1 /* 2 * vhost support 3 * 4 * Copyright Red Hat, Inc. 2010 5 * 6 * Authors: 7 * Michael S. Tsirkin <mst@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 * Contributions after 2012-01-13 are licensed under the terms of the 13 * GNU GPL, version 2 or (at your option) any later version. 14 */ 15 16 #include "qemu/osdep.h" 17 #include "qapi/error.h" 18 #include "hw/virtio/vhost.h" 19 #include "hw/hw.h" 20 #include "qemu/atomic.h" 21 #include "qemu/range.h" 22 #include "qemu/error-report.h" 23 #include "qemu/memfd.h" 24 #include <linux/vhost.h> 25 #include "exec/address-spaces.h" 26 #include "hw/virtio/virtio-bus.h" 27 #include "hw/virtio/virtio-access.h" 28 #include "migration/blocker.h" 29 #include "sysemu/dma.h" 30 #include "trace.h" 31 32 /* enabled until disconnected backend stabilizes */ 33 #define _VHOST_DEBUG 1 34 35 #ifdef _VHOST_DEBUG 36 #define VHOST_OPS_DEBUG(fmt, ...) \ 37 do { error_report(fmt ": %s (%d)", ## __VA_ARGS__, \ 38 strerror(errno), errno); } while (0) 39 #else 40 #define VHOST_OPS_DEBUG(fmt, ...) \ 41 do { } while (0) 42 #endif 43 44 static struct vhost_log *vhost_log; 45 static struct vhost_log *vhost_log_shm; 46 47 static unsigned int used_memslots; 48 static QLIST_HEAD(, vhost_dev) vhost_devices = 49 QLIST_HEAD_INITIALIZER(vhost_devices); 50 51 bool vhost_has_free_slot(void) 52 { 53 unsigned int slots_limit = ~0U; 54 struct vhost_dev *hdev; 55 56 QLIST_FOREACH(hdev, &vhost_devices, entry) { 57 unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 58 slots_limit = MIN(slots_limit, r); 59 } 60 return slots_limit > used_memslots; 61 } 62 63 static void vhost_dev_sync_region(struct vhost_dev *dev, 64 MemoryRegionSection *section, 65 uint64_t mfirst, uint64_t mlast, 66 uint64_t rfirst, uint64_t rlast) 67 { 68 vhost_log_chunk_t *log = dev->log->log; 69 70 uint64_t start = MAX(mfirst, rfirst); 71 uint64_t end = MIN(mlast, rlast); 72 vhost_log_chunk_t *from = log + start / VHOST_LOG_CHUNK; 73 vhost_log_chunk_t *to = log + end / VHOST_LOG_CHUNK + 1; 74 uint64_t addr = QEMU_ALIGN_DOWN(start, VHOST_LOG_CHUNK); 75 76 if (end < start) { 77 return; 78 } 79 assert(end / VHOST_LOG_CHUNK < dev->log_size); 80 assert(start / VHOST_LOG_CHUNK < dev->log_size); 81 82 for (;from < to; ++from) { 83 vhost_log_chunk_t log; 84 /* We first check with non-atomic: much cheaper, 85 * and we expect non-dirty to be the common case. */ 86 if (!*from) { 87 addr += VHOST_LOG_CHUNK; 88 continue; 89 } 90 /* Data must be read atomically. We don't really need barrier semantics 91 * but it's easier to use atomic_* than roll our own. */ 92 log = atomic_xchg(from, 0); 93 while (log) { 94 int bit = ctzl(log); 95 hwaddr page_addr; 96 hwaddr section_offset; 97 hwaddr mr_offset; 98 page_addr = addr + bit * VHOST_LOG_PAGE; 99 section_offset = page_addr - section->offset_within_address_space; 100 mr_offset = section_offset + section->offset_within_region; 101 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 102 log &= ~(0x1ull << bit); 103 } 104 addr += VHOST_LOG_CHUNK; 105 } 106 } 107 108 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 109 MemoryRegionSection *section, 110 hwaddr first, 111 hwaddr last) 112 { 113 int i; 114 hwaddr start_addr; 115 hwaddr end_addr; 116 117 if (!dev->log_enabled || !dev->started) { 118 return 0; 119 } 120 start_addr = section->offset_within_address_space; 121 end_addr = range_get_last(start_addr, int128_get64(section->size)); 122 start_addr = MAX(first, start_addr); 123 end_addr = MIN(last, end_addr); 124 125 for (i = 0; i < dev->mem->nregions; ++i) { 126 struct vhost_memory_region *reg = dev->mem->regions + i; 127 vhost_dev_sync_region(dev, section, start_addr, end_addr, 128 reg->guest_phys_addr, 129 range_get_last(reg->guest_phys_addr, 130 reg->memory_size)); 131 } 132 for (i = 0; i < dev->nvqs; ++i) { 133 struct vhost_virtqueue *vq = dev->vqs + i; 134 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 135 range_get_last(vq->used_phys, vq->used_size)); 136 } 137 return 0; 138 } 139 140 static void vhost_log_sync(MemoryListener *listener, 141 MemoryRegionSection *section) 142 { 143 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 144 memory_listener); 145 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 146 } 147 148 static void vhost_log_sync_range(struct vhost_dev *dev, 149 hwaddr first, hwaddr last) 150 { 151 int i; 152 /* FIXME: this is N^2 in number of sections */ 153 for (i = 0; i < dev->n_mem_sections; ++i) { 154 MemoryRegionSection *section = &dev->mem_sections[i]; 155 vhost_sync_dirty_bitmap(dev, section, first, last); 156 } 157 } 158 159 /* Assign/unassign. Keep an unsorted array of non-overlapping 160 * memory regions in dev->mem. */ 161 static void vhost_dev_unassign_memory(struct vhost_dev *dev, 162 uint64_t start_addr, 163 uint64_t size) 164 { 165 int from, to, n = dev->mem->nregions; 166 /* Track overlapping/split regions for sanity checking. */ 167 int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0; 168 169 for (from = 0, to = 0; from < n; ++from, ++to) { 170 struct vhost_memory_region *reg = dev->mem->regions + to; 171 uint64_t reglast; 172 uint64_t memlast; 173 uint64_t change; 174 175 /* clone old region */ 176 if (to != from) { 177 memcpy(reg, dev->mem->regions + from, sizeof *reg); 178 } 179 180 /* No overlap is simple */ 181 if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size, 182 start_addr, size)) { 183 continue; 184 } 185 186 /* Split only happens if supplied region 187 * is in the middle of an existing one. Thus it can not 188 * overlap with any other existing region. */ 189 assert(!split); 190 191 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 192 memlast = range_get_last(start_addr, size); 193 194 /* Remove whole region */ 195 if (start_addr <= reg->guest_phys_addr && memlast >= reglast) { 196 --dev->mem->nregions; 197 --to; 198 ++overlap_middle; 199 continue; 200 } 201 202 /* Shrink region */ 203 if (memlast >= reglast) { 204 reg->memory_size = start_addr - reg->guest_phys_addr; 205 assert(reg->memory_size); 206 assert(!overlap_end); 207 ++overlap_end; 208 continue; 209 } 210 211 /* Shift region */ 212 if (start_addr <= reg->guest_phys_addr) { 213 change = memlast + 1 - reg->guest_phys_addr; 214 reg->memory_size -= change; 215 reg->guest_phys_addr += change; 216 reg->userspace_addr += change; 217 assert(reg->memory_size); 218 assert(!overlap_start); 219 ++overlap_start; 220 continue; 221 } 222 223 /* This only happens if supplied region 224 * is in the middle of an existing one. Thus it can not 225 * overlap with any other existing region. */ 226 assert(!overlap_start); 227 assert(!overlap_end); 228 assert(!overlap_middle); 229 /* Split region: shrink first part, shift second part. */ 230 memcpy(dev->mem->regions + n, reg, sizeof *reg); 231 reg->memory_size = start_addr - reg->guest_phys_addr; 232 assert(reg->memory_size); 233 change = memlast + 1 - reg->guest_phys_addr; 234 reg = dev->mem->regions + n; 235 reg->memory_size -= change; 236 assert(reg->memory_size); 237 reg->guest_phys_addr += change; 238 reg->userspace_addr += change; 239 /* Never add more than 1 region */ 240 assert(dev->mem->nregions == n); 241 ++dev->mem->nregions; 242 ++split; 243 } 244 } 245 246 /* Called after unassign, so no regions overlap the given range. */ 247 static void vhost_dev_assign_memory(struct vhost_dev *dev, 248 uint64_t start_addr, 249 uint64_t size, 250 uint64_t uaddr) 251 { 252 int from, to; 253 struct vhost_memory_region *merged = NULL; 254 for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) { 255 struct vhost_memory_region *reg = dev->mem->regions + to; 256 uint64_t prlast, urlast; 257 uint64_t pmlast, umlast; 258 uint64_t s, e, u; 259 260 /* clone old region */ 261 if (to != from) { 262 memcpy(reg, dev->mem->regions + from, sizeof *reg); 263 } 264 prlast = range_get_last(reg->guest_phys_addr, reg->memory_size); 265 pmlast = range_get_last(start_addr, size); 266 urlast = range_get_last(reg->userspace_addr, reg->memory_size); 267 umlast = range_get_last(uaddr, size); 268 269 /* check for overlapping regions: should never happen. */ 270 assert(prlast < start_addr || pmlast < reg->guest_phys_addr); 271 /* Not an adjacent or overlapping region - do not merge. */ 272 if ((prlast + 1 != start_addr || urlast + 1 != uaddr) && 273 (pmlast + 1 != reg->guest_phys_addr || 274 umlast + 1 != reg->userspace_addr)) { 275 continue; 276 } 277 278 if (dev->vhost_ops->vhost_backend_can_merge && 279 !dev->vhost_ops->vhost_backend_can_merge(dev, uaddr, size, 280 reg->userspace_addr, 281 reg->memory_size)) { 282 continue; 283 } 284 285 if (merged) { 286 --to; 287 assert(to >= 0); 288 } else { 289 merged = reg; 290 } 291 u = MIN(uaddr, reg->userspace_addr); 292 s = MIN(start_addr, reg->guest_phys_addr); 293 e = MAX(pmlast, prlast); 294 uaddr = merged->userspace_addr = u; 295 start_addr = merged->guest_phys_addr = s; 296 size = merged->memory_size = e - s + 1; 297 assert(merged->memory_size); 298 } 299 300 if (!merged) { 301 struct vhost_memory_region *reg = dev->mem->regions + to; 302 memset(reg, 0, sizeof *reg); 303 reg->memory_size = size; 304 assert(reg->memory_size); 305 reg->guest_phys_addr = start_addr; 306 reg->userspace_addr = uaddr; 307 ++to; 308 } 309 assert(to <= dev->mem->nregions + 1); 310 dev->mem->nregions = to; 311 } 312 313 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 314 { 315 uint64_t log_size = 0; 316 int i; 317 for (i = 0; i < dev->mem->nregions; ++i) { 318 struct vhost_memory_region *reg = dev->mem->regions + i; 319 uint64_t last = range_get_last(reg->guest_phys_addr, 320 reg->memory_size); 321 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 322 } 323 for (i = 0; i < dev->nvqs; ++i) { 324 struct vhost_virtqueue *vq = dev->vqs + i; 325 uint64_t last = vq->used_phys + vq->used_size - 1; 326 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 327 } 328 return log_size; 329 } 330 331 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 332 { 333 Error *err = NULL; 334 struct vhost_log *log; 335 uint64_t logsize = size * sizeof(*(log->log)); 336 int fd = -1; 337 338 log = g_new0(struct vhost_log, 1); 339 if (share) { 340 log->log = qemu_memfd_alloc("vhost-log", logsize, 341 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 342 &fd, &err); 343 if (err) { 344 error_report_err(err); 345 g_free(log); 346 return NULL; 347 } 348 memset(log->log, 0, logsize); 349 } else { 350 log->log = g_malloc0(logsize); 351 } 352 353 log->size = size; 354 log->refcnt = 1; 355 log->fd = fd; 356 357 return log; 358 } 359 360 static struct vhost_log *vhost_log_get(uint64_t size, bool share) 361 { 362 struct vhost_log *log = share ? vhost_log_shm : vhost_log; 363 364 if (!log || log->size != size) { 365 log = vhost_log_alloc(size, share); 366 if (share) { 367 vhost_log_shm = log; 368 } else { 369 vhost_log = log; 370 } 371 } else { 372 ++log->refcnt; 373 } 374 375 return log; 376 } 377 378 static void vhost_log_put(struct vhost_dev *dev, bool sync) 379 { 380 struct vhost_log *log = dev->log; 381 382 if (!log) { 383 return; 384 } 385 386 --log->refcnt; 387 if (log->refcnt == 0) { 388 /* Sync only the range covered by the old log */ 389 if (dev->log_size && sync) { 390 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 391 } 392 393 if (vhost_log == log) { 394 g_free(log->log); 395 vhost_log = NULL; 396 } else if (vhost_log_shm == log) { 397 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 398 log->fd); 399 vhost_log_shm = NULL; 400 } 401 402 g_free(log); 403 } 