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 vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx); 927 vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx); 928 vq->ring = cpu_physical_memory_map(a, &l, 1); 929 if (!vq->ring || l != s) { 930 r = -ENOMEM; 931 goto fail_alloc_ring; 932 } 933 934 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 935 if (r < 0) { 936 r = -errno; 937 goto fail_alloc; 938 } 939 940 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 941 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 942 if (r) { 943 VHOST_OPS_DEBUG("vhost_set_vring_kick failed"); 944 r = -errno; 945 goto fail_kick; 946 } 947 948 /* Clear and discard previous events if any. */ 949 event_notifier_test_and_clear(&vq->masked_notifier); 950 951 /* Init vring in unmasked state, unless guest_notifier_mask 952 * will do it later. 953 */ 954 if (!vdev->use_guest_notifier_mask) { 955 /* TODO: check and handle errors. */ 956 vhost_virtqueue_mask(dev, vdev, idx, false); 957 } 958 959 if (k->query_guest_notifiers && 960 k->query_guest_notifiers(qbus->parent) && 961 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 962 file.fd = -1; 963 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 964 if (r) { 965 goto fail_vector; 966 } 967 } 968 969 return 0; 970 971 fail_vector: 972 fail_kick: 973 fail_alloc: 974 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 975 0, 0); 976 fail_alloc_ring: 977 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 978 0, 0); 979 fail_alloc_used: 980 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 981 0, 0); 982 fail_alloc_avail: 983 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 984 0, 0); 985 fail_alloc_desc: 986 return r; 987 } 988 989 static void vhost_virtqueue_stop(struct vhost_dev *dev, 990 struct VirtIODevice *vdev, 991 struct vhost_virtqueue *vq, 992 unsigned idx) 993 { 994 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 995 struct vhost_vring_state state = { 996 .index = vhost_vq_index, 997 }; 998 int r; 999 1000 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1001 if (r < 0) { 1002 VHOST_OPS_DEBUG("vhost VQ %d ring restore failed: %d", idx, r); 1003 } else { 1004 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1005 } 1006 virtio_queue_invalidate_signalled_used(vdev, idx); 1007 1008 /* In the cross-endian case, we need to reset the vring endianness to 1009 * native as legacy devices expect so by default. 1010 */ 1011 if (vhost_needs_vring_endian(vdev)) { 1012 vhost_virtqueue_set_vring_endian_legacy(dev, 1013 !virtio_is_big_endian(vdev), 1014 vhost_vq_index); 1015 } 1016 1017 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 1018 0, virtio_queue_get_ring_size(vdev, idx)); 1019 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 1020 1, virtio_queue_get_used_size(vdev, idx)); 1021 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 1022 0, virtio_queue_get_avail_size(vdev, idx)); 1023 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 1024 0, virtio_queue_get_desc_size(vdev, idx)); 1025 } 1026 1027 static void vhost_eventfd_add(MemoryListener *listener, 1028 MemoryRegionSection *section, 1029 bool match_data, uint64_t data, EventNotifier *e) 1030 { 1031 } 1032 1033 static void vhost_eventfd_del(MemoryListener *listener, 1034 MemoryRegionSection *section, 1035 bool match_data, uint64_t data, EventNotifier *e) 1036 { 1037 } 1038 1039 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1040 int n, uint32_t timeout) 1041 { 1042 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1043 struct vhost_vring_state state = { 1044 .index = vhost_vq_index, 1045 .num = timeout, 1046 }; 1047 int r; 1048 1049 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1050 return -EINVAL; 1051 } 1052 1053 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1054 if (r) { 1055 VHOST_OPS_DEBUG("vhost_set_vring_busyloop_timeout failed"); 1056 return r; 1057 } 1058 1059 return 0; 1060 } 1061 1062 static int vhost_virtqueue_init(struct vhost_dev *dev, 1063 struct vhost_virtqueue *vq, int n) 1064 { 1065 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1066 struct vhost_vring_file file = { 1067 .index = vhost_vq_index, 1068 }; 1069 int r = event_notifier_init(&vq->masked_notifier, 0); 1070 if (r < 0) { 1071 return r; 1072 } 1073 1074 file.fd = event_notifier_get_fd(&vq->masked_notifier); 1075 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1076 if (r) { 1077 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1078 r = -errno; 1079 goto fail_call; 1080 } 1081 return 0; 1082 fail_call: 1083 event_notifier_cleanup(&vq->masked_notifier); 1084 return r; 1085 } 1086 1087 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1088 { 1089 event_notifier_cleanup(&vq->masked_notifier); 1090 } 1091 1092 