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 <linux/vhost.h> 21 #include "exec/address-spaces.h" 22 #include "hw/virtio/virtio-bus.h" 23 #include "migration/migration.h" 24 25 static void vhost_dev_sync_region(struct vhost_dev *dev, 26 MemoryRegionSection *section, 27 uint64_t mfirst, uint64_t mlast, 28 uint64_t rfirst, uint64_t rlast) 29 { 30 uint64_t start = MAX(mfirst, rfirst); 31 uint64_t end = MIN(mlast, rlast); 32 vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK; 33 vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1; 34 uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK; 35 36 if (end < start) { 37 return; 38 } 39 assert(end / VHOST_LOG_CHUNK < dev->log_size); 40 assert(start / VHOST_LOG_CHUNK < dev->log_size); 41 42 for (;from < to; ++from) { 43 vhost_log_chunk_t log; 44 /* We first check with non-atomic: much cheaper, 45 * and we expect non-dirty to be the common case. */ 46 if (!*from) { 47 addr += VHOST_LOG_CHUNK; 48 continue; 49 } 50 /* Data must be read atomically. We don't really need barrier semantics 51 * but it's easier to use atomic_* than roll our own. */ 52 log = atomic_xchg(from, 0); 53 while (log) { 54 int bit = ctzl(log); 55 hwaddr page_addr; 56 hwaddr section_offset; 57 hwaddr mr_offset; 58 page_addr = addr + bit * VHOST_LOG_PAGE; 59 section_offset = page_addr - section->offset_within_address_space; 60 mr_offset = section_offset + section->offset_within_region; 61 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 62 log &= ~(0x1ull << bit); 63 } 64 addr += VHOST_LOG_CHUNK; 65 } 66 } 67 68 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 69 MemoryRegionSection *section, 70 hwaddr first, 71 hwaddr last) 72 { 73 int i; 74 hwaddr start_addr; 75 hwaddr end_addr; 76 77 if (!dev->log_enabled || !dev->started) { 78 return 0; 79 } 80 start_addr = section->offset_within_address_space; 81 end_addr = range_get_last(start_addr, int128_get64(section->size)); 82 start_addr = MAX(first, start_addr); 83 end_addr = MIN(last, end_addr); 84 85 for (i = 0; i < dev->mem->nregions; ++i) { 86 struct vhost_memory_region *reg = dev->mem->regions + i; 87 vhost_dev_sync_region(dev, section, start_addr, end_addr, 88 reg->guest_phys_addr, 89 range_get_last(reg->guest_phys_addr, 90 reg->memory_size)); 91 } 92 for (i = 0; i < dev->nvqs; ++i) { 93 struct vhost_virtqueue *vq = dev->vqs + i; 94 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 95 range_get_last(vq->used_phys, vq->used_size)); 96 } 97 return 0; 98 } 99 100 static void vhost_log_sync(MemoryListener *listener, 101 MemoryRegionSection *section) 102 { 103 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 104 memory_listener); 105 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 106 } 107 108 static void vhost_log_sync_range(struct vhost_dev *dev, 109 hwaddr first, hwaddr last) 110 { 111 int i; 112 /* FIXME: this is N^2 in number of sections */ 113 for (i = 0; i < dev->n_mem_sections; ++i) { 114 MemoryRegionSection *section = &dev->mem_sections[i]; 115 vhost_sync_dirty_bitmap(dev, section, first, last); 116 } 117 } 118 119 /* Assign/unassign. Keep an unsorted array of non-overlapping 120 * memory regions in dev->mem. */ 121 static void vhost_dev_unassign_memory(struct vhost_dev *dev, 122 uint64_t start_addr, 123 uint64_t size) 124 { 125 int from, to, n = dev->mem->nregions; 126 /* Track overlapping/split regions for sanity checking. */ 127 int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0; 128 129 for (from = 0, to = 0; from < n; ++from, ++to) { 130 struct vhost_memory_region *reg = dev->mem->regions + to; 131 uint64_t reglast; 132 uint64_t memlast; 133 uint64_t change; 134 135 /* clone old region */ 136 if (to != from) { 137 memcpy(reg, dev->mem->regions + from, sizeof *reg); 138 } 139 140 /* No overlap is simple */ 141 