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 * userspace pages pinned into memory. We also assume devices and IOMMU 20 * domains are PCI based as the IOMMU API is still centered around a 21 * device/bus interface rather than a group interface. 22 */ 23 24 #include <linux/compat.h> 25 #include <linux/device.h> 26 #include <linux/fs.h> 27 #include <linux/highmem.h> 28 #include <linux/iommu.h> 29 #include <linux/module.h> 30 #include <linux/mm.h> 31 #include <linux/kthread.h> 32 #include <linux/rbtree.h> 33 #include <linux/sched/signal.h> 34 #include <linux/sched/mm.h> 35 #include <linux/slab.h> 36 #include <linux/uaccess.h> 37 #include <linux/vfio.h> 38 #include <linux/workqueue.h> 39 #include <linux/mdev.h> 40 #include <linux/notifier.h> 41 #include <linux/dma-iommu.h> 42 #include <linux/irqdomain.h> 43 44 #define DRIVER_VERSION "0.2" 45 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" 46 #define DRIVER_DESC "Type1 IOMMU driver for VFIO" 47 48 static bool allow_unsafe_interrupts; 49 module_param_named(allow_unsafe_interrupts, 50 allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR); 51 MODULE_PARM_DESC(allow_unsafe_interrupts, 52 "Enable VFIO IOMMU support for on platforms without interrupt remapping support."); 53 54 static bool disable_hugepages; 55 module_param_named(disable_hugepages, 56 disable_hugepages, bool, S_IRUGO | S_IWUSR); 57 MODULE_PARM_DESC(disable_hugepages, 58 "Disable VFIO IOMMU support for IOMMU hugepages."); 59 60 static unsigned int dma_entry_limit __read_mostly = U16_MAX; 61 module_param_named(dma_entry_limit, dma_entry_limit, uint, 0644); 62 MODULE_PARM_DESC(dma_entry_limit, 63 "Maximum number of user DMA mappings per container (65535)."); 64 65 struct vfio_iommu { 66 struct list_head domain_list; 67 struct list_head iova_list; 68 struct vfio_domain *external_domain; /* domain for external user */ 69 struct mutex lock; 70 struct rb_root dma_list; 71 struct blocking_notifier_head notifier; 72 unsigned int dma_avail; 73 unsigned int vaddr_invalid_count; 74 uint64_t pgsize_bitmap; 75 uint64_t num_non_pinned_groups; 76 wait_queue_head_t vaddr_wait; 77 bool v2; 78 bool nesting; 79 bool dirty_page_tracking; 80 bool container_open; 81 }; 82 83 struct vfio_domain { 84 struct iommu_domain *domain; 85 struct list_head next; 86 struct list_head group_list; 87 int prot; /* IOMMU_CACHE */ 88 bool fgsp; /* Fine-grained super pages */ 89 }; 90 91 struct vfio_dma { 92 struct rb_node node; 93 dma_addr_t iova; /* Device address */ 94 unsigned long vaddr; /* Process virtual addr */ 95 size_t size; /* Map size (bytes) */ 96 int prot; /* IOMMU_READ/WRITE */ 97 bool iommu_mapped; 98 bool lock_cap; /* capable(CAP_IPC_LOCK) */ 99 bool vaddr_invalid; 100 struct task_struct *task; 101 struct rb_root pfn_list; /* Ex-user pinned pfn list */ 102 unsigned long *bitmap; 103 }; 104 105 struct vfio_batch { 106 struct page **pages; /* for pin_user_pages_remote */ 107 struct page *fallback_page; /* if pages alloc fails */ 108 int capacity; /* length of pages array */ 109 int size; /* of batch currently */ 110 int offset; /* of next entry in pages */ 111 }; 112 113 struct vfio_iommu_group { 114 struct iommu_group *iommu_group; 115 struct list_head next; 116 bool mdev_group; /* An mdev group */ 117 bool pinned_page_dirty_scope; 118 }; 119 120 struct vfio_iova { 121 struct list_head list; 122 dma_addr_t start; 123 dma_addr_t end; 124 }; 125 126 /* 127 * Guest RAM pinning working set or DMA target 128 */ 129 struct vfio_pfn { 130 struct rb_node node; 131 dma_addr_t iova; /* Device address */ 132 unsigned long pfn; /* Host pfn */ 133 unsigned int ref_count; 134 }; 135 136 struct vfio_regions { 137 struct list_head list; 138 dma_addr_t iova; 139 phys_addr_t phys; 140 size_t len; 141 }; 142 143 #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ 144 (!list_empty(&iommu->domain_list)) 145 146 #define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE) 147 148 /* 149 * Input argument of number of bits to bitmap_set() is unsigned integer, which 150 * further casts to signed integer for unaligned multi-bit operation, 151 * __bitmap_set(). 152 * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte, 153 * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page 154 * system. 155 */ 156 #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) 157 #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) 158 159 #define WAITED 1 160 161 static int put_pfn(unsigned long pfn, int prot); 162 163 static struct vfio_iommu_group* 164 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu, 165 struct iommu_group *iommu_group); 166 167 /* 168 * This code handles mapping and unmapping of user data buffers 169 * into DMA'ble space using the IOMMU 170 */ 171 172 static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, 173 dma_addr_t start, size_t size) 174 { 175 struct rb_node *node = iommu->dma_list.rb_node; 176 177 while (node) { 178 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); 179 180 if (start + size <= dma->iova) 181 node = node->rb_left; 182 else if (start >= dma->iova + dma->size) 183 node = node->rb_right; 184 else 185 return dma; 186 } 187 188 return NULL; 189 } 190 191 static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu, 192 dma_addr_t start, u64 size) 193 { 194 struct rb_node *res = NULL; 195 struct rb_node *node = iommu->dma_list.rb_node; 196 struct vfio_dma *dma_res = NULL; 197 198 while (node) { 199 struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); 200 201 if (start < dma->iova + dma->size) { 202 res = node; 203 dma_res = dma; 204 if (start >= dma->iova) 205 break; 206 node = node->rb_left; 207 } else { 208 node = node->rb_right; 209 } 210 } 211 if (res && size && dma_res->iova >= start + size) 212 res = NULL; 213 return res; 214 } 215 216 static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new) 217 { 218 struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL; 219 struct vfio_dma *dma; 220 221 while (*link) { 222 parent = *link; 223 dma = rb_entry(parent, struct vfio_dma, node); 224 225 if (new->iova + new->size <= dma->iova) 226 link = &(*link)->rb_left; 227 else 228 link = &(*link)->rb_right; 229 } 230 231 rb_link_node(&new->node, parent, link); 232 rb_insert_color(&new->node, &iommu->dma_list); 233 } 234 235 static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old) 236 { 237 rb_erase(&old->node, &iommu->dma_list); 238 } 239 240 241 static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize) 242 { 243 uint64_t npages = dma->size / pgsize; 244 245 if (npages > DIRTY_BITMAP_PAGES_MAX) 246 return -EINVAL; 247 248 /* 249 * Allocate extra 64 bits that are used to calculate shift required for 250 * bitmap_shift_left() to manipulate and club unaligned number of pages 251 * in adjacent vfio_dma ranges. 252 */ 253 dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64), 254 GFP_KERNEL); 255 if (!dma->bitmap) 256 return -ENOMEM; 257 258 return 0; 259 } 260 261 static void vfio_dma_bitmap_free(struct vfio_dma *dma) 262 { 263 kfree(dma->bitmap); 264 dma->bitmap = NULL; 265 } 266 267 static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) 268 { 269 struct rb_node *p; 270 unsigned long pgshift = __ffs(pgsize); 271 272 for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) { 273 struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node); 274 275 bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1); 276 } 277 } 278 279 static void vfio_iommu_populate_bitmap_full(struct vfio_iommu *iommu) 280 { 281 struct rb_node *n; 282 unsigned long pgshift = __ffs(iommu->pgsize_bitmap); 283 284 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { 285 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); 286 287 bitmap_set(dma->bitmap, 0, dma->size >> pgshift); 288 } 289 } 290 291 static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize) 292 { 293 struct rb_node *n; 294 295 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { 296 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); 297 int ret; 298 299 ret = vfio_dma_bitmap_alloc(dma, pgsize); 300 if (ret) { 301 struct rb_node *p; 302 303 for (p = rb_prev(n); p; p = rb_prev(p)) { 304 struct vfio_dma *dma = rb_entry(n, 305 struct vfio_dma, node); 306 307 vfio_dma_bitmap_free(dma); 308 } 309 return ret; 310 } 311 vfio_dma_populate_bitmap(dma, pgsize); 312 } 313 return 0; 314 } 315 316 static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu) 317 { 318 struct rb_node *n; 319 320 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { 321 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); 322 323 vfio_dma_bitmap_free(dma); 324 } 325 } 326 327 /* 328 * Helper Functions for host iova-pfn list 329 */ 330 static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova) 331 { 332 struct vfio_pfn *vpfn; 333 struct rb_node *node = dma->pfn_list.rb_node; 334 335 while (node) { 336 vpfn = rb_entry(node, struct vfio_pfn, node); 337 338 if (iova < vpfn->iova) 339 node = node->rb_left; 340 else if (iova > vpfn->iova) 341 node = node->rb_right; 342 else 343 return vpfn; 344 } 345 return NULL; 346 } 347 348 static void vfio_link_pfn(struct vfio_dma *dma, 349 struct vfio_pfn *new) 350 { 351 struct rb_node **link, *parent = NULL; 352 struct vfio_pfn *vpfn; 353 354 link = &dma->pfn_list.rb_node; 355 while (*link) { 356 parent = *link; 357 vpfn = rb_entry(parent, struct vfio_pfn, node); 358 359 if (new->iova < vpfn->iova) 360 link = &(*link)->rb_left; 361 else 362 link = &(*link)->rb_right; 363 } 364 365 rb_link_node(&new->node, parent, link); 366 rb_insert_color(&new->node, &dma->pfn_list); 367 } 368 369 static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old) 370 { 371 rb_erase(&old->node, &dma->pfn_list); 372 } 373 374 static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova, 375 unsigned long pfn) 376 { 377 struct vfio_pfn *vpfn; 378 379 vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL); 380 if (!vpfn) 381 return -ENOMEM; 382 383 vpfn->iova = iova; 384 vpfn->pfn = pfn; 385 vpfn->ref_count = 1; 386 vfio_link_pfn(dma, vpfn); 387 return 0; 388 } 389 390 static void vfio_remove_from_pfn_list(struct vfio_dma *dma, 391 struct vfio_pfn *vpfn) 392 { 393 vfio_unlink_pfn(dma, vpfn); 394 kfree(vpfn); 395 } 396 397 static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma, 398 unsigned long iova) 399 { 400 struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova); 401 402 if (vpfn) 403 vpfn->ref_count++; 404 return vpfn; 405 } 406 407 static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn) 408 { 409 int ret = 0; 410 411 vpfn->ref_count--; 412 if (!vpfn->ref_count) { 413 ret = put_pfn(vpfn->pfn, dma->prot); 414 vfio_remove_from_pfn_list(dma, vpfn); 415 } 416 return ret; 417 } 418 419 static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async) 420 { 421 struct mm_struct *mm; 422 int ret; 423 424 if (!npage) 425 return 0; 426 427 mm = async ? get_task_mm(dma->task) : dma->task->mm; 428 if (!mm) 429 return -ESRCH; /* process exited */ 430 431 ret = mmap_write_lock_killable(mm); 432 if (!ret) { 433 ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task, 434 dma->lock_cap); 435 mmap_write_unlock(mm); 436 } 437 438 if (async) 439 mmput(mm); 440 441 return ret; 442 } 443 444 /* 445 * Some mappings aren't backed by a struct page, for example an mmap'd 446 * MMIO range for our own or another device. These use a different 447 * pfn conversion and shouldn't be tracked as locked pages. 