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 <sys/ioctl.h> 17 #include "hw/virtio/vhost.h" 18 #include "hw/hw.h" 19 #include "qemu/range.h" 20 #include <linux/vhost.h> 21 #include "exec/address-spaces.h" 22 23 static void vhost_dev_sync_region(struct vhost_dev *dev, 24 MemoryRegionSection *section, 25 uint64_t mfirst, uint64_t mlast, 26 uint64_t rfirst, uint64_t rlast) 27 { 28 uint64_t start = MAX(mfirst, rfirst); 29 uint64_t end = MIN(mlast, rlast); 30 vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK; 31 vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1; 32 uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK; 33 34 if (end < start) { 35 return; 36 } 37 assert(end / VHOST_LOG_CHUNK < dev->log_size); 38 assert(start / VHOST_LOG_CHUNK < dev->log_size); 39 40 for (;from < to; ++from) { 41 vhost_log_chunk_t log; 42 int bit; 43 /* We first check with non-atomic: much cheaper, 44 * and we expect non-dirty to be the common case. */ 45 if (!*from) { 46 addr += VHOST_LOG_CHUNK; 47 continue; 48 } 49 /* Data must be read atomically. We don't really 50 * need the barrier semantics of __sync 51 * builtins, but it's easier to use them than 52 * roll our own. */ 53 log = __sync_fetch_and_and(from, 0); 54 while ((bit = sizeof(log) > sizeof(int) ? 55 ffsll(log) : ffs(log))) { 56 hwaddr page_addr; 57 hwaddr section_offset; 58 hwaddr mr_offset; 59 bit -= 1; 60 page_addr = addr + bit * VHOST_LOG_PAGE; 61 section_offset = page_addr - section->offset_within_address_space; 62 mr_offset = section_offset + section->offset_within_region; 63 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 64 log &= ~(0x1ull << bit); 65 } 66 addr += VHOST_LOG_CHUNK; 67 } 68 } 69 70 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 71 MemoryRegionSection *section, 72 hwaddr first, 73 hwaddr last) 74 { 75 int i; 76 hwaddr start_addr; 77 hwaddr end_addr; 78 79 if (!dev->log_enabled || !dev->started) { 80 return 0; 81 } 82 start_addr = section->offset_within_address_space; 83 end_addr = range_get_last(start_addr, section->size); 84 start_addr = MAX(first, start_addr); 85 end_addr = MIN(last, end_addr); 86 87 for (i = 0; i < dev->mem->nregions; ++i) { 88 struct vhost_memory_region *reg = dev->mem->regions + i; 89 vhost_dev_sync_region(dev, section, start_addr, end_addr, 90 reg->guest_phys_addr, 91 range_get_last(reg->guest_phys_addr, 92 reg->memory_size)); 93 } 94 for (i = 0; i < dev->nvqs; ++i) { 95 struct vhost_virtqueue *vq = dev->vqs + i; 96 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 97 range_get_last(vq->used_phys, vq->used_size)); 98 } 99 return 0; 100 } 101 102 static void vhost_log_sync(MemoryListener *listener, 103 MemoryRegionSection *section) 104 { 105 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 106 memory_listener); 107 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 108 } 109 110 static void vhost_log_sync_range(struct vhost_dev *dev, 111 hwaddr first, hwaddr last) 112 { 113 int i; 114 /* FIXME: this is N^2 in number of sections */ 115 for (i = 0; i < dev->n_mem_sections; ++i) { 116 MemoryRegionSection *section = &dev->mem_sections[i]; 117 vhost_sync_dirty_bitmap(dev, section, first, last); 118 } 119 } 120 121 /* Assign/unassign. Keep an unsorted array of non-overlapping 122 * memory regions in dev->mem. */ 123 static void vhost_dev_unassign_memory(struct vhost_dev *dev, 124 uint64_t start_addr, 125 uint64_t size) 126 { 127 int from, to, n = dev->mem->nregions; 128 /* Track overlapping/split regions for sanity checking. */ 129 int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0; 130 131 for (from = 0, to = 0; from < n; ++from, ++to) { 132 struct vhost_memory_region *reg = dev->mem->regions + to; 133 uint64_t reglast; 134 uint64_t memlast; 135 uint64_t change; 136 137 /* clone old region */ 138 if (to != from) { 139 memcpy(reg, dev->mem->regions + from, sizeof *reg); 140 } 141 142 /* No overlap is simple */ 143 if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size, 144 start_addr, size)) { 145 continue; 146 } 147 148 /* Split only happens if supplied region 149 * is in the middle of an existing one. Thus it can not 150 * overlap with any other existing region. */ 151 assert(!split); 152 153 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 154 memlast = range_get_last(start_addr, size); 155 156 /* Remove whole region */ 157 if (start_addr <= reg->guest_phys_addr && memlast >= reglast) { 158 --dev->mem->nregions; 159 --to; 160 ++overlap_middle; 161 continue; 162 } 163 164 /* Shrink region */ 165 if (memlast >= reglast) { 166 reg->memory_size = start_addr - reg->guest_phys_addr; 167 assert(reg->memory_size); 168 assert(!overlap_end); 169 ++overlap_end; 170 continue; 171 } 172 173 /* Shift region */ 174 if (start_addr <= reg->guest_phys_addr) { 175 change = memlast + 1 - reg->guest_phys_addr; 176 reg->memory_size -= change; 177 reg->guest_phys_addr += change; 178 reg->userspace_addr += change; 179 assert(reg->memory_size); 180 assert(!overlap_start); 181 ++overlap_start; 182 continue; 183 } 184 185 /* This only happens if supplied region 186 * is in the middle of an existing one. Thus it can not 187 * overlap with any other existing region. */ 188 assert(!overlap_start); 189 assert(!overlap_end); 190 assert(!overlap_middle); 191 /* Split region: shrink first part, shift second part. */ 192 memcpy(dev->mem->regions + n, reg, sizeof *reg); 193 reg->memory_size = start_addr - reg->guest_phys_addr; 194 assert(reg->memory_size); 195 change = memlast + 1 - reg->guest_phys_addr; 196 reg = dev->mem->regions + n; 197 reg->memory_size -= change; 198 assert(reg->memory_size); 199 reg->guest_phys_addr += change; 200 reg->userspace_addr += change; 201 /* Never add more than 1 region */ 202 assert(dev->mem->nregions == n); 203 ++dev->mem->nregions; 204 ++split; 205 } 206 } 207 208 /* Called after unassign, so no regions overlap the given range. */ 209 static void vhost_dev_assign_memory(struct vhost_dev *dev, 210 uint64_t start_addr, 211 uint64_t size, 212 uint64_t uaddr) 213 { 214 int from, to; 215 struct vhost_memory_region *merged = NULL; 216 for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) { 217 struct vhost_memory_region *reg = dev->mem->regions + to; 218 uint64_t prlast, urlast; 219 uint64_t pmlast, umlast; 220 uint64_t s, e, u; 221 222 /* clone old region */ 223 if (to != from) { 224 memcpy(reg, dev->mem->regions + from, sizeof *reg); 225 } 226 prlast = range_get_last(reg->guest_phys_addr, reg->memory_size); 227 pmlast = range_get_last(start_addr, size); 228 urlast = range_get_last(reg->userspace_addr, reg->memory_size); 229 umlast = range_get_last(uaddr, size); 230 231 /* check for overlapping regions: should never happen. */ 232 assert(prlast < start_addr || pmlast < reg->guest_phys_addr); 233 /* Not an adjacent or overlapping region - do not merge. */ 234 if ((prlast + 1 != start_addr || urlast + 1 != uaddr) && 235 (pmlast + 1 != reg->guest_phys_addr || 236 umlast + 1 != reg->userspace_addr)) { 237 continue; 238 } 239 240 if (merged) { 241 --to; 242 assert(to >= 0); 243 } else { 244 merged = reg; 245 } 246 u = MIN(uaddr, reg->userspace_addr); 247 s = MIN(start_addr, reg->guest_phys_addr); 248 e = MAX(pmlast, prlast); 249 uaddr = merged->userspace_addr = u; 250 start_addr = merged->guest_phys_addr = s; 251 size = merged->memory_size = e - s + 1; 252 assert(merged->memory_size); 253 } 254 255 if (!merged) { 256 struct vhost_memory_region *reg = dev->mem->regions + to; 257 memset(reg, 0, sizeof *reg); 258 reg->memory_size = size; 259 assert(reg->memory_size); 260 reg->guest_phys_addr = start_addr; 261 reg->userspace_addr = uaddr; 262 ++to; 263 } 264 assert(to <= dev->mem->nregions + 1); 265 dev->mem->nregions = to; 266 } 267 268 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 269 { 270 uint64_t log_size = 0; 271 int i; 272 for (i = 0; i < dev->mem->nregions; ++i) { 273 struct vhost_memory_region *reg = dev->mem->regions + i; 274 uint64_t last = range_get_last(reg->guest_phys_addr, 275 reg->memory_size); 276 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 