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 "qemu/osdep.h" 17 #include "qapi/error.h" 18 #include "hw/virtio/vhost.h" 19 #include "hw/hw.h" 20 #include "qemu/atomic.h" 21 #include "qemu/range.h" 22 #include "qemu/error-report.h" 23 #include "qemu/memfd.h" 24 #include <linux/vhost.h> 25 #include "exec/address-spaces.h" 26 #include "hw/virtio/virtio-bus.h" 27 #include "hw/virtio/virtio-access.h" 28 #include "migration/migration.h" 29 #include "sysemu/dma.h" 30 31 /* enabled until disconnected backend stabilizes */ 32 #define _VHOST_DEBUG 1 33 34 #ifdef _VHOST_DEBUG 35 #define VHOST_OPS_DEBUG(fmt, ...) \ 36 do { error_report(fmt ": %s (%d)", ## __VA_ARGS__, \ 37 strerror(errno), errno); } while (0) 38 #else 39 #define VHOST_OPS_DEBUG(fmt, ...) \ 40 do { } while (0) 41 #endif 42 43 static struct vhost_log *vhost_log; 44 static struct vhost_log *vhost_log_shm; 45 46 static unsigned int used_memslots; 47 static QLIST_HEAD(, vhost_dev) vhost_devices = 48 QLIST_HEAD_INITIALIZER(vhost_devices); 49 50 bool vhost_has_free_slot(void) 51 { 52 unsigned int slots_limit = ~0U; 53 struct vhost_dev *hdev; 54 55 QLIST_FOREACH(hdev, &vhost_devices, entry) { 56 unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 57 slots_limit = MIN(slots_limit, r); 58 } 59 return slots_limit > used_memslots; 60 } 61 62 static void vhost_dev_sync_region(struct vhost_dev *dev, 63 MemoryRegionSection *section, 64 uint64_t mfirst, uint64_t mlast, 65 uint64_t rfirst, uint64_t rlast) 66 { 67 vhost_log_chunk_t *log = dev->log->log; 68 69 uint64_t start = MAX(mfirst, rfirst); 70 uint64_t end = MIN(mlast, rlast); 71 vhost_log_chunk_t *from = log + start / VHOST_LOG_CHUNK; 72 vhost_log_chunk_t *to = log + end / VHOST_LOG_CHUNK + 1; 73 uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK; 74 75 if (end < start) { 76 return; 77 } 78 assert(end / VHOST_LOG_CHUNK < dev->log_size); 79 assert(start / VHOST_LOG_CHUNK < dev->log_size); 80 81 for (;from < to; ++from) { 82 vhost_log_chunk_t log; 83 /* We first check with non-atomic: much cheaper, 84 * and we expect non-dirty to be the common case. */ 85 if (!*from) { 86 addr += VHOST_LOG_CHUNK; 87 continue; 88 } 89 /* Data must be read atomically. We don't really need barrier semantics 90 * but it's easier to use atomic_* than roll our own. */ 91 log = atomic_xchg(from, 0); 92 while (log) { 93 int bit = ctzl(log); 94 hwaddr page_addr; 95 hwaddr section_offset; 96 hwaddr mr_offset; 97 page_addr = addr + bit * VHOST_LOG_PAGE; 98 section_offset = page_addr - section->offset_within_address_space; 99 mr_offset = section_offset + section->offset_within_region; 100 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 101 log &= ~(0x1ull << bit); 102 } 103 addr += VHOST_LOG_CHUNK; 104 } 105 } 106 107 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 108 MemoryRegionSection *section, 109 hwaddr first, 110 hwaddr last) 111 { 112 int i; 113 hwaddr start_addr; 114 hwaddr end_addr; 115 116 if (!dev->log_enabled || !dev->started) { 117 return 0; 118 } 119 start_addr = section->offset_within_address_space; 120 end_addr = range_get_last(start_addr, int128_get64(section->size)); 121 start_addr = MAX(first, start_addr); 122 end_addr = MIN(last, end_addr); 123 124 for (i = 0; i < dev->mem->nregions; ++i) { 125 struct vhost_memory_region *reg = dev->mem->regions + i; 126 vhost_dev_sync_region(dev, section, start_addr, end_addr, 127 reg->guest_phys_addr, 128 range_get_last(reg->guest_phys_addr, 129 reg->memory_size)); 130 } 131 for (i = 0; i < dev->nvqs; ++i) { 132 struct vhost_virtqueue *vq = dev->vqs + i; 133 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 134 range_get_last(vq->used_phys, vq->used_size)); 135 } 136 return 0; 137 } 138 139 static void vhost_log_sync(MemoryListener *listener, 140 MemoryRegionSection *section) 141 { 142 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 143 memory_listener); 144 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 145 } 146 147 static void vhost_log_sync_range(struct vhost_dev *dev, 148 hwaddr first, hwaddr last) 149 { 150 int i; 151 /* FIXME: this is N^2 in number of sections */ 152 for (i = 0; i < dev->n_mem_sections; ++i) { 153 MemoryRegionSection *section = &dev->mem_sections[i]; 