404 405 dev->log = NULL; 406 dev->log_size = 0; 407 } 408 409 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 410 { 411 return dev->vhost_ops->vhost_requires_shm_log && 412 dev->vhost_ops->vhost_requires_shm_log(dev); 413 } 414 415 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 416 { 417 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 418 uint64_t log_base = (uintptr_t)log->log; 419 int r; 420 421 /* inform backend of log switching, this must be done before 422 releasing the current log, to ensure no logging is lost */ 423 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 424 if (r < 0) { 425 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 426 } 427 428 vhost_log_put(dev, true); 429 dev->log = log; 430 dev->log_size = size; 431 } 432 433 static int vhost_dev_has_iommu(struct vhost_dev *dev) 434 { 435 VirtIODevice *vdev = dev->vdev; 436 437 return virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 438 } 439 440 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 441 hwaddr *plen, int is_write) 442 { 443 if (!vhost_dev_has_iommu(dev)) { 444 return cpu_physical_memory_map(addr, plen, is_write); 445 } else { 446 return (void *)(uintptr_t)addr; 447 } 448 } 449 450 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 451 hwaddr len, int is_write, 452 hwaddr access_len) 453 { 454 if (!vhost_dev_has_iommu(dev)) { 455 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 456 } 457 } 458 459 static int vhost_verify_ring_part_mapping(struct vhost_dev *dev, 460 void *part, 461 uint64_t part_addr, 462 uint64_t part_size, 463 uint64_t start_addr, 464 uint64_t size) 465 { 466 hwaddr l; 467 void *p; 468 int r = 0; 469 470 if (!ranges_overlap(start_addr, size, part_addr, part_size)) { 471 return 0; 472 } 473 l = part_size; 474 p = vhost_memory_map(dev, part_addr, &l, 1); 475 if (!p || l != part_size) { 476 r = -ENOMEM; 477 } 478 if (p != part) { 479 r = -EBUSY; 480 } 481 vhost_memory_unmap(dev, p, l, 0, 0); 482 return r; 483 } 484 485 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 486 uint64_t start_addr, 487 uint64_t size) 488 { 489 int i, j; 490 int r = 0; 491 const char *part_name[] = { 492 "descriptor table", 493 "available ring", 494 "used ring" 495 }; 496 497 for (i = 0; i < dev->nvqs; ++i) { 498 struct vhost_virtqueue *vq = dev->vqs + i; 499 500 j = 0; 501 r = vhost_verify_ring_part_mapping(dev, vq->desc, vq->desc_phys, 502 vq->desc_size, start_addr, size); 503 if (r) { 504 break; 505 } 506 507 j++; 508 r = vhost_verify_ring_part_mapping(dev, vq->avail, vq->avail_phys, 509 vq->avail_size, start_addr, size); 510 if (r) { 511 break; 512 } 513 514 j++; 515 r = vhost_verify_ring_part_mapping(dev, vq->used, vq->used_phys, 516 vq->used_size, start_addr, size); 517 if (r) { 518 break; 519 } 520 } 521 522 if (r == -ENOMEM) { 523 error_report("Unable to map %s for ring %d", part_name[j], i); 524 } else if (r == -EBUSY) { 525 error_report("%s relocated for ring %d", part_name[j], i); 526 } 527 return r; 528 } 529 530 static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, 531 uint64_t start_addr, 532 uint64_t size) 533 { 534 int i, n = dev->mem->nregions; 535 for (i = 0; i < n; ++i) { 536 struct vhost_memory_region *reg = dev->mem->regions + i; 537 if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, 538 start_addr, size)) { 539 return reg; 540 } 541 } 542 return NULL; 543 } 544 545 static bool vhost_dev_cmp_memory(struct vhost_dev *dev, 546 uint64_t start_addr, 547 uint64_t size, 548 uint64_t uaddr) 549 { 550 struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); 551 uint64_t reglast; 552 uint64_t memlast; 553 554 if (!reg) { 555 return true; 556 } 557 558 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 559 memlast = range_get_last(start_addr, size); 560 561 /* Need to extend region? */ 562 if (start_addr < reg->guest_phys_addr || memlast > reglast) { 563 return true; 564 } 565 /* userspace_addr changed? */ 566 return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; 567 } 568 569 static void vhost_set_memory(MemoryListener *listener, 570 MemoryRegionSection *section, 571 bool add) 572 { 573 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 574 memory_listener); 575 hwaddr start_addr = section->offset_within_address_space; 576 ram_addr_t size = int128_get64(section->size); 577 bool log_dirty = 578 memory_region_get_dirty_log_mask(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); 579 int s = offsetof(struct vhost_memory, regions) + 580 (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; 581 void *ram; 582 583 dev->mem = g_realloc(dev->mem, s); 584 585 if (log_dirty) { 586 add = false; 587 } 588 589 assert(size); 590 591 /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ 592 ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; 593 if (add) { 594 if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { 595 /* Region exists with same address. Nothing to do. */ 596 return; 597 } 598 } else { 599 if (!vhost_dev_find_reg(dev, start_addr, size)) { 600 /* Removing region that we don't access. Nothing to do. */ 601 return; 602 } 603 } 604 605 vhost_dev_unassign_memory(dev, start_addr, size); 606 if (add) { 607 /* Add given mapping, merging adjacent regions if any */ 608 vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); 609 } else { 610 /* Remove old mapping for this memory, if any. */ 611 vhost_dev_unassign_memory(dev, start_addr, size); 612 } 613 dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr); 614 dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1); 615 dev->memory_changed = true; 616 used_memslots = dev->mem->nregions; 617 } 618 619 static bool vhost_section(MemoryRegionSection *section) 620 { 621 return memory_region_is_ram(section->mr) && 