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 "hw/virtio/vhost.h" 17 #include "hw/hw.h" 18 #include "qemu/atomic.h" 19 #include "qemu/range.h" 20 #include "qemu/error-report.h" 21 #include "qemu/memfd.h" 22 #include <linux/vhost.h> 23 #include "exec/address-spaces.h" 24 #include "hw/virtio/virtio-bus.h" 25 #include "hw/virtio/virtio-access.h" 26 #include "migration/migration.h" 27 28 static struct vhost_log *vhost_log; 29 static struct vhost_log *vhost_log_shm; 30 31 static unsigned int used_memslots; 32 static QLIST_HEAD(, vhost_dev) vhost_devices = 33 QLIST_HEAD_INITIALIZER(vhost_devices); 34 35 bool vhost_has_free_slot(void) 36 { 37 unsigned int slots_limit = ~0U; 38 struct vhost_dev *hdev; 39 40 QLIST_FOREACH(hdev, &vhost_devices, entry) { 41 unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 42 slots_limit = MIN(slots_limit, r); 43 } 44 return slots_limit > used_memslots; 45 } 46 47 static void vhost_dev_sync_region(struct vhost_dev *dev, 48 MemoryRegionSection *section, 49 uint64_t mfirst, uint64_t mlast, 50 uint64_t rfirst, uint64_t rlast) 51 { 52 vhost_log_chunk_t *log = dev->log->log; 53 54 uint64_t start = MAX(mfirst, rfirst); 55 uint64_t end = MIN(mlast, rlast); 56 vhost_log_chunk_t *from = log + start / VHOST_LOG_CHUNK; 57 vhost_log_chunk_t *to = log + end / VHOST_LOG_CHUNK + 1; 58 uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK; 59 60 if (end < start) { 61 return; 62 } 63 assert(end / VHOST_LOG_CHUNK < dev->log_size); 64 assert(start / VHOST_LOG_CHUNK < dev->log_size); 65 66 for (;from < to; ++from) { 67 vhost_log_chunk_t log; 68 /* We first check with non-atomic: much cheaper, 69 * and we expect non-dirty to be the common case. */ 70 if (!*from) { 71 addr += VHOST_LOG_CHUNK; 72 continue; 73 } 74 /* Data must be read atomically. We don't really need barrier semantics 75 * but it's easier to use atomic_* than roll our own. */ 76 log = atomic_xchg(from, 0); 77 while (log) { 78 int bit = ctzl(log); 79 hwaddr page_addr; 80 hwaddr section_offset; 81 hwaddr mr_offset; 82 page_addr = addr + bit * VHOST_LOG_PAGE; 83 section_offset = page_addr - section->offset_within_address_space; 84 mr_offset = section_offset + section->offset_within_region; 85 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 86 log &= ~(0x1ull << bit); 87 } 88 addr += VHOST_LOG_CHUNK; 89 } 90 } 91 92 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 93 MemoryRegionSection *section, 94 hwaddr first, 95 hwaddr last) 96 { 97 int i; 98 hwaddr start_addr; 99 hwaddr end_addr; 100 101 if (!dev->log_enabled || !dev->started) { 102 return 0; 103 } 104 start_addr = section->offset_within_address_space; 105 end_addr = range_get_last(start_addr, int128_get64(section->size)); 106 start_addr = MAX(first, start_addr); 107 end_addr = MIN(last, end_addr); 108 109 for (i = 0; i < dev->mem->nregions; ++i) { 110 struct vhost_memory_region *reg = dev->mem->regions + i; 111 vhost_dev_sync_region(dev, section, start_addr, end_addr, 112 reg->guest_phys_addr, 113 range_get_last(reg->guest_phys_addr, 114 reg->memory_size)); 115 } 116 for (i = 0; i < dev->nvqs; ++i) { 117 struct vhost_virtqueue *vq = dev->vqs + i; 118 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 119 range_get_last(vq->used_phys, vq->used_size)); 120 } 121 return 0; 122 } 123 124 static void vhost_log_sync(MemoryListener *listener, 125 MemoryRegionSection *section) 126 { 127 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 128 memory_listener); 129 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 130 } 131 132 static void vhost_log_sync_range(struct vhost_dev *dev, 133 hwaddr first, hwaddr last) 134 { 135 int i; 136 /* FIXME: this is N^2 in number of sections */ 137 for (i = 0; i < dev->n_mem_sections; ++i) { 138 MemoryRegionSection *section = &dev->mem_sections[i]; 139 vhost_sync_dirty_bitmap(dev, section, first, last); 140 } 141 } 142 143 /* Assign/unassign. Keep an unsorted array of non-overlapping 144 * memory regions in dev->mem. */ 145 static void vhost_dev_unassign_memory(struct vhost_dev *dev, 146 uint64_t start_addr, 147 uint64_t size) 148 { 149 int from, to, n = dev->mem->nregions; 150 /* Track overlapping/split regions for sanity checking. */ 151 int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0; 152 153 for (from = 0, to = 0; from < n; ++from, ++to) { 