448 * For compound pages, any driver that sets the reserved bit in head 449 * page needs to set the reserved bit in all subpages to be safe. 450 */ 451 static bool is_invalid_reserved_pfn(unsigned long pfn) 452 { 453 if (pfn_valid(pfn)) 454 return PageReserved(pfn_to_page(pfn)); 455 456 return true; 457 } 458 459 static int put_pfn(unsigned long pfn, int prot) 460 { 461 if (!is_invalid_reserved_pfn(pfn)) { 462 struct page *page = pfn_to_page(pfn); 463 464 unpin_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE); 465 return 1; 466 } 467 return 0; 468 } 469 470 #define VFIO_BATCH_MAX_CAPACITY (PAGE_SIZE / sizeof(struct page *)) 471 472 static void vfio_batch_init(struct vfio_batch *batch) 473 { 474 batch->size = 0; 475 batch->offset = 0; 476 477 if (unlikely(disable_hugepages)) 478 goto fallback; 479 480 batch->pages = (struct page **) __get_free_page(GFP_KERNEL); 481 if (!batch->pages) 482 goto fallback; 483 484 batch->capacity = VFIO_BATCH_MAX_CAPACITY; 485 return; 486 487 fallback: 488 batch->pages = &batch->fallback_page; 489 batch->capacity = 1; 490 } 491 492 static void vfio_batch_unpin(struct vfio_batch *batch, struct vfio_dma *dma) 493 { 494 while (batch->size) { 495 unsigned long pfn = page_to_pfn(batch->pages[batch->offset]); 496 497 put_pfn(pfn, dma->prot); 498 batch->offset++; 499 batch->size--; 500 } 501 } 502 503 static void vfio_batch_fini(struct vfio_batch *batch) 504 { 505 if (batch->capacity == VFIO_BATCH_MAX_CAPACITY) 506 free_page((unsigned long)batch->pages); 507 } 508 509 static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, 510 unsigned long vaddr, unsigned long *pfn, 511 bool write_fault) 512 { 513 pte_t *ptep; 514 spinlock_t *ptl; 515 int ret; 516 517 ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); 518 if (ret) { 519 bool unlocked = false; 520 521 ret = fixup_user_fault(mm, vaddr, 522 FAULT_FLAG_REMOTE | 523 (write_fault ? FAULT_FLAG_WRITE : 0), 524 &unlocked); 525 if (unlocked) 526 return -EAGAIN; 527 528 if (ret) 529 return ret; 530 531 ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); 532 if (ret) 533 return ret; 534 } 535 536 if (write_fault && !pte_write(*ptep)) 537 ret = -EFAULT; 538 else 539 *pfn = pte_pfn(*ptep); 540 541 pte_unmap_unlock(ptep, ptl); 542 return ret; 543 } 544 545 /* 546 * Returns the positive number of pfns successfully obtained or a negative 547 * error code. 548 */ 549 static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr, 550 long npages, int prot, unsigned long *pfn, 551 struct page **pages) 552 { 553 struct vm_area_struct *vma; 554 unsigned int flags = 0; 555 int ret; 556 557 if (prot & IOMMU_WRITE) 558 flags |= FOLL_WRITE; 559 560 mmap_read_lock(mm); 561 ret = pin_user_pages_remote(mm, vaddr, npages, flags | FOLL_LONGTERM, 562 pages, NULL, NULL); 563 if (ret > 0) { 564 *pfn = page_to_pfn(pages[0]); 565 goto done; 566 } 567 568 vaddr = untagged_addr(vaddr); 569 570 retry: 571 vma = vma_lookup(mm, vaddr); 572 573 if (vma && vma->vm_flags & VM_PFNMAP) { 574 ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE); 575 if (ret == -EAGAIN) 576 goto retry; 577 578 if (!ret) { 579 if (is_invalid_reserved_pfn(*pfn)) 580 ret = 1; 581 else 582 ret = -EFAULT; 583 } 584 } 585 done: 586 mmap_read_unlock(mm); 587 return ret; 588 } 589 590 static int vfio_wait(struct vfio_iommu *iommu) 591 { 592 DEFINE_WAIT(wait); 593 594 prepare_to_wait(&iommu->vaddr_wait, &wait, TASK_KILLABLE); 595 mutex_unlock(&iommu->lock); 596 schedule(); 597 mutex_lock(&iommu->lock); 598 finish_wait(&iommu->vaddr_wait, &wait); 599 if (kthread_should_stop() || !iommu->container_open || 600 fatal_signal_pending(current)) { 601 return -EFAULT; 602 } 603 return WAITED; 604 } 605 606 /* 607 * Find dma struct and wait for its vaddr to be valid. iommu lock is dropped 608 * if the task waits, but is re-locked on return. Return result in *dma_p. 609 * Return 0 on success with no waiting, WAITED on success if waited, and -errno 610 * on error. 611 */ 612 static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start, 613 size_t size, struct vfio_dma **dma_p) 614 { 615 int ret; 616 617 do { 618 *dma_p = vfio_find_dma(iommu, start, size); 619 if (!*dma_p) 620 ret = -EINVAL; 621 else if (!(*dma_p)->vaddr_invalid) 622 ret = 0; 623 else 624 ret = vfio_wait(iommu); 625 } while (ret > 0); 626 627 return ret; 628 } 629 630 /* 631 * Wait for all vaddr in the dma_list to become valid. iommu lock is dropped 632 * if the task waits, but is re-locked on return. Return 0 on success with no 633 * waiting, WAITED on success if waited, and -errno on error. 634 */ 635 static int vfio_wait_all_valid(struct vfio_iommu *iommu) 636 { 637 int ret = 0; 638 639 while (iommu->vaddr_invalid_count && ret >= 0) 640 ret = vfio_wait(iommu); 641 642 return ret; 643 } 644 645 /* 646 * Attempt to pin pages. We really don't want to track all the pfns and 647 * the iommu can only map chunks of consecutive pfns anyway, so get the 648 * first page and all consecutive pages with the same locking. 649 */ 650 static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr, 651 long npage, unsigned long *pfn_base, 652 unsigned long limit, struct vfio_batch *batch) 653 { 654 unsigned long pfn; 655 struct mm_struct *mm = current->mm; 656 long ret, pinned = 0, lock_acct = 0; 657 bool rsvd; 658 dma_addr_t iova = vaddr - dma->vaddr + dma->iova; 659 660 /* This code path is only user initiated */ 661 if (!mm) 662 return -ENODEV; 663 664 if (batch->size) { 665 /* Leftover pages in batch from an earlier call. */ 666 *pfn_base = page_to_pfn(batch->pages[batch->offset]); 667 pfn = *pfn_base; 668 rsvd = is_invalid_reserved_pfn(*pfn_base); 669 } else { 670 *pfn_base = 0; 671 } 672 673 while (npage) { 674 if (!batch->size) { 675 /* Empty batch, so refill it. */ 676 long req_pages = min_t(long, npage, batch->capacity); 677 678 ret = vaddr_get_pfns(mm, vaddr, req_pages, dma->prot, 679 &pfn, batch->pages); 680 if (ret < 0) 681 goto unpin_out; 682 683 batch->size = ret; 684 batch->offset = 0; 685 686 if (!*pfn_base) { 687 *pfn_base = pfn; 688 rsvd = is_invalid_reserved_pfn(*pfn_base); 689 } 690 } 691 692 /* 693 * pfn is preset for the first iteration of this inner loop and 694 * updated at the end to handle a VM_PFNMAP pfn. In that case, 695 * batch->pages isn't valid (there's no struct page), so allow 696 * batch->pages to be touched only when there's more than one 697 * pfn to check, which guarantees the pfns are from a 698 * !VM_PFNMAP vma. 699 */ 700 while (true) { 701 if (pfn != *pfn_base + pinned || 702 rsvd != is_invalid_reserved_pfn(pfn)) 703 goto out; 704 705 /* 706 * Reserved pages aren't counted against the user, 707 * externally pinned pages are already counted against 708 * the user. 709 */ 710 if (!rsvd && !vfio_find_vpfn(dma, iova)) { 711 if (!dma->lock_cap && 712 mm->locked_vm + lock_acct + 1 > limit) { 713 pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", 714 __func__, limit << PAGE_SHIFT); 715 ret = -ENOMEM; 716 goto unpin_out; 717 } 718 lock_acct++; 719 } 720 721 pinned++; 722 npage--; 723 vaddr += PAGE_SIZE; 724 iova += PAGE_SIZE; 725 batch->offset++; 726 batch->size--; 727 728 if (!batch->size) 729 break; 730 731 pfn = page_to_pfn(batch->pages[batch->offset]); 732 } 733 734 if (unlikely(disable_hugepages)) 735 break; 736 } 737 738 out: 739 ret = vfio_lock_acct(dma, lock_acct, false); 740 741 unpin_out: 742 if (batch->size == 1 && !batch->offset) { 743 /* May be a VM_PFNMAP pfn, which the batch can't remember. */ 744 put_pfn(pfn, dma->prot); 745 batch->size = 0; 746 } 747 748 if (ret < 0) { 749 if (pinned && !rsvd) { 750 for (pfn = *pfn_base ; pinned ; pfn++, pinned--) 751 put_pfn(pfn, dma->prot); 752 } 753 vfio_batch_unpin(batch, dma); 754 755 return ret; 756 } 757 758 return pinned; 759 } 760 761 static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova, 762 unsigned long pfn, long npage, 763 bool do_accounting) 764 { 765 long unlocked = 0, locked = 0; 766 long i; 767 768 for (i = 0; i < npage; i++, iova += PAGE_SIZE) { 769 if (put_pfn(pfn++, dma->prot)) { 770 unlocked++; 771 if (vfio_find_vpfn(dma, iova)) 772 locked++; 773 } 774 } 775 776 if (do_accounting) 777 vfio_lock_acct(dma, locked - unlocked, true); 778 779 return unlocked; 780 } 781 782 static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr, 783 unsigned long *pfn_base, bool do_accounting) 784 { 785 struct page *pages[1]; 786 struct mm_struct *mm; 787 int ret; 788 789 mm = get_task_mm(dma->task); 790 if (!mm) 791 return -ENODEV; 792 793 ret = vaddr_get_pfns(mm, vaddr, 1, dma->prot, pfn_base, pages); 794 if (ret != 1) 795 goto out; 796 797 ret = 0; 798 799 if (do_accounting && !is_invalid_reserved_pfn(*pfn_base)) { 800 ret = vfio_lock_acct(dma, 1, true); 801 if (ret) { 802 put_pfn(*pfn_base, dma->prot); 803 if (ret == -ENOMEM) 804 pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK " 805 "(%ld) exceeded\n", __func__, 806 dma->task->comm, task_pid_nr(dma->task), 807 task_rlimit(dma->task, RLIMIT_MEMLOCK)); 808 } 809 } 810 811 out: 812 mmput(mm); 813 return ret; 814 } 815 816 static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova, 817 bool do_accounting) 818 { 819 int unlocked; 820 struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova); 821 822 if (!vpfn) 823 return 0; 824 825 unlocked = vfio_iova_put_vfio_pfn(dma, vpfn); 826 827 if (do_accounting) 828 vfio_lock_acct(dma, -unlocked, true); 829 830 return unlocked; 831 } 832 833 static int vfio_iommu_type1_pin_pages(void *iommu_data, 834 struct iommu_group *iommu_group, 835 unsigned long *user_pfn, 836 int npage, int prot, 837 unsigned long *phys_pfn) 838 { 839 struct vfio_iommu *iommu = iommu_data; 840 struct vfio_iommu_group *group; 841 int i, j, ret; 842 unsigned long remote_vaddr; 843 struct vfio_dma *dma; 844 bool do_accounting; 845 dma_addr_t iova; 846 847 if (!iommu || !user_pfn || !phys_pfn) 848 return -EINVAL; 849 850 /* Supported for v2 version only */ 851 if (!iommu->v2) 852 return -EACCES; 853 854 mutex_lock(&iommu->lock); 855 856 /* 857 * Wait for all necessary vaddr's to be valid so they can be used in 858 * the main loop without dropping the lock, to avoid racing vs unmap. 859 */ 860 again: 861 if (iommu->vaddr_invalid_count) { 862 for (i = 0; i < npage; i++) { 863 iova = user_pfn[i] << PAGE_SHIFT; 864 ret = vfio_find_dma_valid(iommu, iova, PAGE_SIZE, &dma); 865 if (ret < 0) 866 goto pin_done; 867 if (ret == WAITED) 868 goto again; 869 } 870 } 871 872 /* Fail if notifier list is empty */ 873 if (!iommu->notifier.head) { 874 ret = -EINVAL; 875 goto pin_done; 876 } 877 878 /* 879 * If iommu capable domain exist in the container then all pages are 880 * already pinned and accounted. Accounting should be done if there is no 881 * iommu capable domain in the container. 