if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size, 142 start_addr, size)) { 143 continue; 144 } 145 146 /* Split only happens if supplied region 147 * is in the middle of an existing one. Thus it can not 148 * overlap with any other existing region. */ 149 assert(!split); 150 151 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 152 memlast = range_get_last(start_addr, size); 153 154 /* Remove whole region */ 155 if (start_addr <= reg->guest_phys_addr && memlast >= reglast) { 156 --dev->mem->nregions; 157 --to; 158 ++overlap_middle; 159 continue; 160 } 161 162 /* Shrink region */ 163 if (memlast >= reglast) { 164 reg->memory_size = start_addr - reg->guest_phys_addr; 165 assert(reg->memory_size); 166 assert(!overlap_end); 167 ++overlap_end; 168 continue; 169 } 170 171 /* Shift region */ 172 if (start_addr <= reg->guest_phys_addr) { 173 change = memlast + 1 - reg->guest_phys_addr; 174 reg->memory_size -= change; 175 reg->guest_phys_addr += change; 176 reg->userspace_addr += change; 177 assert(reg->memory_size); 178 assert(!overlap_start); 179 ++overlap_start; 180 continue; 181 } 182 183 /* This only happens if supplied region 184 * is in the middle of an existing one. Thus it can not 185 * overlap with any other existing region. */ 186 assert(!overlap_start); 187 assert(!overlap_end); 188 assert(!overlap_middle); 189 /* Split region: shrink first part, shift second part. */ 190 memcpy(dev->mem->regions + n, reg, sizeof *reg); 191 reg->memory_size = start_addr - reg->guest_phys_addr; 192 assert(reg->memory_size); 193 change = memlast + 1 - reg->guest_phys_addr; 194 reg = dev->mem->regions + n; 195 reg->memory_size -= change; 196 assert(reg->memory_size); 197 reg->guest_phys_addr += change; 198 reg->userspace_addr += change; 199 /* Never add more than 1 region */ 200 assert(dev->mem->nregions == n); 201 ++dev->mem->nregions; 202 ++split; 203 } 204 } 205 206 /* Called after unassign, so no regions overlap the given range. */ 207 static void vhost_dev_assign_memory(struct vhost_dev *dev, 208 uint64_t start_addr, 209 uint64_t size, 210 uint64_t uaddr) 211 { 212 int from, to; 213 struct vhost_memory_region *merged = NULL; 214 for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) { 215 struct vhost_memory_region *reg = dev->mem->regions + to; 216 uint64_t prlast, urlast; 217 uint64_t pmlast, umlast; 218 uint64_t s, e, u; 219 220 /* clone old region */ 221 if (to != from) { 222 memcpy(reg, dev->mem->regions + from, sizeof *reg); 223 } 224 prlast = range_get_last(reg->guest_phys_addr, reg->memory_size); 225 pmlast = range_get_last(start_addr, size); 226 urlast = range_get_last(reg->userspace_addr, reg->memory_size); 227 umlast = range_get_last(uaddr, size); 228 229 /* check for overlapping regions: should never happen. */ 230 assert(prlast < start_addr || pmlast < reg->guest_phys_addr); 231 /* Not an adjacent or overlapping region - do not merge. */ 232 if ((prlast + 1 != start_addr || urlast + 1 != uaddr) && 233 (pmlast + 1 != reg->guest_phys_addr || 234 umlast + 1 != reg->userspace_addr)) { 235 continue; 236 } 237 238 if (merged) { 239 --to; 240 assert(to >= 0); 241 } else { 242 merged = reg; 243 } 244 u = MIN(uaddr, reg->userspace_addr); 245 s = MIN(start_addr, reg->guest_phys_addr); 246 e = MAX(pmlast, prlast); 247 uaddr = merged->userspace_addr = u; 248 start_addr = merged->guest_phys_addr = s; 249 size = merged->memory_size = e - s + 1; 250 assert(merged->memory_size); 251 } 252 253 if (!merged) { 254 struct vhost_memory_region *reg = dev->mem->regions + to; 255 memset(reg, 0, sizeof *reg); 256 reg->memory_size = size; 257 assert(reg->memory_size); 258 reg->guest_phys_addr = start_addr; 259 reg->userspace_addr = uaddr; 260 ++to; 261 } 262 assert(to <= dev->mem->nregions + 1); 263 dev->mem->nregions = to; 264 } 265 266 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 