struct task_struct      *task;
  92         struct rb_root          pfn_list;       /* Ex-user pinned pfn list */
  93 };
  94 
  95 struct vfio_group {
  96         struct iommu_group      *iommu_group;
  97         struct list_head        next;
  98         bool                    mdev_group;     /* An mdev group */
  99 };
 100 
 101 struct vfio_iova {
 102         struct list_head        list;
 103         dma_addr_t              start;
 104         dma_addr_t              end;
 105 };
 106 
 107 /*
 108  * Guest RAM pinning working set or DMA target
 109  */
 110 struct vfio_pfn {
 111         struct rb_node          node;
 112         dma_addr_t              iova;           /* Device address */
 113         unsigned long           pfn;            /* Host pfn */
 114         atomic_t                ref_count;
 115 };
 116 
 117 struct vfio_regions {
 118         struct list_head list;
 119         dma_addr_t iova;
 120         phys_addr_t phys;
 121         size_t len;
 122 };
 123 
 124 #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \
 125                                         (!list_empty(&iommu->domain_list))
 126 
 127 static int put_pfn(unsigned long pfn, int prot);
 128 
 129 /*
 130  * This code handles mapping and unmapping of user data buffers
 131  * into DMA'ble space using the IOMMU
 132  */
 133 
 134 static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
 135                                       dma_addr_t start, size_t size)
 136 {
 137         struct rb_node *node = iommu->dma_list.rb_node;
 138 
 139         while (node) {
 140                 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
 141 
 142                 if (start + size <= dma->iova)
 143                         node = node->rb_left;
 144                 else if (start >= dma->iova + dma->size)
 145                         node = node->rb_right;
 146                 else
 147                         return dma;
 148         }
 149 
 150         return NULL;
 151 }
 152 
 153 static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
 154 {
 155         struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
 156         struct vfio_dma *dma;
 157 
 158         while (*link) {
 159                 parent = *link;
 160                 dma = rb_entry(parent, struct vfio_dma, node);
 161 
 162                 if (new->iova + new->size <= dma->iova)
 163                         link = &(*link)->rb_left;
 164                 else
 165                         link = &(*link)->rb_right;
 166         }
 167 
 168         rb_link_node(&new->node, parent, link);
 169         rb_insert_color(&new->node, &iommu->dma_list);
 170 }
 171 
 172 static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
 173 {
 174         rb_erase(&old->node, &iommu->dma_list);
 175 }
 176 
 177 /*
 178  * Helper Functions for host iova-pfn list
 179  */
 180 static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
 181 {
 182         struct vfio_pfn *vpfn;
 183         struct rb_node *node = dma->pfn_list.rb_node;
 184 
 185         while (node) {
 186                 vpfn = rb_entry(node, struct vfio_pfn, node);
 187 
 188                 if (iova < vpfn->iova)
 189                         node = node->rb_left;
 190                 else if (iova > vpfn->iova)
 191                         node = node->rb_right;
 192                 else
 193                         return vpfn;
 194         }
 195         return NULL;
 196 }
 197 
 198 static void vfio_link_pfn(struct vfio_dma *dma,
 199                           struct vfio_pfn *new)
 200 {
 201         struct rb_node **link, *parent = NULL;
 202         struct vfio_pfn *vpfn;
 203 
 204         link = &dma->pfn_list.rb_node;
 205         while (*link) {
 206                 parent = *link;
 207                 vpfn = rb_entry(parent, struct vfio_pfn, node);
 208 
 209                 if (new->iova < vpfn->iova)
 210                         link = &(*link)->rb_left;
 211                 else
 212                         link = &(*link)->rb_right;
 213         }
 214 
 215         rb_link_node(&new->node, parent, link);
 216         rb_insert_color(&new->node, &dma->pfn_list);
 217 }
 218 
 219 static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
 220 {
 221         rb_erase(&old->node, &dma->pfn_list);
 222 }
 223 
 224 static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
 225                                 unsigned long pfn)
 226 {
 227         struct vfio_pfn *vpfn;
 228 
 229         vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
 230         if (!vpfn)
 231                 return -ENOMEM;
 232 
 233         vpfn->iova = iova;
 234         vpfn->pfn = pfn;
 235         atomic_set(&vpfn->ref_count, 1);
 236         vfio_link_pfn(dma, vpfn);
 237         return 0;
 238 }
 239 
 240 static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
 241                                       struct vfio_pfn *vpfn)
 242 {
 243         vfio_unlink_pfn(dma, vpfn);
 244         kfree(vpfn);
 245 }
 246 
 247 static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
 248                                                unsigned long iova)
 249 {
 250         struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
 251 
 252         if (vpfn)
 253                 atomic_inc(&vpfn->ref_count);
 254         return vpfn;
 255 }
 256 
 257 static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
 258 {
 259         int ret = 0;
 260 
 261         if (atomic_dec_and_test(&vpfn->ref_count)) {
 262                 ret = put_pfn(vpfn->pfn, dma->prot);
 263                 vfio_remove_from_pfn_list(dma, vpfn);
 264         }
 265         return ret;
 266 }
 267 
 268 static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
 269 {
 270         struct mm_struct *mm;
 271         int ret;
 272 
 273         if (!npage)
 274                 return 0;
 275 
 276         mm = async ? get_task_mm(dma->task) : dma->task->mm;
 277         if (!mm)
 278                 return -ESRCH; /* process exited */
 279 
 280         ret = down_write_killable(&mm->mmap_sem);
 281         if (!ret) {
 282                 ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task,
 283                                           dma->lock_cap);
 284                 up_write(&mm->mmap_sem);
 285         }
 286 
 287         if (async)
 288                 mmput(mm);
 289 
 290         return ret;
 291 }
 292 
 293 /*
 294  * Some mappings aren't backed by a struct page, for example an mmap'd
 295  * MMIO range for our own or another device.  These use a different
 296  * pfn conversion and shouldn't be tracked as locked pages.
 297  */
 298 static bool is_invalid_reserved_pfn(unsigned long pfn)
 299 {
 300         if (pfn_valid(pfn)) {
 301                 bool reserved;
 302                 struct page *tail = pfn_to_page(pfn);
 303                 struct page *head = compound_head(tail);
 304                 reserved = !!(PageReserved(head));
 305                 if (head != tail) {
 306                         /*
 307                          * "head" is not a dangling pointer
 308                          * (compound_head takes care of that)
 309                          * but the hugepage may have been split
 310                          * from under us (and we may not hold a
 311                          * reference count on the head page so it can
 312                          * be reused before we run PageReferenced), so
 313                          * we've to check PageTail before returning
 314                          * what we just read.
 315                          */
 316                         smp_rmb();
 317                         if (PageTail(tail))
 318                                 return reserved;
 319                 }
 320                 return PageReserved(tail);
 321         }
 322 
 323         return true;
 324 }
 325 
 326 static int put_pfn(unsigned long pfn, int prot)
 327 {
 328         if (!is_invalid_reserved_pfn(pfn)) {
 329                 struct page *page = pfn_to_page(pfn);
 330                 if (prot & IOMMU_WRITE)
 331                         SetPageDirty(page);
 332                 put_page(page);
 333                 return 1;
 334         }
 335         return 0;
 336 }
 337 
 338 static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
 339                          int prot, unsigned long *pfn)
 340 {
 341         struct page *page[1];
 342         struct vm_area_struct *vma;
 343         struct vm_area_struct *vmas[1];
 344         unsigned int flags = 0;
 345         int ret;
 346 
 347         if (prot & IOMMU_WRITE)
 348                 flags |= FOLL_WRITE;
 349 
 350         down_read(&mm->mmap_sem);
 351         if (mm == current->mm) {
 352                 ret = get_user_pages(vaddr, 1, flags | FOLL_LONGTERM, page,
 353                                      vmas);
 354         } else {
 355                 ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,
 356                                             vmas, NULL);
 357                 /*
 358                  * The lifetime of a vaddr_get_pfn() page pin is
 359                  * userspace-controlled. In the fs-dax case this could
 360                  * lead to indefinite stalls in filesystem operations.
 361                  * Disallow attempts to pin fs-dax pages via this
 362                  * interface.
 363                  */
 364                 if (ret > 0 && vma_is_fsdax(vmas[0])) {
 365                         ret = -EOPNOTSUPP;
 366                         put_page(page[0]);
 367                 }
 368         }
 369         up_read(&mm->mmap_sem);
 370 
 371         if (ret == 1) {
 372                 *pfn = page_to_pfn(page[0]);
 373                 return 0;
 374         }
 375 
 376         down_read(&mm->mmap_sem);
 377 
 378         vaddr = untagged_addr(vaddr);
 379 
 380         vma = find_vma_intersection(mm, vaddr, vaddr + 1);
 381 
 382         if (vma && vma->vm_flags & VM_PFNMAP) {
 383                 if (!follow_pfn(vma, vaddr, pfn) &&
 384                     is_invalid_reserved_pfn(*pfn))
 385                         ret = 0;
 386         }
 387 
 388         up_read(&mm->mmap_sem);
 389         return ret;
 390 }
 391 
 392 /*
 393  * Attempt to pin pages.  We really don't want to track all the pfns and
 394  * the iommu can only map chunks of consecutive pfns anyway, so get the
 395  * first page and all consecutive pages with the same locking.
