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/atomic.h" 20 #include "qemu/range.h" 21 #include <linux/vhost.h> 22 #include "exec/address-spaces.h" 23 #include "hw/virtio/virtio-bus.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 = ioctl(dev->control, 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 if (dev->log) { 299 g_free(dev->log); 300 } 301 dev->log = log; 302 dev->log_size = size; 303 } 304 305 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 306 uint64_t start_addr, 307 uint64_t size) 308 { 309 int i; 310 for (i = 0; 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 return -ENOMEM; 323 } 324 if (p != vq->ring) { 325 fprintf(stderr, "Ring buffer relocated for ring %d\n", i); 326 return -EBUSY; 327 } 328 cpu_physical_memory_unmap(p, l, 0, 0); 329 } 330 return 0; 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 = ioctl(dev->control, 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 = ioctl(dev->control, 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 = ioctl(dev->control, 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 = ioctl(dev->control, 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 if (dev->log) { 605 g_free(dev->log); 606 } 607 dev->log = NULL; 608 dev->log_size = 0; 609 } else { 610 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 611 r = vhost_dev_set_log(dev, true); 612 if (r < 0) { 613 return r; 614 } 615 } 616 dev->log_enabled = enable; 617 return 0; 618 } 619 620 static void vhost_log_global_start(MemoryListener *listener) 621 { 622 int r; 623 624 r = vhost_migration_log(listener, true); 625 if (r < 0) { 626 abort(); 627 } 628 } 629 630 static void vhost_log_global_stop(MemoryListener *listener) 631 { 632 int r; 633 634 r = vhost_migration_log(listener, false); 635 if (r < 0) { 636 abort(); 637 } 638 } 639 640 static void vhost_log_start(MemoryListener *listener, 641 MemoryRegionSection *section) 642 { 643 /* FIXME: implement */ 644 } 645 646 static void vhost_log_stop(MemoryListener *listener, 647 MemoryRegionSection *section) 648 { 649 /* FIXME: implement */ 650 } 651 652 static int vhost_virtqueue_start(struct vhost_dev *dev, 653 struct VirtIODevice *vdev, 654 struct vhost_virtqueue *vq, 655 unsigned idx) 656 { 657 hwaddr s, l, a; 658 int r; 659 int vhost_vq_index = idx - dev->vq_index; 660 struct vhost_vring_file file = { 661 .index = vhost_vq_index 662 }; 663 struct vhost_vring_state state = { 664 .index = vhost_vq_index 665 }; 666 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 667 668 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 669 670 vq->num = state.num = virtio_queue_get_num(vdev, idx); 671 r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state); 672 if (r) { 673 return -errno; 674 } 675 676 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 677 r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state); 678 if (r) { 679 return -errno; 680 } 681 682 s = l = virtio_queue_get_desc_size(vdev, idx); 683 a = virtio_queue_get_desc_addr(vdev, idx); 684 vq->desc = cpu_physical_memory_map(a, &l, 0); 685 if (!vq->desc || l != s) { 686 r = -ENOMEM; 687 goto fail_alloc_desc; 688 } 689 s = l = virtio_queue_get_avail_size(vdev, idx); 690 a = virtio_queue_get_avail_addr(vdev, idx); 691 vq->avail = cpu_physical_memory_map(a, &l, 0); 692 if (!vq->avail || l != s) { 693 r = -ENOMEM; 694 goto fail_alloc_avail; 695 } 696 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 697 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 698 vq->used = cpu_physical_memory_map(a, &l, 1); 699 if (!vq->used || l != s) { 700 r = -ENOMEM; 701 goto fail_alloc_used; 702 } 703 704 vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx); 705 vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx); 706 vq->ring = cpu_physical_memory_map(a, &l, 1); 707 if (!vq->ring || l != s) { 708 r = -ENOMEM; 709 goto fail_alloc_ring; 710 } 711 712 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 713 if (r < 0) { 714 r = -errno; 715 goto fail_alloc; 716 } 717 718 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 719 r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file); 720 if (r) { 721 r = -errno; 722 goto fail_kick; 723 } 724 725 /* Clear and discard previous events if any. */ 726 event_notifier_test_and_clear(&vq->masked_notifier); 727 728 return 0; 729 730 fail_kick: 731 fail_alloc: 732 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 733 0, 0); 734 fail_alloc_ring: 735 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 736 