154 vhost_sync_dirty_bitmap(dev, section, first, last); 155 } 156 } 157 158 /* Assign/unassign. Keep an unsorted array of non-overlapping 159 * memory regions in dev->mem. */ 160 static void vhost_dev_unassign_memory(struct vhost_dev *dev, 161 uint64_t start_addr, 162 uint64_t size) 163 { 164 int from, to, n = dev->mem->nregions; 165 /* Track overlapping/split regions for sanity checking. */ 166 int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0; 167 168 for (from = 0, to = 0; from < n; ++from, ++to) { 169 struct vhost_memory_region *reg = dev->mem->regions + to; 170 uint64_t reglast; 171 uint64_t memlast; 172 uint64_t change; 173 174 /* clone old region */ 175 if (to != from) { 176 memcpy(reg, dev->mem->regions + from, sizeof *reg); 177 } 178 179 /* No overlap is simple */ 180 if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size, 181 start_addr, size)) { 182 continue; 183 } 184 185 /* Split 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(!split); 189 190 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 191 memlast = range_get_last(start_addr, size); 192 193 /* Remove whole region */ 194 if (start_addr <= reg->guest_phys_addr && memlast >= reglast) { 195 --dev->mem->nregions; 196 --to; 197 ++overlap_middle; 198 continue; 199 } 200 201 /* Shrink region */ 202 if (memlast >= reglast) { 203 reg->memory_size = start_addr - reg->guest_phys_addr; 204 assert(reg->memory_size); 205 assert(!overlap_end); 206 ++overlap_end; 207 continue; 208 } 209 210 /* Shift region */ 211 if (start_addr <= reg->guest_phys_addr) { 212 change = memlast + 1 - reg->guest_phys_addr; 213 reg->memory_size -= change; 214 reg->guest_phys_addr += change; 215 reg->userspace_addr += change; 216 assert(reg->memory_size); 217 assert(!overlap_start); 218 ++overlap_start; 219 continue; 220 } 221 222 /* This only happens if supplied region 223 * is in the middle of an existing one. Thus it can not 224 * overlap with any other existing region. */ 225 assert(!overlap_start); 226 assert(!overlap_end); 227 assert(!overlap_middle); 228 /* Split region: shrink first part, shift second part. */ 229 memcpy(dev->mem->regions + n, reg, sizeof *reg); 230 reg->memory_size = start_addr - reg->guest_phys_addr; 231 assert(reg->memory_size); 232 change = memlast + 1 - reg->guest_phys_addr; 233 reg = dev->mem->regions + n; 234 reg->memory_size -= change; 235 assert(reg->memory_size); 236 reg->guest_phys_addr += change; 237 reg->userspace_addr += change; 238 /* Never add more than 1 region */ 239 assert(dev->mem->nregions == n); 240 ++dev->mem->nregions; 241 ++split; 242 } 243 } 244 245 /* Called after unassign, so no regions overlap the given range. */ 246 static void vhost_dev_assign_memory(struct vhost_dev *dev, 247 uint64_t start_addr, 248 uint64_t size, 249 uint64_t uaddr) 250 { 251 int from, to; 252 struct vhost_memory_region *merged = NULL; 253 for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) { 254 struct vhost_memory_region *reg = dev->mem->regions + to; 255 uint64_t prlast, urlast; 256 uint64_t pmlast, umlast; 257 uint64_t s, e, u; 258 259 /* clone old region */ 260 if (to != from) { 261 memcpy(reg, dev->mem->regions + from, sizeof *reg); 262 } 263 prlast = range_get_last(reg->guest_phys_addr, reg->memory_size); 264 pmlast = range_get_last(start_addr, size); 265 urlast = range_get_last(reg->userspace_addr, reg->memory_size); 266 umlast = range_get_last(uaddr, size); 267 268 /* check for overlapping regions: should never happen. */ 269 assert(prlast < start_addr || pmlast < reg->guest_phys_addr); 270 /* Not an adjacent or overlapping region - do not merge. */ 271 if ((prlast + 1 != start_addr || urlast + 1 != uaddr) && 272 (pmlast + 1 != reg->guest_phys_addr || 273 umlast + 1 != reg->userspace_addr)) { 274 continue; 275 } 276 277 if (dev->vhost_ops->vhost_backend_can_merge && 278 !dev->vhost_ops->vhost_backend_can_merge(dev, uaddr, size, 279 reg->userspace_addr, 280 reg->memory_size)) { 281 continue; 282 } 283 284 if (merged) { 285 --to; 286 assert(to >= 0); 287 } else { 288 merged = reg; 289 } 290 u = MIN(uaddr, reg->userspace_addr); 291 s = MIN(start_addr, reg->guest_phys_addr); 292 e = MAX(pmlast, prlast); 293 uaddr = merged->userspace_addr = u; 294 