882 */ 883 do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu); 884 885 for (i = 0; i < npage; i++) { 886 struct vfio_pfn *vpfn; 887 888 iova = user_pfn[i] << PAGE_SHIFT; 889 dma = vfio_find_dma(iommu, iova, PAGE_SIZE); 890 if (!dma) { 891 ret = -EINVAL; 892 goto pin_unwind; 893 } 894 895 if ((dma->prot & prot) != prot) { 896 ret = -EPERM; 897 goto pin_unwind; 898 } 899 900 vpfn = vfio_iova_get_vfio_pfn(dma, iova); 901 if (vpfn) { 902 phys_pfn[i] = vpfn->pfn; 903 continue; 904 } 905 906 remote_vaddr = dma->vaddr + (iova - dma->iova); 907 ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i], 908 do_accounting); 909 if (ret) 910 goto pin_unwind; 911 912 ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]); 913 if (ret) { 914 if (put_pfn(phys_pfn[i], dma->prot) && do_accounting) 915 vfio_lock_acct(dma, -1, true); 916 goto pin_unwind; 917 } 918 919 if (iommu->dirty_page_tracking) { 920 unsigned long pgshift = __ffs(iommu->pgsize_bitmap); 921 922 /* 923 * Bitmap populated with the smallest supported page 924 * size 925 */ 926 bitmap_set(dma->bitmap, 927 (iova - dma->iova) >> pgshift, 1); 928 } 929 } 930 ret = i; 931 932 group = vfio_iommu_find_iommu_group(iommu, iommu_group); 933 if (!group->pinned_page_dirty_scope) { 934 group->pinned_page_dirty_scope = true; 935 iommu->num_non_pinned_groups--; 936 } 937 938 goto pin_done; 939 940 pin_unwind: 941 phys_pfn[i] = 0; 942 for (j = 0; j < i; j++) { 943 dma_addr_t iova; 944 945 iova = user_pfn[j] << PAGE_SHIFT; 946 dma = vfio_find_dma(iommu, iova, PAGE_SIZE); 947 vfio_unpin_page_external(dma, iova, do_accounting); 948 phys_pfn[j] = 0; 949 } 950 pin_done: 951 mutex_unlock(&iommu->lock); 952 return ret; 953 } 954 955 static int vfio_iommu_type1_unpin_pages(void *iommu_data, 956 unsigned long *user_pfn, 957 int npage) 958 { 959 struct vfio_iommu *iommu = iommu_data; 960 bool do_accounting; 961 int i; 962 963 if (!iommu || !user_pfn || npage <= 0) 964 return -EINVAL; 965 966 /* Supported for v2 version only */ 967 if (!iommu->v2) 968 return -EACCES; 969 970 mutex_lock(&iommu->lock); 971 972 do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu); 973 for (i = 0; i < npage; i++) { 974 struct vfio_dma *dma; 975 dma_addr_t iova; 976 977 iova = user_pfn[i] << PAGE_SHIFT; 978 dma = vfio_find_dma(iommu, iova, PAGE_SIZE); 979 if (!dma) 980 break; 981 982 vfio_unpin_page_external(dma, iova, do_accounting); 983 } 984 985 mutex_unlock(&iommu->lock); 986 return i > 0 ? i : -EINVAL; 987 } 988 989 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain, 990 struct list_head *regions, 991 struct iommu_iotlb_gather *iotlb_gather) 992 { 993 long unlocked = 0; 994 struct vfio_regions *entry, *next; 995 996 iommu_iotlb_sync(domain->domain, iotlb_gather); 997 998 list_for_each_entry_safe(entry, next, regions, list) { 999 unlocked += vfio_unpin_pages_remote(dma, 1000 entry->iova, 1001 entry->phys >> PAGE_SHIFT, 1002 entry->len >> PAGE_SHIFT, 1003 false); 1004 list_del(&entry->list); 1005 kfree(entry); 1006 } 1007 1008 cond_resched(); 1009 1010 return unlocked; 1011 } 1012 1013 /* 1014 * Generally, VFIO needs to unpin remote pages after each IOTLB flush. 1015 * Therefore, when using IOTLB flush sync interface, VFIO need to keep track 1016 * of these regions (currently using a list). 1017 * 1018 * This value specifies maximum number of regions for each IOTLB flush sync. 1019 */ 1020 #define VFIO_IOMMU_TLB_SYNC_MAX 512 1021 1022 static size_t unmap_unpin_fast(struct vfio_domain *domain, 1023 struct vfio_dma *dma, dma_addr_t *iova, 1024 size_t len, phys_addr_t phys, long *unlocked, 1025 struct list_head *unmapped_list, 1026 int *unmapped_cnt, 1027 struct iommu_iotlb_gather *iotlb_gather) 1028 { 1029 size_t unmapped = 0; 1030 struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL); 1031 1032 if (entry) { 1033 unmapped = iommu_unmap_fast(domain->domain, *iova, len, 1034 iotlb_gather); 1035 1036 if (!unmapped) { 1037 kfree(entry); 1038 } else { 1039 entry->iova = *iova; 1040 entry->phys = phys; 1041 entry->len = unmapped; 1042 list_add_tail(&entry->list, unmapped_list); 1043 1044 *iova += unmapped; 1045 (*unmapped_cnt)++; 1046 } 1047 } 1048 1049 /* 1050 * Sync if the number of fast-unmap regions hits the limit 1051 * or in case of errors. 1052 */ 1053 if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) { 1054 *unlocked += vfio_sync_unpin(dma, domain, unmapped_list, 1055 iotlb_gather); 1056 *unmapped_cnt = 0; 1057 } 1058 1059 return unmapped; 1060 } 1061 1062 static size_t unmap_unpin_slow(struct vfio_domain *domain, 1063 struct vfio_dma *dma, dma_addr_t *iova, 1064 size_t len, phys_addr_t phys, 1065 long *unlocked) 1066 { 1067 size_t unmapped = iommu_unmap(domain->domain, *iova, len); 1068 1069 if (unmapped) { 1070 *unlocked += vfio_unpin_pages_remote(dma, *iova, 1071 phys >> PAGE_SHIFT, 1072 unmapped >> PAGE_SHIFT, 1073 false); 1074 *iova += unmapped; 1075 cond_resched(); 1076 } 1077 return unmapped; 1078 } 1079 1080 static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, 1081 bool do_accounting) 1082 { 1083 dma_addr_t iova = dma->iova, end = dma->iova + dma->size; 1084 struct vfio_domain *domain, *d; 1085 LIST_HEAD(unmapped_region_list); 1086 struct iommu_iotlb_gather iotlb_gather; 1087 int unmapped_region_cnt = 0; 1088 long unlocked = 0; 1089 1090 if (!dma->size) 1091 return 0; 1092 1093 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) 1094 return 0; 1095 1096 /* 1097 * We use the IOMMU to track the physical addresses, otherwise we'd 1098 * need a much more complicated tracking system. Unfortunately that 1099 * means we need to use one of the iommu domains to figure out the 1100 * pfns to unpin. The rest need to be unmapped in advance so we have 1101 * no iommu translations remaining when the pages are unpinned. 1102 */ 1103 domain = d = list_first_entry(&iommu->domain_list, 1104 struct vfio_domain, next); 1105 1106 list_for_each_entry_continue(d, &iommu->domain_list, next) { 1107 iommu_unmap(d->domain, dma->iova, dma->size); 1108 cond_resched(); 1109 } 1110 1111 iommu_iotlb_gather_init(&iotlb_gather); 1112 while (iova < end) { 1113 size_t unmapped, len; 1114 phys_addr_t phys, next; 1115 1116 phys = iommu_iova_to_phys(domain->domain, iova); 1117 if (WARN_ON(!phys)) { 1118 iova += PAGE_SIZE; 1119 continue; 1120 } 1121 1122 /* 1123 * To optimize for fewer iommu_unmap() calls, each of which 1124 * may require hardware cache flushing, try to find the 1125 * largest contiguous physical memory chunk to unmap. 1126 */ 1127 for (len = PAGE_SIZE; 1128 !domain->fgsp && iova + len < end; len += PAGE_SIZE) { 1129 next = iommu_iova_to_phys(domain->domain, iova + len); 1130 if (next != phys + len) 1131 break; 1132 } 1133 1134 /* 1135 * First, try to use fast unmap/unpin. In case of failure, 1136 * switch to slow unmap/unpin path. 1137 */ 1138 unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys, 1139 &unlocked, &unmapped_region_list, 1140 &unmapped_region_cnt, 1141 &iotlb_gather); 1142 if (!unmapped) { 1143 unmapped = unmap_unpin_slow(domain, dma, &iova, len, 1144 phys, &unlocked); 1145 if (WARN_ON(!unmapped)) 1146 break; 1147 } 1148 } 1149 1150 dma->iommu_mapped = false; 1151 1152 if (unmapped_region_cnt) { 1153 unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list, 1154 &iotlb_gather); 1155 } 1156 1157 if (do_accounting) { 1158 vfio_lock_acct(dma, -unlocked, true); 1159 return 0; 1160 } 1161 return unlocked; 1162 } 1163 1164 static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) 1165 { 1166 WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)); 1167 vfio_unmap_unpin(iommu, dma, true); 1168 vfio_unlink_dma(iommu, dma); 1169 put_task_struct(dma->task); 1170 vfio_dma_bitmap_free(dma); 1171 if (dma->vaddr_invalid) { 1172 iommu->vaddr_invalid_count--; 1173 wake_up_all(&iommu->vaddr_wait); 1174 } 1175 kfree(dma); 1176 iommu->dma_avail++; 1177 } 1178 1179 static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu) 1180 { 1181 struct vfio_domain *domain; 1182 1183 iommu->pgsize_bitmap = ULONG_MAX; 1184 1185 list_for_each_entry(domain, &iommu->domain_list, next) 1186 iommu->pgsize_bitmap &= domain->domain->pgsize_bitmap; 1187 1188 /* 1189 * In case the IOMMU supports page sizes smaller than PAGE_SIZE 1190 * we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes. 1191 * That way the user will be able to map/unmap buffers whose size/ 1192 * start address is aligned with PAGE_SIZE. Pinning code uses that 1193 * granularity while iommu driver can use the sub-PAGE_SIZE size 1194 * to map the buffer. 1195 */ 1196 if (iommu->pgsize_bitmap & ~PAGE_MASK) { 1197 iommu->pgsize_bitmap &= PAGE_MASK; 1198 iommu->pgsize_bitmap |= PAGE_SIZE; 1199 } 1200 } 1201 1202 static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, 1203 struct vfio_dma *dma, dma_addr_t base_iova, 1204 size_t pgsize) 1205 { 1206 unsigned long pgshift = __ffs(pgsize); 1207 unsigned long nbits = dma->size >> pgshift; 1208 unsigned long bit_offset = (dma->iova - base_iova) >> pgshift; 1209 unsigned long copy_offset = bit_offset / BITS_PER_LONG; 1210 unsigned long shift = bit_offset % BITS_PER_LONG; 1211 unsigned long leftover; 1212 1213 /* 1214 * mark all pages dirty if any IOMMU capable device is not able 1215 * to report dirty pages and all pages are pinned and mapped. 1216 */ 1217 if (iommu->num_non_pinned_groups && dma->iommu_mapped) 1218 bitmap_set(dma->bitmap, 0, nbits); 1219 1220 if (shift) { 1221 bitmap_shift_left(dma->bitmap, dma->bitmap, shift, 1222 nbits + shift); 1223 1224 if (copy_from_user(&leftover, 1225 (void __user *)(bitmap + copy_offset), 1226 sizeof(leftover))) 1227 return -EFAULT; 1228 1229 bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift); 1230 } 1231 1232 if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap, 1233 DIRTY_BITMAP_BYTES(nbits + shift))) 1234 return -EFAULT; 1235 1236 return 0; 1237 } 1238 1239 static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, 1240 dma_addr_t iova, size_t size, size_t pgsize) 1241 { 1242 struct vfio_dma *dma; 1243 struct rb_node *n; 1244 unsigned long pgshift = __ffs(pgsize); 1245 int ret; 1246 1247 /* 1248 * GET_BITMAP request must fully cover vfio_dma mappings. Multiple 1249 * vfio_dma mappings may be clubbed by specifying large ranges, but 1250 * there must not be any previous mappings bisected by the range. 1251 * An error will be returned if these conditions are not met. 1252 */ 1253 dma = vfio_find_dma(iommu, iova, 1); 1254 if (dma && dma->iova != iova) 1255 return -EINVAL; 1256 1257 dma = vfio_find_dma(iommu, iova + size - 1, 0); 1258 if (dma && dma->iova + dma->size != iova + size) 1259 return -EINVAL; 1260 1261 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { 1262 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); 1263 1264 if (dma->iova < iova) 1265 continue; 1266 1267 if (dma->iova > iova + size - 1) 1268 break; 1269 1270 ret = update_user_bitmap(bitmap, iommu, dma, iova, pgsize); 1271 if (ret) 1272 return ret; 1273 1274 /* 1275 * Re-populate bitmap to include all pinned pages which are 1276 * considered as dirty but exclude pages which are unpinned and 1277 * pages which are marked dirty by vfio_dma_rw() 1278 */ 1279 bitmap_clear(dma->bitmap, 0, dma->size >> pgshift); 1280 vfio_dma_populate_bitmap(dma, pgsize); 1281 } 1282 return 0; 1283 } 1284 1285 static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) 1286 { 1287 if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) || 1288 (bitmap_size < DIRTY_BITMAP_BYTES(npages))) 1289 return -EINVAL; 1290 1291 return 0; 1292 } 1293 1294 static int vfio_dma_do_unmap(struct vfio_iommu *iommu, 1295 struct vfio_iommu_type1_dma_unmap *unmap, 1296 struct vfio_bitmap *bitmap) 1297 { 1298 struct vfio_dma *dma, *dma_last = NULL; 1299 size_t unmapped = 0, pgsize; 1300 int ret = -EINVAL, retries = 0; 1301 unsigned long pgshift; 1302 dma_addr_t iova = unmap->iova; 1303 u64 size = unmap->size; 1304 bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL; 1305 bool invalidate_vaddr = unmap->flags & VFIO_DMA_UNMAP_FLAG_VADDR; 1306 struct rb_node *n, *first_n; 1307 1308 mutex_lock(&iommu->lock); 1309 1310 pgshift = __ffs(iommu->pgsize_bitmap); 1311 pgsize = (size_t)1 << pgshift; 1312 1313 if (iova & (pgsize - 1)) 1314 goto unlock; 1315 1316 if (unmap_all) { 1317 if (iova || size) 1318 goto unlock; 1319 size = U64_MAX; 1320 } else if (!size || size & (pgsize - 1) || 1321 iova + size - 1 < iova || size > SIZE_MAX) { 1322 goto unlock; 1323 } 1324 1325 /* When dirty tracking is enabled, allow only min supported pgsize */ 1326 if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && 1327 (!