622 !memory_region_is_rom(section->mr); 623 } 624 625 static void vhost_begin(MemoryListener *listener) 626 { 627 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 628 memory_listener); 629 dev->mem_changed_end_addr = 0; 630 dev->mem_changed_start_addr = -1; 631 } 632 633 static void vhost_commit(MemoryListener *listener) 634 { 635 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 636 memory_listener); 637 hwaddr start_addr = 0; 638 ram_addr_t size = 0; 639 uint64_t log_size; 640 int r; 641 642 if (!dev->memory_changed) { 643 return; 644 } 645 if (!dev->started) { 646 return; 647 } 648 if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) { 649 return; 650 } 651 652 if (dev->started) { 653 start_addr = dev->mem_changed_start_addr; 654 size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1; 655 656 r = vhost_verify_ring_mappings(dev, start_addr, size); 657 assert(r >= 0); 658 } 659 660 if (!dev->log_enabled) { 661 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 662 if (r < 0) { 663 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 664 } 665 dev->memory_changed = false; 666 return; 667 } 668 log_size = vhost_get_log_size(dev); 669 /* We allocate an extra 4K bytes to log, 670 * to reduce the * number of reallocations. */ 671 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 672 /* To log more, must increase log size before table update. */ 673 if (dev->log_size < log_size) { 674 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 675 } 676 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 677 if (r < 0) { 678 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 679 } 680 /* To log less, can only decrease log size after table update. */ 681 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 682 vhost_dev_log_resize(dev, log_size); 683 } 684 dev->memory_changed = false; 685 } 686 687 static void vhost_region_add(MemoryListener *listener, 688 MemoryRegionSection *section) 689 { 690 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 691 memory_listener); 692 693 if (!vhost_section(section)) { 694 return; 695 } 696 697 trace_vhost_region_add(dev, section->mr->name ?: NULL); 698 ++dev->n_mem_sections; 699 dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections, 700 dev->n_mem_sections); 701 dev->mem_sections[dev->n_mem_sections - 1] = *section; 702 memory_region_ref(section->mr); 703 vhost_set_memory(listener, section, true); 704 } 705 706 static void vhost_region_del(MemoryListener *listener, 707 MemoryRegionSection *section) 708 { 709 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 710 memory_listener); 711 int i; 712 713 if (!vhost_section(section)) { 714 return; 715 } 716 717 trace_vhost_region_del(dev, section->mr->name ?: NULL); 718 vhost_set_memory(listener, section, false); 719 memory_region_unref(section->mr); 720 for (i = 0; i < dev->n_mem_sections; ++i) { 721 if (dev->mem_sections[i].offset_within_address_space 722 == section->offset_within_address_space) { 723 --dev->n_mem_sections; 724 memmove(&dev->mem_sections[i], &dev->mem_sections[i+1], 725 (dev->n_mem_sections - i) * sizeof(*dev->mem_sections)); 726 break; 727 } 728 } 729 } 730 731 static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 732 { 733 struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n); 734 struct vhost_dev *hdev = iommu->hdev; 735 hwaddr iova = iotlb->iova + iommu->iommu_offset; 736 737 if (vhost_backend_invalidate_device_iotlb(hdev, iova, 738 iotlb->addr_mask + 1)) { 739 error_report("Fail to invalidate device iotlb"); 740 } 741 } 742 743 static void vhost_iommu_region_add(MemoryListener *listener, 744 MemoryRegionSection *section) 745 { 746 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 747 iommu_listener); 748 struct vhost_iommu *iommu; 749 Int128 end; 750 751 if (!memory_region_is_iommu(section->mr)) { 752 return; 753 } 754 755 trace_vhost_iommu_region_add(dev, section->mr->name ?: NULL); 756 757 iommu = g_malloc0(sizeof(*iommu)); 758 end = int128_add(int128_make64(section->offset_within_region), 759 section->size); 760 end = int128_sub(end, int128_one()); 761 iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, 762 IOMMU_NOTIFIER_UNMAP, 763 section->offset_within_region, 764 int128_get64(end)); 765 iommu->mr = section->mr; 766 iommu->iommu_offset = section->offset_within_address_space - 767 section->offset_within_region; 768 iommu->hdev = dev; 769 memory_region_register_iommu_notifier(section->mr, &iommu->n); 770 QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next); 771 /* TODO: can replay help performance here? */ 772 } 773 774 static void vhost_iommu_region_del(MemoryListener *listener, 775 MemoryRegionSection *section) 776 { 777 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 778 iommu_listener); 779 struct vhost_iommu *iommu; 780 781 if (!memory_region_is_iommu(section->mr)) { 782 return; 783 } 784 785 trace_vhost_iommu_region_del(dev, section->mr->name ?: NULL); 786 787 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 788 if (iommu->mr == section->mr && 789 iommu->n.start == section->offset_within_region) { 790 memory_region_unregister_iommu_notifier(iommu->mr, 791 &iommu->n); 792 QLIST_REMOVE(iommu, iommu_next); 793 g_free(iommu); 794 break; 795 } 796 } 797 } 798 799 static void vhost_region_nop(MemoryListener *listener, 800 MemoryRegionSection *section) 801 { 802 } 803 804 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 805 struct vhost_virtqueue *vq, 806 unsigned idx, bool enable_log) 807 { 808 struct vhost_vring_addr addr = { 809 .index = idx, 810 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 811 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 812 .used_user_addr = (uint64_t)(unsigned long)vq->used, 813 .log_guest_addr = vq->used_phys, 814 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 815 }; 816 int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 817 if (r < 0) { 818 VHOST_OPS_DEBUG("vhost_set_vring_addr failed"); 819 return -errno; 820 } 821 return 0; 822 } 823 824 static int vhost_dev_set_features(struct vhost_dev *dev, 825 bool enable_log) 826 { 827 uint64_t features = dev->acked_features; 828 int r; 829 if (enable_log) { 830 features |= 0x1ULL << VHOST_F_LOG_ALL; 831 } 832 r = dev->vhost_ops->vhost_set_features(dev, features); 833 if (r < 0) { 834 VHOST_OPS_DEBUG("vhost_set_features failed"); 835 } 836 return r < 0 ? -errno : 0; 837 } 838 839 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 840 { 841 int r, i, idx; 842 r = vhost_dev_set_features(dev, enable_log); 843 if (r < 0) { 844 goto err_features; 845 } 846 for (i = 0; i < dev->nvqs; ++i) { 847 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 848 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 849 enable_log); 850 if (r < 0) { 851 goto err_vq; 852 } 853 } 854 return 0; 855 err_vq: 856 for (; i >= 0; --i) { 857 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 858 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 859 dev->log_enabled); 860 } 861 vhost_dev_set_features(dev, dev->log_enabled); 862 err_features: 863 return r; 864 } 865 866 static int vhost_migration_log(MemoryListener *listener, int enable) 867 { 868 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 869 memory_listener); 870 int r; 871 if (!!enable == dev->log_enabled) { 872 return 0; 873 } 874 if (!dev->started) { 875 dev->log_enabled = enable; 876 return 0; 877 } 878 if (!enable) { 879 r = vhost_dev_set_log(dev, false); 880 if (r < 0) { 881 return r; 882 } 883 vhost_log_put(dev, false); 884 } else { 885 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 886 r = vhost_dev_set_log(dev, true); 887 if (r < 0) { 888 return r; 889 } 890 } 891 dev->log_enabled = enable; 892 return 0; 893 } 894 895 static void vhost_log_global_start(MemoryListener *listener) 896 { 897 int r; 898 899 r = vhost_migration_log(listener, true); 900 if (r < 0) { 901 abort(); 902 } 903 } 904 905 static void vhost_log_global_stop(MemoryListener *listener) 906 { 907 int r; 908 909 r = vhost_migration_log(listener, false); 910 if (r < 0) { 911 abort(); 912 } 913 } 914 915 static void vhost_log_start(MemoryListener *listener, 916 MemoryRegionSection *section, 917 int old, int new) 918 { 919 /* FIXME: implement */ 920 } 921 922 static void vhost_log_stop(MemoryListener *listener, 923 MemoryRegionSection *section, 924 int old, int new) 925 { 926 /* FIXME: implement */ 927 } 928 929 /* The vhost driver natively knows how to handle the vrings of non 930 * cross-endian legacy devices and modern devices. Only legacy devices 931 * exposed to a bi-endian guest may require the vhost driver to use a 932 * specific endianness. 933 */ 934 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 935 { 936 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 937 return false; 938 } 939 #ifdef HOST_WORDS_BIGENDIAN 940 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 941 #else 942 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 943 #endif 944 } 945 946 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 947 bool is_big_endian, 948 int vhost_vq_index) 949 { 950 struct vhost_vring_state s = { 951 .index = vhost_vq_index, 952 .num = is_big_endian 953 }; 954 955 if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { 956 return 0; 957 } 958 959 VHOST_OPS_DEBUG("vhost_set_vring_endian failed"); 960 if (errno == ENOTTY) { 961 error_report("vhost does not support cross-endian"); 962 return -ENOSYS; 963 } 964 965 return -errno; 966 } 967 968 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 969 uint64_t gpa, uint64_t *uaddr, 970 uint64_t *len) 971 { 972 int i; 973 974 for (i = 0; i < hdev->mem->nregions; i++) { 975 struct vhost_memory_region *reg = hdev->mem->regions + i; 976 977 if (gpa >= reg->guest_phys_addr && 978 reg->guest_phys_addr + reg->memory_size > gpa) { 979 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 980 *len = reg->guest_phys_addr + reg->memory_size - gpa; 981 return 0; 982 } 983 } 984 985 return -EFAULT; 986 } 987 988 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 989 { 990 IOMMUTLBEntry iotlb; 991 uint64_t uaddr, len; 992 int ret = -EFAULT; 993 994 rcu_read_lock(); 995 996 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 997 iova, write); 998 if (iotlb.target_as != NULL) { 999 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 1000 &uaddr, &len); 1001 if (ret) { 1002 error_report("Fail to lookup the translated address " 1003 "%"PRIx64, iotlb.translated_addr); 1004 goto out; 1005 } 1006 1007 len = MIN(iotlb.addr_mask + 1, len); 1008 iova = iova & ~iotlb.addr_mask; 1009 1010 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 1011 len, iotlb.perm); 1012 if (ret) { 1013 error_report("Fail to update device iotlb"); 1014 goto out; 1015 } 1016 } 1017 out: 1018 rcu_read_unlock(); 1019 1020 return ret; 1021 } 1022 1023 static int vhost_virtqueue_start(struct vhost_dev *dev, 1024 struct VirtIODevice *vdev, 1025 struct vhost_virtqueue *vq, 1026 unsigned idx) 1027 { 1028 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1029 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1030 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1031 hwaddr s, l, a; 1032 int r; 1033 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1034 struct vhost_vring_file file = { 1035 .index = vhost_vq_index 1036 }; 1037 struct vhost_vring_state state = { 1038 .index = vhost_vq_index 1039 }; 1040 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1041 1042 1043 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1044 