start_addr = merged->guest_phys_addr = s; 295 size = merged->memory_size = e - s + 1; 296 assert(merged->memory_size); 297 } 298 299 if (!merged) { 300 struct vhost_memory_region *reg = dev->mem->regions + to; 301 memset(reg, 0, sizeof *reg); 302 reg->memory_size = size; 303 assert(reg->memory_size); 304 reg->guest_phys_addr = start_addr; 305 reg->userspace_addr = uaddr; 306 ++to; 307 } 308 assert(to <= dev->mem->nregions + 1); 309 dev->mem->nregions = to; 310 } 311 312 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 313 { 314 uint64_t log_size = 0; 315 int i; 316 for (i = 0; i < dev->mem->nregions; ++i) { 317 struct vhost_memory_region *reg = dev->mem->regions + i; 318 uint64_t last = range_get_last(reg->guest_phys_addr, 319 reg->memory_size); 320 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 321 } 322 for (i = 0; i < dev->nvqs; ++i) { 323 struct vhost_virtqueue *vq = dev->vqs + i; 324 uint64_t last = vq->used_phys + vq->used_size - 1; 325 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 326 } 327 return log_size; 328 } 329 330 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 331 { 332 struct vhost_log *log; 333 uint64_t logsize = size * sizeof(*(log->log)); 334 int fd = -1; 335 336 log = g_new0(struct vhost_log, 1); 337 if (share) { 338 log->log = qemu_memfd_alloc("vhost-log", logsize, 339 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 340 &fd); 341 memset(log->log, 0, logsize); 342 } else { 343 log->log = g_malloc0(logsize); 344 } 345 346 log->size = size; 347 log->refcnt = 1; 348 log->fd = fd; 349 350 return log; 351 } 352 353 static struct vhost_log *vhost_log_get(uint64_t size, bool share) 354 { 355 struct vhost_log *log = share ? vhost_log_shm : vhost_log; 356 357 if (!log || log->size != size) { 358 log = vhost_log_alloc(size, share); 359 if (share) { 360 vhost_log_shm = log; 361 } else { 362 vhost_log = log; 363 } 364 } else { 365 ++log->refcnt; 366 } 367 368 return log; 369 } 370 371 static void vhost_log_put(struct vhost_dev *dev, bool sync) 372 { 373 struct vhost_log *log = dev->log; 374 375 if (!log) { 376 return; 377 } 378 dev->log = NULL; 379 dev->log_size = 0; 380 381 --log->refcnt; 382 if (log->refcnt == 0) { 383 /* Sync only the range covered by the old log */ 384 if (dev->log_size && sync) { 385 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 386 } 387 388 if (vhost_log == log) { 389 g_free(log->log); 390 vhost_log = NULL; 391 } else if (vhost_log_shm == log) { 392 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 393 log->fd); 394 vhost_log_shm = NULL; 395 } 396 397 g_free(log); 398 } 399 } 400 401 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 402 { 403 return dev->vhost_ops->vhost_requires_shm_log && 404 dev->vhost_ops->vhost_requires_shm_log(dev); 405 } 406 407 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 408 { 409 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 410 uint64_t log_base = (uintptr_t)log->log; 411 int r; 412 413 /* inform backend of log switching, this must be done before 414 releasing the current log, to ensure no logging is lost */ 415 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 416 if (r < 0) { 417 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 418 } 419 420 vhost_log_put(dev, true); 421 dev->log = log; 422 dev->log_size = size; 423 } 424 425 static int vhost_dev_has_iommu(struct vhost_dev *dev) 426 { 427 VirtIODevice *vdev = dev->vdev; 428 AddressSpace *dma_as = vdev->dma_as; 429 430 return memory_region_is_iommu(dma_as->root) && 431 virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 432 } 433 434 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 435 hwaddr *plen, int is_write) 436 { 437 if (!vhost_dev_has_iommu(dev)) { 438 return cpu_physical_memory_map(addr, plen, is_write); 439 } else { 440 return (void *)(uintptr_t)addr; 441 } 442 } 443 444 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 445 hwaddr len, int is_write, 446 hwaddr access_len) 447 { 448 if (!vhost_dev_has_iommu(dev)) { 449 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 450 } 451 } 452 453 static int vhost_verify_ring_part_mapping(struct vhost_dev *dev, 454 void *part, 455 uint64_t part_addr, 456 uint64_t part_size, 457 uint64_t start_addr, 