277 } 278 for (i = 0; i < dev->nvqs; ++i) { 279 struct vhost_virtqueue *vq = dev->vqs + i; 280 uint64_t last = vq->used_phys + vq->used_size - 1; 281 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 282 } 283 return log_size; 284 } 285 286 static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size) 287 { 288 vhost_log_chunk_t *log; 289 uint64_t log_base; 290 int r; 291 292 log = g_malloc0(size * sizeof *log); 293 log_base = (uint64_t)(unsigned long)log; 294 r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base); 295 assert(r >= 0); 296 /* Sync only the range covered by the old log */ 297 if (dev->log_size) { 298 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 299 } 300 if (dev->log) { 301 g_free(dev->log); 302 } 303 dev->log = log; 304 dev->log_size = size; 305 } 306 307 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 308 uint64_t start_addr, 309 uint64_t size) 310 { 311 int i; 312 for (i = 0; i < dev->nvqs; ++i) { 313 struct vhost_virtqueue *vq = dev->vqs + i; 314 hwaddr l; 315 void *p; 316 317 if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) { 318 continue; 319 } 320 l = vq->ring_size; 321 p = cpu_physical_memory_map(vq->ring_phys, &l, 1); 322 if (!p || l != vq->ring_size) { 323 fprintf(stderr, "Unable to map ring buffer for ring %d\n", i); 324 return -ENOMEM; 325 } 326 if (p != vq->ring) { 327 fprintf(stderr, "Ring buffer relocated for ring %d\n", i); 328 return -EBUSY; 329 } 330 cpu_physical_memory_unmap(p, l, 0, 0); 331 } 332 return 0; 333 } 334 335 static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, 336 uint64_t start_addr, 337 uint64_t size) 338 { 339 int i, n = dev->mem->nregions; 340 for (i = 0; i < n; ++i) { 341 struct vhost_memory_region *reg = dev->mem->regions + i; 342 if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, 343 start_addr, size)) { 344 return reg; 345 } 346 } 347 return NULL; 348 } 349 350 static bool vhost_dev_cmp_memory(struct vhost_dev *dev, 351 uint64_t start_addr, 352 uint64_t size, 353 uint64_t uaddr) 354 { 355 struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); 356 uint64_t reglast; 357 uint64_t memlast; 358 359 if (!reg) { 360 return true; 361 } 362 363 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 364 memlast = range_get_last(start_addr, size); 365 366 /* Need to extend region? */ 367 if (start_addr < reg->guest_phys_addr || memlast > reglast) { 368 return true; 369 } 370 /* userspace_addr changed? */ 371 return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; 372 } 373 374 static void vhost_set_memory(MemoryListener *listener, 375 MemoryRegionSection *section, 376 bool add) 377 { 378 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 379 memory_listener); 380 hwaddr start_addr = section->offset_within_address_space; 381 ram_addr_t size = section->size; 382 bool log_dirty = memory_region_is_logging(section->mr); 383 int s = offsetof(struct vhost_memory, regions) + 384 (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; 385 uint64_t log_size; 386 int r; 387 void *ram; 388 389 dev->mem = g_realloc(dev->mem, s); 390 391 if (log_dirty) { 392 add = false; 393 } 394 395 assert(size); 396 397 /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ 398 ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; 399 if (add) { 400 if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { 401 /* Region exists with same address. Nothing to do. */ 402 return; 403 } 404 } else { 405 if (!vhost_dev_find_reg(dev, start_addr, size)) { 406 /* Removing region that we don't access. Nothing to do. */ 407 return; 408 } 409 } 410 411 vhost_dev_unassign_memory(dev, start_addr, size); 412 if (add) { 413 /* Add given mapping, merging adjacent regions if any */ 414 vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); 415 } else { 416 /* Remove old mapping for this memory, if any. */ 417 vhost_dev_unassign_memory(dev, start_addr, size); 418 } 419 420 if (!dev->started) { 421 return; 422 } 423 424 if (dev->started) { 425 r = vhost_verify_ring_mappings(dev, start_addr, size); 426 assert(r >= 0); 427 } 428 429 if (!dev->log_enabled) { 430 r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem); 431 assert(r >= 0); 432 return; 433 } 434 log_size = vhost_get_log_size(dev); 435 /* We allocate an extra 4K bytes to log, 436 * to reduce the * number of reallocations. */ 437 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 438 /* To log more, must increase log size before table update. */ 439 if (dev->log_size < log_size) { 440 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 441 } 442 r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem); 443 assert(r >= 0); 444 /* To log less, can only decrease log size after table update. */ 445 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 446 vhost_dev_log_resize(dev, log_size); 447 } 448 } 449 450 static bool vhost_section(MemoryRegionSection *section) 451 { 452 return memory_region_is_ram(section->mr); 453 } 454 455 static void vhost_begin(MemoryListener *listener) 456 { 457 } 458 459 static void vhost_commit(MemoryListener *listener) 460 { 461 } 462 463 static void vhost_region_add(MemoryListener *listener, 464 MemoryRegionSection *section) 465 { 466 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 467 memory_listener); 468 469 if (!vhost_section(section)) { 470 return; 471 } 472 473 ++dev->n_mem_sections; 474 dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections, 475 dev->n_mem_sections); 476 dev->mem_sections[dev->n_mem_sections - 1] = *section; 477 vhost_set_memory(listener, section, true); 478 } 479 480 static void vhost_region_del(MemoryListener *listener, 481 MemoryRegionSection *section) 482 { 483 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 484 memory_listener); 485 int i; 486 487 if (!vhost_section(section)) { 488 return; 489 } 490 491 vhost_set_memory(listener, section, false); 492 for (i = 0; i < dev->n_mem_sections; ++i) { 493 if (dev->mem_sections[i].offset_within_address_space 494 == section->offset_within_address_space) { 495 --dev->n_mem_sections; 496 memmove(&dev->mem_sections[i], &dev->mem_sections[i+1], 497 (dev->n_mem_sections - i) * sizeof(*dev->mem_sections)); 498 break; 499 } 500 } 501 } 502 503 static void vhost_region_nop(MemoryListener *listener, 504 MemoryRegionSection *section) 505 { 506 } 507 508 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 509 struct vhost_virtqueue *vq, 510 unsigned idx, bool enable_log) 511 { 512 struct vhost_vring_addr addr = { 513 .index = idx, 514 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 515 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 516 .used_user_addr = (uint64_t)(unsigned long)vq->used, 517 .log_guest_addr = vq->used_phys, 518 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 519 }; 520 int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr); 521 if (r < 0) { 522 return -errno; 523 } 524 return 0; 525 } 526 527 static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log) 528 { 529 uint64_t features = dev->acked_features; 530 int r; 531 if (enable_log) { 532 features |= 0x1 << VHOST_F_LOG_ALL; 533 } 534 r = ioctl(dev->control, VHOST_SET_FEATURES, &features); 535 return r < 0 ? -errno : 0; 536 } 537 538 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 539 { 540 int r, t, i; 541 r = vhost_dev_set_features(dev, enable_log); 542 if (r < 0) { 543 goto err_features; 544 } 545 for (i = 0; i < dev->nvqs; ++i) { 546 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, 547 enable_log); 548 if (r < 0) { 549 goto err_vq; 550 } 551 } 552 return 0; 553 err_vq: 554 for (; i >= 0; --i) { 555 t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, 556 dev->log_enabled); 557 assert(t >= 0); 558 } 559 t = vhost_dev_set_features(dev, dev->log_enabled); 560 assert(t >= 0); 561 err_features: 562 return r; 563 } 564 565 static int vhost_migration_log(MemoryListener *listener, int enable) 566 { 567 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 568 memory_listener); 569 int r; 570 if (!!enable == dev->log_enabled) { 