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) { 1328 goto unlock; 1329 } 1330 1331 WARN_ON((pgsize - 1) & PAGE_MASK); 1332 again: 1333 /* 1334 * vfio-iommu-type1 (v1) - User mappings were coalesced together to 1335 * avoid tracking individual mappings. This means that the granularity 1336 * of the original mapping was lost and the user was allowed to attempt 1337 * to unmap any range. Depending on the contiguousness of physical 1338 * memory and page sizes supported by the IOMMU, arbitrary unmaps may 1339 * or may not have worked. We only guaranteed unmap granularity 1340 * matching the original mapping; even though it was untracked here, 1341 * the original mappings are reflected in IOMMU mappings. This 1342 * resulted in a couple unusual behaviors. First, if a range is not 1343 * able to be unmapped, ex. a set of 4k pages that was mapped as a 1344 * 2M hugepage into the IOMMU, the unmap ioctl returns success but with 1345 * a zero sized unmap. Also, if an unmap request overlaps the first 1346 * address of a hugepage, the IOMMU will unmap the entire hugepage. 1347 * This also returns success and the returned unmap size reflects the 1348 * actual size unmapped. 1349 * 1350 * We attempt to maintain compatibility with this "v1" interface, but 1351 * we take control out of the hands of the IOMMU. Therefore, an unmap 1352 * request offset from the beginning of the original mapping will 1353 * return success with zero sized unmap. And an unmap request covering 1354 * the first iova of mapping will unmap the entire range. 1355 * 1356 * The v2 version of this interface intends to be more deterministic. 1357 * Unmap requests must fully cover previous mappings. Multiple 1358 * mappings may still be unmaped by specifying large ranges, but there 1359 * must not be any previous mappings bisected by the range. An error 1360 * will be returned if these conditions are not met. The v2 interface 1361 * will only return success and a size of zero if there were no 1362 * mappings within the range. 1363 */ 1364 if (iommu->v2 && !unmap_all) { 1365 dma = vfio_find_dma(iommu, iova, 1); 1366 if (dma && dma->iova != iova) 1367 goto unlock; 1368 1369 dma = vfio_find_dma(iommu, iova + size - 1, 0); 1370 if (dma && dma->iova + dma->size != iova + size) 1371 goto unlock; 1372 } 1373 1374 ret = 0; 1375 n = first_n = vfio_find_dma_first_node(iommu, iova, size); 1376 1377 while (n) { 1378 dma = rb_entry(n, struct vfio_dma, node); 1379 if (dma->iova >= iova + size) 1380 break; 1381 1382 if (!iommu->v2 && iova > dma->iova) 1383 break; 1384 /* 1385 * Task with same address space who mapped this iova range is 1386 * allowed to unmap the iova range. 1387 */ 1388 if (dma->task->mm != current->mm) 1389 break; 1390 1391 if (invalidate_vaddr) { 1392 if (dma->vaddr_invalid) { 1393 struct rb_node *last_n = n; 1394 1395 for (n = first_n; n != last_n; n = rb_next(n)) { 1396 dma = rb_entry(n, 1397 struct vfio_dma, node); 1398 dma->vaddr_invalid = false; 1399 iommu->vaddr_invalid_count--; 1400 } 1401 ret = -EINVAL; 1402 unmapped = 0; 1403 break; 1404 } 1405 dma->vaddr_invalid = true; 1406 iommu->vaddr_invalid_count++; 1407 unmapped += dma->size; 1408 n = rb_next(n); 1409 continue; 1410 } 1411 1412 if (!RB_EMPTY_ROOT(&dma->pfn_list)) { 1413 struct vfio_iommu_type1_dma_unmap nb_unmap; 1414 1415 if (dma_last == dma) { 1416 BUG_ON(++retries > 10); 1417 } else { 1418 dma_last = dma; 1419 retries = 0; 1420 } 1421 1422 nb_unmap.iova = dma->iova; 1423 nb_unmap.size = dma->size; 1424 1425 /* 1426 * Notify anyone (mdev vendor drivers) to invalidate and 1427 * unmap iovas within the range we're about to unmap. 1428 * Vendor drivers MUST unpin pages in response to an 1429 * invalidation. 1430 */ 1431 mutex_unlock(&iommu->lock); 1432 blocking_notifier_call_chain(&iommu->notifier, 1433 VFIO_IOMMU_NOTIFY_DMA_UNMAP, 1434 &nb_unmap); 1435 mutex_lock(&iommu->lock); 1436 goto again; 1437 } 1438 1439 if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { 1440 ret = update_user_bitmap(bitmap->data, iommu, dma, 1441 iova, pgsize); 1442 if (ret) 1443 break; 1444 } 1445 1446 unmapped += dma->size; 1447 n = rb_next(n); 1448 vfio_remove_dma(iommu, dma); 1449 } 1450 1451 unlock: 1452 mutex_unlock(&iommu->lock); 1453 1454 /* Report how much was unmapped */ 1455 unmap->size = unmapped; 1456 1457 return ret; 1458 } 1459 1460 static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova, 1461 unsigned long pfn, long npage, int prot) 1462 { 1463 struct vfio_domain *d; 1464 int ret; 1465 1466 list_for_each_entry(d, &iommu->domain_list, next) { 1467 ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT, 1468 npage << PAGE_SHIFT, prot | d->prot); 1469 if (ret) 1470 goto unwind; 1471 1472 cond_resched(); 1473 } 1474 1475 return 0; 1476 1477 unwind: 1478 list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) { 1479 iommu_unmap(d->domain, iova, npage << PAGE_SHIFT); 1480 cond_resched(); 1481 } 1482 1483 return ret; 1484 } 1485 1486 static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma, 1487 size_t map_size) 1488 { 1489 dma_addr_t iova = dma->iova; 1490 unsigned long vaddr = dma->vaddr; 1491 struct vfio_batch batch; 1492 size_t size = map_size; 1493 long npage; 1494 unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 1495 int ret = 0; 1496 1497 vfio_batch_init(&batch); 1498 1499 while (size) { 1500 /* Pin a contiguous chunk of memory */ 1501 npage = vfio_pin_pages_remote(dma, vaddr + dma->size, 1502 size >> PAGE_SHIFT, &pfn, limit, 1503 &batch); 1504 if (npage <= 0) { 1505 WARN_ON(!npage); 1506 ret = (int)npage; 1507 break; 1508 } 1509 1510 /* Map it! */ 1511 ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, 1512 dma->prot); 1513 if (ret) { 1514 vfio_unpin_pages_remote(dma, iova + dma->size, pfn, 1515 npage, true); 1516 vfio_batch_unpin(&batch, dma); 1517 break; 1518 } 1519 1520 size -= npage << PAGE_SHIFT; 1521 dma->size += npage << PAGE_SHIFT; 1522 } 1523 1524 vfio_batch_fini(&batch); 1525 dma->iommu_mapped = true; 1526 1527 if (ret) 1528 vfio_remove_dma(iommu, dma); 1529 1530 return ret; 1531 } 1532 1533 /* 1534 * Check dma map request is within a valid iova range 1535 */ 1536 static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu, 1537 dma_addr_t start, dma_addr_t end) 1538 { 1539 struct list_head *iova = &iommu->iova_list; 1540 struct vfio_iova *node; 1541 1542 list_for_each_entry(node, iova, list) { 1543 if (start >= node->start && end <= node->end) 1544 return true; 1545 } 1546 1547 /* 1548 * Check for list_empty() as well since a container with 1549 * a single mdev device will have an empty list. 1550 */ 1551 return list_empty(iova); 1552 } 1553 1554 static int vfio_dma_do_map(struct vfio_iommu *iommu, 1555 struct vfio_iommu_type1_dma_map *map) 1556 { 1557 bool set_vaddr = map->flags & VFIO_DMA_MAP_FLAG_VADDR; 1558 dma_addr_t iova = map->iova; 1559 unsigned long vaddr = map->vaddr; 1560 size_t size = map->size; 1561 int ret = 0, prot = 0; 1562 size_t pgsize; 1563 struct vfio_dma *dma; 1564 1565 /* Verify that none of our __u64 fields overflow */ 1566 if (map->size != size || map->vaddr != vaddr || map->iova != iova) 1567 return -EINVAL; 1568 1569 /* READ/WRITE from device perspective */ 1570 if (map->flags & VFIO_DMA_MAP_FLAG_WRITE) 1571 prot |= IOMMU_WRITE; 1572 if (map->flags & VFIO_DMA_MAP_FLAG_READ) 1573 prot |= IOMMU_READ; 1574 1575 if ((prot && set_vaddr) || (!prot && !set_vaddr)) 1576 return -EINVAL; 1577 1578 mutex_lock(&iommu->lock); 1579 1580 pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); 1581 1582 WARN_ON((pgsize - 1) & PAGE_MASK); 1583 1584 if (!size || (size | iova | vaddr) & (pgsize - 1)) { 1585 ret = -EINVAL; 1586 goto out_unlock; 1587 } 1588 1589 /* Don't allow IOVA or virtual address wrap */ 1590 if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) { 1591 ret = -EINVAL; 1592 goto out_unlock; 1593 } 1594 1595 dma = vfio_find_dma(iommu, iova, size); 1596 if (set_vaddr) { 1597 if (!dma) { 1598 ret = -ENOENT; 1599 } else if (!dma->vaddr_invalid || dma->iova != iova || 1600 dma->size != size) { 1601 ret = -EINVAL; 1602 } else { 1603 dma->vaddr = vaddr; 1604 dma->vaddr_invalid = false; 1605 iommu->vaddr_invalid_count--; 1606 wake_up_all(&iommu->vaddr_wait); 1607 } 1608 goto out_unlock; 1609 } else if (dma) { 1610 ret = -EEXIST; 1611 goto out_unlock; 1612 } 1613 1614 if (!iommu->dma_avail) { 1615 ret = -ENOSPC; 1616 goto out_unlock; 1617 } 1618 1619 if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) { 1620 ret = -EINVAL; 1621 goto out_unlock; 1622 } 1623 1624 dma = kzalloc(sizeof(*dma), GFP_KERNEL); 1625 if (!dma) { 1626 ret = -ENOMEM; 1627 goto out_unlock; 1628 } 1629 1630 iommu->dma_avail--; 1631 dma->iova = iova; 1632 dma->vaddr = vaddr; 1633 dma->prot = prot; 1634 1635 /* 1636 * We need to be able to both add to a task's locked memory and test 1637 * against the locked memory limit and we need to be able to do both 1638 * outside of this call path as pinning can be asynchronous via the 1639 * external interfaces for mdev devices. RLIMIT_MEMLOCK requires a 1640 * task_struct and VM locked pages requires an mm_struct, however 1641 * holding an indefinite mm reference is not recommended, therefore we 1642 * only hold a reference to a task. We could hold a reference to 1643 * current, however QEMU uses this call path through vCPU threads, 1644 * which can be killed resulting in a NULL mm and failure in the unmap 1645 * path when called via a different thread. Avoid this problem by 1646 * using the group_leader as threads within the same group require 1647 * both CLONE_THREAD and CLONE_VM and will therefore use the same 1648 * mm_struct. 