267 { 268 uint64_t log_size = 0; 269 int i; 270 for (i = 0; i < dev->mem->nregions; ++i) { 271 struct vhost_memory_region *reg = dev->mem->regions + i; 272 uint64_t last = range_get_last(reg->guest_phys_addr, 273 reg->memory_size); 274 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 275 } 276 for (i = 0; i < dev->nvqs; ++i) { 277 struct vhost_virtqueue *vq = dev->vqs + i; 278 uint64_t last = vq->used_phys + vq->used_size - 1; 279 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 280 } 281 return log_size; 282 } 283 284 static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size) 285 { 286 vhost_log_chunk_t *log; 287 uint64_t log_base; 288 int r; 289 290 log = g_malloc0(size * sizeof *log); 291 log_base = (uint64_t)(unsigned long)log; 292 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_LOG_BASE, &log_base); 293 assert(r >= 0); 294 /* Sync only the range covered by the old log */ 295 if (dev->log_size) { 296 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 297 } 298 g_free(dev->log); 299 dev->log = log; 300 dev->log_size = size; 301 } 302 303 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 304 uint64_t start_addr, 305 uint64_t size) 306 { 307 int i; 308 int r = 0; 309 310 for (i = 0; !r && i < dev->nvqs; ++i) { 311 struct vhost_virtqueue *vq = dev->vqs + i; 312 hwaddr l; 313 void *p; 314 315 if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) { 316 continue; 317 } 318 l = vq->ring_size; 319 p = cpu_physical_memory_map(vq->ring_phys, &l, 1); 320 if (!p || l != vq->ring_size) { 321 fprintf(stderr, "Unable to map ring buffer for ring %d\n", i); 322 r = -ENOMEM; 323 } 324 if (p != vq->ring) { 325 fprintf(stderr, "Ring buffer relocated for ring %d\n", i); 326 r = -EBUSY; 327 } 328 cpu_physical_memory_unmap(p, l, 0, 0); 329 } 330 return r; 331 } 332 333 static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, 334 uint64_t start_addr, 335 uint64_t size) 336 { 337 int i, n = dev->mem->nregions; 338 for (i = 0; i < n; ++i) { 339 struct vhost_memory_region *reg = dev->mem->regions + i; 340 if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, 341 start_addr, size)) { 342 return reg; 343 } 344 } 345 return NULL; 346 } 347 348 static bool vhost_dev_cmp_memory(struct vhost_dev *dev, 349 uint64_t start_addr, 350 uint64_t size, 351 uint64_t uaddr) 352 { 353 struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); 354 uint64_t reglast; 355 uint64_t memlast; 356 357 if (!reg) { 358 return true; 359 } 360 361 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 362 memlast = range_get_last(start_addr, size); 363 364 /* Need to extend region? */ 365 if (start_addr < reg->guest_phys_addr || memlast > reglast) { 366 return true; 367 } 368 /* userspace_addr changed? */ 369 return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; 370 } 371 372 static void vhost_set_memory(MemoryListener *listener, 373 MemoryRegionSection *section, 374 bool add) 375 { 376 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 377 memory_listener); 378 hwaddr start_addr = section->offset_within_address_space; 379 ram_addr_t size = int128_get64(section->size); 380 bool log_dirty = memory_region_is_logging(section->mr); 381 int s = offsetof(struct vhost_memory, regions) + 382 (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; 383 void *ram; 384 385 dev->mem = g_realloc(dev->mem, s); 386 387 if (log_dirty) { 388 add = false; 389 } 390 391 assert(size); 392 393 /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ 394 ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; 395 if (add) { 396 if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { 397 /* Region exists with same address. Nothing to do. */ 398 return; 399 } 400 } else { 401 if (!vhost_dev_find_reg(dev, start_addr, size)) { 402 /* Removing region that we don't