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1045 if (r) { 1046 VHOST_OPS_DEBUG("vhost_set_vring_num failed"); 1047 return -errno; 1048 } 1049 1050 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1051 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1052 if (r) { 1053 VHOST_OPS_DEBUG("vhost_set_vring_base failed"); 1054 return -errno; 1055 } 1056 1057 if (vhost_needs_vring_endian(vdev)) { 1058 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1059 virtio_is_big_endian(vdev), 1060 vhost_vq_index); 1061 if (r) { 1062 return -errno; 1063 } 1064 } 1065 1066 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1067 vq->desc_phys = a = virtio_queue_get_desc_addr(vdev, idx); 1068 vq->desc = vhost_memory_map(dev, a, &l, 0); 1069 if (!vq->desc || l != s) { 1070 r = -ENOMEM; 1071 goto fail_alloc_desc; 1072 } 1073 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1074 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1075 vq->avail = vhost_memory_map(dev, a, &l, 0); 1076 if (!vq->avail || l != s) { 1077 r = -ENOMEM; 1078 goto fail_alloc_avail; 1079 } 1080 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1081 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1082 vq->used = vhost_memory_map(dev, a, &l, 1); 1083 if (!vq->used || l != s) { 1084 r = -ENOMEM; 1085 goto fail_alloc_used; 1086 } 1087 1088 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1089 if (r < 0) { 1090 r = -errno; 1091 goto fail_alloc; 1092 } 1093 1094 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1095 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1096 if (r) { 1097 VHOST_OPS_DEBUG("vhost_set_vring_kick failed"); 1098 r = -errno; 1099 goto fail_kick; 1100 } 1101 1102 /* Clear and discard previous events if any. */ 1103 event_notifier_test_and_clear(&vq->masked_notifier); 1104 1105 /* Init vring in unmasked state, unless guest_notifier_mask 1106 * will do it later. 1107 */ 1108 if (!vdev->use_guest_notifier_mask) { 1109 /* TODO: check and handle errors. */ 1110 vhost_virtqueue_mask(dev, vdev, idx, false); 1111 } 1112 1113 if (k->query_guest_notifiers && 1114 k->query_guest_notifiers(qbus->parent) && 1115 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1116 file.fd = -1; 1117 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1118 if (r) { 1119 goto fail_vector; 1120 } 1121 } 1122 1123 return 0; 1124 1125 fail_vector: 1126 fail_kick: 1127 fail_alloc: 1128 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1129 0, 0); 1130 fail_alloc_used: 1131 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1132 0, 0); 1133 fail_alloc_avail: 1134 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1135 0, 0); 1136 fail_alloc_desc: 1137 return r; 1138 } 1139 1140 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1141 struct VirtIODevice *vdev, 1142 struct vhost_virtqueue *vq, 1143 unsigned idx) 1144 { 1145 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1146 struct vhost_vring_state state = { 1147 .index = vhost_vq_index, 1148 }; 1149 int r; 1150 1151 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1152 if (r < 0) { 1153 VHOST_OPS_DEBUG("vhost VQ %d ring restore failed: %d", idx, r); 1154 /* Connection to the backend is broken, so let's sync internal 1155 * last avail idx to the device used idx. 1156 */ 1157 virtio_queue_restore_last_avail_idx(vdev, idx); 1158 } else { 1159 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1160 } 1161 virtio_queue_invalidate_signalled_used(vdev, idx); 1162 virtio_queue_update_used_idx(vdev, idx); 1163 1164 /* In the cross-endian case, we need to reset the vring endianness to 1165 * native as legacy devices expect so by default. 1166 */ 1167 if (vhost_needs_vring_endian(vdev)) { 1168 vhost_virtqueue_set_vring_endian_legacy(dev, 1169 !virtio_is_big_endian(vdev), 1170 vhost_vq_index); 1171 } 1172 1173 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1174 1, virtio_queue_get_used_size(vdev, idx)); 1175 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1176 0, virtio_queue_get_avail_size(vdev, idx)); 1177 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1178 0, virtio_queue_get_desc_size(vdev, idx)); 1179 } 1180 1181 static void vhost_eventfd_add(MemoryListener *listener, 1182 MemoryRegionSection *section, 1183 bool match_data, uint64_t data, EventNotifier *e) 1184 { 1185 } 1186 1187 static void vhost_eventfd_del(MemoryListener *listener, 1188 MemoryRegionSection *section, 1189 bool match_data, uint64_t data, EventNotifier *e) 1190 { 1191 } 1192 1193 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1194 int n, uint32_t timeout) 1195 { 1196 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1197 struct vhost_vring_state state = { 1198 .index = vhost_vq_index, 1199 .num = timeout, 1200 }; 1201 int r; 1202 1203 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1204 return -EINVAL; 1205 } 1206 1207 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1208 if (r) { 1209 VHOST_OPS_DEBUG("vhost_set_vring_busyloop_timeout failed"); 1210 return r; 1211 } 1212 1213 return 0; 1214 } 1215 1216 static int vhost_virtqueue_init(struct vhost_dev *dev, 1217 struct vhost_virtqueue *vq, int n) 1218 { 1219 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1220 struct vhost_vring_file file = { 1221 .index = vhost_vq_index, 1222 }; 1223 int r = event_notifier_init(&vq->masked_notifier, 0); 1224 if (r < 0) { 1225 return r; 1226 } 1227 1228 file.fd = event_notifier_get_fd(&vq->masked_notifier); 1229 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1230 if (r) { 1231 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1232 r = -errno; 1233 goto fail_call; 1234 } 1235 1236 vq->dev = dev; 1237 1238 return 0; 1239 fail_call: 1240 event_notifier_cleanup(&vq->masked_notifier); 