154 struct vhost_memory_region *reg = dev->mem->regions + to; 155 uint64_t reglast; 156 uint64_t memlast; 157 uint64_t change; 158 159 /* clone old region */ 160 if (to != from) { 161 memcpy(reg, dev->mem->regions + from, sizeof *reg); 162 } 163 164 /* No overlap is simple */ 165 if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size, 166 start_addr, size)) { 167 continue; 168 } 169 170 /* Split only happens if supplied region 171 * is in the middle of an existing one. Thus it can not 172 * overlap with any other existing region. */ 173 assert(!split); 174 175 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 176 memlast = range_get_last(start_addr, size); 177 178 /* Remove whole region */ 179 if (start_addr <= reg->guest_phys_addr && memlast >= reglast) { 180 --dev->mem->nregions; 181 --to; 182 ++overlap_middle; 183 continue; 184 } 185 186 /* Shrink region */ 187 if (memlast >= reglast) { 188 reg->memory_size = start_addr - reg->guest_phys_addr; 189 assert(reg->memory_size); 190 assert(!overlap_end); 191 ++overlap_end; 192 continue; 193 } 194 195 /* Shift region */ 196 if (start_addr <= reg->guest_phys_addr) { 197 change = memlast + 1 - reg->guest_phys_addr; 198 reg->memory_size -= change; 199 reg->guest_phys_addr += change; 200 reg->userspace_addr += change; 201 assert(reg->memory_size); 202 assert(!overlap_start); 203 ++overlap_start; 204 continue; 205 } 206 207 /* This only happens if supplied region 208 * is in the middle of an existing one. Thus it can not 209 * overlap with any other existing region. */ 210 assert(!overlap_start); 211 assert(!overlap_end); 212 assert(!overlap_middle); 213 /* Split region: shrink first part, shift second part. */ 214 memcpy(dev->mem->regions + n, reg, sizeof *reg); 215 reg->memory_size = start_addr - reg->guest_phys_addr; 216 assert(reg->memory_size); 217 change = memlast + 1 - reg->guest_phys_addr; 218 reg = dev->mem->regions + n; 219 reg->memory_size -= change; 220 assert(reg->memory_size); 221 reg->guest_phys_addr += change; 222 reg->userspace_addr += change; 223 /* Never add more than 1 region */ 224 assert(dev->mem->nregions == n); 225 ++dev->mem->nregions; 226 ++split; 227 } 228 } 229 230 /* Called after unassign, so no regions overlap the given range. */ 231 static void vhost_dev_assign_memory(struct vhost_dev *dev, 232 uint64_t start_addr, 233 uint64_t size, 234 uint64_t uaddr) 235 { 236 int from, to; 237 struct vhost_memory_region *merged = NULL; 238 for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) { 239 struct vhost_memory_region *reg = dev->mem->regions + to; 240 uint64_t prlast, urlast; 241 uint64_t pmlast, umlast; 242 uint64_t s, e, u; 243 244 /* clone old region */ 245 if (to != from) { 246 memcpy(reg, dev->mem->regions + from, sizeof *reg); 247 } 248 prlast = range_get_last(reg->guest_phys_addr, reg->memory_size); 249 pmlast = range_get_last(start_addr, size); 250 urlast = range_get_last(reg->userspace_addr, reg->memory_size); 251 umlast = range_get_last(uaddr, size); 252 253 /* check for overlapping regions: should never happen. */ 254 assert(prlast < start_addr || pmlast < reg->guest_phys_addr); 255 /* Not an adjacent or overlapping region - do not merge. */ 256 if ((prlast + 1 != start_addr || urlast + 1 != uaddr) && 257 (pmlast + 1 != reg->guest_phys_addr || 258 umlast + 1 != reg->userspace_addr)) { 259 continue; 260 } 261 262 if (merged) { 263 --to; 264 assert(to >= 0); 265 } else { 266 merged = reg; 267 } 268 u = MIN(uaddr, reg->userspace_addr); 269 s = MIN(start_addr, reg->guest_phys_addr); 270 e = MAX(pmlast, prlast); 271 uaddr = merged->userspace_addr = u; 272 start_addr = merged->guest_phys_addr = s; 273 size = merged->memory_size = e - s + 1; 274 assert(merged->memory_size); 275 } 276 277 if (!merged) { 278 struct vhost_memory_region *reg = dev->mem->regions + to; 279 memset(reg, 0, sizeof *reg); 280 reg->memory_size = size; 281 assert(reg->memory_size); 282 reg->guest_phys_addr = start_addr; 283 reg->userspace_addr = uaddr; 284 ++to; 285 } 286 assert(to <= dev->mem->nregions + 1); 287 dev->mem->nregions = to; 288 } 289 290 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 291 { 292 uint64_t log_size = 0; 293 int i; 294 for (i = 0; i < dev->mem->nregions; ++i) { 295 struct vhost_memory_region *reg = dev->mem->regions + i; 296 uint64_t last = range_get_last(reg->guest_phys_addr, 297 reg->memory_size); 298 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 299 } 300 for (i = 0; i < dev->nvqs; ++i) { 301 struct vhost_virtqueue *vq = dev->vqs + i; 302 uint64_t last = vq->used_phys + vq->used_size - 1; 303 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 304 } 305 return log_size; 306 } 307 308 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 309 { 310 struct vhost_log *log; 311 uint64_t logsize = size * sizeof(*(log->log)); 312 int fd = -1; 313 314 log = g_new0(struct vhost_log, 1); 315 if (share) { 316 log->log = qemu_memfd_alloc("vhost-log", logsize, 317 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 318 &fd); 319 memset(log->log, 0, logsize); 320 } else { 321 log->log = g_malloc0(logsize); 322 } 323 324 log->size = size; 325 log->refcnt = 1; 326 log->fd = fd; 327 328 return log; 329 } 330 331 static struct vhost_log *vhost_log_get(uint64_t size, bool share) 332 { 333 struct vhost_log *log = share ? vhost_log_shm : vhost_log; 334 335 if (!log || log->size != size) { 336 log = vhost_log_alloc(size, share); 337 if (share) { 338 vhost_log_shm = log; 339 } else { 340 vhost_log = log; 341 } 342 } else { 343 ++log->refcnt; 344 } 345 346 return log; 347 } 348 349 static void vhost_log_put(struct vhost_dev *dev, bool sync) 350 { 351 struct vhost_log *log = dev->log; 352 353 if (!log) { 354 return; 355 } 356 357 --log->refcnt; 358 if (log->refcnt == 0) { 359 /* Sync only the range covered by the old log */ 360 if (dev->log_size && sync) { 361 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 362 } 363 364 if (vhost_log == log) { 365 g_free(log->log); 366 vhost_log = NULL; 367 } else if (vhost_log_shm == log) { 368 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 369 log->fd); 370 vhost_log_shm = NULL; 371 } 372 373 g_free(log); 374 } 375 } 376 377 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 378 { 379 return dev->vhost_ops->vhost_requires_shm_log && 380 dev->vhost_ops->vhost_requires_shm_log(dev); 381 } 382 383 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 384 { 385 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 386 uint64_t log_base = (uintptr_t)log->log; 387 int r; 388 389 /* inform backend of log switching, this must be done before 390 releasing the current log, to ensure no logging is lost */ 391 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 392 assert(r >= 0); 393 vhost_log_put(dev, true); 394 dev->log = log; 395 dev->log_size = size; 396 } 397 398 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 399 uint64_t start_addr, 400 uint64_t size) 401 { 402 int i; 403 int r = 0; 404 405 for (i = 0; !r && i < dev->nvqs; ++i) { 406 struct vhost_virtqueue *vq = dev->vqs + i; 407 hwaddr l; 408 void *p; 409 410 if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) { 411 continue; 412 } 413 l = vq->ring_size; 414 p = cpu_physical_memory_map(vq->ring_phys, &l, 1); 415 if (!p || l != vq->ring_size) { 416 fprintf(stderr, "Unable to map ring buffer for ring %d\n", i); 417 r = -ENOMEM; 418 } 419 if (p != vq->ring) { 420 fprintf(stderr, "Ring buffer relocated for ring %d\n", i); 421 r = -EBUSY; 422 } 423 cpu_physical_memory_unmap(p, l, 0, 0); 424 } 425 return r; 426 } 427 428 static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, 429 uint64_t start_addr, 430 uint64_t size) 431 { 432 int i, n = dev->mem->nregions; 433 for (i = 0; i < n; ++i) { 434 struct vhost_memory_region *reg = dev->mem->regions + i; 435 if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, 436 start_addr, size)) { 437 return reg; 438 } 439 } 440 return NULL; 441 } 442 443 static bool vhost_dev_cmp_memory(struct vhost_dev *dev, 444 uint64_t start_addr, 445 uint64_t size, 446 uint64_t uaddr) 447 { 448 struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); 449 uint64_t reglast; 450 uint64_t memlast; 451 452 if (!reg) { 453 return true; 454 } 455 456 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 457 memlast = range_get_last(start_addr, size); 458 459 /* Need to extend region? */ 460 if (start_addr < reg->guest_phys_addr || memlast > reglast) { 461 return true; 462 } 463 /* userspace_addr changed? */ 464 return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; 465 } 466 467 static void vhost_set_memory(MemoryListener *listener, 468 MemoryRegionSection *section, 469 bool add) 470 { 471 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 472 memory_listener); 473 hwaddr start_addr = section->offset_within_address_space; 474 ram_addr_t size = int128_get64(section->size); 475 bool log_dirty = 476 memory_region_get_dirty_log_mask(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); 477 int s = offsetof(struct vhost_memory, regions) + 478 (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; 479 void *ram; 480 481 dev->mem = g_realloc(dev->mem, s); 482 483 if (log_dirty) { 484 add = false; 485 } 486 487 assert(size); 488 489 /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ 490 ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; 491 if (add) { 492 if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { 493 /* Region exists with same address. Nothing to do. */ 494 return; 495 } 496 } else { 497 if (!vhost_dev_find_reg(dev, start_addr, size)) { 498 /* Removing region that we don't access. Nothing to do. */ 499 return; 500 } 501 } 502 503 vhost_dev_unassign_memory(dev, start_addr, size); 504 if (add) { 505 /* Add given mapping, merging adjacent regions if any */ 506 vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); 507 } else { 508 /* Remove old mapping for this memory, if any. */ 509 vhost_dev_unassign_memory(dev, start_addr, size); 510 } 511 dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr); 512 dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1); 513 dev->memory_changed = true; 514 used_memslots = dev->mem->nregions; 515 } 516 517 static bool vhost_section(MemoryRegionSection *section) 518 { 519 return memory_region_is_ram(section->mr); 520 } 521 522 static void vhost_begin(MemoryListener *listener) 523 { 524 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 525 memory_listener); 526 dev->mem_changed_end_addr = 0; 527 dev->mem_changed_start_addr = -1; 528 } 529 530 static void vhost_commit(MemoryListener *listener) 531 { 532 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 533 memory_listener); 534 hwaddr start_addr = 0; 535 ram_addr_t size = 0; 536 uint64_t log_size; 537 int r; 538 539 if (!dev->memory_changed) { 540 return; 541 } 542 if (!dev->started) { 543 return; 544 } 545 if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) { 546 return; 547 } 548 549 if (dev->started) { 550 start_addr = dev->mem_changed_start_addr; 551 size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1; 552 553 r = vhost_verify_ring_mappings(dev, start_addr, size); 554 assert(r >= 0); 555 } 556 557 if (!dev->log_enabled) { 558 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 559 assert(r >= 0); 560 dev->memory_changed = false; 561 return; 562 } 563 log_size = vhost_get_log_size(dev); 564 /* We allocate an extra 4K bytes to log, 565 * to reduce the * number of reallocations. */ 566 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 567 /* To log more, must increase log size before table update. */ 568 if (dev->log_size < log_size) { 569 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 570 } 571 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 572 assert(r >= 0); 573 /* To log less, can only decrease log size after table update. */ 574 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 575 vhost_dev_log_resize(dev, log_size); 576 } 577 dev->memory_changed = false; 578 } 579 580 static void vhost_region_add(MemoryListener *listener, 581 MemoryRegionSection *section) 582 { 583 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 584 memory_listener); 585 586 if (!vhost_section(section)) { 587 return; 588 } 589 590 ++dev->n_mem_sections; 591 dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections, 592 dev->n_mem_sections); 593 dev->mem_sections[dev->n_mem_sections - 1] = *section; 594 memory_region_ref(section->mr); 595 vhost_set_memory(listener, section, true); 596 } 597 598 static void vhost_region_del(MemoryListener *listener, 599 MemoryRegionSection *section) 600 { 601 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 602 memory_listener); 603 int i; 604 605 if (!vhost_section(section)) { 606 return; 607 } 608 609 vhost_set_memory(listener, section, false); 610 memory_region_unref(section->mr); 611 for (i = 0; i < dev->n_mem_sections; ++i) { 612 if (dev->mem_sections[i].offset_within_address_space 613 == section->offset_within_address_space) { 