access. Nothing to do. */ 403 return; 404 } 405 } 406 407 vhost_dev_unassign_memory(dev, start_addr, size); 408 if (add) { 409 /* Add given mapping, merging adjacent regions if any */ 410 vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); 411 } else { 412 /* Remove old mapping for this memory, if any. */ 413 vhost_dev_unassign_memory(dev, start_addr, size); 414 } 415 dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr); 416 dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1); 417 dev->memory_changed = true; 418 } 419 420 static bool vhost_section(MemoryRegionSection *section) 421 { 422 return memory_region_is_ram(section->mr); 423 } 424 425 static void vhost_begin(MemoryListener *listener) 426 { 427 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 428 memory_listener); 429 dev->mem_changed_end_addr = 0; 430 dev->mem_changed_start_addr = -1; 431 } 432 433 static void vhost_commit(MemoryListener *listener) 434 { 435 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 436 memory_listener); 437 hwaddr start_addr = 0; 438 ram_addr_t size = 0; 439 uint64_t log_size; 440 int r; 441 442 if (!dev->memory_changed) { 443 return; 444 } 445 if (!dev->started) { 446 return; 447 } 448 if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) { 449 return; 450 } 451 452 if (dev->started) { 453 start_addr = dev->mem_changed_start_addr; 454 size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1; 455 456 r = vhost_verify_ring_mappings(dev, start_addr, size); 457 assert(r >= 0); 458 } 459 460 if (!dev->log_enabled) { 461 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_MEM_TABLE, dev->mem); 462 assert(r >= 0); 463 dev->memory_changed = false; 464 return; 465 } 466 log_size = vhost_get_log_size(dev); 467 /* We allocate an extra 4K bytes to log, 468 * to reduce the * number of reallocations. */ 469 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 470 /* To log more, must increase log size before table update. */ 471 if (dev->log_size < log_size) { 472 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 473 } 474 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_MEM_TABLE, dev->mem); 475 assert(r >= 0); 476 /* To log less, can only decrease log size after table update. */ 477 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 478 vhost_dev_log_resize(dev, log_size); 479 } 480 dev->memory_changed = false; 481 } 482 483 static void vhost_region_add(MemoryListener *listener, 484 MemoryRegionSection *section) 485 { 486 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 487 memory_listener); 488 489 if (!vhost_section(section)) { 490 return; 491 } 492 493 ++dev->n_mem_sections; 494 dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections, 495 dev->n_mem_sections); 496 dev->mem_sections[dev->n_mem_sections - 1] = *section; 497 memory_region_ref(section->mr); 498 vhost_set_memory(listener, section, true); 499 } 500 501 static void vhost_region_del(MemoryListener *listener, 502 MemoryRegionSection *section) 503 { 504 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 505 memory_listener); 506 int i; 507 508 if (!vhost_section(section)) { 509 return; 510 } 511 512 vhost_set_memory(listener, section, false); 513 memory_region_unref(section->mr); 514 for (i = 0; i < dev->n_mem_sections; ++i) { 515 if (dev->mem_sections[i].offset_within_address_space 516 == section->offset_within_address_space) { 517 --dev->n_mem_sections; 518 memmove(&dev->mem_sections[i], &dev->mem_sections[i+1], 519 (dev->n_mem_sections - i) * sizeof(*dev->mem_sections)); 520 break; 521 } 522 } 523 } 524 525 static void vhost_region_nop(MemoryListener *listener, 526 MemoryRegionSection *section) 527 { 528 } 529 530 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 531 struct vhost_virtqueue *vq, 532 unsigned idx, bool enable_log) 533 { 534 struct vhost_vring_addr