 396  */
 397 static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
 398                                   long npage, unsigned long *pfn_base,
 399                                   unsigned long limit)
 400 {
 401         unsigned long pfn = 0;
 402         long ret, pinned = 0, lock_acct = 0;
 403         bool rsvd;
 404         dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
 405 
 406         /* This code path is only user initiated */
 407         if (!current->mm)
 408                 return -ENODEV;
 409 
 410         ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, pfn_base);
 411         if (ret)
 412                 return ret;
 413 
 414         pinned++;
 415         rsvd = is_invalid_reserved_pfn(*pfn_base);
 416 
 417         /*
 418          * Reserved pages aren't counted against the user, externally pinned
 419          * pages are already counted against the user.
 420          */
 421         if (!rsvd && !vfio_find_vpfn(dma, iova)) {
 422                 if (!dma->lock_cap && current->mm->locked_vm + 1 > limit) {
 423                         put_pfn(*pfn_base, dma->prot);
 424                         pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
 425                                         limit << PAGE_SHIFT);
 426                         return -ENOMEM;
 427                 }
 428                 lock_acct++;
 429         }
 430 
 431         if (unlikely(disable_hugepages))
 432                 goto out;
 433 
 434         /* Lock all the consecutive pages from pfn_base */
 435         for (vaddr += PAGE_SIZE, iova += PAGE_SIZE; pinned < npage;
 436              pinned++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
 437                 ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, &pfn);
 438                 if (ret)
 439                         break;
 440 
 441                 if (pfn != *pfn_base + pinned ||
 442                     rsvd != is_invalid_reserved_pfn(pfn)) {
 443                         put_pfn(pfn, dma->prot);
 444                         break;
 445                 }
 446 
 447                 if (!rsvd && !vfio_find_vpfn(dma, iova)) {
 448                         if (!dma->lock_cap &&
 449                             current->mm->locked_vm + lock_acct + 1 > limit) {
 450                                 put_pfn(pfn, dma->prot);
 451                                 pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
 452                                         __func__, limit << PAGE_SHIFT);
 453                                 ret = -ENOMEM;
 454                                 goto unpin_out;
 455                         }
 456                         lock_acct++;
 457                 }
 458         }
 459 
 460 out:
 461         ret = vfio_lock_acct(dma, lock_acct, false);
 462 
 463 unpin_out:
 464         if (ret) {
 465                 if (!rsvd) {
 466                         for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
 467                                 put_pfn(pfn, dma->prot);
 468                 }
 469 
 470                 return ret;
 471         }
 472 
 473         return pinned;
 474 }
 475 
 476 static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
 477                                     unsigned long pfn, long npage,
 478                                     bool do_accounting)
 479 {
 480         long unlocked = 0, locked = 0;
 481         long i;
 482 
 483         for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
 484                 if (put_pfn(pfn++, dma->prot)) {
 485                         unlocked++;
 486                         if (vfio_find_vpfn(dma, iova))
 487                                 locked++;
 488                 }
 489         }
 490 
 491         if (do_accounting)
 492                 vfio_lock_acct(dma, locked - unlocked, true);
 493 
 494         return unlocked;
 495 }
 496 
 497 static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
 498                                   unsigned long *pfn_base, bool do_accounting)
 499 {
 500         struct mm_struct *mm;
 501         int ret;
 502 
 503         mm = get_task_mm(dma->task);
 504         if (!mm)
 505                 return -ENODEV;
 506 
 507         ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
 508         if (!ret && do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
 509                 ret = vfio_lock_acct(dma, 1, true);
 510                 if (ret) {
 511                         put_pfn(*pfn_base, dma->prot);
 512                         if (ret == -ENOMEM)
 513                                 pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK "
 514                                         "(%ld) exceeded\n", __func__,
 515                                         dma->task->comm, task_pid_nr(dma->task),
 516                                         task_rlimit(dma->task, RLIMIT_MEMLOCK));
 517                 }
 518         }
 519 
 520         mmput(mm);
 521         return ret;
 522 }
 523 
 524 static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
 525                                     bool do_accounting)
 526 {
 527         int unlocked;
 528         struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
 529 
 530         if (!vpfn)
 531                 return 0;
 532 
 533         unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
 534 
 535         if (do_accounting)
 536                 vfio_lock_acct(dma, -unlocked, true);
 537 
 538         return unlocked;
 539 }
 540 
 541 static int vfio_iommu_type1_pin_pages(void *iommu_data,
 542                                       unsigned long *user_pfn,
 543                                       int npage, int prot,
 544                                       unsigned long *phys_pfn)
 545 {
 546         struct vfio_iommu *iommu = iommu_data;
 547         int i, j, ret;
 548         unsigned long remote_vaddr;
 549         struct vfio_dma *dma;
 550         bool do_accounting;
 551 
 552         if (!iommu || !user_pfn || !phys_pfn)
 553                 return -EINVAL;
 554 
 555         /* Supported for v2 version only */
 556         if (!iommu->v2)
 557                 return -EACCES;
 558 
 559         mutex_lock(&iommu->lock);
 560 
 561         /* Fail if notifier list is empty */
 562         if (!iommu->notifier.head) {
 563                 ret = -EINVAL;
 564                 goto pin_done;
 565         }
 566 
 567         /*
 568          * If iommu capable domain exist in the container then all pages are
 569          * already pinned and accounted. Accouting should be done if there is no
 570          * iommu capable domain in the container.
 571          */
 572         do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
 573 
 574         for (i = 0; i < npage; i++) {
 575                 dma_addr_t iova;
 576                 struct vfio_pfn *vpfn;
 577 
 578                 iova = user_pfn[i] << PAGE_SHIFT;
 579                 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
 580                 if (!dma) {
 581                         ret = -EINVAL;
 582                         goto pin_unwind;
 583                 }
 584 
 585                 if ((dma->prot & prot) != prot) {
 586                         ret = -EPERM;
 587                         goto pin_unwind;
 588                 }
 589 
 590                 vpfn = vfio_iova_get_vfio_pfn(dma, iova);
 591                 if (vpfn) {
 592                         phys_pfn[i] = vpfn->pfn;
 593                         continue;
 594                 }
 595 
 596                 remote_vaddr = dma->vaddr + (iova - dma->iova);
 597                 ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
 598                                              do_accounting);
 599                 if (ret)
 600                         goto pin_unwind;
 601 
 602                 ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
 603                 if (ret) {
 604                         vfio_unpin_page_external(dma, iova, do_accounting);
 605                         goto pin_unwind;
 606                 }
 607         }
 608 
 609         ret = i;
 610         goto pin_done;
 611 
 612 pin_unwind:
 613         phys_pfn[i] = 0;
 614         for (j = 0; j < i; j++) {
 615                 dma_addr_t iova;
 616 
 617                 iova = user_pfn[j] << PAGE_SHIFT;
 618                 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
 619                 vfio_unpin_page_external(dma, iova, do_accounting);
 620                 phys_pfn[j] = 0;
 621         }
 622 pin_done:
 623         mutex_unlock(&iommu->lock);
 624         return ret;
 625 }
 626 
 627 static int vfio_iommu_type1_unpin_pages(void *iommu_data,
 628                                         unsigned long *user_pfn,
 629                                         int npage)
 630 {
 631         struct vfio_iommu *iommu = iommu_data;
 632         bool do_accounting;
 633         int i;
 634 
 635         if (!iommu || !user_pfn)
 636                 return -EINVAL;
 637 
 638         /* Supported for v2 version only */
 639         if (!iommu->v2)
 640                 return -EACCES;
 641 
 642         mutex_lock(&iommu->lock);
 643 
 644         do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
 645         for (i = 0; i < npage; i++) {
 646                 struct vfio_dma *dma;
 647                 dma_addr_t iova;
 648 
 649                 iova = user_pfn[i] << PAGE_SHIFT;
 650                 dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
 651                 if (!dma)
 652                         goto unpin_exit;
 653                 vfio_unpin_page_external(dma, iova, do_accounting);
 654         }
 655 
 656 unpin_exit:
 657         mutex_unlock(&iommu->lock);
 658         return i > npage ? npage : (i > 0 ? i : -EINVAL);
 659 }
 660 
 661 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
 662                             struct list_head *regions,
 663                             struct iommu_iotlb_gather *iotlb_gather)
 664 {
 665         long unlocked = 0;
 666         struct vfio_regions *entry, *next;
 667 
 668         iommu_tlb_sync(domain->domain, iotlb_gather);
 669 
 670         list_for_each_entry_safe(entry, next, regions, list) {
 671                 unlocked += vfio_unpin_pages_remote(dma,
 672                                                     entry->iova,
 673                                                     entry->phys >> PAGE_SHIFT,
 674                                                     entry->len >> PAGE_SHIFT,
 675                                                     false);
 676                 list_del(&entry->list);
 677                 kfree(entry);
 678         }
 679 
 680         cond_resched();
 681 
 682         return unlocked;
 683 }
 684 
 685 /*
 686  * Generally, VFIO needs to unpin remote pages after each IOTLB flush.
 687  * Therefore, when using IOTLB flush sync interface, VFIO need to keep track
 688  * of these regions (currently using a list).
 689  *
 690  * This value specifies maximum number of regions for each IOTLB flush sync.