1241 return r; 1242 } 1243 1244 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1245 { 1246 event_notifier_cleanup(&vq->masked_notifier); 1247 } 1248 1249 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1250 VhostBackendType backend_type, uint32_t busyloop_timeout) 1251 { 1252 uint64_t features; 1253 int i, r, n_initialized_vqs = 0; 1254 Error *local_err = NULL; 1255 1256 hdev->vdev = NULL; 1257 hdev->migration_blocker = NULL; 1258 1259 r = vhost_set_backend_type(hdev, backend_type); 1260 assert(r >= 0); 1261 1262 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque); 1263 if (r < 0) { 1264 goto fail; 1265 } 1266 1267 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1268 error_report("vhost backend memory slots limit is less" 1269 " than current number of present memory slots"); 1270 r = -1; 1271 goto fail; 1272 } 1273 1274 r = hdev->vhost_ops->vhost_set_owner(hdev); 1275 if (r < 0) { 1276 VHOST_OPS_DEBUG("vhost_set_owner failed"); 1277 goto fail; 1278 } 1279 1280 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1281 if (r < 0) { 1282 VHOST_OPS_DEBUG("vhost_get_features failed"); 1283 goto fail; 1284 } 1285 1286 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1287 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1288 if (r < 0) { 1289 goto fail; 1290 } 1291 } 1292 1293 if (busyloop_timeout) { 1294 for (i = 0; i < hdev->nvqs; ++i) { 1295 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1296 busyloop_timeout); 1297 if (r < 0) { 1298 goto fail_busyloop; 1299 } 1300 } 1301 } 1302 1303 hdev->features = features; 1304 1305 hdev->memory_listener = (MemoryListener) { 1306 .begin = vhost_begin, 1307 .commit = vhost_commit, 1308 .region_add = vhost_region_add, 1309 .region_del = vhost_region_del, 1310 .region_nop = vhost_region_nop, 1311 .log_start = vhost_log_start, 1312 .log_stop = vhost_log_stop, 1313 .log_sync = vhost_log_sync, 1314 .log_global_start = vhost_log_global_start, 1315 .log_global_stop = vhost_log_global_stop, 1316 .eventfd_add = vhost_eventfd_add, 1317 .eventfd_del = vhost_eventfd_del, 1318 .priority = 10 1319 }; 1320 1321 hdev->iommu_listener = (MemoryListener) { 1322 .region_add = vhost_iommu_region_add, 1323 .region_del = vhost_iommu_region_del, 1324 }; 1325 1326 if (hdev->migration_blocker == NULL) { 1327 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1328 error_setg(&hdev->migration_blocker, 1329 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1330 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_check()) { 1331 error_setg(&hdev->migration_blocker, 1332 "Migration disabled: failed to allocate shared memory"); 1333 } 1334 } 1335 1336 if (hdev->migration_blocker != NULL) { 1337 r = migrate_add_blocker(hdev->migration_blocker, &local_err); 1338 if (local_err) { 1339 error_report_err(local_err); 1340 error_free(hdev->migration_blocker); 1341 goto fail_busyloop; 1342 } 1343 } 1344 1345 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1346 hdev->n_mem_sections = 0; 1347 hdev->mem_sections = NULL; 1348 hdev->log = NULL; 1349 hdev->log_size = 0; 1350 hdev->log_enabled = false; 1351 hdev->started = false; 1352 hdev->memory_changed = false; 1353 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1354 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1355 return 0; 1356 1357 fail_busyloop: 1358 while (--i >= 0) { 1359 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1360 } 1361 fail: 1362 hdev->nvqs = n_initialized_vqs; 1363 vhost_dev_cleanup(hdev); 1364 return r; 1365 } 1366 1367 void vhost_dev_cleanup(struct vhost_dev *hdev) 1368 { 1369 int i; 1370 1371 for (i = 0; i < hdev->nvqs; ++i) { 1372 vhost_virtqueue_cleanup(hdev->vqs + i); 1373 } 1374 if (hdev->mem) { 1375 /* those are only safe after successful init */ 1376 memory_listener_unregister(&hdev->memory_listener); 1377 QLIST_REMOVE(hdev, entry); 1378 } 1379 if (hdev->migration_blocker) { 1380 migrate_del_blocker(hdev->migration_blocker); 1381 error_free(hdev->migration_blocker); 1382 } 1383 g_free(hdev->mem); 1384 g_free(hdev->mem_sections); 1385 if (hdev->vhost_ops) { 1386 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1387 } 1388 assert(!hdev->log); 1389 1390 memset(hdev, 0, sizeof(struct vhost_dev)); 1391 } 1392 1393 /* Stop processing guest IO notifications in qemu. 1394 * Start processing them in vhost in kernel. 1395 */ 1396 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1397 { 1398 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1399 int i, r, e; 1400 1401 /* We will pass the notifiers to the kernel, make sure that QEMU 1402 * doesn't interfere. 1403 */ 1404 r = virtio_device_grab_ioeventfd(vdev); 1405 if (r < 0) { 1406 error_report("binding does not support host notifiers"); 1407 goto fail; 1408 } 1409 1410 for (i = 0; i < hdev->nvqs; ++i) { 1411 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1412 true); 1413 if (r < 0) { 1414 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1415 goto fail_vq; 1416 } 1417 } 1418 1419 return 0; 1420 fail_vq: 1421 while (--i >= 0) { 1422 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1423 false); 1424 if (e < 0) { 1425 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1426 } 1427 assert (e >= 0); 1428 } 1429 virtio_device_release_ioeventfd(vdev); 1430 fail: 1431 return r; 1432 } 1433 1434 /* Stop processing guest IO notifications in vhost. 1435 * Start processing them in qemu. 1436 * This might actually run the qemu handlers right away, 1437 * so virtio in qemu must be completely setup when this is called. 