addr = { 535 .index = idx, 536 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 537 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 538 .used_user_addr = (uint64_t)(unsigned long)vq->used, 539 .log_guest_addr = vq->used_phys, 540 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 541 }; 542 int r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_ADDR, &addr); 543 if (r < 0) { 544 return -errno; 545 } 546 return 0; 547 } 548 549 static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log) 550 { 551 uint64_t features = dev->acked_features; 552 int r; 553 if (enable_log) { 554 features |= 0x1 << VHOST_F_LOG_ALL; 555 } 556 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_FEATURES, &features); 557 return r < 0 ? -errno : 0; 558 } 559 560 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 561 { 562 int r, t, i; 563 r = vhost_dev_set_features(dev, enable_log); 564 if (r < 0) { 565 goto err_features; 566 } 567 for (i = 0; i < dev->nvqs; ++i) { 568 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, 569 enable_log); 570 if (r < 0) { 571 goto err_vq; 572 } 573 } 574 return 0; 575 err_vq: 576 for (; i >= 0; --i) { 577 t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, 578 dev->log_enabled); 579 assert(t >= 0); 580 } 581 t = vhost_dev_set_features(dev, dev->log_enabled); 582 assert(t >= 0); 583 err_features: 584 return r; 585 } 586 587 static int vhost_migration_log(MemoryListener *listener, int enable) 588 { 589 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 590 memory_listener); 591 int r; 592 if (!!enable == dev->log_enabled) { 593 return 0; 594 } 595 if (!dev->started) { 596 dev->log_enabled = enable; 597 return 0; 598 } 599 if (!enable) { 600 r = vhost_dev_set_log(dev, false); 601 if (r < 0) { 602 return r; 603 } 604 g_free(dev->log); 605 dev->log = NULL; 606 dev->log_size = 0; 607 } else { 608 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 609 r = vhost_dev_set_log(dev, true); 610 if (r < 0) { 611 return r; 612 } 613 } 614 dev->log_enabled = enable; 615 return 0; 616 } 617 618 static void vhost_log_global_start(MemoryListener *listener) 619 { 620 int r; 621 622 r = vhost_migration_log(listener, true); 623 if (r < 0) { 624 abort(); 625 } 626 } 627 628 static void vhost_log_global_stop(MemoryListener *listener) 629 { 630 int r; 631 632 r = vhost_migration_log(listener, false); 633 if (r < 0) { 634 abort(); 635 } 636 } 637 638 static void vhost_log_start(MemoryListener *listener, 639 MemoryRegionSection *section) 640 { 641 /* FIXME: implement */ 642 } 643 644 static void vhost_log_stop(MemoryListener *listener, 645 MemoryRegionSection *section) 646 { 647 /* FIXME: implement */ 648 } 649 650 static int vhost_virtqueue_start(struct vhost_dev *dev, 651 struct VirtIODevice *vdev, 652 struct vhost_virtqueue *vq, 653 unsigned idx) 654 { 655 hwaddr s, l, a; 656 int r; 657 int vhost_vq_index = idx - dev->vq_index; 658 struct vhost_vring_file file = { 659 .index = vhost_vq_index 660 }; 661 struct vhost_vring_state state = { 662 .index = vhost_vq_index 663 }; 664 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 665 666 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 667 668 vq->num = state.num = virtio_queue_get_num(vdev, idx); 669 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_NUM, &state); 670 if (r) { 671 return -errno; 672 } 673 674 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 675 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_BASE, &state); 676 if (r) { 677 return -errno; 678 } 679 680 s = l = virtio_queue_get_desc_size(vdev, idx); 681 a = virtio_queue_get_desc_addr(vdev, idx); 682 vq->desc = cpu_physical_memory_map(a, &l, 0); 683 if (!vq->desc || l != s) { 684 r = -ENOMEM; 685 goto fail_alloc_desc; 686 } 687 s = l = virtio_queue_get_avail_size(vdev, idx); 688 a = virtio_queue_get_avail_addr(vdev, idx); 689 vq->avail = cpu_physical_memory_map(a, &l, 0); 690 if (!vq->avail || l != s) { 691 r = -ENOMEM; 692 goto fail_alloc_avail; 693 } 694 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 695 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 696 vq->used = cpu_physical_memory_map(a, &l, 1); 697 if (!vq->used || l != s) { 698 r = -ENOMEM; 699 goto fail_alloc_used; 700 } 701 702 vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx); 703 vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx); 704 vq->ring = cpu_physical_memory_map(a, &l, 1); 705 if (!vq->ring || l != s) { 706 r = -ENOMEM; 707 goto fail_alloc_ring; 708 } 709 710 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 711 if (r < 0) { 712 r = -errno; 713 goto fail_alloc; 714 } 715 716 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 717 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_KICK, &file); 718 if (r) { 719 r = -errno; 720 goto fail_kick; 721 } 722 723 /* Clear and discard previous events if any. */ 724 event_notifier_test_and_clear(&vq->masked_notifier); 725 726 return 0; 727 728 fail_kick: 729 fail_alloc: 730 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 731 0, 0); 732 fail_alloc_ring: 733 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 734 0, 0); 735 fail_alloc_used: 736 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 737 0, 0); 738 fail_alloc_avail: 739 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 740 0, 0); 741 fail_alloc_desc: 742 return r; 743 } 744 745 static void vhost_virtqueue_stop(struct vhost_dev *dev, 746 struct VirtIODevice *vdev, 747 struct vhost_virtqueue *vq, 748 unsigned idx) 749 { 750 struct vhost_vring_state state = { 751 .index = idx - dev->vq_index 752 }; 753 int r; 754 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 755 r = dev->vhost_ops->vhost_call(dev, VHOST_GET_VRING_BASE, &state); 756 if (r < 0) { 757 fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r); 758 fflush(stderr); 759 } 760 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 761 virtio_queue_invalidate_signalled_used(vdev, idx); 762 assert (r >= 0); 763 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 764 0, virtio_queue_get_ring_size(vdev, idx)); 765 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 766 1, virtio_queue_get_used_size(vdev, idx)); 767 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 768 0, virtio_queue_get_avail_size(vdev, idx)); 769 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 770 0, virtio_queue_get_desc_size(vdev, idx)); 771 } 772 773 static void vhost_eventfd_add(MemoryListener *listener, 774 MemoryRegionSection *section, 775 bool match_data, uint64_t data, EventNotifier *e) 776 { 777 } 778 779 static void vhost_eventfd_del(MemoryListener *listener, 780 MemoryRegionSection *section, 781 bool match_data, uint64_t data, EventNotifier *e) 782 { 783 } 784 785 static int vhost_virtqueue_init(struct vhost_dev *dev, 786 struct vhost_virtqueue *vq, int n) 787 { 788 struct vhost_vring_file file = { 789 .index = n, 790 }; 791 int r = event_notifier_init(&vq->masked_notifier, 0); 792 if (r < 0) { 793 return r; 794 } 795 796 file.fd = event_notifier_get_fd(&vq->masked_notifier); 797 r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_CALL, &file); 798 if (r) { 799 r = -errno; 800 goto fail_call; 801 } 802 return 0; 803 fail_call: 804 event_notifier_cleanup(&vq->masked_notifier); 805 return r; 806 } 807 808 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 809 { 810 event_notifier_cleanup(&vq->masked_notifier); 811 } 812 813 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 814 VhostBackendType backend_type, bool force) 815 { 816 uint64_t features; 817 int i, r; 818 819 if (vhost_set_backend_type(hdev, backend_type) < 0) { 820 return -1; 821 } 822 823 if (hdev->vhost_ops->vhost_backend_init(hdev, opaque) < 0) { 824 return -errno; 825 } 826 827 r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_OWNER, NULL); 828 if (r < 0) { 829 goto fail; 830 } 831 832 r = hdev->vhost_ops->vhost_call(hdev, VHOST_GET_FEATURES, &features); 833 if (r < 0) { 834 goto fail; 835 } 836 837 for (i = 0; i < hdev->nvqs; ++i) { 838 r = vhost_virtqueue_init(hdev, hdev->vqs + i, i); 839 if (r < 0) { 840 goto fail_vq; 841 } 842 } 843 hdev->features = features; 844 845 hdev->memory_listener = (MemoryListener) { 846 .begin = vhost_begin, 847 .commit = vhost_commit, 848 .region_add = vhost_region_add, 849 .region_del = vhost_region_del, 850 .region_nop = vhost_region_nop, 851 .log_start = vhost_log_start, 852 .log_stop = vhost_log_stop, 853 .log_sync = vhost_log_sync, 854 .log_global_start = vhost_log_global_start, 855 .log_global_stop = vhost_log_global_stop, 856 .eventfd_add = vhost_eventfd_add, 857 .eventfd_del = vhost_eventfd_del, 858 .priority = 10 859 }; 860 hdev->migration_blocker = NULL; 861 if (!(hdev->features & (0x1 << VHOST_F_LOG_ALL))) { 862 error_setg(&hdev->migration_blocker, 863 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 864 migrate_add_blocker(hdev->migration_blocker); 865 } 866 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 867 hdev->n_mem_sections = 0; 868 hdev->mem_sections = NULL; 869 hdev->log = NULL; 870 hdev->log_size = 0; 871 hdev->log_enabled = false; 872 hdev->started = false; 873 hdev->memory_changed = false; 874 memory_listener_register(&hdev->memory_listener, &address_space_memory); 875 hdev->force = force; 876 return 0; 877 fail_vq: 878 while (--i >= 0) { 879 vhost_virtqueue_cleanup(hdev->vqs + i); 880 } 881 fail: 882 r = -errno; 883 hdev->vhost_ops->vhost_backend_cleanup(hdev); 884 return r; 885 } 886 887 void vhost_dev_cleanup(struct vhost_dev *hdev) 888 { 889 int i; 890 for (i = 0; i < hdev->nvqs; ++i) { 891 vhost_virtqueue_cleanup(hdev->vqs + i); 892 } 893 memory_listener_unregister(&hdev->memory_listener); 894 if (hdev->migration_blocker) { 895 migrate_del_blocker(hdev->migration_blocker); 896 error_free(hdev->migration_blocker); 897 } 898 g_free(hdev->mem); 899 g_free(hdev->mem_sections); 900 hdev->vhost_ops->vhost_backend_cleanup(hdev); 901 } 902 903 bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev) 904 { 905 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 906 VirtioBusState *vbus = VIRTIO_BUS(qbus); 907 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 908 909 return !k->query_guest_notifiers || 910 k->query_guest_notifiers(qbus->parent) || 911 hdev->force; 912 } 913 914 /* Stop processing guest IO notifications in qemu. 915 * Start processing them in vhost in kernel. 916 */ 917 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 918 { 919 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 920 VirtioBusState *vbus = VIRTIO_BUS(qbus); 921 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 922 int i, r; 923 if (!k->set_host_notifier) { 924 fprintf(stderr, "binding does not support host notifiers\n"); 925 r = -ENOSYS; 926 goto fail; 927 } 928 929 for (i = 0; i < hdev->nvqs; ++i) { 930 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, true); 931 if (r < 0) { 932 fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r); 933 goto fail_vq; 934 } 935 } 936 937 return 0; 938 fail_vq: 939 while (--i >= 0) { 940 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); 941 if (r < 0) { 942 fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); 943 fflush(stderr); 944 } 945 assert (r >= 0); 946 } 947 fail: 948 return r; 949 } 950 951 /* Stop processing guest IO notifications in vhost. 952 * Start processing them in qemu. 953 * This might actually run the qemu handlers right away, 954 * so virtio in qemu must be completely setup when this is called. 