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