458 uint64_t size) 459 { 460 hwaddr l; 461 void *p; 462 int r = 0; 463 464 if (!ranges_overlap(start_addr, size, part_addr, part_size)) { 465 return 0; 466 } 467 l = part_size; 468 p = vhost_memory_map(dev, part_addr, &l, 1); 469 if (!p || l != part_size) { 470 r = -ENOMEM; 471 } 472 if (p != part) { 473 r = -EBUSY; 474 } 475 vhost_memory_unmap(dev, p, l, 0, 0); 476 return r; 477 } 478 479 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 480 uint64_t start_addr, 481 uint64_t size) 482 { 483 int i, j; 484 int r = 0; 485 const char *part_name[] = { 486 "descriptor table", 487 "available ring", 488 "used ring" 489 }; 490 491 for (i = 0; i < dev->nvqs; ++i) { 492 struct vhost_virtqueue *vq = dev->vqs + i; 493 494 j = 0; 495 r = vhost_verify_ring_part_mapping(dev, vq->desc, vq->desc_phys, 496 vq->desc_size, start_addr, size); 497 if (!r) { 498 break; 499 } 500 501 j++; 502 r = vhost_verify_ring_part_mapping(dev, vq->avail, vq->avail_phys, 503 vq->avail_size, start_addr, size); 504 if (!r) { 505 break; 506 } 507 508 j++; 509 r = vhost_verify_ring_part_mapping(dev, vq->used, vq->used_phys, 510 vq->used_size, start_addr, size); 511 if (!r) { 512 break; 513 } 514 } 515 516 if (r == -ENOMEM) { 517 error_report("Unable to map %s for ring %d", part_name[j], i); 518 } else if (r == -EBUSY) { 519 error_report("%s relocated for ring %d", part_name[j], i); 520 } 521 return r; 522 } 523 524 static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, 525 uint64_t start_addr, 526 uint64_t size) 527 { 528 int i, n = dev->mem->nregions; 529 for (i = 0; i < n; ++i) { 530 struct vhost_memory_region *reg = dev->mem->regions + i; 531 if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, 532 start_addr, size)) { 533 return reg; 534 } 535 } 536 return NULL; 537 } 538 539 static bool vhost_dev_cmp_memory(struct vhost_dev *dev, 540 uint64_t start_addr, 541 uint64_t size, 542 uint64_t uaddr) 543 { 544 struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); 545 uint64_t reglast; 546 uint64_t memlast; 547 548 if (!reg) { 549 return true; 550 } 551 552 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 553 memlast = range_get_last(start_addr, size); 554 555 /* Need to extend region? */ 556 if (start_addr < reg->guest_phys_addr || memlast > reglast) { 557 return true; 558 } 559 /* userspace_addr changed? */ 560 return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; 561 } 562 563 static void vhost_set_memory(MemoryListener *listener, 564 MemoryRegionSection *section, 565 bool add) 566 { 567 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 568 memory_listener); 569 hwaddr start_addr = section->offset_within_address_space; 570 ram_addr_t size = int128_get64(section->size); 571 bool log_dirty = 572 memory_region_get_dirty_log_mask(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); 573 int s = offsetof(struct vhost_memory, regions) + 574 (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; 575 void *ram; 576 577 dev->mem = g_realloc(dev->mem, s); 578 579 if (log_dirty) { 580 add = false; 581 } 582 583 assert(size); 584 585 /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ 586 ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; 587 if (add) { 588 if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { 589 /* Region exists with same address. Nothing to do. */ 590 return; 591 } 592 } else { 593 if (!vhost_dev_find_reg(dev, start_addr, size)) { 594 /* Removing region that we don't access. Nothing to do. */ 595 return; 596 } 597 } 598 599 vhost_dev_unassign_memory(dev, start_addr, size); 600 if (add) { 601 /* Add given mapping, merging adjacent regions if any */ 602 vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); 603 } else { 604 /* Remove old mapping for this memory, if any. */ 605 vhost_dev_unassign_memory(dev, start_addr, size); 606 } 607 dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr); 608 dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1); 609 dev->memory_changed = true; 610 used_memslots = dev->mem->nregions; 611 } 612 613 static bool vhost_section(MemoryRegionSection *section) 614 { 615 return memory_region_is_ram(section->mr); 616 } 617 618 static void vhost_begin(MemoryListener *listener) 619 { 620 