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