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1093 VhostBackendType backend_type, uint32_t busyloop_timeout) 1094 { 1095 uint64_t features; 1096 int i, r, n_initialized_vqs = 0; 1097 1098 hdev->migration_blocker = NULL; 1099 1100 r = vhost_set_backend_type(hdev, backend_type); 1101 assert(r >= 0); 1102 1103 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque); 1104 if (r < 0) { 1105 goto fail; 1106 } 1107 1108 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1109 error_report("vhost backend memory slots limit is less" 1110 " than current number of present memory slots"); 1111 r = -1; 1112 goto fail; 1113 } 1114 1115 r = hdev->vhost_ops->vhost_set_owner(hdev); 1116 if (r < 0) { 1117 VHOST_OPS_DEBUG("vhost_set_owner failed"); 1118 goto fail; 1119 } 1120 1121 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1122 if (r < 0) { 1123 VHOST_OPS_DEBUG("vhost_get_features failed"); 1124 goto fail; 1125 } 1126 1127 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1128 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1129 if (r < 0) { 1130 goto fail; 1131 } 1132 } 1133 1134 if (busyloop_timeout) { 1135 for (i = 0; i < hdev->nvqs; ++i) { 1136 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1137 busyloop_timeout); 1138 if (r < 0) { 1139 goto fail_busyloop; 1140 } 1141 } 1142 } 1143 1144 hdev->features = features; 1145 1146 hdev->memory_listener = (MemoryListener) { 1147 .begin = vhost_begin, 1148 .commit = vhost_commit, 1149 .region_add = vhost_region_add, 1150 .region_del = vhost_region_del, 1151 .region_nop = vhost_region_nop, 1152 .log_start = vhost_log_start, 1153 .log_stop = vhost_log_stop, 1154 .log_sync = vhost_log_sync, 1155 .log_global_start = vhost_log_global_start, 1156 .log_global_stop = vhost_log_global_stop, 1157 .eventfd_add = vhost_eventfd_add, 1158 .eventfd_del = vhost_eventfd_del, 1159 .priority = 10 1160 }; 1161 1162 if (hdev->migration_blocker == NULL) { 1163 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1164 error_setg(&hdev->migration_blocker, 1165 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1166 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_check()) { 1167 error_setg(&hdev->migration_blocker, 1168 "Migration disabled: failed to allocate shared memory"); 1169 } 1170 } 1171 1172 if (hdev->migration_blocker != NULL) { 1173 migrate_add_blocker(hdev->migration_blocker); 1174 } 1175 1176 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1177 hdev->n_mem_sections = 0; 1178 hdev->mem_sections = NULL; 1179 hdev->log = NULL; 1180 hdev->log_size = 0; 1181 hdev->log_enabled = false; 1182 hdev->started = false; 1183 hdev->memory_changed = false; 1184 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1185 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1186 return 0; 1187 1188 fail_busyloop: 1189 while (--i >= 0) { 1190 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1191 } 1192 fail: 1193 hdev->nvqs = n_initialized_vqs; 1194 vhost_dev_cleanup(hdev); 1195 return r; 1196 } 1197 1198 void vhost_dev_cleanup(struct vhost_dev *hdev) 1199 { 1200 int i; 1201 1202 for (i = 0; i < hdev->nvqs; ++i) { 1203 vhost_virtqueue_cleanup(hdev->vqs + i); 1204 } 1205 if (hdev->mem) { 1206 /* those are only safe after successful init */ 1207 memory_listener_unregister(&hdev->memory_listener); 1208 QLIST_REMOVE(hdev, entry); 1209 } 1210 if (hdev->migration_blocker) { 1211 migrate_del_blocker(hdev->migration_blocker); 1212 error_free(hdev->migration_blocker); 1213 } 1214 g_free(hdev->mem); 1215 g_free(hdev->mem_sections); 1216 if (hdev->vhost_ops) { 1217 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1218 } 1219 assert(!hdev->log); 1220 1221 memset(hdev, 0, sizeof(struct vhost_dev)); 1222 } 1223 1224 /* Stop processing guest IO notifications in qemu. 1225 * Start processing them in vhost in kernel. 1226 */ 1227 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1228 { 1229 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1230 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1231 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1232 int i, r, e; 1233 1234 if (!k->ioeventfd_assign) { 1235 error_report("binding does not support host notifiers"); 1236 r = -ENOSYS; 1237 goto fail; 1238 } 1239 1240 virtio_device_stop_ioeventfd(vdev); 1241 for (i = 0; i < hdev->nvqs; ++i) { 1242 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1243 true); 1244 if (r < 0) { 1245 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1246 goto fail_vq; 1247 } 1248 } 1249 1250 return 0; 1251 fail_vq: 1252 while (--i >= 0) { 1253 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1254 false); 1255 if (e < 0) { 1256 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1257 } 1258 assert (e >= 0); 1259 } 1260 virtio_device_start_ioeventfd(vdev); 1261 fail: 1262 return r; 1263 } 1264 1265 /* Stop processing guest IO notifications in vhost. 