1649 * 1650 * Previously we also used the task for testing CAP_IPC_LOCK at the 1651 * time of pinning and accounting, however has_capability() makes use 1652 * of real_cred, a copy-on-write field, so we can't guarantee that it 1653 * matches group_leader, or in fact that it might not change by the 1654 * time it's evaluated. If a process were to call MAP_DMA with 1655 * CAP_IPC_LOCK but later drop it, it doesn't make sense that they 1656 * possibly see different results for an iommu_mapped vfio_dma vs 1657 * externally mapped. Therefore track CAP_IPC_LOCK in vfio_dma at the 1658 * time of calling MAP_DMA. 1659 */ 1660 get_task_struct(current->group_leader); 1661 dma->task = current->group_leader; 1662 dma->lock_cap = capable(CAP_IPC_LOCK); 1663 1664 dma->pfn_list = RB_ROOT; 1665 1666 /* Insert zero-sized and grow as we map chunks of it */ 1667 vfio_link_dma(iommu, dma); 1668 1669 /* Don't pin and map if container doesn't contain IOMMU capable domain*/ 1670 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) 1671 dma->size = size; 1672 else 1673 ret = vfio_pin_map_dma(iommu, dma, size); 1674 1675 if (!ret && iommu->dirty_page_tracking) { 1676 ret = vfio_dma_bitmap_alloc(dma, pgsize); 1677 if (ret) 1678 vfio_remove_dma(iommu, dma); 1679 } 1680 1681 out_unlock: 1682 mutex_unlock(&iommu->lock); 1683 return ret; 1684 } 1685 1686 static int vfio_bus_type(struct device *dev, void *data) 1687 { 1688 struct bus_type **bus = data; 1689 1690 if (*bus && *bus != dev->bus) 1691 return -EINVAL; 1692 1693 *bus = dev->bus; 1694 1695 return 0; 1696 } 1697 1698 static int vfio_iommu_replay(struct vfio_iommu *iommu, 1699 struct vfio_domain *domain) 1700 { 1701 struct vfio_batch batch; 1702 struct vfio_domain *d = NULL; 1703 struct rb_node *n; 1704 unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 1705 int ret; 1706 1707 ret = vfio_wait_all_valid(iommu); 1708 if (ret < 0) 1709 return ret; 1710 1711 /* Arbitrarily pick the first domain in the list for lookups */ 1712 if (!list_empty(&iommu->domain_list)) 1713 d = list_first_entry(&iommu->domain_list, 1714 struct vfio_domain, next); 1715 1716 vfio_batch_init(&batch); 1717 1718 n = rb_first(&iommu->dma_list); 1719 1720 for (; n; n = rb_next(n)) { 1721 struct vfio_dma *dma; 1722 dma_addr_t iova; 1723 1724 dma = rb_entry(n, struct vfio_dma, node); 1725 iova = dma->iova; 1726 1727 while (iova < dma->iova + dma->size) { 1728 phys_addr_t phys; 1729 size_t size; 1730 1731 if (dma->iommu_mapped) { 1732 phys_addr_t p; 1733 dma_addr_t i; 1734 1735 if (WARN_ON(!d)) { /* mapped w/o a domain?! */ 1736 ret = -EINVAL; 1737 goto unwind; 1738 } 1739 1740 phys = iommu_iova_to_phys(d->domain, iova); 1741 1742 if (WARN_ON(!phys)) { 1743 iova += PAGE_SIZE; 1744 continue; 1745 } 1746 1747 size = PAGE_SIZE; 1748 p = phys + size; 1749 i = iova + size; 1750 while (i < dma->iova + dma->size && 1751 p == iommu_iova_to_phys(d->domain, i)) { 1752 size += PAGE_SIZE; 1753 p += PAGE_SIZE; 1754 i += PAGE_SIZE; 1755 } 1756 } else { 1757 unsigned long pfn; 1758 unsigned long vaddr = dma->vaddr + 1759 (iova - dma->iova); 1760 size_t n = dma->iova + dma->size - iova; 1761 long npage; 1762 1763 npage = vfio_pin_pages_remote(dma, vaddr, 1764 n >> PAGE_SHIFT, 1765 &pfn, limit, 1766 &batch); 1767 if (npage <= 0) { 1768 WARN_ON(!npage); 1769 ret = (int)npage; 1770 goto unwind; 1771 } 1772 1773 phys = pfn << PAGE_SHIFT; 1774 size = npage << PAGE_SHIFT; 1775 } 1776 1777 ret = iommu_map(domain->domain, iova, phys, 1778 size, dma->prot | domain->prot); 1779 if (ret) { 1780 if (!dma->iommu_mapped) { 1781 vfio_unpin_pages_remote(dma, iova, 1782 phys >> PAGE_SHIFT, 1783 size >> PAGE_SHIFT, 1784 true); 1785 vfio_batch_unpin(&batch, dma); 1786 } 1787 goto unwind; 1788 } 1789 1790 iova += size; 1791 } 1792 } 1793 1794 /* All dmas are now mapped, defer to second tree walk for unwind */ 1795 for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { 1796 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); 1797 1798 dma->iommu_mapped = true; 1799 } 1800 1801 vfio_batch_fini(&batch); 1802 return 0; 1803 1804 unwind: 1805 for (; n; n = rb_prev(n)) { 1806 struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); 1807 dma_addr_t iova; 1808 1809 if (dma->iommu_mapped) { 1810 iommu_unmap(domain->domain, dma->iova, dma->size); 1811 continue; 1812 } 1813 1814 iova = dma->iova; 1815 while (iova < dma->iova + dma->size) { 1816 phys_addr_t phys, p; 1817 size_t size; 1818 dma_addr_t i; 1819 1820 phys = iommu_iova_to_phys(domain->domain, iova); 1821 if (!phys) { 1822 iova += PAGE_SIZE; 1823 continue; 1824 } 1825 1826 size = PAGE_SIZE; 1827 p = phys + size; 1828 i = iova + size; 1829 while (i < dma->iova + dma->size && 1830 p == iommu_iova_to_phys(domain->domain, i)) { 1831 size += PAGE_SIZE; 1832 p += PAGE_SIZE; 1833 i += PAGE_SIZE; 1834 } 1835 1836 iommu_unmap(domain->domain, iova, size); 1837 vfio_unpin_pages_remote(dma, iova, phys >> PAGE_SHIFT, 1838 size >> PAGE_SHIFT, true); 1839 } 1840 } 1841 1842 vfio_batch_fini(&batch); 1843 return ret; 1844 } 1845 1846 /* 1847 * We change our unmap behavior slightly depending on whether the IOMMU 1848 * supports fine-grained superpages. IOMMUs like AMD-Vi will use a superpage 1849 * for practically any contiguous power-of-two mapping we give it. This means 1850 * we don't need to look for contiguous chunks ourselves to make unmapping 1851 * more efficient. On IOMMUs with coarse-grained super pages, like Intel VT-d 1852 * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks 1853 * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when 1854 * hugetlbfs is in use. 1855 */ 1856 static void vfio_test_domain_fgsp(struct vfio_domain *domain) 1857 { 1858 struct page *pages; 1859 int ret, order = get_order(PAGE_SIZE * 2); 1860 1861 pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); 1862 if (!pages) 1863 return; 1864 1865 ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2, 1866 IOMMU_READ | IOMMU_WRITE | domain->prot); 1867 if (!ret) { 1868 size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE); 1869 1870 if (unmapped == PAGE_SIZE) 1871 iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE); 1872 else 1873 domain->fgsp = true; 1874 } 1875 1876 __free_pages(pages, order); 1877 } 1878 1879 static struct vfio_iommu_group *find_iommu_group(struct vfio_domain *domain, 1880 struct iommu_group *iommu_group) 1881 { 1882 struct vfio_iommu_group *g; 1883 1884 list_for_each_entry(g, &domain->group_list, next) { 1885 if (g->iommu_group == iommu_group) 1886 return g; 1887 } 1888 1889 return NULL; 1890 } 1891 1892 static struct vfio_iommu_group* 1893 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu, 1894 struct iommu_group *iommu_group) 1895 { 1896 struct vfio_domain *domain; 1897 struct vfio_iommu_group *group = NULL; 1898 1899 list_for_each_entry(domain, &iommu->domain_list, next) { 1900 group = find_iommu_group(domain, iommu_group); 1901 if (group) 1902 return group; 1903 } 1904 1905 if (iommu->external_domain) 1906 group = find_iommu_group(iommu->external_domain, iommu_group); 1907 1908 return group; 1909 } 1910 1911 static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions, 1912 phys_addr_t *base) 1913 { 1914 struct iommu_resv_region *region; 1915 bool ret = false; 1916 1917 list_for_each_entry(region, group_resv_regions, list) { 1918 /* 1919 * The presence of any 'real' MSI regions should take 1920 * precedence over the software-managed one if the 1921 * IOMMU driver happens to advertise both types. 1922 */ 1923 if (region->type == IOMMU_RESV_MSI) { 1924 ret = false; 1925 break; 1926 } 1927 1928 if (region->type == IOMMU_RESV_SW_MSI) { 1929 *base = region->start; 1930 ret = true; 1931 } 1932 } 1933 1934 return ret; 1935 } 1936 1937 static int vfio_mdev_attach_domain(struct device *dev, void *data) 1938 { 1939 struct mdev_device *mdev = to_mdev_device(dev); 1940 struct iommu_domain *domain = data; 1941 struct device *iommu_device; 1942 1943 iommu_device = mdev_get_iommu_device(mdev); 1944 if (iommu_device) { 1945 if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX)) 1946 return iommu_aux_attach_device(domain, iommu_device); 1947 else 1948 return iommu_attach_device(domain, iommu_device); 1949 } 1950 1951 return -EINVAL; 1952 } 1953 1954 static int vfio_mdev_detach_domain(struct device *dev, void *data) 1955 { 1956 struct mdev_device *mdev = to_mdev_device(dev); 1957 struct iommu_domain *domain = data; 1958 struct device *iommu_device; 1959 1960 iommu_device = mdev_get_iommu_device(mdev); 1961 if (iommu_device) { 1962 if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX)) 1963 iommu_aux_detach_device(domain, iommu_device); 1964 else 1965 iommu_detach_device(domain, iommu_device); 1966 } 1967 1968 return 0; 1969 } 1970 1971 static int vfio_iommu_attach_group(struct vfio_domain *domain, 1972 struct vfio_iommu_group *group) 1973 { 1974 if (group->mdev_group) 1975 return iommu_group_for_each_dev(group->iommu_group, 1976 domain->domain, 1977 vfio_mdev_attach_domain); 1978 else 1979 return iommu_attach_group(domain->domain, group->iommu_group); 1980 } 1981 1982 static void vfio_iommu_detach_group(struct vfio_domain *domain, 1983 struct vfio_iommu_group *group) 1984 { 1985 if (group->mdev_group) 1986 iommu_group_for_each_dev(group->iommu_group, domain->domain, 1987 vfio_mdev_detach_domain); 1988 else 1989 iommu_detach_group(domain->domain, group->iommu_group); 1990 } 1991 1992 static bool vfio_bus_is_mdev(struct bus_type *bus) 1993 { 1994 struct bus_type *mdev_bus; 1995 bool ret = false; 1996 1997 mdev_bus = symbol_get(mdev_bus_type); 1998 if (mdev_bus) { 1999 ret = (bus == mdev_bus); 2000 symbol_put(mdev_bus_type); 2001 } 2002 2003 return ret; 2004 } 2005 2006 static int vfio_mdev_iommu_device(struct device *dev, void *data) 2007 { 2008 struct mdev_device *mdev = to_mdev_device(dev); 2009 struct device **old = data, *new; 2010 2011 new = mdev_get_iommu_device(mdev); 2012 if (!new || (*old && *old != new)) 2013 return -EINVAL; 2014 2015 *old = new; 2016 2017 return 0; 2018 } 2019 2020 /* 2021 * This is a helper function to insert an address range to iova list. 2022 * The list is initially created with a single entry corresponding to 2023 * the IOMMU domain geometry to which the device group is attached. 2024 * The list aperture gets modified when a new domain is added to the 2025 * container if the new aperture doesn't conflict with the current one 2026 * or with any existing dma mappings. The list is also modified to 2027 * exclude any reserved regions associated with the device group. 2028 */ 2029 static int vfio_iommu_iova_insert(struct list_head *head, 2030 dma_addr_t start, dma_addr_t end) 2031 { 2032 struct vfio_iova *region; 2033 2034 region = kmalloc(sizeof(*region), GFP_KERNEL); 2035 if (!region) 2036 return -ENOMEM; 2037 2038 INIT_LIST_HEAD(®ion->list); 2039 region->start = start; 2040 region->end = end; 2041 2042 list_add_tail(®ion->list, head); 2043 return 0; 2044 } 2045 2046 /* 2047 * Check the new iommu aperture conflicts with existing aper or with any 2048 * existing dma mappings. 2049 */ 2050 static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu, 2051 dma_addr_t start, dma_addr_t end) 2052 { 2053 struct vfio_iova *first, *last; 2054 struct list_head *iova = &iommu->iova_list; 2055 2056 if (list_empty(iova)) 2057 return false; 2058 2059 /* Disjoint sets, return conflict */ 2060 first = list_first_entry(iova, struct vfio_iova, list); 2061 last = list_last_entry(iova, struct vfio_iova, list); 2062 if (start > last->end || end < first->start) 2063 return true; 2064 2065 /* Check for any existing dma mappings below the new start */ 2066 if (start > first->start) { 2067 if (vfio_find_dma(iommu, first->start, start - first->start)) 2068 return true; 2069 } 2070 2071 /* Check for any existing dma mappings beyond the new end */ 2072 if (end < last->end) { 2073 if (vfio_find_dma(iommu, end + 1, last->end - end)) 2074 return true; 2075 } 2076 2077 return false; 2078 } 2079 2080 /* 2081 * Resize iommu iova aperture window. This is called only if the new 2082 * aperture has no conflict with existing aperture and dma mappings. 