571 return 0; 572 } 573 if (!dev->started) { 574 dev->log_enabled = enable; 575 return 0; 576 } 577 if (!enable) { 578 r = vhost_dev_set_log(dev, false); 579 if (r < 0) { 580 return r; 581 } 582 if (dev->log) { 583 g_free(dev->log); 584 } 585 dev->log = NULL; 586 dev->log_size = 0; 587 } else { 588 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 589 r = vhost_dev_set_log(dev, true); 590 if (r < 0) { 591 return r; 592 } 593 } 594 dev->log_enabled = enable; 595 return 0; 596 } 597 598 static void vhost_log_global_start(MemoryListener *listener) 599 { 600 int r; 601 602 r = vhost_migration_log(listener, true); 603 if (r < 0) { 604 abort(); 605 } 606 } 607 608 static void vhost_log_global_stop(MemoryListener *listener) 609 { 610 int r; 611 612 r = vhost_migration_log(listener, false); 613 if (r < 0) { 614 abort(); 615 } 616 } 617 618 static void vhost_log_start(MemoryListener *listener, 619 MemoryRegionSection *section) 620 { 621 /* FIXME: implement */ 622 } 623 624 static void vhost_log_stop(MemoryListener *listener, 625 MemoryRegionSection *section) 626 { 627 /* FIXME: implement */ 628 } 629 630 static int vhost_virtqueue_start(struct vhost_dev *dev, 631 struct VirtIODevice *vdev, 632 struct vhost_virtqueue *vq, 633 unsigned idx) 634 { 635 hwaddr s, l, a; 636 int r; 637 int vhost_vq_index = idx - dev->vq_index; 638 struct vhost_vring_file file = { 639 .index = vhost_vq_index 640 }; 641 struct vhost_vring_state state = { 642 .index = vhost_vq_index 643 }; 644 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 645 646 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 647 648 vq->num = state.num = virtio_queue_get_num(vdev, idx); 649 r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state); 650 if (r) { 651 return -errno; 652 } 653 654 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 655 r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state); 656 if (r) { 657 return -errno; 658 } 659 660 s = l = virtio_queue_get_desc_size(vdev, idx); 661 a = virtio_queue_get_desc_addr(vdev, idx); 662 vq->desc = cpu_physical_memory_map(a, &l, 0); 663 if (!vq->desc || l != s) { 664 r = -ENOMEM; 665 goto fail_alloc_desc; 666 } 667 s = l = virtio_queue_get_avail_size(vdev, idx); 668 a = virtio_queue_get_avail_addr(vdev, idx); 669 vq->avail = cpu_physical_memory_map(a, &l, 0); 670 if (!vq->avail || l != s) { 671 r = -ENOMEM; 672 goto fail_alloc_avail; 673 } 674 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 675 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 676 vq->used = cpu_physical_memory_map(a, &l, 1); 677 if (!vq->used || l != s) { 678 r = -ENOMEM; 679 goto fail_alloc_used; 680 } 681 682 vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx); 683 vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx); 684 vq->ring = cpu_physical_memory_map(a, &l, 1); 685 if (!vq->ring || l != s) { 686 r = -ENOMEM; 687 goto fail_alloc_ring; 688 } 689 690 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 691 if (r < 0) { 692 r = -errno; 693 goto fail_alloc; 694 } 695 696 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 697 r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file); 698 if (r) { 699 r = -errno; 700 goto fail_kick; 701 } 702 703 /* Clear and discard previous events if any. */ 704 event_notifier_test_and_clear(&vq->masked_notifier); 705 706 return 0; 707 708 fail_kick: 709 fail_alloc: 710 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 711 0, 0); 712 fail_alloc_ring: 713 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 714 0, 0); 715 fail_alloc_used: 716 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 717 0, 0); 718 fail_alloc_avail: 719 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 720 0, 0); 721 fail_alloc_desc: 722 return r; 723 } 724 725 static void vhost_virtqueue_stop(struct vhost_dev *dev, 726 struct VirtIODevice *vdev, 727 struct vhost_virtqueue *vq, 728 unsigned idx) 729 { 730 struct vhost_vring_state state = { 731 .index = idx - dev->vq_index 732 }; 733 int r; 734 