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 621 memory_listener); 622 dev->mem_changed_end_addr = 0; 623 dev->mem_changed_start_addr = -1; 624 } 625 626 static void vhost_commit(MemoryListener *listener) 627 { 628 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 629 memory_listener); 630 hwaddr start_addr = 0; 631 ram_addr_t size = 0; 632 uint64_t log_size; 633 int r; 634 635 if (!dev->memory_changed) { 636 return; 637 } 638 if (!dev->started) { 639 return; 640 } 641 if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) { 642 return; 643 } 644 645 if (dev->started) { 646 start_addr = dev->mem_changed_start_addr; 647 size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1; 648 649 r = vhost_verify_ring_mappings(dev, start_addr, size); 650 assert(r >= 0); 651 } 652 653 if (!dev->log_enabled) { 654 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 655 if (r < 0) { 656 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 657 } 658 dev->memory_changed = false; 659 return; 660 } 661 log_size = vhost_get_log_size(dev); 662 /* We allocate an extra 4K bytes to log, 663 * to reduce the * number of reallocations. */ 664 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 665 /* To log more, must increase log size before table update. */ 666 if (dev->log_size < log_size) { 667 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 668 } 669 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 670 if (r < 0) { 671 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 672 } 673 /* To log less, can only decrease log size after table update. */ 674 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 675 vhost_dev_log_resize(dev, log_size); 676 } 677 dev->memory_changed = false; 678 } 679 680 static void vhost_region_add(MemoryListener *listener, 681 MemoryRegionSection *section) 682 { 683 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 684 memory_listener); 685 686 if (!vhost_section(section)) { 687 return; 688 } 689 690 ++dev->n_mem_sections; 691 dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections, 692 dev->n_mem_sections); 693 dev->mem_sections[dev->n_mem_sections - 1] = *section; 694 memory_region_ref(section->mr); 695 vhost_set_memory(listener, section, true); 696 } 697 698 static void vhost_region_del(MemoryListener *listener, 699 MemoryRegionSection *section) 700 { 701 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 702 memory_listener); 703 int i; 704 705 if (!vhost_section(section)) { 706 return; 707 } 708 709 vhost_set_memory(listener, section, false); 710 memory_region_unref(section->mr); 711 for (i = 0; i < dev->n_mem_sections; ++i) { 712 if (dev->mem_sections[i].offset_within_address_space 713 == section->offset_within_address_space) { 714 --dev->n_mem_sections; 715 memmove(&dev->mem_sections[i], &dev->mem_sections[i+1], 716 (dev->n_mem_sections - i) * sizeof(*dev->mem_sections)); 717 break; 718 } 719 } 720 } 721 722 static void vhost_region_nop(MemoryListener *listener, 723 MemoryRegionSection *section) 724 { 725 } 726 727 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 728 struct vhost_virtqueue *vq, 729 unsigned idx, bool enable_log) 730 { 731 struct vhost_vring_addr addr = { 732 .index = idx, 733 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 734 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 735 .used_user_addr = (uint64_t)(unsigned long)vq->used, 736 .log_guest_addr = vq->used_phys, 737 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 738 }; 739 int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 740 if (r < 0) { 741 VHOST_OPS_DEBUG("vhost_set_vring_addr failed"); 742 return -errno; 743 } 744 return 0; 745 } 746 747 static int vhost_dev_set_features(struct vhost_dev *dev, 748 bool enable_log) 749 { 750 uint64_t features = dev->acked_features; 751 int r; 752 if (enable_log) { 753 features |= 0x1ULL << VHOST_F_LOG_ALL; 754 } 755 r = dev->vhost_ops->vhost_set_features(dev, features); 756 if (r < 0) { 757 VHOST_OPS_DEBUG("vhost_set_features failed"); 758 } 759 return r < 0 ? -errno : 0; 760 } 761 762 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 763 { 764 int r, i, idx; 765 r = vhost_dev_set_features(dev, enable_log); 766 if (r < 0) { 767 goto err_features; 