 691  */
 692 #define VFIO_IOMMU_TLB_SYNC_MAX         512
 693 
 694 static size_t unmap_unpin_fast(struct vfio_domain *domain,
 695                                struct vfio_dma *dma, dma_addr_t *iova,
 696                                size_t len, phys_addr_t phys, long *unlocked,
 697                                struct list_head *unmapped_list,
 698                                int *unmapped_cnt,
 699                                struct iommu_iotlb_gather *iotlb_gather)
 700 {
 701         size_t unmapped = 0;
 702         struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 703 
 704         if (entry) {
 705                 unmapped = iommu_unmap_fast(domain->domain, *iova, len,
 706                                             iotlb_gather);
 707 
 708                 if (!unmapped) {
 709                         kfree(entry);
 710                 } else {
 711                         entry->iova = *iova;
 712                         entry->phys = phys;
 713                         entry->len  = unmapped;
 714                         list_add_tail(&entry->list, unmapped_list);
 715 
 716                         *iova += unmapped;
 717                         (*unmapped_cnt)++;
 718                 }
 719         }
 720 
 721         /*
 722          * Sync if the number of fast-unmap regions hits the limit
 723          * or in case of errors.
 724          */
 725         if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) {
 726                 *unlocked += vfio_sync_unpin(dma, domain, unmapped_list,
 727                                              iotlb_gather);
 728                 *unmapped_cnt = 0;
 729         }
 730 
 731         return unmapped;
 732 }
 733 
 734 static size_t unmap_unpin_slow(struct vfio_domain *domain,
 735                                struct vfio_dma *dma, dma_addr_t *iova,
 736                                size_t len, phys_addr_t phys,
 737                                long *unlocked)
 738 {
 739         size_t unmapped = iommu_unmap(domain->domain, *iova, len);
 740 
 741         if (unmapped) {
 742                 *unlocked += vfio_unpin_pages_remote(dma, *iova,
 743                                                      phys >> PAGE_SHIFT,
 744                                                      unmapped >> PAGE_SHIFT,
 745                                                      false);
 746                 *iova += unmapped;
 747                 cond_resched();
 748         }
 749         return unmapped;
 750 }
 751 
 752 static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
 753                              bool do_accounting)
 754 {
 755         dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
 756         struct vfio_domain *domain, *d;
 757         LIST_HEAD(unmapped_region_list);
 758         struct iommu_iotlb_gather iotlb_gather;
 759         int unmapped_region_cnt = 0;
 760         long unlocked = 0;
 761 
 762         if (!dma->size)
 763                 return 0;
 764 
 765         if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
 766                 return 0;
 767 
 768         /*
 769          * We use the IOMMU to track the physical addresses, otherwise we'd
 770          * need a much more complicated tracking system.  Unfortunately that
 771          * means we need to use one of the iommu domains to figure out the
 772          * pfns to unpin.  The rest need to be unmapped in advance so we have
 773          * no iommu translations remaining when the pages are unpinned.
 774          */
 775         domain = d = list_first_entry(&iommu->domain_list,
 776                                       struct vfio_domain, next);
 777 
 778         list_for_each_entry_continue(d, &iommu->domain_list, next) {
 779                 iommu_unmap(d->domain, dma->iova, dma->size);
 780                 cond_resched();
 781         }
 782 
 783         iommu_iotlb_gather_init(&iotlb_gather);
 784         while (iova < end) {
 785                 size_t unmapped, len;
 786                 phys_addr_t phys, next;
 787 
 788                 phys = iommu_iova_to_phys(domain->domain, iova);
 789                 if (WARN_ON(!phys)) {
 790                         iova += PAGE_SIZE;
 791                         continue;
 792                 }
 793 
 794                 /*
 795                  * To optimize for fewer iommu_unmap() calls, each of which
 796                  * may require hardware cache flushing, try to find the
 797                  * largest contiguous physical memory chunk to unmap.
 798                  */
 799                 for (len = PAGE_SIZE;
 800                      !domain->fgsp && iova + len < end; len += PAGE_SIZE) {
 801                         next = iommu_iova_to_phys(domain->domain, iova + len);
 802                         if (next != phys + len)
 803                                 break;
 804                 }
 805 
 806                 /*
 807                  * First, try to use fast unmap/unpin. In case of failure,
 808                  * switch to slow unmap/unpin path.
 809                  */
 810                 unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys,
 811                                             &unlocked, &unmapped_region_list,
 812                                             &unmapped_region_cnt,
 813                                             &iotlb_gather);
 814                 if (!unmapped) {
 815                         unmapped = unmap_unpin_slow(domain, dma, &iova, len,
 816                                                     phys, &unlocked);
 817                         if (WARN_ON(!unmapped))
 818                                 break;
 819                 }
 820         }
 821 
 822         dma->iommu_mapped = false;
 823 
 824         if (unmapped_region_cnt) {
 825                 unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list,
 826                                             &iotlb_gather);
 827         }
 828 
 829         if (do_accounting) {
 830                 vfio_lock_acct(dma, -unlocked, true);
 831                 return 0;
 832         }
 833         return unlocked;
 834 }
 835 
 836 static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
 837 {
 838         vfio_unmap_unpin(iommu, dma, true);
 839         vfio_unlink_dma(iommu, dma);
 840         put_task_struct(dma->task);
 841         kfree(dma);
 842         iommu->dma_avail++;
 843 }
 844 
 845 static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
 846 {
 847         struct vfio_domain *domain;
 848         unsigned long bitmap = ULONG_MAX;
 849 
 850         mutex_lock(&iommu->lock);
 851         list_for_each_entry(domain, &iommu->domain_list, next)
 852                 bitmap &= domain->domain->pgsize_bitmap;
 853         mutex_unlock(&iommu->lock);
 854 
 855         /*
 856          * In case the IOMMU supports page sizes smaller than PAGE_SIZE
 857          * we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
 858          * That way the user will be able to map/unmap buffers whose size/
 859          * start address is aligned with PAGE_SIZE. Pinning code uses that
 860          * granularity while iommu driver can use the sub-PAGE_SIZE size
 861          * to map the buffer.
 862          */
 863         if (bitmap & ~PAGE_MASK) {
 864                 bitmap &= PAGE_MASK;
 865                 bitmap |= PAGE_SIZE;
 866         }
 867 
 868         return bitmap;
 869 }
 870 
 871 static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 872                              struct vfio_iommu_type1_dma_unmap *unmap)
 873 {
 874         uint64_t mask;
 875         struct vfio_dma *dma, *dma_last = NULL;
 876         size_t unmapped = 0;
 877         int ret = 0, retries = 0;
 878 
 879         mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
 880 
 881         if (unmap->iova & mask)
 882                 return -EINVAL;
 883         if (!unmap->size || unmap->size & mask)
 884                 return -EINVAL;
 885         if (unmap->iova + unmap->size - 1 < unmap->iova ||
 886             unmap->size > SIZE_MAX)
 887                 return -EINVAL;
 888 
 889         WARN_ON(mask & PAGE_MASK);
 890 again:
 891         mutex_lock(&iommu->lock);
 892 
 893         /*
 894          * vfio-iommu-type1 (v1) - User mappings were coalesced together to
 895          * avoid tracking individual mappings.  This means that the granularity
 896          * of the original mapping was lost and the user was allowed to attempt
 897          * to unmap any range.  Depending on the contiguousness of physical
 898          * memory and page sizes supported by the IOMMU, arbitrary unmaps may
 899          * or may not have worked.  We only guaranteed unmap granularity
 900          * matching the original mapping; even though it was untracked here,
 901          * the original mappings are reflected in IOMMU mappings.  This
 902          * resulted in a couple unusual behaviors.  First, if a range is not
 903          * able to be unmapped, ex. a set of 4k pages that was mapped as a
 904          * 2M hugepage into the IOMMU, the unmap ioctl returns success but with
 905          * a zero sized unmap.  Also, if an unmap request overlaps the first
 906          * address of a hugepage, the IOMMU will unmap the entire hugepage.
 907          * This also returns success and the returned unmap size reflects the
 908          * actual size unmapped.
 909          *
 910          * We attempt to maintain compatibility with this "v1" interface, but
 911          * we take control out of the hands of the IOMMU.  Therefore, an unmap
 912          * request offset from the beginning of the original mapping will
 913          * return success with zero sized unmap.  And an unmap request covering
 914          * the first iova of mapping will unmap the entire range.
 915          *
 916          * The v2 version of this interface intends to be more deterministic.
 917          * Unmap requests must fully cover previous mappings.  Multiple
 918          * mappings may still be unmaped by specifying large ranges, but there
 919          * must not be any previous mappings bisected by the range.  An error
 920          * will be returned if these conditions are not met.  The v2 interface
 921          * will only return success and a size of zero if there were no
 922          * mappings within the range.
 923          */
 924         if (iommu->v2) {
 925                 dma = vfio_find_dma(iommu, unmap->iova, 1);
 926                 if (dma && dma->iova != unmap->iova) {
 927                         ret = -EINVAL;
 928                         goto unlock;
 929                 }
 930                 dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
 931                 if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
 932                         ret = -EINVAL;
 933                         goto unlock;
 934                 }
 935         }
 936 
 937         while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
 938                 if (!iommu->v2 && unmap->iova > dma->iova)
 939                         break;
 940                 /*
 941                  * Task with same address space who mapped this iova range is
 942                  * allowed to unmap the iova range.
 943                  */
 944                 if (dma->task->mm != current->mm)
 945                         break;
 946 
 947                 if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
 948                         struct vfio_iommu_type1_dma_unmap nb_unmap;
 949 
 950                         if (dma_last == dma) {
 951                                 BUG_ON(++retries > 10);
 952                         } else {
 953                                 dma_last = dma;
 954                                 retries = 0;
 955                         }
 956 
 957                         nb_unmap.iova = dma->iova;
 958                         nb_unmap.size = dma->size;
 959 
 960                         /*
 961                          * Notify anyone (mdev vendor drivers) to invalidate and
 962                          * unmap iovas within the range we're about to unmap.