614 --dev->n_mem_sections; 615 memmove(&dev->mem_sections[i], &dev->mem_sections[i+1], 616 (dev->n_mem_sections - i) * sizeof(*dev->mem_sections)); 617 break; 618 } 619 } 620 } 621 622 static void vhost_region_nop(MemoryListener *listener, 623 MemoryRegionSection *section) 624 { 625 } 626 627 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 628 struct vhost_virtqueue *vq, 629 unsigned idx, bool enable_log) 630 { 631 struct vhost_vring_addr addr = { 632 .index = idx, 633 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 634 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 635 .used_user_addr = (uint64_t)(unsigned long)vq->used, 636 .log_guest_addr = vq->used_phys, 637 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 638 }; 639 int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 640 if (r < 0) { 641 return -errno; 642 } 643 return 0; 644 } 645 646 static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log) 647 { 648 uint64_t features = dev->acked_features; 649 int r; 650 if (enable_log) { 651 features |= 0x1ULL << VHOST_F_LOG_ALL; 652 } 653 r = dev->vhost_ops->vhost_set_features(dev, features); 654 return r < 0 ? -errno : 0; 655 } 656 657 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 658 { 659 int r, t, i; 660 r = vhost_dev_set_features(dev, enable_log); 661 if (r < 0) { 662 goto err_features; 663 } 664 for (i = 0; i < dev->nvqs; ++i) { 665 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, 666 enable_log); 667 if (r < 0) { 668 goto err_vq; 669 } 670 } 671 return 0; 672 err_vq: 673 for (; i >= 0; --i) { 674 t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, 675 dev->log_enabled); 676 assert(t >= 0); 677 } 678 t = vhost_dev_set_features(dev, dev->log_enabled); 679 assert(t >= 0); 680 err_features: 681 return r; 682 } 683 684 static int vhost_migration_log(MemoryListener *listener, int enable) 685 { 686 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 687 memory_listener); 688 int r; 689 if (!!enable == dev->log_enabled) { 690 return 0; 691 } 692 if (!dev->started) { 693 dev->log_enabled = enable; 694 return 0; 695 } 696 if (!enable) { 697 r = vhost_dev_set_log(dev, false); 698 if (r < 0) { 699 return r; 700 } 701 vhost_log_put(dev, false); 702 dev->log = NULL; 703 dev->log_size = 0; 704 } else { 705 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 706 r = vhost_dev_set_log(dev, true); 707 if (r < 0) { 708 return r; 709 } 710 } 711 dev->log_enabled = enable; 712 return 0; 713 } 714 715 static void vhost_log_global_start(MemoryListener *listener) 716 { 717 int r; 718 719 r = vhost_migration_log(listener, true); 720 if (r < 0) { 721 abort(); 722 } 723 } 724 725 static void vhost_log_global_stop(MemoryListener *listener) 726 { 727 int r; 728 729 r = vhost_migration_log(listener, false); 730 if (r < 0) { 731 abort(); 732 } 733 } 734 735 static void vhost_log_start(MemoryListener *listener, 736 MemoryRegionSection *section, 737 int old, int new) 738 { 739 /* FIXME: implement */ 740 } 741 742 static void vhost_log_stop(MemoryListener *listener, 743 MemoryRegionSection *section, 744 int old, int new) 745 { 746 /* FIXME: implement */ 747 } 748 749 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 750 bool is_big_endian, 751 int vhost_vq_index) 752 { 753 struct vhost_vring_state s = { 754 .index = vhost_vq_index, 755 .num = is_big_endian 756 }; 757 758 if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { 759 return 0; 760 } 761 762 if (errno == ENOTTY) { 763 error_report("vhost does not support cross-endian"); 764 return -ENOSYS; 765 } 766 767 return -errno; 768 } 769 770 static int vhost_virtqueue_start(struct vhost_dev *dev, 771 struct VirtIODevice *vdev, 772 struct vhost_virtqueue *vq, 773 unsigned idx) 774 { 775 hwaddr s, l, a; 776 int r; 777 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 778 struct vhost_vring_file file = { 779 .index = vhost_vq_index 780 }; 781 struct vhost_vring_state state = { 782 .index = vhost_vq_index 783 }; 784 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 785 786 787 vq->num = state.num = virtio_queue_get_num(vdev, idx); 788 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 789 if (r) { 790 return -errno; 791 } 792 793 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 794 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 