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 735 r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state); 736 if (r < 0) { 737 fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r); 738 fflush(stderr); 739 } 740 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 741 assert (r >= 0); 742 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 743 0, virtio_queue_get_ring_size(vdev, idx)); 744 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 745 1, virtio_queue_get_used_size(vdev, idx)); 746 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 747 0, virtio_queue_get_avail_size(vdev, idx)); 748 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 749 0, virtio_queue_get_desc_size(vdev, idx)); 750 } 751 752 static void vhost_eventfd_add(MemoryListener *listener, 753 MemoryRegionSection *section, 754 bool match_data, uint64_t data, EventNotifier *e) 755 { 756 } 757 758 static void vhost_eventfd_del(MemoryListener *listener, 759 MemoryRegionSection *section, 760 bool match_data, uint64_t data, EventNotifier *e) 761 { 762 } 763 764 static int vhost_virtqueue_init(struct vhost_dev *dev, 765 struct vhost_virtqueue *vq, int n) 766 { 767 struct vhost_vring_file file = { 768 .index = n, 769 }; 770 int r = event_notifier_init(&vq->masked_notifier, 0); 771 if (r < 0) { 772 return r; 773 } 774 775 file.fd = event_notifier_get_fd(&vq->masked_notifier); 776 r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file); 777 if (r) { 778 r = -errno; 779 goto fail_call; 780 } 781 return 0; 782 fail_call: 783 event_notifier_cleanup(&vq->masked_notifier); 784 return r; 785 } 786 787 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 788 { 789 event_notifier_cleanup(&vq->masked_notifier); 790 } 791 792 int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath, 793 bool force) 794 { 795 uint64_t features; 796 int i, r; 797 if (devfd >= 0) { 798 hdev->control = devfd; 799 } else { 800 hdev->control = open(devpath, O_RDWR); 801 if (hdev->control < 0) { 802 return -errno; 803 } 804 } 805 r = ioctl(hdev->control, VHOST_SET_OWNER, NULL); 806 if (r < 0) { 807 goto fail; 808 } 809 810 r = ioctl(hdev->control, VHOST_GET_FEATURES, &features); 811 if (r < 0) { 812 goto fail; 813 } 814 815 for (i = 0; i < hdev->nvqs; ++i) { 816 r = vhost_virtqueue_init(hdev, hdev->vqs + i, i); 817 if (r < 0) { 818 goto fail_vq; 819 } 820 } 821 hdev->features = features; 822 823 hdev->memory_listener = (MemoryListener) { 824 .begin = vhost_begin, 825 .commit = vhost_commit, 826 .region_add = vhost_region_add, 827 .region_del = vhost_region_del, 828 .region_nop = vhost_region_nop, 829 .log_start = vhost_log_start, 830 .log_stop = vhost_log_stop, 831 .log_sync = vhost_log_sync, 832 .log_global_start = vhost_log_global_start, 833 .log_global_stop = vhost_log_global_stop, 834 .eventfd_add = vhost_eventfd_add, 835 .eventfd_del = vhost_eventfd_del, 836 .priority = 10 837 }; 838 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 839 hdev->n_mem_sections = 0; 840 hdev->mem_sections = NULL; 841 hdev->log = NULL; 842 hdev->log_size = 0; 843 hdev->log_enabled = false; 844 hdev->started = false; 845 memory_listener_register(&hdev->memory_listener, &address_space_memory); 846 hdev->force = force; 847 return 0; 848 fail_vq: 849 while (--i >= 0) { 850 vhost_virtqueue_cleanup(hdev->vqs + i); 851 } 852 fail: 853 r = -errno; 854 close(hdev->control); 855 return r; 856 } 857 858 void vhost_dev_cleanup(struct vhost_dev *hdev) 859 { 860 int i; 861 for (i = 0; i < hdev->nvqs; ++i) { 862 vhost_virtqueue_cleanup(hdev->vqs + i); 863 } 864 memory_listener_unregister(&hdev->memory_listener); 865 g_free(hdev->mem); 866 g_free(hdev->mem_sections); 867 close(hdev->control); 868 } 869 870 bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev) 871 { 872 return !vdev->binding->query_guest_notifiers || 873 vdev->binding->query_guest_notifiers(vdev->binding_opaque) || 874 hdev->force; 875 } 876 877 /* Stop processing guest IO notifications in qemu. 878 * Start processing them in vhost in kernel. 