 963                          * Vendor drivers MUST unpin pages in response to an
 964                          * invalidation.
 965                          */
 966                         mutex_unlock(&iommu->lock);
 967                         blocking_notifier_call_chain(&iommu->notifier,
 968                                                     VFIO_IOMMU_NOTIFY_DMA_UNMAP,
 969                                                     &nb_unmap);
 970                         goto again;
 971                 }
 972                 unmapped += dma->size;
 973                 vfio_remove_dma(iommu, dma);
 974         }
 975 
 976 unlock:
 977         mutex_unlock(&iommu->lock);
 978 
 979         /* Report how much was unmapped */
 980         unmap->size = unmapped;
 981 
 982         return ret;
 983 }
 984 
 985 static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
 986                           unsigned long pfn, long npage, int prot)
 987 {
 988         struct vfio_domain *d;
 989         int ret;
 990 
 991         list_for_each_entry(d, &iommu->domain_list, next) {
 992                 ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
 993                                 npage << PAGE_SHIFT, prot | d->prot);
 994                 if (ret)
 995                         goto unwind;
 996 
 997                 cond_resched();
 998         }
 999 
1000         return 0;
1001 
1002 unwind:
1003         list_for_each_entry_continue_reverse(d, &iommu->domain_list, next)
1004                 iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
1005 
1006         return ret;
1007 }
1008 
1009 static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
1010                             size_t map_size)
1011 {
1012         dma_addr_t iova = dma->iova;
1013         unsigned long vaddr = dma->vaddr;
1014         size_t size = map_size;
1015         long npage;
1016         unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1017         int ret = 0;
1018 
1019         while (size) {
1020                 /* Pin a contiguous chunk of memory */
1021                 npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
1022                                               size >> PAGE_SHIFT, &pfn, limit);
1023                 if (npage <= 0) {
1024                         WARN_ON(!npage);
1025                         ret = (int)npage;
1026                         break;
1027                 }
1028 
1029                 /* Map it! */
1030                 ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
1031                                      dma->prot);
1032                 if (ret) {
1033                         vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
1034                                                 npage, true);
1035                         break;
1036                 }
1037 
1038                 size -= npage << PAGE_SHIFT;
1039                 dma->size += npage << PAGE_SHIFT;
1040         }
1041 
1042         dma->iommu_mapped = true;
1043 
1044         if (ret)
1045                 vfio_remove_dma(iommu, dma);
1046 
1047         return ret;
1048 }
1049 
1050 /*
1051  * Check dma map request is within a valid iova range
1052  */
1053 static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu,
1054                                       dma_addr_t start, dma_addr_t end)
1055 {
1056         struct list_head *iova = &iommu->iova_list;
1057         struct vfio_iova *node;
1058 
1059         list_for_each_entry(node, iova, list) {
1060                 if (start >= node->start && end <= node->end)
1061                         return true;
1062         }
1063 
1064         /*
1065          * Check for list_empty() as well since a container with
1066          * a single mdev device will have an empty list.
1067          */
1068         return list_empty(iova);
1069 }
1070 
1071 static int vfio_dma_do_map(struct vfio_iommu *iommu,
1072                            struct vfio_iommu_type1_dma_map *map)
1073 {
1074         dma_addr_t iova = map->iova;
1075         unsigned long vaddr = map->vaddr;
1076         size_t size = map->size;
1077         int ret = 0, prot = 0;
1078         uint64_t mask;
1079         struct vfio_dma *dma;
1080 
1081         /* Verify that none of our __u64 fields overflow */
1082         if (map->size != size || map->vaddr != vaddr || map->iova != iova)
1083                 return -EINVAL;
1084 
1085         mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
1086 
1087         WARN_ON(mask & PAGE_MASK);
1088 
1089         /* READ/WRITE from device perspective */
1090         if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
1091                 prot |= IOMMU_WRITE;
1092         if (map->flags & VFIO_DMA_MAP_FLAG_READ)
1093                 prot |= IOMMU_READ;
1094 
1095         if (!prot || !size || (size | iova | vaddr) & mask)
1096                 return -EINVAL;
1097 
1098         /* Don't allow IOVA or virtual address wrap */
1099         if (iova + size - 1 < iova || vaddr + size - 1 < vaddr)
1100                 return -EINVAL;
1101 
1102         mutex_lock(&iommu->lock);
1103 
1104         if (vfio_find_dma(iommu, iova, size)) {
1105                 ret = -EEXIST;
1106                 goto out_unlock;
1107         }
1108 
1109         if (!iommu->dma_avail) {
1110                 ret = -ENOSPC;
1111                 goto out_unlock;
1112         }
1113 
1114         if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) {
1115                 ret = -EINVAL;
1116                 goto out_unlock;
1117         }
1118 
1119         dma = kzalloc(sizeof(*dma), GFP_KERNEL);
1120         if (!dma) {
1121                 ret = -ENOMEM;
1122                 goto out_unlock;
1123         }
1124 
1125         iommu->dma_avail--;
1126         dma->iova = iova;
1127         dma->vaddr = vaddr;
1128         dma->prot = prot;
1129 
1130         /*
1131          * We need to be able to both add to a task's locked memory and test
1132          * against the locked memory limit and we need to be able to do both
1133          * outside of this call path as pinning can be asynchronous via the
1134          * external interfaces for mdev devices.  RLIMIT_MEMLOCK requires a
1135          * task_struct and VM locked pages requires an mm_struct, however
1136          * holding an indefinite mm reference is not recommended, therefore we
1137          * only hold a reference to a task.  We could hold a reference to
1138          * current, however QEMU uses this call path through vCPU threads,
1139          * which can be killed resulting in a NULL mm and failure in the unmap
1140          * path when called via a different thread.  Avoid this problem by
1141          * using the group_leader as threads within the same group require
1142          * both CLONE_THREAD and CLONE_VM and will therefore use the same
1143          * mm_struct.
1144          *
1145          * Previously we also used the task for testing CAP_IPC_LOCK at the
1146          * time of pinning and accounting, however has_capability() makes use
1147          * of real_cred, a copy-on-write field, so we can't guarantee that it
1148          * matches group_leader, or in fact that it might not change by the
1149          * time it's evaluated.  If a process were to call MAP_DMA with
1150          * CAP_IPC_LOCK but later drop it, it doesn't make sense that they
1151          * possibly see different results for an iommu_mapped vfio_dma vs
1152          * externally mapped.  Therefore track CAP_IPC_LOCK in vfio_dma at the
1153          * time of calling MAP_DMA.
1154          */
1155         get_task_struct(current->group_leader);
1156         dma->task = current->group_leader;
1157         dma->lock_cap = capable(CAP_IPC_LOCK);
1158 
1159         dma->pfn_list = RB_ROOT;
1160 
1161         /* Insert zero-sized and grow as we map chunks of it */
1162         vfio_link_dma(iommu, dma);
1163 
1164         /* Don't pin and map if container doesn't contain IOMMU capable domain*/
1165         if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
1166                 dma->size = size;
1167         else
1168                 ret = vfio_pin_map_dma(iommu, dma, size);
1169 
1170 out_unlock:
1171         mutex_unlock(&iommu->lock);
1172         return ret;
1173 }
1174 
1175 static int vfio_bus_type(struct device *dev, void *data)
1176 {
1177         struct bus_type **bus = data;
1178 
1179         if (*bus && *bus != dev->bus)
1180                 return -EINVAL;
1181 
1182         *bus = dev->bus;
1183 
1184         return 0;
1185 }
1186 
1187 static int vfio_iommu_replay(struct vfio_iommu *iommu,
1188                              struct vfio_domain *domain)
1189 {
1190         struct vfio_domain *d;
1191         struct rb_node *n;
1192         unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1193         int ret;
1194 
1195         /* Arbitrarily pick the first domain in the list for lookups */
1196         d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
1197         n = rb_first(&iommu->dma_list);
1198 
1199         for (; n; n = rb_next(n)) {
1200                 struct vfio_dma *dma;
1201                 dma_addr_t iova;
1202 
1203                 dma = rb_entry(n, struct vfio_dma, node);
1204                 iova = dma->iova;
1205 
1206                 while (iova < dma->iova + dma->size) {
1207                         phys_addr_t phys;
1208                         size_t size;
1209 
1210                         if (dma->iommu_mapped) {
1211                                 phys_addr_t p;
1212                                 dma_addr_t i;
1213 
1214                                 phys = iommu_iova_to_phys(d->domain, iova);
1215 
1216                                 if (WARN_ON(!phys)) {
1217                                         iova += PAGE_SIZE;
1218                                         continue;
1219                                 }
1220 
1221                                 size = PAGE_SIZE;
1222                                 p = phys + size;
1223                                 i = iova + size;
1224                                 while (i < dma->iova + dma->size &&
1225                                        p == iommu_iova_to_phys(d->domain, i)) {
1226                                         size += PAGE_SIZE;
1227                                         p += PAGE_SIZE;
1228                                         i += PAGE_SIZE;
1229                                 }
1230                         } else {
1231                                 unsigned long pfn;
1232                                 unsigned long vaddr = dma->vaddr +
1233                                                      (iova - dma->iova);
1234                                 size_t n = dma->iova + dma->size - iova;
1235                                 long npage;
1236 
1237                                 npage = vfio_pin_pages_remote(dma, vaddr,
1238                                                               n >> PAGE_SHIFT,
1239                                                               &pfn, limit);
1240                                 if (npage <= 0) {
1241                                         WARN_ON(!npage);
1242                                         ret = (int)npage;
1243                                         return ret;
1244                                 }
1245 
1246                                 phys = pfn << PAGE_SHIFT;
1247                                 size = npage << PAGE_SHIFT;
1248                         }
1249 
1250                         ret = iommu_map(domain->domain, iova, phys,
1251                                         size, dma->prot | domain->prot);
1252                         if (ret)
1253                                 return ret;
1254 
1255                         iova += size;
1256                 }
1257                 dma->iommu_mapped = true;
1258         }
1259         return 0;
1260 }
1261 
1262 /*
1263  * We change our unmap behavior slightly depending on whether the IOMMU
1264  * supports fine-grained superpages.  IOMMUs like AMD-Vi will use a superpage
1265  * for practically any contiguous power-of-two mapping we give it.  This means
1266  * we don't need to look for contiguous chunks ourselves to make unmapping
1267  * more efficient.  On IOMMUs with coarse-grained super pages, like Intel VT-d
1268  * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
1269  * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
1270  * hugetlbfs is in use.