1266 * Start processing them in qemu. 1267 * This might actually run the qemu handlers right away, 1268 * so virtio in qemu must be completely setup when this is called. 1269 */ 1270 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1271 { 1272 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1273 int i, r; 1274 1275 for (i = 0; i < hdev->nvqs; ++i) { 1276 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1277 false); 1278 if (r < 0) { 1279 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1280 } 1281 assert (r >= 0); 1282 } 1283 virtio_device_start_ioeventfd(vdev); 1284 } 1285 1286 /* Test and clear event pending status. 1287 * Should be called after unmask to avoid losing events. 1288 */ 1289 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1290 { 1291 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1292 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1293 return event_notifier_test_and_clear(&vq->masked_notifier); 1294 } 1295 1296 /* Mask/unmask events from this vq. */ 1297 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1298 bool mask) 1299 { 1300 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1301 int r, index = n - hdev->vq_index; 1302 struct vhost_vring_file file; 1303 1304 /* should only be called after backend is connected */ 1305 assert(hdev->vhost_ops); 1306 1307 if (mask) { 1308 assert(vdev->use_guest_notifier_mask); 1309 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1310 } else { 1311 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1312 } 1313 1314 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1315 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1316 if (r < 0) { 1317 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1318 } 1319 } 1320 1321 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1322 uint64_t features) 1323 { 1324 const int *bit = feature_bits; 1325 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1326 uint64_t bit_mask = (1ULL << *bit); 1327 if (!(hdev->features & bit_mask)) { 1328 features &= ~bit_mask; 1329 } 1330 bit++; 1331 } 1332 return features; 1333 } 1334 1335 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1336 uint64_t features) 1337 { 1338 const int *bit = feature_bits; 1339 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1340 uint64_t bit_mask = (1ULL << *bit); 1341 if (features & bit_mask) { 1342 hdev->acked_features |= bit_mask; 1343 } 1344 bit++; 1345 } 1346 } 1347 1348 /* Host notifiers must be enabled at this point. */ 1349 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1350 { 1351 int i, r; 1352 1353 /* should only be called after backend is connected */ 1354 assert(hdev->vhost_ops); 1355 1356 hdev->started = true; 1357 1358 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1359 if (r < 0) { 1360 goto fail_features; 1361 } 1362 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1363 if (r < 0) { 1364 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 1365 r = -errno; 1366 goto fail_mem; 1367 } 1368 for (i = 0; i < hdev->nvqs; ++i) { 1369 r = vhost_virtqueue_start(hdev, 1370 vdev, 1371 hdev->vqs + i, 1372 hdev->vq_index + i); 1373 if (r < 0) { 1374 goto fail_vq; 1375 } 1376 } 1377 1378 if (hdev->log_enabled) { 1379 uint64_t log_base; 1380 1381 hdev->log_size = vhost_get_log_size(hdev); 1382 hdev->log = vhost_log_get(hdev->log_size, 1383 vhost_dev_log_is_shared(hdev)); 1384 log_base = (uintptr_t)hdev->log->log; 1385 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1386 hdev->log_size ? log_base : 0, 1387 hdev->log); 1388 if (r < 0) { 1389 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 1390 r = -errno; 1391 goto fail_log; 1392 } 1393 } 1394 1395 return 0; 1396 fail_log: 1397 vhost_log_put(hdev, false); 1398 fail_vq: 1399 while (--i >= 0) { 1400 vhost_virtqueue_stop(hdev, 1401 vdev, 1402 hdev->vqs + i, 1403 hdev->vq_index + i); 1404 } 1405 i = hdev->nvqs; 1406 fail_mem: 1407 fail_features: 1408 1409 hdev->started = false; 1410 return r; 1411 } 1412 1413 /* Host notifiers must be enabled at this point. */ 1414 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1415 { 1416 int i; 1417 1418 /* should only be called after backend is connected */ 1419 assert(hdev->vhost_ops); 1420 1421 for (i = 0; i < hdev->nvqs; ++i) { 1422 vhost_virtqueue_stop(hdev, 1423 vdev, 1424 hdev->vqs + i, 1425 hdev->vq_index + i); 1426 } 1427 1428 vhost_log_put(hdev, true); 1429 hdev->started = false; 1430 } 1431 1432 int vhost_net_set_backend(struct vhost_dev *hdev, 1433 struct vhost_vring_file *file) 1434 { 1435 if (hdev->vhost_ops->vhost_net_set_backend) { 1436 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1437 } 1438 1439 return -1; 1440 } 1441