2083 */ 2084 static int vfio_iommu_aper_resize(struct list_head *iova, 2085 dma_addr_t start, dma_addr_t end) 2086 { 2087 struct vfio_iova *node, *next; 2088 2089 if (list_empty(iova)) 2090 return vfio_iommu_iova_insert(iova, start, end); 2091 2092 /* Adjust iova list start */ 2093 list_for_each_entry_safe(node, next, iova, list) { 2094 if (start < node->start) 2095 break; 2096 if (start >= node->start && start < node->end) { 2097 node->start = start; 2098 break; 2099 } 2100 /* Delete nodes before new start */ 2101 list_del(&node->list); 2102 kfree(node); 2103 } 2104 2105 /* Adjust iova list end */ 2106 list_for_each_entry_safe(node, next, iova, list) { 2107 if (end > node->end) 2108 continue; 2109 if (end > node->start && end <= node->end) { 2110 node->end = end; 2111 continue; 2112 } 2113 /* Delete nodes after new end */ 2114 list_del(&node->list); 2115 kfree(node); 2116 } 2117 2118 return 0; 2119 } 2120 2121 /* 2122 * Check reserved region conflicts with existing dma mappings 2123 */ 2124 static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu, 2125 struct list_head *resv_regions) 2126 { 2127 struct iommu_resv_region *region; 2128 2129 /* Check for conflict with existing dma mappings */ 2130 list_for_each_entry(region, resv_regions, list) { 2131 if (region->type == IOMMU_RESV_DIRECT_RELAXABLE) 2132 continue; 2133 2134 if (vfio_find_dma(iommu, region->start, region->length)) 2135 return true; 2136 } 2137 2138 return false; 2139 } 2140 2141 /* 2142 * Check iova region overlap with reserved regions and 2143 * exclude them from the iommu iova range 2144 */ 2145 static int vfio_iommu_resv_exclude(struct list_head *iova, 2146 struct list_head *resv_regions) 2147 { 2148 struct iommu_resv_region *resv; 2149 struct vfio_iova *n, *next; 2150 2151 list_for_each_entry(resv, resv_regions, list) { 2152 phys_addr_t start, end; 2153 2154 if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE) 2155 continue; 2156 2157 start = resv->start; 2158 end = resv->start + resv->length - 1; 2159 2160 list_for_each_entry_safe(n, next, iova, list) { 2161 int ret = 0; 2162 2163 /* No overlap */ 2164 if (start > n->end || end < n->start) 2165 continue; 2166 /* 2167 * Insert a new node if current node overlaps with the 2168 * reserve region to exclude that from valid iova range. 2169 * Note that, new node is inserted before the current 2170 * node and finally the current node is deleted keeping 2171 * the list updated and sorted. 2172 */ 2173 if (start > n->start) 2174 ret = vfio_iommu_iova_insert(&n->list, n->start, 2175 start - 1); 2176 if (!ret && end < n->end) 2177 ret = vfio_iommu_iova_insert(&n->list, end + 1, 2178 n->end); 2179 if (ret) 2180 return ret; 2181 2182 list_del(&n->list); 2183 kfree(n); 2184 } 2185 } 2186 2187 if (list_empty(iova)) 2188 return -EINVAL; 2189 2190 return 0; 2191 } 2192 2193 static void vfio_iommu_resv_free(struct list_head *resv_regions) 2194 { 2195 struct iommu_resv_region *n, *next; 2196 2197 list_for_each_entry_safe(n, next, resv_regions, list) { 2198 list_del(&n->list); 2199 kfree(n); 2200 } 2201 } 2202 2203 static void vfio_iommu_iova_free(struct list_head *iova) 2204 { 2205 struct vfio_iova *n, *next; 2206 2207 list_for_each_entry_safe(n, next, iova, list) { 2208 list_del(&n->list); 2209 kfree(n); 2210 } 2211 } 2212 2213 static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu, 2214 struct list_head *iova_copy) 2215 { 2216 struct list_head *iova = &iommu->iova_list; 2217 struct vfio_iova *n; 2218 int ret; 2219 2220 list_for_each_entry(n, iova, list) { 2221 ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end); 2222 if (ret) 2223 goto out_free; 2224 } 2225 2226 return 0; 2227 2228 out_free: 2229 vfio_iommu_iova_free(iova_copy); 2230 return ret; 2231 } 2232 2233 static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu, 2234 struct list_head *iova_copy) 2235 { 2236 struct list_head *iova = &iommu->iova_list; 2237 2238 vfio_iommu_iova_free(iova); 2239 2240 list_splice_tail(iova_copy, iova); 2241 } 2242 2243 static int vfio_iommu_type1_attach_group(void *iommu_data, 2244 struct iommu_group *iommu_group) 2245 { 2246 struct vfio_iommu *iommu = iommu_data; 2247 struct vfio_iommu_group *group; 2248 struct vfio_domain *domain, *d; 2249 struct bus_type *bus = NULL; 2250 int ret; 2251 bool resv_msi, msi_remap; 2252 phys_addr_t resv_msi_base = 0; 2253 struct iommu_domain_geometry *geo; 2254 LIST_HEAD(iova_copy); 2255 LIST_HEAD(group_resv_regions); 2256 2257 mutex_lock(&iommu->lock); 2258 2259 /* Check for duplicates */ 2260 if (vfio_iommu_find_iommu_group(iommu, iommu_group)) { 2261 mutex_unlock(&iommu->lock); 2262 return -EINVAL; 2263 } 2264 2265 group = kzalloc(sizeof(*group), GFP_KERNEL); 2266 domain = kzalloc(sizeof(*domain), GFP_KERNEL); 2267 if (!group || !domain) { 2268 ret = -ENOMEM; 2269 goto out_free; 2270 } 2271 2272 group->iommu_group = iommu_group; 2273 2274 /* Determine bus_type in order to allocate a domain */ 2275 ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type); 2276 if (ret) 2277 goto out_free; 2278 2279 if (vfio_bus_is_mdev(bus)) { 2280 struct device *iommu_device = NULL; 2281 2282 group->mdev_group = true; 2283 2284 /* Determine the isolation type */ 2285 ret = iommu_group_for_each_dev(iommu_group, &iommu_device, 2286 vfio_mdev_iommu_device); 2287 if (ret || !iommu_device) { 2288 if (!iommu->external_domain) { 2289 INIT_LIST_HEAD(&domain->group_list); 2290 iommu->external_domain = domain; 2291 vfio_update_pgsize_bitmap(iommu); 2292 } else { 2293 kfree(domain); 2294 } 2295 2296 list_add(&group->next, 2297 &iommu->external_domain->group_list); 2298 /* 2299 * Non-iommu backed group cannot dirty memory directly, 2300 * it can only use interfaces that provide dirty 2301 * tracking. 2302 * The iommu scope can only be promoted with the 2303 * addition of a dirty tracking group. 2304 */ 2305 group->pinned_page_dirty_scope = true; 2306 mutex_unlock(&iommu->lock); 2307 2308 return 0; 2309 } 2310 2311 bus = iommu_device->bus; 2312 } 2313 2314 domain->domain = iommu_domain_alloc(bus); 2315 if (!domain->domain) { 2316 ret = -EIO; 2317 goto out_free; 2318 } 2319 2320 if (iommu->nesting) { 2321 ret = iommu_enable_nesting(domain->domain); 2322 if (ret) 2323 goto out_domain; 2324 } 2325 2326 ret = vfio_iommu_attach_group(domain, group); 2327 if (ret) 2328 goto out_domain; 2329 2330 /* Get aperture info */ 2331 geo = &domain->domain->geometry; 2332 if (vfio_iommu_aper_conflict(iommu, geo->aperture_start, 2333 geo->aperture_end)) { 2334 ret = -EINVAL; 2335 goto out_detach; 2336 } 2337 2338 ret = iommu_get_group_resv_regions(iommu_group, &group_resv_regions); 2339 if (ret) 2340 goto out_detach; 2341 2342 if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) { 2343 ret = -EINVAL; 2344 goto out_detach; 2345 } 2346 2347 /* 2348 * We don't want to work on the original iova list as the list 2349 * gets modified and in case of failure we have to retain the 2350 * original list. Get a copy here. 2351 */ 2352 ret = vfio_iommu_iova_get_copy(iommu, &iova_copy); 2353 if (ret) 2354 goto out_detach; 2355 2356 ret = vfio_iommu_aper_resize(&iova_copy, geo->aperture_start, 2357 geo->aperture_end); 2358 if (ret) 2359 goto out_detach; 2360 2361 ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions); 2362 if (ret) 2363 goto out_detach; 2364 2365 resv_msi = vfio_iommu_has_sw_msi(&group_resv_regions, &resv_msi_base); 2366 2367 INIT_LIST_HEAD(&domain->group_list); 2368 list_add(&group->next, &domain->group_list); 2369 2370 msi_remap = irq_domain_check_msi_remap() || 2371 iommu_capable(bus, IOMMU_CAP_INTR_REMAP); 2372 2373 if (!allow_unsafe_interrupts && !msi_remap) { 2374 pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n", 2375 __func__); 2376 ret = -EPERM; 2377 goto out_detach; 2378 } 2379 2380 if (iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY)) 2381 domain->prot |= IOMMU_CACHE; 2382 2383 /* 2384 * Try to match an existing compatible domain. We don't want to 2385 * preclude an IOMMU driver supporting multiple bus_types and being 2386 * able to include different bus_types in the same IOMMU domain, so 2387 * we test whether the domains use the same iommu_ops rather than 2388 * testing if they're on the same bus_type. 2389 */ 2390 list_for_each_entry(d, &iommu->domain_list, next) { 2391 if (d->domain->ops == domain->domain->ops && 2392 d->prot == domain->prot) { 2393 vfio_iommu_detach_group(domain, group); 2394 if (!vfio_iommu_attach_group(d, group)) { 2395 list_add(&group->next, &d->group_list); 2396 iommu_domain_free(domain->domain); 2397 kfree(domain); 2398 goto done; 2399 } 2400 2401 ret = vfio_iommu_attach_group(domain, group); 2402 if (ret) 2403 goto out_domain; 2404 } 2405 } 2406 2407 vfio_test_domain_fgsp(domain); 2408 2409 /* replay mappings on new domains */ 2410 ret = vfio_iommu_replay(iommu, domain); 2411 if (ret) 2412 goto out_detach; 2413 2414 if (resv_msi) { 2415 ret = iommu_get_msi_cookie(domain->domain, resv_msi_base); 2416 if (ret && ret != -ENODEV) 2417 goto out_detach; 2418 } 2419 2420 list_add(&domain->next, &iommu->domain_list); 2421 vfio_update_pgsize_bitmap(iommu); 2422 done: 2423 /* Delete the old one and insert new iova list */ 2424 vfio_iommu_iova_insert_copy(iommu, &iova_copy); 2425 2426 /* 2427 * An iommu backed group can dirty memory directly and therefore 2428 * demotes the iommu scope until it declares itself dirty tracking 2429 * capable via the page pinning interface. 2430 */ 2431 iommu->num_non_pinned_groups++; 2432 mutex_unlock(&iommu->lock); 2433 vfio_iommu_resv_free(&group_resv_regions); 2434 2435 return 0; 2436 2437 out_detach: 2438 vfio_iommu_detach_group(domain, group); 2439 out_domain: 2440 iommu_domain_free(domain->domain); 2441 vfio_iommu_iova_free(&iova_copy); 2442 vfio_iommu_resv_free(&group_resv_regions); 2443 out_free: 2444 kfree(domain); 2445 kfree(group); 2446 mutex_unlock(&iommu->lock); 2447 return ret; 2448 } 2449 2450 static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu) 2451 { 2452 struct rb_node *node; 2453 2454 while ((node = rb_first(&iommu->dma_list))) 2455 vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node)); 2456 } 2457 2458 static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu) 2459 { 2460 struct rb_node *n, *p; 2461 2462 n = rb_first(&iommu->dma_list); 2463 for (; n; n = rb_next(n)) { 2464 struct vfio_dma *dma; 2465 long locked = 0, unlocked = 0; 2466 2467 dma = rb_entry(n, struct vfio_dma, node); 2468 unlocked += vfio_unmap_unpin(iommu, dma, false); 2469 p = rb_first(&dma->pfn_list); 2470 for (; p; p = rb_next(p)) { 2471 struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, 2472 node); 2473 2474 if (!is_invalid_reserved_pfn(vpfn->pfn)) 2475 locked++; 2476 } 2477 vfio_lock_acct(dma, locked - unlocked, true); 2478 } 2479 } 2480 2481 /* 2482 * Called when a domain is removed in detach. It is possible that 2483 * the removed domain decided the iova aperture window. Modify the 2484 * iova aperture with the smallest window among existing domains. 