1271  */
1272 static void vfio_test_domain_fgsp(struct vfio_domain *domain)
1273 {
1274         struct page *pages;
1275         int ret, order = get_order(PAGE_SIZE * 2);
1276 
1277         pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
1278         if (!pages)
1279                 return;
1280 
1281         ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
1282                         IOMMU_READ | IOMMU_WRITE | domain->prot);
1283         if (!ret) {
1284                 size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
1285 
1286                 if (unmapped == PAGE_SIZE)
1287                         iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
1288                 else
1289                         domain->fgsp = true;
1290         }
1291 
1292         __free_pages(pages, order);
1293 }
1294 
1295 static struct vfio_group *find_iommu_group(struct vfio_domain *domain,
1296                                            struct iommu_group *iommu_group)
1297 {
1298         struct vfio_group *g;
1299 
1300         list_for_each_entry(g, &domain->group_list, next) {
1301                 if (g->iommu_group == iommu_group)
1302                         return g;
1303         }
1304 
1305         return NULL;
1306 }
1307 
1308 static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
1309                                   phys_addr_t *base)
1310 {
1311         struct iommu_resv_region *region;
1312         bool ret = false;
1313 
1314         list_for_each_entry(region, group_resv_regions, list) {
1315                 /*
1316                  * The presence of any 'real' MSI regions should take
1317                  * precedence over the software-managed one if the
1318                  * IOMMU driver happens to advertise both types.
1319                  */
1320                 if (region->type == IOMMU_RESV_MSI) {
1321                         ret = false;
1322                         break;
1323                 }
1324 
1325                 if (region->type == IOMMU_RESV_SW_MSI) {
1326                         *base = region->start;
1327                         ret = true;
1328                 }
1329         }
1330 
1331         return ret;
1332 }
1333 
1334 static struct device *vfio_mdev_get_iommu_device(struct device *dev)
1335 {
1336         struct device *(*fn)(struct device *dev);
1337         struct device *iommu_device;
1338 
1339         fn = symbol_get(mdev_get_iommu_device);
1340         if (fn) {
1341                 iommu_device = fn(dev);
1342                 symbol_put(mdev_get_iommu_device);
1343 
1344                 return iommu_device;
1345         }
1346 
1347         return NULL;
1348 }
1349 
1350 static int vfio_mdev_attach_domain(struct device *dev, void *data)
1351 {
1352         struct iommu_domain *domain = data;
1353         struct device *iommu_device;
1354 
1355         iommu_device = vfio_mdev_get_iommu_device(dev);
1356         if (iommu_device) {
1357                 if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
1358                         return iommu_aux_attach_device(domain, iommu_device);
1359                 else
1360                         return iommu_attach_device(domain, iommu_device);
1361         }
1362 
1363         return -EINVAL;
1364 }
1365 
1366 static int vfio_mdev_detach_domain(struct device *dev, void *data)
1367 {
1368         struct iommu_domain *domain = data;
1369         struct device *iommu_device;
1370 
1371         iommu_device = vfio_mdev_get_iommu_device(dev);
1372         if (iommu_device) {
1373                 if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
1374                         iommu_aux_detach_device(domain, iommu_device);
1375                 else
1376                         iommu_detach_device(domain, iommu_device);
1377         }
1378 
1379         return 0;
1380 }
1381 
1382 static int vfio_iommu_attach_group(struct vfio_domain *domain,
1383                                    struct vfio_group *group)
1384 {
1385         if (group->mdev_group)
1386                 return iommu_group_for_each_dev(group->iommu_group,
1387                                                 domain->domain,
1388                                                 vfio_mdev_attach_domain);
1389         else
1390                 return iommu_attach_group(domain->domain, group->iommu_group);
1391 }
1392 
1393 static void vfio_iommu_detach_group(struct vfio_domain *domain,
1394                                     struct vfio_group *group)
1395 {
1396         if (group->mdev_group)
1397                 iommu_group_for_each_dev(group->iommu_group, domain->domain,
1398                                          vfio_mdev_detach_domain);
1399         else
1400                 iommu_detach_group(domain->domain, group->iommu_group);
1401 }
1402 
1403 static bool vfio_bus_is_mdev(struct bus_type *bus)
1404 {
1405         struct bus_type *mdev_bus;
1406         bool ret = false;
1407 
1408         mdev_bus = symbol_get(mdev_bus_type);
1409         if (mdev_bus) {
1410                 ret = (bus == mdev_bus);
1411                 symbol_put(mdev_bus_type);
1412         }
1413 
1414         return ret;
1415 }
1416 
1417 static int vfio_mdev_iommu_device(struct device *dev, void *data)
1418 {
1419         struct device **old = data, *new;
1420 
1421         new = vfio_mdev_get_iommu_device(dev);
1422         if (!new || (*old && *old != new))
1423                 return -EINVAL;
1424 
1425         *old = new;
1426 
1427         return 0;
1428 }
1429 
1430 /*
1431  * This is a helper function to insert an address range to iova list.
1432  * The list is initially created with a single entry corresponding to
1433  * the IOMMU domain geometry to which the device group is attached.
1434  * The list aperture gets modified when a new domain is added to the
1435  * container if the new aperture doesn't conflict with the current one
1436  * or with any existing dma mappings. The list is also modified to
1437  * exclude any reserved regions associated with the device group.
1438  */
1439 static int vfio_iommu_iova_insert(struct list_head *head,
1440                                   dma_addr_t start, dma_addr_t end)
1441 {
1442         struct vfio_iova *region;
1443 
1444         region = kmalloc(sizeof(*region), GFP_KERNEL);
1445         if (!region)
1446                 return -ENOMEM;
1447 
1448         INIT_LIST_HEAD(&region->list);
1449         region->start = start;
1450         region->end = end;
1451 
1452         list_add_tail(&region->list, head);
1453         return 0;
1454 }
1455 
1456 /*
1457  * Check the new iommu aperture conflicts with existing aper or with any
1458  * existing dma mappings.
1459  */
1460 static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu,
1461                                      dma_addr_t start, dma_addr_t end)
1462 {
1463         struct vfio_iova *first, *last;
1464         struct list_head *iova = &iommu->iova_list;
1465 
1466         if (list_empty(iova))
1467                 return false;
1468 
1469         /* Disjoint sets, return conflict */
1470         first = list_first_entry(iova, struct vfio_iova, list);
1471         last = list_last_entry(iova, struct vfio_iova, list);
1472         if (start > last->end || end < first->start)
1473                 return true;
1474 
1475         /* Check for any existing dma mappings below the new start */
1476         if (start > first->start) {
1477                 if (vfio_find_dma(iommu, first->start, start - first->start))
1478                         return true;
1479         }
1480 
1481         /* Check for any existing dma mappings beyond the new end */
1482         if (end < last->end) {
1483                 if (vfio_find_dma(iommu, end + 1, last->end - end))
1484                         return true;
1485         }
1486 
1487         return false;
1488 }
1489 
1490 /*
1491  * Resize iommu iova aperture window. This is called only if the new
1492  * aperture has no conflict with existing aperture and dma mappings.
1493  */
1494 static int vfio_iommu_aper_resize(struct list_head *iova,
1495                                   dma_addr_t start, dma_addr_t end)
1496 {
1497         struct vfio_iova *node, *next;
1498 
1499         if (list_empty(iova))
1500                 return vfio_iommu_iova_insert(iova, start, end);
1501 
1502         /* Adjust iova list start */
1503         list_for_each_entry_safe(node, next, iova, list) {
1504                 if (start < node->start)
1505                         break;
1506                 if (start >= node->start && start < node->end) {
1507                         node->start = start;
1508                         break;
1509                 }
1510                 /* Delete nodes before new start */
1511                 list_del(&node->list);
1512                 kfree(node);
1513         }
1514 
1515         /* Adjust iova list end */
1516         list_for_each_entry_safe(node, next, iova, list) {
1517                 if (end > node->end)
1518                         continue;
1519                 if (end > node->start && end <= node->end) {
1520                         node->end = end;
1521                         continue;
1522                 }
1523                 /* Delete nodes after new end */
1524                 list_del(&node->list);
1525                 kfree(node);
1526         }
1527 
1528         return 0;
1529 }
1530 
1531 /*
1532  * Check reserved region conflicts with existing dma mappings
1533  */
1534 static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
1535                                      struct list_head *resv_regions)
1536 {
1537         struct iommu_resv_region *region;
1538 
1539         /* Check for conflict with existing dma mappings */
1540         list_for_each_entry(region, resv_regions, list) {
1541                 if (region->type == IOMMU_RESV_DIRECT_RELAXABLE)
1542                         continue;
1543 
1544                 if (vfio_find_dma(iommu, region->start, region->length))
1545                         return true;
1546         }
1547 
1548         return false;
1549 }
1550 
1551 /*
1552  * Check iova region overlap with  reserved regions and
1553  * exclude them from the iommu iova range
1554  */
1555 static int vfio_iommu_resv_exclude(struct list_head *iova,
1556                                    struct list_head *resv_regions)
1557 {
1558         struct iommu_resv_region *resv;
1559         struct vfio_iova *n, *next;
1560 
1561         list_for_each_entry(resv, resv_regions, list) {
1562                 phys_addr_t start, end;
1563 
1564                 if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE)
1565                         continue;
1566 
1567                 start = resv->start;
1568                 end = resv->start + resv->length - 1;
1569 
1570                 list_for_each_entry_safe(n, next, iova, list) {
1571                         int ret = 0;
1572 
1573                         /* No overlap */
1574                         if (start > n->end || end < n->start)
1575                                 continue;
1576                         /*
1577                          * Insert a new node if current node overlaps with the
1578                          * reserve region to exlude that from valid iova range.