795 if (r) { 796 return -errno; 797 } 798 799 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) && 800 virtio_legacy_is_cross_endian(vdev)) { 801 r = vhost_virtqueue_set_vring_endian_legacy(dev, 802 virtio_is_big_endian(vdev), 803 vhost_vq_index); 804 if (r) { 805 return -errno; 806 } 807 } 808 809 s = l = virtio_queue_get_desc_size(vdev, idx); 810 a = virtio_queue_get_desc_addr(vdev, idx); 811 vq->desc = cpu_physical_memory_map(a, &l, 0); 812 if (!vq->desc || l != s) { 813 r = -ENOMEM; 814 goto fail_alloc_desc; 815 } 816 s = l = virtio_queue_get_avail_size(vdev, idx); 817 a = virtio_queue_get_avail_addr(vdev, idx); 818 vq->avail = cpu_physical_memory_map(a, &l, 0); 819 if (!vq->avail || l != s) { 820 r = -ENOMEM; 821 goto fail_alloc_avail; 822 } 823 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 824 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 825 vq->used = cpu_physical_memory_map(a, &l, 1); 826 if (!vq->used || l != s) { 827 r = -ENOMEM; 828 goto fail_alloc_used; 829 } 830 831 vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx); 832 vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx); 833 vq->ring = cpu_physical_memory_map(a, &l, 1); 834 if (!vq->ring || l != s) { 835 r = -ENOMEM; 836 goto fail_alloc_ring; 837 } 838 839 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 840 if (r < 0) { 841 r = -errno; 842 goto fail_alloc; 843 } 844 845 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 846 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 847 if (r) { 848 r = -errno; 849 goto fail_kick; 850 } 851 852 /* Clear and discard previous events if any. */ 853 event_notifier_test_and_clear(&vq->masked_notifier); 854 855 return 0; 856 857 fail_kick: 858 fail_alloc: 859 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 860 0, 0); 861 fail_alloc_ring: 862 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 863 0, 0); 864 fail_alloc_used: 865 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 866 0, 0); 867 fail_alloc_avail: 868 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 869 0, 0); 870 fail_alloc_desc: 871 return r; 872 } 873 874 static void vhost_virtqueue_stop(struct vhost_dev *dev, 875 struct VirtIODevice *vdev, 876 struct vhost_virtqueue *vq, 877 unsigned idx) 878 { 879 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 880 struct vhost_vring_state state = { 881 .index = vhost_vq_index, 882 }; 883 int r; 884 885 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 886 if (r < 0) { 887 fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r); 888 fflush(stderr); 889 } 890 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 891 virtio_queue_invalidate_signalled_used(vdev, idx); 892 893 /* In the cross-endian case, we need to reset the vring endianness to 894 * native as legacy devices expect so by default. 895 */ 896 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) && 897 virtio_legacy_is_cross_endian(vdev)) { 898 r = vhost_virtqueue_set_vring_endian_legacy(dev, 899 !virtio_is_big_endian(vdev), 900 vhost_vq_index); 901 if (r < 0) { 902 error_report("failed to reset vring endianness"); 903 } 904 } 905 906 assert (r >= 0); 907 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 908 0, virtio_queue_get_ring_size(vdev, idx)); 909 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 910 1, virtio_queue_get_used_size(vdev, idx)); 911 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 912 0, virtio_queue_get_avail_size(vdev, idx)); 913 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 914 0, virtio_queue_get_desc_size(vdev, idx)); 915 } 916 917 static void vhost_eventfd_add(MemoryListener *listener, 918 MemoryRegionSection *section, 919 bool match_data, uint64_t data, EventNotifier *e) 920 { 921 } 922 923 static void vhost_eventfd_del(MemoryListener *listener, 924 MemoryRegionSection *section, 925 bool match_data, uint64_t data, EventNotifier *e) 926 { 927 } 928 929 static int vhost_virtqueue_init(struct vhost_dev *dev, 930 struct vhost_virtqueue *vq, int n) 931 { 932 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 933 struct vhost_vring_file file = { 934 .index = vhost_vq_index, 935 }; 936 int r = event_notifier_init(&vq->masked_notifier, 0); 937 if (r < 0) { 938 return r; 939 } 940 941 file.fd = event_notifier_get_fd(&vq->masked_notifier); 942 