0, 0); 737 fail_alloc_used: 738 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 739 0, 0); 740 fail_alloc_avail: 741 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 742 0, 0); 743 fail_alloc_desc: 744 return r; 745 } 746 747 static void vhost_virtqueue_stop(struct vhost_dev *dev, 748 struct VirtIODevice *vdev, 749 struct vhost_virtqueue *vq, 750 unsigned idx) 751 { 752 struct vhost_vring_state state = { 753 .index = idx - dev->vq_index 754 }; 755 int r; 756 assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); 757 r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state); 758 if (r < 0) { 759 fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r); 760 fflush(stderr); 761 } 762 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 763 virtio_queue_invalidate_signalled_used(vdev, idx); 764 assert (r >= 0); 765 cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), 766 0, virtio_queue_get_ring_size(vdev, idx)); 767 cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), 768 1, virtio_queue_get_used_size(vdev, idx)); 769 cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), 770 0, virtio_queue_get_avail_size(vdev, idx)); 771 cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), 772 0, virtio_queue_get_desc_size(vdev, idx)); 773 } 774 775 static void vhost_eventfd_add(MemoryListener *listener, 776 MemoryRegionSection *section, 777 bool match_data, uint64_t data, EventNotifier *e) 778 { 779 } 780 781 static void vhost_eventfd_del(MemoryListener *listener, 782 MemoryRegionSection *section, 783 bool match_data, uint64_t data, EventNotifier *e) 784 { 785 } 786 787 static int vhost_virtqueue_init(struct vhost_dev *dev, 788 struct vhost_virtqueue *vq, int n) 789 { 790 struct vhost_vring_file file = { 791 .index = n, 792 }; 793 int r = event_notifier_init(&vq->masked_notifier, 0); 794 if (r < 0) { 795 return r; 796 } 797 798 file.fd = event_notifier_get_fd(&vq->masked_notifier); 799 r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file); 800 if (r) { 801 r = -errno; 802 goto fail_call; 803 } 804 return 0; 805 fail_call: 806 event_notifier_cleanup(&vq->masked_notifier); 807 return r; 808 } 809 810 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 811 { 812 event_notifier_cleanup(&vq->masked_notifier); 813 } 814 815 int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath, 816 bool force) 817 { 818 uint64_t features; 819 int i, r; 820 if (devfd >= 0) { 821 hdev->control = devfd; 822 } else { 823 hdev->control = open(devpath, O_RDWR); 824 if (hdev->control < 0) { 825 return -errno; 826 } 827 } 828 r = ioctl(hdev->control, VHOST_SET_OWNER, NULL); 829 if (r < 0) { 830 goto fail; 831 } 832 833 r = ioctl(hdev->control, VHOST_GET_FEATURES, &features); 834 if (r < 0) { 835 goto fail; 836 } 837 838 for (i = 0; i < hdev->nvqs; ++i) { 839 r = vhost_virtqueue_init(hdev, hdev->vqs + i, i); 840 if (r < 0) { 841 goto fail_vq; 842 } 843 } 844 hdev->features = features; 845 846 hdev->memory_listener = (MemoryListener) { 847 .begin = vhost_begin, 848 .commit = vhost_commit, 849 .region_add = vhost_region_add, 850 .region_del = vhost_region_del, 851 .region_nop = vhost_region_nop, 852 .log_start = vhost_log_start, 853 .log_stop = vhost_log_stop, 854 .log_sync = vhost_log_sync, 855 .log_global_start = vhost_log_global_start, 856 .log_global_stop = vhost_log_global_stop, 857 .eventfd_add = vhost_eventfd_add, 858 .eventfd_del = vhost_eventfd_del, 859 .priority = 10 860 }; 861 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 862 hdev->n_mem_sections = 0; 863 hdev->mem_sections = NULL; 864 hdev->log = NULL; 865 hdev->log_size = 0; 866 hdev->log_enabled = false; 867 hdev->started = false; 868 hdev->memory_changed = false; 869 memory_listener_register(&hdev->memory_listener, &address_space_memory); 870 hdev->force = force; 871 return 0; 872 fail_vq: 873 while (--i >= 0) { 874 vhost_virtqueue_cleanup(hdev->vqs + i); 875 } 876 fail: 877 r = -errno; 878 close(hdev->control); 879 return r; 880 } 881 882 void vhost_dev_cleanup(struct vhost_dev *hdev) 883 { 884 int i; 885 for (i = 0; i < hdev->nvqs; ++i) { 886 vhost_virtqueue_cleanup(hdev->vqs + i); 887 } 888 memory_listener_unregister(&hdev->memory_listener); 889 g_free(hdev->mem); 890 g_free(hdev->mem_sections); 891 close(hdev->control); 892 } 893 894 bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev) 895 { 896 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 897 VirtioBusState *vbus = VIRTIO_BUS(qbus); 898 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 899 900 return !k->query_guest_notifiers || 901 k->query_guest_notifiers(qbus->parent) || 902 hdev->force; 903 } 904 905 /* Stop processing guest IO notifications in qemu. 906 * Start processing them in vhost in kernel. 