1579                          * Note that, new node is inserted before the current
1580                          * node and finally the current node is deleted keeping
1581                          * the list updated and sorted.
1582                          */
1583                         if (start > n->start)
1584                                 ret = vfio_iommu_iova_insert(&n->list, n->start,
1585                                                              start - 1);
1586                         if (!ret && end < n->end)
1587                                 ret = vfio_iommu_iova_insert(&n->list, end + 1,
1588                                                              n->end);
1589                         if (ret)
1590                                 return ret;
1591 
1592                         list_del(&n->list);
1593                         kfree(n);
1594                 }
1595         }
1596 
1597         if (list_empty(iova))
1598                 return -EINVAL;
1599 
1600         return 0;
1601 }
1602 
1603 static void vfio_iommu_resv_free(struct list_head *resv_regions)
1604 {
1605         struct iommu_resv_region *n, *next;
1606 
1607         list_for_each_entry_safe(n, next, resv_regions, list) {
1608                 list_del(&n->list);
1609                 kfree(n);
1610         }
1611 }
1612 
1613 static void vfio_iommu_iova_free(struct list_head *iova)
1614 {
1615         struct vfio_iova *n, *next;
1616 
1617         list_for_each_entry_safe(n, next, iova, list) {
1618                 list_del(&n->list);
1619                 kfree(n);
1620         }
1621 }
1622 
1623 static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu,
1624                                     struct list_head *iova_copy)
1625 {
1626         struct list_head *iova = &iommu->iova_list;
1627         struct vfio_iova *n;
1628         int ret;
1629 
1630         list_for_each_entry(n, iova, list) {
1631                 ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end);
1632                 if (ret)
1633                         goto out_free;
1634         }
1635 
1636         return 0;
1637 
1638 out_free:
1639         vfio_iommu_iova_free(iova_copy);
1640         return ret;
1641 }
1642 
1643 static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu,
1644                                         struct list_head *iova_copy)
1645 {
1646         struct list_head *iova = &iommu->iova_list;
1647 
1648         vfio_iommu_iova_free(iova);
1649 
1650         list_splice_tail(iova_copy, iova);
1651 }
1652 static int vfio_iommu_type1_attach_group(void *iommu_data,
1653                                          struct iommu_group *iommu_group)
1654 {
1655         struct vfio_iommu *iommu = iommu_data;
1656         struct vfio_group *group;
1657         struct vfio_domain *domain, *d;
1658         struct bus_type *bus = NULL;
1659         int ret;
1660         bool resv_msi, msi_remap;
1661         phys_addr_t resv_msi_base = 0;
1662         struct iommu_domain_geometry geo;
1663         LIST_HEAD(iova_copy);
1664         LIST_HEAD(group_resv_regions);
1665 
1666         mutex_lock(&iommu->lock);
1667 
1668         list_for_each_entry(d, &iommu->domain_list, next) {
1669                 if (find_iommu_group(d, iommu_group)) {
1670                         mutex_unlock(&iommu->lock);
1671                         return -EINVAL;
1672                 }
1673         }
1674 
1675         if (iommu->external_domain) {
1676                 if (find_iommu_group(iommu->external_domain, iommu_group)) {
1677                         mutex_unlock(&iommu->lock);
1678                         return -EINVAL;
1679                 }
1680         }
1681 
1682         group = kzalloc(sizeof(*group), GFP_KERNEL);
1683         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
1684         if (!group || !domain) {
1685                 ret = -ENOMEM;
1686                 goto out_free;
1687         }
1688 
1689         group->iommu_group = iommu_group;
1690 
1691         /* Determine bus_type in order to allocate a domain */
1692         ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type);
1693         if (ret)
1694                 goto out_free;
1695 
1696         if (vfio_bus_is_mdev(bus)) {
1697                 struct device *iommu_device = NULL;
1698 
1699                 group->mdev_group = true;
1700 
1701                 /* Determine the isolation type */
1702                 ret = iommu_group_for_each_dev(iommu_group, &iommu_device,
1703                                                vfio_mdev_iommu_device);
1704                 if (ret || !iommu_device) {
1705                         if (!iommu->external_domain) {
1706                                 INIT_LIST_HEAD(&domain->group_list);
1707                                 iommu->external_domain = domain;
1708                         } else {
1709                                 kfree(domain);
1710                         }
1711 
1712                         list_add(&group->next,
1713                                  &iommu->external_domain->group_list);
1714                         mutex_unlock(&iommu->lock);
1715 
1716                         return 0;
1717                 }
1718 
1719                 bus = iommu_device->bus;
1720         }
1721 
1722         domain->domain = iommu_domain_alloc(bus);
1723         if (!domain->domain) {
1724                 ret = -EIO;
1725                 goto out_free;
1726         }
1727 
1728         if (iommu->nesting) {
1729                 int attr = 1;
1730 
1731                 ret = iommu_domain_set_attr(domain->domain, DOMAIN_ATTR_NESTING,
1732                                             &attr);
1733                 if (ret)
1734                         goto out_domain;
1735         }
1736 
1737         ret = vfio_iommu_attach_group(domain, group);
1738         if (ret)
1739                 goto out_domain;
1740 
1741         /* Get aperture info */
1742         iommu_domain_get_attr(domain->domain, DOMAIN_ATTR_GEOMETRY, &geo);
1743 
1744         if (vfio_iommu_aper_conflict(iommu, geo.aperture_start,
1745                                      geo.aperture_end)) {
1746                 ret = -EINVAL;
1747                 goto out_detach;
1748         }
1749 
1750         ret = iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
1751         if (ret)
1752                 goto out_detach;
1753 
1754         if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
1755                 ret = -EINVAL;
1756                 goto out_detach;
1757         }
1758 
1759         /*
1760          * We don't want to work on the original iova list as the list
1761          * gets modified and in case of failure we have to retain the
1762          * original list. Get a copy here.
1763          */
1764         ret = vfio_iommu_iova_get_copy(iommu, &iova_copy);
1765         if (ret)
1766                 goto out_detach;
1767 
1768         ret = vfio_iommu_aper_resize(&iova_copy, geo.aperture_start,
1769                                      geo.aperture_end);
1770         if (ret)
1771                 goto out_detach;
1772 
1773         ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
1774         if (ret)
1775                 goto out_detach;
1776 
1777         resv_msi = vfio_iommu_has_sw_msi(&group_resv_regions, &resv_msi_base);
1778 
1779         INIT_LIST_HEAD(&domain->group_list);
1780         list_add(&group->next, &domain->group_list);
1781 
1782         msi_remap = irq_domain_check_msi_remap() ||
1783                     iommu_capable(bus, IOMMU_CAP_INTR_REMAP);
1784 
1785         if (!allow_unsafe_interrupts && !msi_remap) {
1786                 pr_warn("%s: No interrupt remapping support.  Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
1787                        __func__);
1788                 ret = -EPERM;
1789                 goto out_detach;
1790         }
1791 
1792         if (iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
1793                 domain->prot |= IOMMU_CACHE;
1794 
1795         /*
1796          * Try to match an existing compatible domain.  We don't want to
1797          * preclude an IOMMU driver supporting multiple bus_types and being
1798          * able to include different bus_types in the same IOMMU domain, so
1799          * we test whether the domains use the same iommu_ops rather than
1800          * testing if they're on the same bus_type.