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 943 if (r) { 944 r = -errno; 945 goto fail_call; 946 } 947 return 0; 948 fail_call: 949 event_notifier_cleanup(&vq->masked_notifier); 950 return r; 951 } 952 953 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 954 { 955 event_notifier_cleanup(&vq->masked_notifier); 956 } 957 958 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 959 VhostBackendType backend_type) 960 { 961 uint64_t features; 962 int i, r; 963 964 hdev->migration_blocker = NULL; 965 966 if (vhost_set_backend_type(hdev, backend_type) < 0) { 967 close((uintptr_t)opaque); 968 return -1; 969 } 970 971 if (hdev->vhost_ops->vhost_backend_init(hdev, opaque) < 0) { 972 close((uintptr_t)opaque); 973 return -errno; 974 } 975 976 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 977 fprintf(stderr, "vhost backend memory slots limit is less" 978 " than current number of present memory slots\n"); 979 close((uintptr_t)opaque); 980 return -1; 981 } 982 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 983 984 r = hdev->vhost_ops->vhost_set_owner(hdev); 985 if (r < 0) { 986 goto fail; 987 } 988 989 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 990 if (r < 0) { 991 goto fail; 992 } 993 994 for (i = 0; i < hdev->nvqs; ++i) { 995 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 996 if (r < 0) { 997 goto fail_vq; 998 } 999 } 1000 hdev->features = features; 1001 1002 hdev->memory_listener = (MemoryListener) { 1003 .begin = vhost_begin, 1004 .commit = vhost_commit, 1005 .region_add = vhost_region_add, 1006 .region_del = vhost_region_del, 1007 .region_nop = vhost_region_nop, 1008 .log_start = vhost_log_start, 1009 .log_stop = vhost_log_stop, 1010 .log_sync = vhost_log_sync, 1011 .log_global_start = vhost_log_global_start, 1012 .log_global_stop = vhost_log_global_stop, 1013 .eventfd_add = vhost_eventfd_add, 1014 .eventfd_del = vhost_eventfd_del, 1015 .priority = 10 1016 }; 1017 1018 if (hdev->migration_blocker == NULL) { 1019 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1020 error_setg(&hdev->migration_blocker, 1021 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1022 } else if (!qemu_memfd_check()) { 1023 error_setg(&hdev->migration_blocker, 1024 "Migration disabled: failed to allocate shared memory"); 1025 } 1026 } 1027 1028 if (hdev->migration_blocker != NULL) { 1029 migrate_add_blocker(hdev->migration_blocker); 1030 } 1031 1032 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1033 hdev->n_mem_sections = 0; 1034 hdev->mem_sections = NULL; 1035 hdev->log = NULL; 1036 hdev->log_size = 0; 1037 hdev->log_enabled = false; 1038 hdev->started = false; 1039 hdev->memory_changed = false; 1040 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1041 return 0; 1042 fail_vq: 1043 while (--i >= 0) { 1044 vhost_virtqueue_cleanup(hdev->vqs + i); 1045 } 1046 fail: 1047 r = -errno; 1048 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1049 QLIST_REMOVE(hdev, entry); 1050 return r; 1051 } 1052 1053 void vhost_dev_cleanup(struct vhost_dev *hdev) 1054 { 1055 int i; 1056 for (i = 0; i < hdev->nvqs; ++i) { 1057 vhost_virtqueue_cleanup(hdev->vqs + i); 1058 } 1059 memory_listener_unregister(&hdev->memory_listener); 1060 if (hdev->migration_blocker) { 1061 migrate_del_blocker(hdev->migration_blocker); 1062 error_free(hdev->migration_blocker); 1063 } 1064 g_free(hdev->mem); 1065 g_free(hdev->mem_sections); 1066 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1067 QLIST_REMOVE(hdev, entry); 1068 } 1069 1070 /* Stop processing guest IO notifications in qemu. 1071 * Start processing them in vhost in kernel. 1072 */ 1073 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1074 { 1075 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1076 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1077 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1078 int i, r, e; 1079 if (!k->set_host_notifier) { 1080 fprintf(stderr, "binding does not support host notifiers\n"); 1081 r = -ENOSYS; 1082 goto fail; 1083 } 1084 1085 for (i = 0; i < hdev->nvqs; ++i) { 1086 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, true); 1087 if (r < 0) { 1088 fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r); 1089 goto fail_vq; 1090 } 1091 } 1092 1093 return 0; 1094 fail_vq: 1095 while (--i >= 0) { 1096 e = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); 1097 if (e < 0) { 1098 fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); 1099 fflush(stderr); 1100 } 1101 assert (e >= 0); 1102 } 1103 fail: 1104 return r; 1105 } 1106 1107 /* Stop processing guest IO notifications in vhost. 