2485 */ 2486 static void vfio_iommu_aper_expand(struct vfio_iommu *iommu, 2487 struct list_head *iova_copy) 2488 { 2489 struct vfio_domain *domain; 2490 struct vfio_iova *node; 2491 dma_addr_t start = 0; 2492 dma_addr_t end = (dma_addr_t)~0; 2493 2494 if (list_empty(iova_copy)) 2495 return; 2496 2497 list_for_each_entry(domain, &iommu->domain_list, next) { 2498 struct iommu_domain_geometry *geo = &domain->domain->geometry; 2499 2500 if (geo->aperture_start > start) 2501 start = geo->aperture_start; 2502 if (geo->aperture_end < end) 2503 end = geo->aperture_end; 2504 } 2505 2506 /* Modify aperture limits. The new aper is either same or bigger */ 2507 node = list_first_entry(iova_copy, struct vfio_iova, list); 2508 node->start = start; 2509 node = list_last_entry(iova_copy, struct vfio_iova, list); 2510 node->end = end; 2511 } 2512 2513 /* 2514 * Called when a group is detached. The reserved regions for that 2515 * group can be part of valid iova now. But since reserved regions 2516 * may be duplicated among groups, populate the iova valid regions 2517 * list again. 2518 */ 2519 static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu, 2520 struct list_head *iova_copy) 2521 { 2522 struct vfio_domain *d; 2523 struct vfio_iommu_group *g; 2524 struct vfio_iova *node; 2525 dma_addr_t start, end; 2526 LIST_HEAD(resv_regions); 2527 int ret; 2528 2529 if (list_empty(iova_copy)) 2530 return -EINVAL; 2531 2532 list_for_each_entry(d, &iommu->domain_list, next) { 2533 list_for_each_entry(g, &d->group_list, next) { 2534 ret = iommu_get_group_resv_regions(g->iommu_group, 2535 &resv_regions); 2536 if (ret) 2537 goto done; 2538 } 2539 } 2540 2541 node = list_first_entry(iova_copy, struct vfio_iova, list); 2542 start = node->start; 2543 node = list_last_entry(iova_copy, struct vfio_iova, list); 2544 end = node->end; 2545 2546 /* purge the iova list and create new one */ 2547 vfio_iommu_iova_free(iova_copy); 2548 2549 ret = vfio_iommu_aper_resize(iova_copy, start, end); 2550 if (ret) 2551 goto done; 2552 2553 /* Exclude current reserved regions from iova ranges */ 2554 ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions); 2555 done: 2556 vfio_iommu_resv_free(&resv_regions); 2557 return ret; 2558 } 2559 2560 static void vfio_iommu_type1_detach_group(void *iommu_data, 2561 struct iommu_group *iommu_group) 2562 { 2563 struct vfio_iommu *iommu = iommu_data; 2564 struct vfio_domain *domain; 2565 struct vfio_iommu_group *group; 2566 bool update_dirty_scope = false; 2567 LIST_HEAD(iova_copy); 2568 2569 mutex_lock(&iommu->lock); 2570 2571 if (iommu->external_domain) { 2572 group = find_iommu_group(iommu->external_domain, iommu_group); 2573 if (group) { 2574 update_dirty_scope = !group->pinned_page_dirty_scope; 2575 list_del(&group->next); 2576 kfree(group); 2577 2578 if (list_empty(&iommu->external_domain->group_list)) { 2579 if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) { 2580 WARN_ON(iommu->notifier.head); 2581 vfio_iommu_unmap_unpin_all(iommu); 2582 } 2583 2584 kfree(iommu->external_domain); 2585 iommu->external_domain = NULL; 2586 } 2587 goto detach_group_done; 2588 } 2589 } 2590 2591 /* 2592 * Get a copy of iova list. This will be used to update 2593 * and to replace the current one later. Please note that 2594 * we will leave the original list as it is if update fails. 2595 */ 2596 vfio_iommu_iova_get_copy(iommu, &iova_copy); 2597 2598 list_for_each_entry(domain, &iommu->domain_list, next) { 2599 group = find_iommu_group(domain, iommu_group); 2600 if (!group) 2601 continue; 2602 2603 vfio_iommu_detach_group(domain, group); 2604 update_dirty_scope = !group->pinned_page_dirty_scope; 2605 list_del(&group->next); 2606 kfree(group); 2607 /* 2608 * Group ownership provides privilege, if the group list is 2609 * empty, the domain goes away. If it's the last domain with 2610 * iommu and external domain doesn't exist, then all the 2611 * mappings go away too. If it's the last domain with iommu and 2612 * external domain exist, update accounting 2613 */ 2614 if (list_empty(&domain->group_list)) { 2615 if (list_is_singular(&iommu->domain_list)) { 2616 if (!iommu->external_domain) { 2617 WARN_ON(iommu->notifier.head); 2618 vfio_iommu_unmap_unpin_all(iommu); 2619 } else { 2620 vfio_iommu_unmap_unpin_reaccount(iommu); 2621 } 2622 } 2623 iommu_domain_free(domain->domain); 2624 list_del(&domain->next); 2625 kfree(domain); 2626 vfio_iommu_aper_expand(iommu, &iova_copy); 2627 vfio_update_pgsize_bitmap(iommu); 2628 } 2629 break; 2630 } 2631 2632 if (!vfio_iommu_resv_refresh(iommu, &iova_copy)) 2633 vfio_iommu_iova_insert_copy(iommu, &iova_copy); 2634 else 2635 vfio_iommu_iova_free(&iova_copy); 2636 2637 detach_group_done: 2638 /* 2639 * Removal of a group without dirty tracking may allow the iommu scope 2640 * to be promoted. 2641 */ 2642 if (update_dirty_scope) { 2643 iommu->num_non_pinned_groups--; 2644 if (iommu->dirty_page_tracking) 2645 vfio_iommu_populate_bitmap_full(iommu); 2646 } 2647 mutex_unlock(&iommu->lock); 2648 } 2649 2650 static void *vfio_iommu_type1_open(unsigned long arg) 2651 { 2652 struct vfio_iommu *iommu; 2653 2654 iommu = kzalloc(sizeof(*iommu), GFP_KERNEL); 2655 if (!iommu) 2656 return ERR_PTR(-ENOMEM); 2657 2658 switch (arg) { 2659 case VFIO_TYPE1_IOMMU: 2660 break; 2661 case VFIO_TYPE1_NESTING_IOMMU: 2662 iommu->nesting = true; 2663 fallthrough; 2664 case VFIO_TYPE1v2_IOMMU: 2665 iommu->v2 = true; 2666 break; 2667 default: 2668 kfree(iommu); 2669 return ERR_PTR(-EINVAL); 2670 } 2671 2672 INIT_LIST_HEAD(&iommu->domain_list); 2673 INIT_LIST_HEAD(&iommu->iova_list); 2674 iommu->dma_list = RB_ROOT; 2675 iommu->dma_avail = dma_entry_limit; 2676 iommu->container_open = true; 2677 mutex_init(&iommu->lock); 2678 BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier); 2679 init_waitqueue_head(&iommu->vaddr_wait); 2680 2681 return iommu; 2682 } 2683 2684 static void vfio_release_domain(struct vfio_domain *domain, bool external) 2685 { 2686 struct vfio_iommu_group *group, *group_tmp; 2687 2688 list_for_each_entry_safe(group, group_tmp, 2689 &domain->group_list, next) { 2690 if (!external) 2691 vfio_iommu_detach_group(domain, group); 2692 list_del(&group->next); 2693 kfree(group); 2694 } 2695 2696 if (!external) 2697 iommu_domain_free(domain->domain); 2698 } 2699 2700 static void vfio_iommu_type1_release(void *iommu_data) 2701 { 2702 struct vfio_iommu *iommu = iommu_data; 2703 struct vfio_domain *domain, *domain_tmp; 2704 2705 if (iommu->external_domain) { 2706 vfio_release_domain(iommu->external_domain, true); 2707 kfree(iommu->external_domain); 2708 } 2709 2710 vfio_iommu_unmap_unpin_all(iommu); 2711 2712 list_for_each_entry_safe(domain, domain_tmp, 2713 &iommu->domain_list, next) { 2714 vfio_release_domain(domain, false); 2715 list_del(&domain->next); 2716 kfree(domain); 2717 } 2718 2719 vfio_iommu_iova_free(&iommu->iova_list); 2720 2721 kfree(iommu); 2722 } 2723 2724 static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu) 2725 { 2726 struct vfio_domain *domain; 2727 int ret = 1; 2728 2729 mutex_lock(&iommu->lock); 2730 list_for_each_entry(domain, &iommu->domain_list, next) { 2731 if (!(domain->prot & IOMMU_CACHE)) { 2732 ret = 0; 2733 break; 2734 } 2735 } 2736 mutex_unlock(&iommu->lock); 2737 2738 return ret; 2739 } 2740 2741 static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu, 2742 unsigned long arg) 2743 { 2744 switch (arg) { 2745 case VFIO_TYPE1_IOMMU: 2746 case VFIO_TYPE1v2_IOMMU: 2747 case VFIO_TYPE1_NESTING_IOMMU: 2748 case VFIO_UNMAP_ALL: 2749 case VFIO_UPDATE_VADDR: 2750 return 1; 2751 case VFIO_DMA_CC_IOMMU: 2752 if (!iommu) 2753 return 0; 2754 return vfio_domains_have_iommu_cache(iommu); 2755 default: 2756 return 0; 2757 } 2758 } 2759 2760 static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps, 2761 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas, 2762 size_t size) 2763 { 2764 struct vfio_info_cap_header *header; 2765 struct vfio_iommu_type1_info_cap_iova_range *iova_cap; 2766 2767 header = vfio_info_cap_add(caps, size, 2768 VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1); 2769 if (IS_ERR(header)) 2770 return PTR_ERR(header); 2771 2772 iova_cap = container_of(header, 2773 struct vfio_iommu_type1_info_cap_iova_range, 2774 header); 2775 iova_cap->nr_iovas = cap_iovas->nr_iovas; 2776 memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges, 2777 cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges)); 2778 return 0; 2779 } 2780 2781 static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu, 2782 struct vfio_info_cap *caps) 2783 { 2784 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas; 2785 struct vfio_iova *iova; 2786 size_t size; 2787 int iovas = 0, i = 0, ret; 2788 2789 list_for_each_entry(iova, &iommu->iova_list, list) 2790 iovas++; 2791 2792 if (!iovas) { 2793 /* 2794 * Return 0 as a container with a single mdev device 2795 * will have an empty list 2796 */ 2797 return 0; 2798 } 2799 2800 size = struct_size(cap_iovas, iova_ranges, iovas); 2801 2802 cap_iovas = kzalloc(size, GFP_KERNEL); 2803 if (!cap_iovas) 2804 return -ENOMEM; 2805 2806 cap_iovas->nr_iovas = iovas; 2807 2808 list_for_each_entry(iova, &iommu->iova_list, list) { 2809 cap_iovas->iova_ranges[i].start = iova->start; 2810 cap_iovas->iova_ranges[i].end = iova->end; 2811 i++; 2812 } 2813 2814 ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size); 2815 2816 kfree(cap_iovas); 2817 return ret; 2818 } 2819 2820 static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu, 2821 struct vfio_info_cap *caps) 2822 { 2823 struct vfio_iommu_type1_info_cap_migration cap_mig; 2824 2825 cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION; 2826 cap_mig.header.version = 1; 2827 2828 cap_mig.flags = 0; 2829 /* support minimum pgsize */ 2830 cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap); 2831 cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX; 2832 2833 return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig)); 2834 } 2835 2836 static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu, 2837 struct vfio_info_cap *caps) 2838 { 2839 struct vfio_iommu_type1_info_dma_avail cap_dma_avail; 2840 2841 cap_dma_avail.header.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL; 2842 cap_dma_avail.header.version = 1; 2843 2844 cap_dma_avail.avail = iommu->dma_avail; 2845 2846 return vfio_info_add_capability(caps, &cap_dma_avail.header, 2847 sizeof(cap_dma_avail)); 2848 } 2849 2850 static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu, 2851 unsigned long arg) 2852 { 2853 struct vfio_iommu_type1_info info; 2854 unsigned long minsz; 2855 struct vfio_info_cap caps = { .buf = NULL, .size = 0 }; 2856 unsigned long capsz; 2857 int ret; 2858 2859 minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes); 2860 2861 /* For backward compatibility, cannot require this */ 2862 capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset); 2863 2864 if (copy_from_user(&info, (void __user *)arg, minsz)) 2865 return -EFAULT; 2866 2867 if (info.argsz < minsz) 2868 return -EINVAL; 2869 2870 if (info.argsz >= capsz) { 2871 minsz = capsz; 2872 info.cap_offset = 0; /* output, no-recopy necessary */ 2873 } 2874 2875 mutex_lock(&iommu->lock); 2876 info.flags = VFIO_IOMMU_INFO_PGSIZES; 2877 2878 info.iova_pgsizes = iommu->pgsize_bitmap; 2879 2880 ret = vfio_iommu_migration_build_caps(iommu, &caps); 2881 2882 if (!ret) 2883 ret = vfio_iommu_dma_avail_build_caps(iommu, &caps); 2884 2885 if (!ret) 2886 ret = vfio_iommu_iova_build_caps(iommu, &caps); 2887 2888 mutex_unlock(&iommu->lock); 2889 2890 if (ret) 2891 return ret; 2892 2893 if (caps.size) { 2894 info.flags |= VFIO_IOMMU_INFO_CAPS; 2895 2896 if (info.argsz < sizeof(info) + caps.size) { 2897 info.argsz = sizeof(info) + caps.size; 2898 } else { 2899 vfio_info_cap_shift(&caps, sizeof(info)); 2900 if (copy_to_user((void __user *)arg + 2901 sizeof(info), caps.buf, 2902 caps.size)) { 2903 kfree(caps.buf); 2904 return -EFAULT; 2905 } 2906 info.cap_offset = sizeof(info); 2907 } 2908 2909 kfree(caps.buf); 2910 } 2911 2912 return copy_to_user((void __user *)arg, &info, minsz) ? 