1801          */
1802         list_for_each_entry(d, &iommu->domain_list, next) {
1803                 if (d->domain->ops == domain->domain->ops &&
1804                     d->prot == domain->prot) {
1805                         vfio_iommu_detach_group(domain, group);
1806                         if (!vfio_iommu_attach_group(d, group)) {
1807                                 list_add(&group->next, &d->group_list);
1808                                 iommu_domain_free(domain->domain);
1809                                 kfree(domain);
1810                                 goto done;
1811                         }
1812 
1813                         ret = vfio_iommu_attach_group(domain, group);
1814                         if (ret)
1815                                 goto out_domain;
1816                 }
1817         }
1818 
1819         vfio_test_domain_fgsp(domain);
1820 
1821         /* replay mappings on new domains */
1822         ret = vfio_iommu_replay(iommu, domain);
1823         if (ret)
1824                 goto out_detach;
1825 
1826         if (resv_msi) {
1827                 ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
1828                 if (ret)
1829                         goto out_detach;
1830         }
1831 
1832         list_add(&domain->next, &iommu->domain_list);
1833 done:
1834         /* Delete the old one and insert new iova list */
1835         vfio_iommu_iova_insert_copy(iommu, &iova_copy);
1836         mutex_unlock(&iommu->lock);
1837         vfio_iommu_resv_free(&group_resv_regions);
1838 
1839         return 0;
1840 
1841 out_detach:
1842         vfio_iommu_detach_group(domain, group);
1843 out_domain:
1844         iommu_domain_free(domain->domain);
1845         vfio_iommu_iova_free(&iova_copy);
1846         vfio_iommu_resv_free(&group_resv_regions);
1847 out_free:
1848         kfree(domain);
1849         kfree(group);
1850         mutex_unlock(&iommu->lock);
1851         return ret;
1852 }
1853 
1854 static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
1855 {
1856         struct rb_node *node;
1857 
1858         while ((node = rb_first(&iommu->dma_list)))
1859                 vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
1860 }
1861 
1862 static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
1863 {
1864         struct rb_node *n, *p;
1865 
1866         n = rb_first(&iommu->dma_list);
1867         for (; n; n = rb_next(n)) {
1868                 struct vfio_dma *dma;
1869                 long locked = 0, unlocked = 0;
1870 
1871                 dma = rb_entry(n, struct vfio_dma, node);
1872                 unlocked += vfio_unmap_unpin(iommu, dma, false);
1873                 p = rb_first(&dma->pfn_list);
1874                 for (; p; p = rb_next(p)) {
1875                         struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
1876                                                          node);
1877 
1878                         if (!is_invalid_reserved_pfn(vpfn->pfn))
1879                                 locked++;
1880                 }
1881                 vfio_lock_acct(dma, locked - unlocked, true);
1882         }
1883 }
1884 
1885 static void vfio_sanity_check_pfn_list(struct vfio_iommu *iommu)
1886 {
1887         struct rb_node *n;
1888 
1889         n = rb_first(&iommu->dma_list);
1890         for (; n; n = rb_next(n)) {
1891                 struct vfio_dma *dma;
1892 
1893                 dma = rb_entry(n, struct vfio_dma, node);
1894 
1895                 if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
1896                         break;
1897         }
1898         /* mdev vendor driver must unregister notifier */
1899         WARN_ON(iommu->notifier.head);
1900 }
1901 
1902 /*
1903  * Called when a domain is removed in detach. It is possible that
1904  * the removed domain decided the iova aperture window. Modify the
1905  * iova aperture with the smallest window among existing domains.
1906  */
1907 static void vfio_iommu_aper_expand(struct vfio_iommu *iommu,
1908                                    struct list_head *iova_copy)
1909 {
1910         struct vfio_domain *domain;
1911         struct iommu_domain_geometry geo;
1912         struct vfio_iova *node;
1913         dma_addr_t start = 0;
1914         dma_addr_t end = (dma_addr_t)~0;
1915 
1916         if (list_empty(iova_copy))
1917                 return;
1918 
1919         list_for_each_entry(domain, &iommu->domain_list, next) {
1920                 iommu_domain_get_attr(domain->domain, DOMAIN_ATTR_GEOMETRY,
1921                                       &geo);
1922                 if (geo.aperture_start > start)
1923                         start = geo.aperture_start;
1924                 if (geo.aperture_end < end)
1925                         end = geo.aperture_end;
1926         }
1927 
1928         /* Modify aperture limits. The new aper is either same or bigger */
1929         node = list_first_entry(iova_copy, struct vfio_iova, list);
1930         node->start = start;
1931         node = list_last_entry(iova_copy, struct vfio_iova, list);
1932         node->end = end;
1933 }
1934 
1935 /*
1936  * Called when a group is detached. The reserved regions for that
1937  * group can be part of valid iova now. But since reserved regions
1938  * may be duplicated among groups, populate the iova valid regions
1939  * list again.
1940  */
1941 static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu,
1942                                    struct list_head *iova_copy)
1943 {
1944         struct vfio_domain *d;
1945         struct vfio_group *g;
1946         struct vfio_iova *node;
1947         dma_addr_t start, end;
1948         LIST_HEAD(resv_regions);
1949         int ret;
1950 
1951         if (list_empty(iova_copy))
1952                 return -EINVAL;
1953 
1954         list_for_each_entry(d, &iommu->domain_list, next) {
1955                 list_for_each_entry(g, &d->group_list, next) {
1956                         ret = iommu_get_group_resv_regions(g->iommu_group,
1957                                                            &resv_regions);
1958                         if (ret)
1959                                 goto done;
1960                 }
1961         }
1962 
1963         node = list_first_entry(iova_copy, struct vfio_iova, list);
1964         start = node->start;
1965         node = list_last_entry(iova_copy, struct vfio_iova, list);
1966         end = node->end;
1967 
1968         /* purge the iova list and create new one */
1969         vfio_iommu_iova_free(iova_copy);
1970 
1971         ret = vfio_iommu_aper_resize(iova_copy, start, end);
1972         if (ret)
1973                 goto done;
1974 
1975         /* Exclude current reserved regions from iova ranges */
1976         ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions);
1977 done:
1978         vfio_iommu_resv_free(&resv_regions);
1979         return ret;
1980 }
1981 
1982 static void vfio_iommu_type1_detach_group(void *iommu_data,
1983                                           struct iommu_group *iommu_group)
1984 {
1985         struct vfio_iommu *iommu = iommu_data;
1986         struct vfio_domain *domain;
1987         struct vfio_group *group;
1988         LIST_HEAD(iova_copy);
1989 
1990         mutex_lock(&iommu->lock);
1991 
1992         if (iommu->external_domain) {
1993                 group = find_iommu_group(iommu->external_domain, iommu_group);
1994                 if (group) {
1995                         list_del(&group->next);
1996                         kfree(group);
1997 
1998                         if (list_empty(&iommu->external_domain->group_list)) {
1999                                 vfio_sanity_check_pfn_list(iommu);
2000 
2001                                 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
2002                                         vfio_iommu_unmap_unpin_all(iommu);
2003 
2004                                 kfree(iommu->external_domain);
2005                                 iommu->external_domain = NULL;
2006                         }
2007                         goto detach_group_done;
2008                 }
2009         }
2010 
2011         /*
2012          * Get a copy of iova list. This will be used to update
2013          * and to replace the current one later. Please note that
2014          * we will leave the original list as it is if update fails.
2015          */
2016         vfio_iommu_iova_get_copy(iommu, &iova_copy);
2017 
2018         list_for_each_entry(domain, &iommu->domain_list, next) {
2019                 group = find_iommu_group(domain, iommu_group);
2020                 if (!group)
2021                         continue;
2022 
2023                 vfio_iommu_detach_group(domain, group);
2024                 list_del(&group->next);
2025                 kfree(group);
2026                 /*
2027                  * Group ownership provides privilege, if the group list is
2028                  * empty, the domain goes away. If it's the last domain with
2029                  * iommu and external domain doesn't exist, then all the
2030                  * mappings go away too. If it's the last domain with iommu and
2031                  * external domain exist, update accounting
2032                  */
2033                 if (list_empty(&domain->group_list)) {
2034                         if (list_is_singular(&iommu->domain_list)) {
2035                                 if (!iommu->external_domain)
2036                                         vfio_iommu_unmap_unpin_all(iommu);
2037                                 else
2038                                         vfio_iommu_unmap_unpin_reaccount(iommu);
2039                         }
2040                         iommu_domain_free(domain->domain);
2041                         list_del(&domain->next);
2042                         kfree(domain);
2043                         vfio_iommu_aper_expand(iommu, &iova_copy);
2044                 }
2045                 break;
2046         }
2047 
2048         if (!vfio_iommu_resv_refresh(iommu, &iova_copy))
2049                 vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2050         else
2051                 vfio_iommu_iova_free(&iova_copy);
2052 
2053 detach_group_done:
2054         mutex_unlock(&iommu->lock);
2055 }
2056 
2057 static void *vfio_iommu_type1_open(unsigned long arg)
2058 {
2059         struct vfio_iommu *iommu;
2060 
2061         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
2062         if (!iommu)
2063                 return ERR_PTR(-ENOMEM);
2064 
2065         switch (arg) {
2066         case VFIO_TYPE1_IOMMU:
2067                 break;
2068         case VFIO_TYPE1_NESTING_IOMMU:
2069                 iommu->nesting = true;
2070                 /* fall through */
2071         case VFIO_TYPE1v2_IOMMU:
2072                 iommu->v2 = true;
2073                 break;
2074         default:
2075                 kfree(iommu);
2076                 return ERR_PTR(-EINVAL);
2077         }
2078 
2079         INIT_LIST_HEAD(&iommu->domain_list);
2080         INIT_LIST_HEAD(&iommu->iova_list);
2081         iommu->dma_list = RB_ROOT;
2082         iommu->dma_avail = dma_entry_limit;
2083         mutex_init(&iommu->lock);
2084         BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
2085 