1108 * Start processing them in qemu. 1109 * This might actually run the qemu handlers right away, 1110 * so virtio in qemu must be completely setup when this is called. 1111 */ 1112 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1113 { 1114 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1115 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1116 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1117 int i, r; 1118 1119 for (i = 0; i < hdev->nvqs; ++i) { 1120 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); 1121 if (r < 0) { 1122 fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r); 1123 fflush(stderr); 1124 } 1125 assert (r >= 0); 1126 } 1127 } 1128 1129 /* Test and clear event pending status. 1130 * Should be called after unmask to avoid losing events. 1131 */ 1132 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1133 { 1134 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1135 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1136 return event_notifier_test_and_clear(&vq->masked_notifier); 1137 } 1138 1139 /* Mask/unmask events from this vq. */ 1140 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1141 bool mask) 1142 { 1143 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1144 int r, index = n - hdev->vq_index; 1145 struct vhost_vring_file file; 1146 1147 if (mask) { 1148 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1149 } else { 1150 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1151 } 1152 1153 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1154 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1155 assert(r >= 0); 1156 } 1157 1158 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1159 uint64_t features) 1160 { 1161 const int *bit = feature_bits; 1162 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1163 uint64_t bit_mask = (1ULL << *bit); 1164 if (!(hdev->features & bit_mask)) { 1165 features &= ~bit_mask; 1166 } 1167 bit++; 1168 } 1169 return features; 1170 } 1171 1172 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1173 uint64_t features) 1174 { 1175 const int *bit = feature_bits; 1176 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1177 uint64_t bit_mask = (1ULL << *bit); 1178 if (features & bit_mask) { 1179 hdev->acked_features |= bit_mask; 1180 } 1181 bit++; 1182 } 1183 } 1184 1185 /* Host notifiers must be enabled at this point. */ 1186 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1187 { 1188 int i, r; 1189 1190 hdev->started = true; 1191 1192 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1193 if (r < 0) { 1194 goto fail_features; 1195 } 1196 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1197 if (r < 0) { 1198 r = -errno; 1199 goto fail_mem; 1200 } 1201 for (i = 0; i < hdev->nvqs; ++i) { 1202 r = vhost_virtqueue_start(hdev, 1203 vdev, 1204 hdev->vqs + i, 1205 hdev->vq_index + i); 1206 if (r < 0) { 1207 goto fail_vq; 1208 } 1209 } 1210 1211 if (hdev->log_enabled) { 1212 uint64_t log_base; 1213 1214 hdev->log_size = vhost_get_log_size(hdev); 1215 hdev->log = vhost_log_get(hdev->log_size, 1216 vhost_dev_log_is_shared(hdev)); 1217 log_base = (uintptr_t)hdev->log->log; 1218 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1219 hdev->log_size ? log_base : 0, 1220 hdev->log); 1221 if (r < 0) { 1222 r = -errno; 1223 goto fail_log; 1224 } 1225 } 1226 1227 return 0; 1228 fail_log: 1229 vhost_log_put(hdev, false); 1230 fail_vq: 1231 while (--i >= 0) { 1232 vhost_virtqueue_stop(hdev, 1233 vdev, 1234 hdev->vqs + i, 1235 hdev->vq_index + i); 1236 } 1237 i = hdev->nvqs; 1238 fail_mem: 1239 fail_features: 1240 1241 hdev->started = false; 1242 return r; 1243 } 1244 1245 /* Host notifiers must be enabled at this point. */ 1246 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1247 { 1248 int i; 1249 1250 for (i = 0; i < hdev->nvqs; ++i) { 1251 vhost_virtqueue_stop(hdev, 1252 vdev, 1253 hdev->vqs + i, 1254 hdev->vq_index + i); 1255 } 1256 1257 vhost_log_put(hdev, true); 1258 hdev->started = false; 1259 hdev->log = NULL; 1260 hdev->log_size = 0; 1261 } 1262 1263