1438 */ 1439 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1440 { 1441 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1442 int i, r; 1443 1444 for (i = 0; i < hdev->nvqs; ++i) { 1445 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1446 false); 1447 if (r < 0) { 1448 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1449 } 1450 assert (r >= 0); 1451 } 1452 virtio_device_release_ioeventfd(vdev); 1453 } 1454 1455 /* Test and clear event pending status. 1456 * Should be called after unmask to avoid losing events. 1457 */ 1458 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1459 { 1460 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1461 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1462 return event_notifier_test_and_clear(&vq->masked_notifier); 1463 } 1464 1465 /* Mask/unmask events from this vq. */ 1466 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1467 bool mask) 1468 { 1469 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1470 int r, index = n - hdev->vq_index; 1471 struct vhost_vring_file file; 1472 1473 /* should only be called after backend is connected */ 1474 assert(hdev->vhost_ops); 1475 1476 if (mask) { 1477 assert(vdev->use_guest_notifier_mask); 1478 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1479 } else { 1480 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1481 } 1482 1483 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1484 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1485 if (r < 0) { 1486 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1487 } 1488 } 1489 1490 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1491 uint64_t features) 1492 { 1493 const int *bit = feature_bits; 1494 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1495 uint64_t bit_mask = (1ULL << *bit); 1496 if (!(hdev->features & bit_mask)) { 1497 features &= ~bit_mask; 1498 } 1499 bit++; 1500 } 1501 return features; 1502 } 1503 1504 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1505 uint64_t features) 1506 { 1507 const int *bit = feature_bits; 1508 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1509 uint64_t bit_mask = (1ULL << *bit); 1510 if (features & bit_mask) { 1511 hdev->acked_features |= bit_mask; 1512 } 1513 bit++; 1514 } 1515 } 1516 1517 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1518 uint32_t config_len) 1519 { 1520 assert(hdev->vhost_ops); 1521 1522 if (hdev->vhost_ops->vhost_get_config) { 1523 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len); 1524 } 1525 1526 return -1; 1527 } 1528 1529 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1530 uint32_t offset, uint32_t size, uint32_t flags) 1531 { 1532 assert(hdev->vhost_ops); 1533 1534 if (hdev->vhost_ops->vhost_set_config) { 1535 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1536 size, flags); 1537 } 1538 1539 return -1; 1540 } 1541 1542 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1543 const VhostDevConfigOps *ops) 1544 { 1545 assert(hdev->vhost_ops); 1546 hdev->config_ops = ops; 1547 } 1548 1549 /* Host notifiers must be enabled at this point. */ 1550 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1551 { 1552 int i, r; 1553 1554 /* should only be called after backend is connected */ 1555 assert(hdev->vhost_ops); 1556 1557 hdev->started = true; 1558 hdev->vdev = vdev; 1559 1560 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1561 if (r < 0) { 1562 goto fail_features; 1563 } 1564 1565 if (vhost_dev_has_iommu(hdev)) { 1566 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1567 } 1568 1569 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1570 if (r < 0) { 1571 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 1572 r = -errno; 1573 goto fail_mem; 1574 } 1575 for (i = 0; i < hdev->nvqs; ++i) { 1576 r = vhost_virtqueue_start(hdev, 1577 vdev, 1578 hdev->vqs + i, 1579 hdev->vq_index + i); 1580 if (r < 0) { 1581 goto fail_vq; 1582 } 1583 } 1584 1585 if (hdev->log_enabled) { 1586 uint64_t log_base; 1587 1588 hdev->log_size = vhost_get_log_size(hdev); 1589 hdev->log = vhost_log_get(hdev->log_size, 1590 vhost_dev_log_is_shared(hdev)); 1591 log_base = (uintptr_t)hdev->log->log; 1592 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1593 hdev->log_size ? log_base : 0, 1594 hdev->log); 1595 if (r < 0) { 1596 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 1597 r = -errno; 1598 goto fail_log; 1599 } 1600 } 1601 1602 if (vhost_dev_has_iommu(hdev)) { 1603 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1604 1605 /* Update used ring information for IOTLB to work correctly, 1606 * vhost-kernel code requires for this.*/ 1607 for (i = 0; i < hdev->nvqs; ++i) { 1608 struct vhost_virtqueue *vq = hdev->vqs + i; 1609 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1610 } 1611 } 1612 return 0; 1613 fail_log: 1614 vhost_log_put(hdev, false); 1615 fail_vq: 1616 while (--i >= 0) { 1617 vhost_virtqueue_stop(hdev, 1618 vdev, 1619 hdev->vqs + i, 1620 hdev->vq_index + i); 1621 } 1622 i = hdev->nvqs; 1623 1624 fail_mem: 1625 fail_features: 1626 1627 hdev->started = false; 1628 return r; 1629 } 1630 1631 /* Host notifiers must be enabled at this point. */ 1632 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1633 { 1634 int i; 1635 1636 /* should only be called after backend is connected */ 1637 assert(hdev->vhost_ops); 1638 1639 for (i = 0; i < hdev->nvqs; ++i) { 1640 vhost_virtqueue_stop(hdev, 1641 vdev, 1642 hdev->vqs + i, 1643 hdev->vq_index + i); 1644 } 1645 1646 if (vhost_dev_has_iommu(hdev)) { 1647 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1648 memory_listener_unregister(&hdev->iommu_listener); 1649 } 1650 vhost_log_put(hdev, true); 1651 hdev->started = false; 1652 hdev->vdev = NULL; 1653 } 1654 1655 int vhost_net_set_backend(struct vhost_dev *hdev, 1656 struct vhost_vring_file *file) 1657 { 1658 if (hdev->vhost_ops->vhost_net_set_backend) { 1659 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1660 } 1661 1662 return -1; 1663 } 1664