2913 -EFAULT : 0; 2914 } 2915 2916 static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu, 2917 unsigned long arg) 2918 { 2919 struct vfio_iommu_type1_dma_map map; 2920 unsigned long minsz; 2921 uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE | 2922 VFIO_DMA_MAP_FLAG_VADDR; 2923 2924 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size); 2925 2926 if (copy_from_user(&map, (void __user *)arg, minsz)) 2927 return -EFAULT; 2928 2929 if (map.argsz < minsz || map.flags & ~mask) 2930 return -EINVAL; 2931 2932 return vfio_dma_do_map(iommu, &map); 2933 } 2934 2935 static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu, 2936 unsigned long arg) 2937 { 2938 struct vfio_iommu_type1_dma_unmap unmap; 2939 struct vfio_bitmap bitmap = { 0 }; 2940 uint32_t mask = VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP | 2941 VFIO_DMA_UNMAP_FLAG_VADDR | 2942 VFIO_DMA_UNMAP_FLAG_ALL; 2943 unsigned long minsz; 2944 int ret; 2945 2946 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); 2947 2948 if (copy_from_user(&unmap, (void __user *)arg, minsz)) 2949 return -EFAULT; 2950 2951 if (unmap.argsz < minsz || unmap.flags & ~mask) 2952 return -EINVAL; 2953 2954 if ((unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && 2955 (unmap.flags & (VFIO_DMA_UNMAP_FLAG_ALL | 2956 VFIO_DMA_UNMAP_FLAG_VADDR))) 2957 return -EINVAL; 2958 2959 if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { 2960 unsigned long pgshift; 2961 2962 if (unmap.argsz < (minsz + sizeof(bitmap))) 2963 return -EINVAL; 2964 2965 if (copy_from_user(&bitmap, 2966 (void __user *)(arg + minsz), 2967 sizeof(bitmap))) 2968 return -EFAULT; 2969 2970 if (!access_ok((void __user *)bitmap.data, bitmap.size)) 2971 return -EINVAL; 2972 2973 pgshift = __ffs(bitmap.pgsize); 2974 ret = verify_bitmap_size(unmap.size >> pgshift, 2975 bitmap.size); 2976 if (ret) 2977 return ret; 2978 } 2979 2980 ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap); 2981 if (ret) 2982 return ret; 2983 2984 return copy_to_user((void __user *)arg, &unmap, minsz) ? 2985 -EFAULT : 0; 2986 } 2987 2988 static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, 2989 unsigned long arg) 2990 { 2991 struct vfio_iommu_type1_dirty_bitmap dirty; 2992 uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | 2993 VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP | 2994 VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP; 2995 unsigned long minsz; 2996 int ret = 0; 2997 2998 if (!iommu->v2) 2999 return -EACCES; 3000 3001 minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags); 3002 3003 if (copy_from_user(&dirty, (void __user *)arg, minsz)) 3004 return -EFAULT; 3005 3006 if (dirty.argsz < minsz || dirty.flags & ~mask) 3007 return -EINVAL; 3008 3009 /* only one flag should be set at a time */ 3010 if (__ffs(dirty.flags) != __fls(dirty.flags)) 3011 return -EINVAL; 3012 3013 if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) { 3014 size_t pgsize; 3015 3016 mutex_lock(&iommu->lock); 3017 pgsize = 1 << __ffs(iommu->pgsize_bitmap); 3018 if (!iommu->dirty_page_tracking) { 3019 ret = vfio_dma_bitmap_alloc_all(iommu, pgsize); 3020 if (!ret) 3021 iommu->dirty_page_tracking = true; 3022 } 3023 mutex_unlock(&iommu->lock); 3024 return ret; 3025 } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) { 3026 mutex_lock(&iommu->lock); 3027 if (iommu->dirty_page_tracking) { 3028 iommu->dirty_page_tracking = false; 3029 vfio_dma_bitmap_free_all(iommu); 3030 } 3031 mutex_unlock(&iommu->lock); 3032 return 0; 3033 } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) { 3034 struct vfio_iommu_type1_dirty_bitmap_get range; 3035 unsigned long pgshift; 3036 size_t data_size = dirty.argsz - minsz; 3037 size_t iommu_pgsize; 3038 3039 if (!data_size || data_size < sizeof(range)) 3040 return -EINVAL; 3041 3042 if (copy_from_user(&range, (void __user *)(arg + minsz), 3043 sizeof(range))) 3044 return -EFAULT; 3045 3046 if (range.iova + range.size < range.iova) 3047 return -EINVAL; 3048 if (!access_ok((void __user *)range.bitmap.data, 3049 range.bitmap.size)) 3050 return -EINVAL; 3051 3052 pgshift = __ffs(range.bitmap.pgsize); 3053 ret = verify_bitmap_size(range.size >> pgshift, 3054 range.bitmap.size); 3055 if (ret) 3056 return ret; 3057 3058 mutex_lock(&iommu->lock); 3059 3060 iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); 3061 3062 /* allow only smallest supported pgsize */ 3063 if (range.bitmap.pgsize != iommu_pgsize) { 3064 ret = -EINVAL; 3065 goto out_unlock; 3066 } 3067 if (range.iova & (iommu_pgsize - 1)) { 3068 ret = -EINVAL; 3069 goto out_unlock; 3070 } 3071 if (!range.size || range.size & (iommu_pgsize - 1)) { 3072 ret = -EINVAL; 3073 goto out_unlock; 3074 } 3075 3076 if (iommu->dirty_page_tracking) 3077 ret = vfio_iova_dirty_bitmap(range.bitmap.data, 3078 iommu, range.iova, 3079 range.size, 3080 range.bitmap.pgsize); 3081 else 3082 ret = -EINVAL; 3083 out_unlock: 3084 mutex_unlock(&iommu->lock); 3085 3086 return ret; 3087 } 3088 3089 return -EINVAL; 3090 } 3091 3092 static long vfio_iommu_type1_ioctl(void *iommu_data, 3093 unsigned int cmd, unsigned long arg) 3094 { 3095 struct vfio_iommu *iommu = iommu_data; 3096 3097 switch (cmd) { 3098 case VFIO_CHECK_EXTENSION: 3099 return vfio_iommu_type1_check_extension(iommu, arg); 3100 case VFIO_IOMMU_GET_INFO: 3101 return vfio_iommu_type1_get_info(iommu, arg); 3102 case VFIO_IOMMU_MAP_DMA: 3103 return vfio_iommu_type1_map_dma(iommu, arg); 3104 case VFIO_IOMMU_UNMAP_DMA: 3105 return vfio_iommu_type1_unmap_dma(iommu, arg); 3106 case VFIO_IOMMU_DIRTY_PAGES: 3107 return vfio_iommu_type1_dirty_pages(iommu, arg); 3108 default: 3109 return -ENOTTY; 3110 } 3111 } 3112 3113 static int vfio_iommu_type1_register_notifier(void *iommu_data, 3114 unsigned long *events, 3115 struct notifier_block *nb) 3116 { 3117 struct vfio_iommu *iommu = iommu_data; 3118 3119 /* clear known events */ 3120 *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP; 3121 3122 /* refuse to register if still events remaining */ 3123 if (*events) 3124 return -EINVAL; 3125 3126 return blocking_notifier_chain_register(&iommu->notifier, nb); 3127 } 3128 3129 static int vfio_iommu_type1_unregister_notifier(void *iommu_data, 3130 struct notifier_block *nb) 3131 { 3132 struct vfio_iommu *iommu = iommu_data; 3133 3134 return blocking_notifier_chain_unregister(&iommu->notifier, nb); 3135 } 3136 3137 static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, 3138 dma_addr_t user_iova, void *data, 3139 size_t count, bool write, 3140 size_t *copied) 3141 { 3142 struct mm_struct *mm; 3143 unsigned long vaddr; 3144 struct vfio_dma *dma; 3145 bool kthread = current->mm == NULL; 3146 size_t offset; 3147 int ret; 3148 3149 *copied = 0; 3150 3151 ret = vfio_find_dma_valid(iommu, user_iova, 1, &dma); 3152 if (ret < 0) 3153 return ret; 3154 3155 if ((write && !(dma->prot & IOMMU_WRITE)) || 3156 !(dma->prot & IOMMU_READ)) 3157 return -EPERM; 3158 3159 mm = get_task_mm(dma->task); 3160 3161 if (!mm) 3162 return -EPERM; 3163 3164 if (kthread) 3165 kthread_use_mm(mm); 3166 else if (current->mm != mm) 3167 goto out; 3168 3169 offset = user_iova - dma->iova; 3170 3171 if (count > dma->size - offset) 3172 count = dma->size - offset; 3173 3174 vaddr = dma->vaddr + offset; 3175 3176 if (write) { 3177 *copied = copy_to_user((void __user *)vaddr, data, 3178 count) ? 0 : count; 3179 if (*copied && iommu->dirty_page_tracking) { 3180 unsigned long pgshift = __ffs(iommu->pgsize_bitmap); 3181 /* 3182 * Bitmap populated with the smallest supported page 3183 * size 3184 */ 3185 bitmap_set(dma->bitmap, offset >> pgshift, 3186 ((offset + *copied - 1) >> pgshift) - 3187 (offset >> pgshift) + 1); 3188 } 3189 } else 3190 *copied = copy_from_user(data, (void __user *)vaddr, 3191 count) ? 0 : count; 3192 if (kthread) 3193 kthread_unuse_mm(mm); 3194 out: 3195 mmput(mm); 3196 return *copied ? 0 : -EFAULT; 3197 } 3198 3199 static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova, 3200 void *data, size_t count, bool write) 3201 { 3202 struct vfio_iommu *iommu = iommu_data; 3203 int ret = 0; 3204 size_t done; 3205 3206 mutex_lock(&iommu->lock); 3207 while (count > 0) { 3208 ret = vfio_iommu_type1_dma_rw_chunk(iommu, user_iova, data, 3209 count, write, &done); 3210 if (ret) 3211 break; 3212 3213 count -= done; 3214 data += done; 3215 user_iova += done; 3216 } 3217 3218 mutex_unlock(&iommu->lock); 3219 return ret; 3220 } 3221 3222 static struct iommu_domain * 3223 vfio_iommu_type1_group_iommu_domain(void *iommu_data, 3224 struct iommu_group *iommu_group) 3225 { 3226 struct iommu_domain *domain = ERR_PTR(-ENODEV); 3227 struct vfio_iommu *iommu = iommu_data; 3228 struct vfio_domain *d; 3229 3230 if (!iommu || !iommu_group) 3231 return ERR_PTR(-EINVAL); 3232 3233 mutex_lock(&iommu->lock); 3234 list_for_each_entry(d, &iommu->domain_list, next) { 3235 if (find_iommu_group(d, iommu_group)) { 3236 domain = d->domain; 3237 break; 3238 } 3239 } 3240 mutex_unlock(&iommu->lock); 3241 3242 return domain; 3243 } 3244 3245 static void vfio_iommu_type1_notify(void *iommu_data, 3246 enum vfio_iommu_notify_type event) 3247 { 3248 struct vfio_iommu *iommu = iommu_data; 3249 3250 if (event != VFIO_IOMMU_CONTAINER_CLOSE) 3251 return; 3252 mutex_lock(&iommu->lock); 3253 iommu->container_open = false; 3254 mutex_unlock(&iommu->lock); 3255 wake_up_all(&iommu->vaddr_wait); 3256 } 3257 3258 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { 3259 .name = "vfio-iommu-type1", 3260 .owner = THIS_MODULE, 3261 .open = vfio_iommu_type1_open, 3262 .release = vfio_iommu_type1_release, 3263 .ioctl = vfio_iommu_type1_ioctl, 3264 .attach_group = vfio_iommu_type1_attach_group, 3265 .detach_group = vfio_iommu_type1_detach_group, 3266 .pin_pages = vfio_iommu_type1_pin_pages, 3267 .unpin_pages = vfio_iommu_type1_unpin_pages, 3268 .register_notifier = vfio_iommu_type1_register_notifier, 3269 .unregister_notifier = vfio_iommu_type1_unregister_notifier, 3270 .dma_rw = vfio_iommu_type1_dma_rw, 3271 .group_iommu_domain = vfio_iommu_type1_group_iommu_domain, 3272 .notify = vfio_iommu_type1_notify, 3273 }; 3274 3275 static int __init vfio_iommu_type1_init(void) 3276 { 3277 return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1); 3278 } 3279 3280 static void __exit vfio_iommu_type1_cleanup(void) 3281 { 3282 vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1); 3283 } 3284 3285 module_init(vfio_iommu_type1_init); 3286 module_exit(vfio_iommu_type1_cleanup); 3287 3288 MODULE_VERSION(DRIVER_VERSION); 3289 MODULE_LICENSE("GPL v2"); 3290 MODULE_AUTHOR(DRIVER_AUTHOR); 3291 MODULE_DESCRIPTION(DRIVER_DESC); 3292