2086         return iommu;
2087 }
2088 
2089 static void vfio_release_domain(struct vfio_domain *domain, bool external)
2090 {
2091         struct vfio_group *group, *group_tmp;
2092 
2093         list_for_each_entry_safe(group, group_tmp,
2094                                  &domain->group_list, next) {
2095                 if (!external)
2096                         vfio_iommu_detach_group(domain, group);
2097                 list_del(&group->next);
2098                 kfree(group);
2099         }
2100 
2101         if (!external)
2102                 iommu_domain_free(domain->domain);
2103 }
2104 
2105 static void vfio_iommu_type1_release(void *iommu_data)
2106 {
2107         struct vfio_iommu *iommu = iommu_data;
2108         struct vfio_domain *domain, *domain_tmp;
2109 
2110         if (iommu->external_domain) {
2111                 vfio_release_domain(iommu->external_domain, true);
2112                 vfio_sanity_check_pfn_list(iommu);
2113                 kfree(iommu->external_domain);
2114         }
2115 
2116         vfio_iommu_unmap_unpin_all(iommu);
2117 
2118         list_for_each_entry_safe(domain, domain_tmp,
2119                                  &iommu->domain_list, next) {
2120                 vfio_release_domain(domain, false);
2121                 list_del(&domain->next);
2122                 kfree(domain);
2123         }
2124 
2125         vfio_iommu_iova_free(&iommu->iova_list);
2126 
2127         kfree(iommu);
2128 }
2129 
2130 static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
2131 {
2132         struct vfio_domain *domain;
2133         int ret = 1;
2134 
2135         mutex_lock(&iommu->lock);
2136         list_for_each_entry(domain, &iommu->domain_list, next) {
2137                 if (!(domain->prot & IOMMU_CACHE)) {
2138                         ret = 0;
2139                         break;
2140                 }
2141         }
2142         mutex_unlock(&iommu->lock);
2143 
2144         return ret;
2145 }
2146 
2147 static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
2148                  struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
2149                  size_t size)
2150 {
2151         struct vfio_info_cap_header *header;
2152         struct vfio_iommu_type1_info_cap_iova_range *iova_cap;
2153 
2154         header = vfio_info_cap_add(caps, size,
2155                                    VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);
2156         if (IS_ERR(header))
2157                 return PTR_ERR(header);
2158 
2159         iova_cap = container_of(header,
2160                                 struct vfio_iommu_type1_info_cap_iova_range,
2161                                 header);
2162         iova_cap->nr_iovas = cap_iovas->nr_iovas;
2163         memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges,
2164                cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges));
2165         return 0;
2166 }
2167 
2168 static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,
2169                                       struct vfio_info_cap *caps)
2170 {
2171         struct vfio_iommu_type1_info_cap_iova_range *cap_iovas;
2172         struct vfio_iova *iova;
2173         size_t size;
2174         int iovas = 0, i = 0, ret;
2175 
2176         mutex_lock(&iommu->lock);
2177 
2178         list_for_each_entry(iova, &iommu->iova_list, list)
2179                 iovas++;
2180 
2181         if (!iovas) {
2182                 /*
2183                  * Return 0 as a container with a single mdev device
2184                  * will have an empty list
2185                  */
2186                 ret = 0;
2187                 goto out_unlock;
2188         }
2189 
2190         size = sizeof(*cap_iovas) + (iovas * sizeof(*cap_iovas->iova_ranges));
2191 
2192         cap_iovas = kzalloc(size, GFP_KERNEL);
2193         if (!cap_iovas) {
2194                 ret = -ENOMEM;
2195                 goto out_unlock;
2196         }
2197 
2198         cap_iovas->nr_iovas = iovas;
2199 
2200         list_for_each_entry(iova, &iommu->iova_list, list) {
2201                 cap_iovas->iova_ranges[i].start = iova->start;
2202                 cap_iovas->iova_ranges[i].end = iova->end;
2203                 i++;
2204         }
2205 
2206         ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size);
2207 
2208         kfree(cap_iovas);
2209 out_unlock:
2210         mutex_unlock(&iommu->lock);
2211         return ret;
2212 }
2213 
2214 static long vfio_iommu_type1_ioctl(void *iommu_data,
2215                                    unsigned int cmd, unsigned long arg)
2216 {
2217         struct vfio_iommu *iommu = iommu_data;
2218         unsigned long minsz;
2219 
2220         if (cmd == VFIO_CHECK_EXTENSION) {
2221                 switch (arg) {
2222                 case VFIO_TYPE1_IOMMU:
2223                 case VFIO_TYPE1v2_IOMMU:
2224                 case VFIO_TYPE1_NESTING_IOMMU:
2225                         return 1;
2226                 case VFIO_DMA_CC_IOMMU:
2227                         if (!iommu)
2228                                 return 0;
2229                         return vfio_domains_have_iommu_cache(iommu);
2230                 default:
2231                         return 0;
2232                 }
2233         } else if (cmd == VFIO_IOMMU_GET_INFO) {
2234                 struct vfio_iommu_type1_info info;
2235                 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
2236                 unsigned long capsz;
2237                 int ret;
2238 
2239                 minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
2240 
2241                 /* For backward compatibility, cannot require this */
2242                 capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
2243 
2244                 if (copy_from_user(&info, (void __user *)arg, minsz))
2245                         return -EFAULT;
2246 
2247                 if (info.argsz < minsz)
2248                         return -EINVAL;
2249 
2250                 if (info.argsz >= capsz) {
2251                         minsz = capsz;
2252                         info.cap_offset = 0; /* output, no-recopy necessary */
2253                 }
2254 
2255                 info.flags = VFIO_IOMMU_INFO_PGSIZES;
2256 
2257                 info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
2258 
2259                 ret = vfio_iommu_iova_build_caps(iommu, &caps);
2260                 if (ret)
2261                         return ret;
2262 
2263                 if (caps.size) {
2264                         info.flags |= VFIO_IOMMU_INFO_CAPS;
2265 
2266                         if (info.argsz < sizeof(info) + caps.size) {
2267                                 info.argsz = sizeof(info) + caps.size;
2268                         } else {
2269                                 vfio_info_cap_shift(&caps, sizeof(info));
2270                                 if (copy_to_user((void __user *)arg +
2271                                                 sizeof(info), caps.buf,
2272                                                 caps.size)) {
2273                                         kfree(caps.buf);
2274                                         return -EFAULT;
2275                                 }
2276                                 info.cap_offset = sizeof(info);
2277                         }
2278 
2279                         kfree(caps.buf);
2280                 }
2281 
2282                 return copy_to_user((void __user *)arg, &info, minsz) ?
2283                         -EFAULT : 0;
2284 
2285         } else if (cmd == VFIO_IOMMU_MAP_DMA) {
2286                 struct vfio_iommu_type1_dma_map map;
2287                 uint32_t mask = VFIO_DMA_MAP_FLAG_READ |
2288                                 VFIO_DMA_MAP_FLAG_WRITE;
2289 
2290                 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
2291 
2292                 if (copy_from_user(&map, (void __user *)arg, minsz))
2293                         return -EFAULT;
2294 
2295                 if (map.argsz < minsz || map.flags & ~mask)
2296                         return -EINVAL;
2297 
2298                 return vfio_dma_do_map(iommu, &map);
2299 
2300         } else if (cmd == VFIO_IOMMU_UNMAP_DMA) {
2301                 struct vfio_iommu_type1_dma_unmap unmap;
2302                 long ret;
2303 
2304                 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
2305 
2306                 if (copy_from_user(&unmap, (void __user *)arg, minsz))
2307                         return -EFAULT;
2308 
2309                 if (unmap.argsz < minsz || unmap.flags)
2310                         return -EINVAL;
2311 
2312                 ret = vfio_dma_do_unmap(iommu, &unmap);
2313                 if (ret)
2314                         return ret;
2315 
2316                 return copy_to_user((void __user *)arg, &unmap, minsz) ?
2317                         -EFAULT : 0;
2318         }
2319 
2320         return -ENOTTY;
2321 }
2322 
2323 static int vfio_iommu_type1_register_notifier(void *iommu_data,
2324                                               unsigned long *events,
2325                                               struct notifier_block *nb)
2326 {
2327         struct vfio_iommu *iommu = iommu_data;
2328 
2329         /* clear known events */
2330         *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;
2331 
2332         /* refuse to register if still events remaining */
2333         if (*events)
2334                 return -EINVAL;
2335 
2336         return blocking_notifier_chain_register(&iommu->notifier, nb);
2337 }
2338 
2339 static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
2340                                                 struct notifier_block *nb)
2341 {
2342         struct vfio_iommu *iommu = iommu_data;
2343 
2344         return blocking_notifier_chain_unregister(&iommu->notifier, nb);
2345 }
2346 
2347 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
2348         .name                   = "vfio-iommu-type1",
2349         .owner                  = THIS_MODULE,
2350         .open                   = vfio_iommu_type1_open,
2351         .release                = vfio_iommu_type1_release,
2352         .ioctl                  = vfio_iommu_type1_ioctl,
2353         .attach_group           = vfio_iommu_type1_attach_group,
2354         .detach_group           = vfio_iommu_type1_detach_group,
2355         .pin_pages              = vfio_iommu_type1_pin_pages,
2356         .unpin_pages            = vfio_iommu_type1_unpin_pages,
2357         .register_notifier      = vfio_iommu_type1_register_notifier,
2358         .unregister_notifier    = vfio_iommu_type1_unregister_notifier,
2359 };
2360 
2361 static int __init vfio_iommu_type1_init(void)
2362 {
2363         return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
2364 }
2365 
2366 static void __exit vfio_iommu_type1_cleanup(void)
2367 {
2368         vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1);
2369 }
2370 
2371 module_init(vfio_iommu_type1_init);
2372 module_exit(vfio_iommu_type1_cleanup);
2373 
2374 MODULE_VERSION(DRIVER_VERSION);
2375 MODULE_LICENSE("GPL v2");
2376 MODULE_AUTHOR(DRIVER_AUTHOR);
2377 MODULE_DESCRIPTION(DRIVER_DESC);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/vfio/vfio_iommu_type1.c

DEFINITIONS