879 */ 880 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 881 { 882 int i, r; 883 if (!vdev->binding->set_host_notifier) { 884 fprintf(stderr, "binding does not support host notifiers\n"); 885 r = -ENOSYS; 886 goto fail; 887 } 888 889 for (i = 0; i < hdev->nvqs; ++i) { 890 r = vdev->binding->set_host_notifier(vdev->binding_opaque, 891 hdev->vq_index + i, 892 true); 893 if (r < 0) { 894 fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r); 895 goto fail_vq; 896 } 897 } 898 899 return 0; 900 fail_vq: 901 while (--i >= 0) { 902 r = vdev->binding->set_host_notifier(vdev->binding_opaque, 903 hdev->vq_index + i, 904 false); 905 if (r < 0) { 906 fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); 907 fflush(stderr); 908 } 909 assert (r >= 0); 910 } 911 fail: 912 return r; 913 } 914 915 /* Stop processing guest IO notifications in vhost. 916 * Start processing them in qemu. 917 * This might actually run the qemu handlers right away, 918 * so virtio in qemu must be completely setup when this is called. 919 */ 920 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 921 { 922 int i, r; 923 924 for (i = 0; i < hdev->nvqs; ++i) { 925 r = vdev->binding->set_host_notifier(vdev->binding_opaque, 926 hdev->vq_index + i, 927 false); 928 if (r < 0) { 929 fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r); 930 fflush(stderr); 931 } 932 assert (r >= 0); 933 } 934 } 935 936 /* Test and clear event pending status. 937 * Should be called after unmask to avoid losing events. 938 */ 939 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 940 { 941 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 942 assert(hdev->started); 943 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 944 return event_notifier_test_and_clear(&vq->masked_notifier); 945 } 946 947 /* Mask/unmask events from this vq. */ 948 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 949 bool mask) 950 { 951 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 952 int r, index = n - hdev->vq_index; 953 954 assert(hdev->started); 955 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 956 957 struct vhost_vring_file file = { 958 .index = index 959 }; 960 if (mask) { 961 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 962 } else { 963 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 964 } 965 r = ioctl(hdev->control, VHOST_SET_VRING_CALL, &file); 966 assert(r >= 0); 967 } 968 969 /* Host notifiers must be enabled at this point. */ 970 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 971 { 972 int i, r; 973 974 hdev->started = true; 975 976 r = vhost_dev_set_features(hdev, hdev->log_enabled); 977 if (r < 0) { 978 goto fail_features; 979 } 980 r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem); 981 if (r < 0) { 982 r = -errno; 983 goto fail_mem; 984 } 985 for (i = 0; i < hdev->nvqs; ++i) { 986 r = vhost_virtqueue_start(hdev, 987 vdev, 988 hdev->vqs + i, 989 hdev->vq_index + i); 990 if (r < 0) { 991 goto fail_vq; 992 } 993 } 994 995 if (hdev->log_enabled) { 996 hdev->log_size = vhost_get_log_size(hdev); 997 hdev->log = hdev->log_size ? 998 g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL; 999 r = ioctl(hdev->control, VHOST_SET_LOG_BASE, 1000 (uint64_t)(unsigned long)hdev->log); 1001 if (r < 0) { 1002 r = -errno; 1003 goto fail_log; 1004 } 1005 } 1006 1007 return 0; 1008 fail_log: 1009 fail_vq: 1010 while (--i >= 0) { 1011 vhost_virtqueue_stop(hdev, 1012 vdev, 1013 hdev->vqs + i, 1014 hdev->vq_index + i); 1015 } 1016 i = hdev->nvqs; 1017 fail_mem: 1018 fail_features: 1019 1020 hdev->started = false; 1021 return r; 1022 } 1023 1024 /* Host notifiers must be enabled at this point. */ 1025 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1026 { 1027 int i; 1028 1029 for (i = 0; i < hdev->nvqs; ++i) { 1030 vhost_virtqueue_stop(hdev, 1031 vdev, 1032 hdev->vqs + i, 1033 hdev->vq_index + i); 1034 } 1035 vhost_log_sync_range(hdev, 0, ~0x0ull); 1036 1037 hdev->started = false; 1038 g_free(hdev->log); 1039 hdev->log = NULL; 1040 hdev->log_size = 0; 1041 } 1042 1043