907 */ 908 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 909 { 910 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 911 VirtioBusState *vbus = VIRTIO_BUS(qbus); 912 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 913 int i, r; 914 if (!k->set_host_notifier) { 915 fprintf(stderr, "binding does not support host notifiers\n"); 916 r = -ENOSYS; 917 goto fail; 918 } 919 920 for (i = 0; i < hdev->nvqs; ++i) { 921 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, true); 922 if (r < 0) { 923 fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r); 924 goto fail_vq; 925 } 926 } 927 928 return 0; 929 fail_vq: 930 while (--i >= 0) { 931 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); 932 if (r < 0) { 933 fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); 934 fflush(stderr); 935 } 936 assert (r >= 0); 937 } 938 fail: 939 return r; 940 } 941 942 /* Stop processing guest IO notifications in vhost. 943 * Start processing them in qemu. 944 * This might actually run the qemu handlers right away, 945 * so virtio in qemu must be completely setup when this is called. 946 */ 947 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 948 { 949 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 950 VirtioBusState *vbus = VIRTIO_BUS(qbus); 951 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 952 int i, r; 953 954 for (i = 0; i < hdev->nvqs; ++i) { 955 r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); 956 if (r < 0) { 957 fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r); 958 fflush(stderr); 959 } 960 assert (r >= 0); 961 } 962 } 963 964 /* Test and clear event pending status. 965 * Should be called after unmask to avoid losing events. 966 */ 967 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 968 { 969 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 970 assert(hdev->started); 971 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 972 return event_notifier_test_and_clear(&vq->masked_notifier); 973 } 974 975 /* Mask/unmask events from this vq. */ 976 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 977 bool mask) 978 { 979 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 980 int r, index = n - hdev->vq_index; 981 982 assert(hdev->started); 983 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 984 985 struct vhost_vring_file file = { 986 .index = index 987 }; 988 if (mask) { 989 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 990 } else { 991 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 992 } 993 r = ioctl(hdev->control, VHOST_SET_VRING_CALL, &file); 994 assert(r >= 0); 995 } 996 997 /* Host notifiers must be enabled at this point. */ 998 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 999 { 1000 int i, r; 1001 1002 hdev->started = true; 1003 1004 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1005 if (r < 0) { 1006 goto fail_features; 1007 } 1008 r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem); 1009 if (r < 0) { 1010 r = -errno; 1011 goto fail_mem; 1012 } 1013 for (i = 0; i < hdev->nvqs; ++i) { 1014 r = vhost_virtqueue_start(hdev, 1015 vdev, 1016 hdev->vqs + i, 1017 hdev->vq_index + i); 1018 if (r < 0) { 1019 goto fail_vq; 1020 } 1021 } 1022 1023 if (hdev->log_enabled) { 1024 hdev->log_size = vhost_get_log_size(hdev); 1025 hdev->log = hdev->log_size ? 1026 g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL; 1027 r = ioctl(hdev->control, VHOST_SET_LOG_BASE, 1028 (uint64_t)(unsigned long)hdev->log); 1029 if (r < 0) { 1030 r = -errno; 1031 goto fail_log; 1032 } 1033 } 1034 1035 return 0; 1036 fail_log: 1037 fail_vq: 1038 while (--i >= 0) { 1039 vhost_virtqueue_stop(hdev, 1040 vdev, 1041 hdev->vqs + i, 1042 hdev->vq_index + i); 1043 } 1044 i = hdev->nvqs; 1045 fail_mem: 1046 fail_features: 1047 1048 hdev->started = false; 1049 return r; 1050 } 1051 1052 /* Host notifiers must be enabled at this point. */ 1053 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1054 { 1055 int i; 1056 1057 for (i = 0; i < hdev->nvqs; ++i) { 1058 vhost_virtqueue_stop(hdev, 1059 vdev, 1060 hdev->vqs + i, 1061 hdev->vq_index + i); 1062 } 1063 vhost_log_sync_range(hdev, 0, ~0x0ull); 1064 1065 hdev->started = false; 1066 g_free(hdev->log); 1067 hdev->log = NULL; 1068 hdev->log_size = 0; 1069 } 1070 1071