955 */ 956 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 957 { 958 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 959 VirtioBusState *vbus = VIRTIO_BUS(qbus); 960 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 961 int i, r; 962 963 for (i = 0; i < hdev->nvqs; ++i) { 964 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); 965 if (r < 0) { 966 fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r); 967 fflush(stderr); 968 } 969 assert (r >= 0); 970 } 971 } 972 973 /* Test and clear event pending status. 974 * Should be called after unmask to avoid losing events. 975 */ 976 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 977 { 978 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 979 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 980 return event_notifier_test_and_clear(&vq->masked_notifier); 981 } 982 983 /* Mask/unmask events from this vq. */ 984 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 985 bool mask) 986 { 987 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 988 int r, index = n - hdev->vq_index; 989 990 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 991 992 struct vhost_vring_file file = { 993 .index = index 994 }; 995 if (mask) { 996 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 997 } else { 998 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 999 } 1000 r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_VRING_CALL, &file); 1001 assert(r >= 0); 1002 } 1003 1004 unsigned vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1005 unsigned features) 1006 { 1007 const int *bit = feature_bits; 1008 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1009 unsigned bit_mask = (1 << *bit); 1010 if (!(hdev->features & bit_mask)) { 1011 features &= ~bit_mask; 1012 } 1013 bit++; 1014 } 1015 return features; 1016 } 1017 1018 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1019 unsigned features) 1020 { 1021 const int *bit = feature_bits; 1022 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1023 unsigned bit_mask = (1 << *bit); 1024 if (features & bit_mask) { 1025 hdev->acked_features |= bit_mask; 1026 } 1027 bit++; 1028 } 1029 } 1030 1031 /* Host notifiers must be enabled at this point. */ 1032 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1033 { 1034 int i, r; 1035 1036 hdev->started = true; 1037 1038 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1039 if (r < 0) { 1040 goto fail_features; 1041 } 1042 r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_MEM_TABLE, hdev->mem); 1043 if (r < 0) { 1044 r = -errno; 1045 goto fail_mem; 1046 } 1047 for (i = 0; i < hdev->nvqs; ++i) { 1048 r = vhost_virtqueue_start(hdev, 1049 vdev, 1050 hdev->vqs + i, 1051 hdev->vq_index + i); 1052 if (r < 0) { 1053 goto fail_vq; 1054 } 1055 } 1056 1057 if (hdev->log_enabled) { 1058 hdev->log_size = vhost_get_log_size(hdev); 1059 hdev->log = hdev->log_size ? 1060 g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL; 1061 r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_LOG_BASE, hdev->log); 1062 if (r < 0) { 1063 r = -errno; 1064 goto fail_log; 1065 } 1066 } 1067 1068 return 0; 1069 fail_log: 1070 fail_vq: 1071 while (--i >= 0) { 1072 vhost_virtqueue_stop(hdev, 1073 vdev, 1074 hdev->vqs + i, 1075 hdev->vq_index + i); 1076 } 1077 i = hdev->nvqs; 1078 fail_mem: 1079 fail_features: 1080 1081 hdev->started = false; 1082 return r; 1083 } 1084 1085 /* Host notifiers must be enabled at this point. */ 1086 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1087 { 1088 int i; 1089 1090 for (i = 0; i < hdev->nvqs; ++i) { 1091 vhost_virtqueue_stop(hdev, 1092 vdev, 1093 hdev->vqs + i, 1094 hdev->vq_index + i); 1095 } 1096 vhost_log_sync_range(hdev, 0, ~0x0ull); 1097 1098 hdev->started = false; 1099 g_free(hdev->log); 1100 hdev->log = NULL; 1101 hdev->log_size = 0; 1102 } 1103 1104