768 } 769 for (i = 0; i < dev->nvqs; ++i) { 770 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 771 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 772 enable_log); 773 if (r < 0) { 774 goto err_vq; 775 } 776 } 777 return 0; 778 err_vq: 779 for (; i >= 0; --i) { 780 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 781 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 782 dev->log_enabled); 783 } 784 vhost_dev_set_features(dev, dev->log_enabled); 785 err_features: 786 return r; 787 } 788 789 static int vhost_migration_log(MemoryListener *listener, int enable) 790 { 791 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 792 memory_listener); 793 int r; 794 if (!!enable == dev->log_enabled) { 795 return 0; 796 } 797 if (!dev->started) { 798 dev->log_enabled = enable; 799 return 0; 800 } 801 if (!enable) { 802 r = vhost_dev_set_log(dev, false); 803 if (r < 0) { 804 return r; 805 } 806 vhost_log_put(dev, false); 807 } else { 808 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 809 r = vhost_dev_set_log(dev, true); 810 if (r < 0) { 811 return r; 812 } 813 } 814 dev->log_enabled = enable; 815 return 0; 816 } 817 818 static void vhost_log_global_start(MemoryListener *listener) 819 { 820 int r; 821 822 r = vhost_migration_log(listener, true); 823 if (r < 0) { 824 abort(); 825 } 826 } 827 828 static void vhost_log_global_stop(MemoryListener *listener) 829 { 830 int r; 831 832 r = vhost_migration_log(listener, false); 833 if (r < 0) { 834 abort(); 835 } 836 } 837 838 static void vhost_log_start(MemoryListener *listener, 839 MemoryRegionSection *section, 840 int old, int new) 841 { 842 /* FIXME: implement */ 843 } 844 845 static void vhost_log_stop(MemoryListener *listener, 846 MemoryRegionSection *section, 847 int old, int new) 848 { 849 /* FIXME: implement */ 850 } 851 852 /* The vhost driver natively knows how to handle the vrings of non 853 * cross-endian legacy devices and modern devices. Only legacy devices 854 * exposed to a bi-endian guest may require the vhost driver to use a 855 * specific endianness. 856 */ 857 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 858 { 859 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 860 return false; 861 } 862 #ifdef HOST_WORDS_BIGENDIAN 863 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 864 #else 865 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 866 #endif 867 } 868 869 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 870 bool is_big_endian, 871 int vhost_vq_index) 872 { 873 struct vhost_vring_state s = { 874 .index = vhost_vq_index, 875 .num = is_big_endian 876 }; 877 878 if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { 879 return 0; 880 } 881 882 VHOST_OPS_DEBUG("vhost_set_vring_endian failed"); 883 if (errno == ENOTTY) { 884 error_report("vhost does not support cross-endian"); 885 return -ENOSYS; 886 } 887 888 return -errno; 889 } 890 891 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 892 uint64_t gpa, uint64_t *uaddr, 893 uint64_t *len) 894 { 895 int i; 896 897 for (i = 0; i < hdev->mem->nregions; i++) { 898 struct vhost_memory_region *reg = hdev->mem->regions + i; 899 900 if (gpa >= reg->guest_phys_addr && 901 reg->guest_phys_addr + reg->memory_size > gpa) { 902 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 903 *len = reg->guest_phys_addr + reg->memory_size - gpa; 904 return 0; 905 } 906 } 907 908 return -EFAULT; 909 } 910 911 void vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 912 { 913 IOMMUTLBEntry iotlb; 914 uint64_t uaddr, len; 915 916 rcu_read_lock(); 917 918 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 919 iova, write); 920 if (iotlb.target_as != NULL) { 921 if (vhost_memory_region_lookup(dev, iotlb.translated_addr, 922 &uaddr, &len)) { 923 error_report("Fail to lookup the translated address " 924 "%"PRIx64, iotlb.translated_addr); 925 goto out; 926 } 927 928 len = MIN(iotlb.addr_mask + 1, len); 929 iova = iova & ~iotlb.addr_mask; 930 931 if (dev->vhost_ops->vhost_update_device_iotlb(dev, iova, uaddr, 932 len, iotlb.perm)) { 933 error_report("Fail to update device iotlb"); 934 goto out; 935 } 936 } 937 out: 938 rcu_read_unlock(); 939 } 940 941 static int vhost_virtqueue_start(struct vhost_dev *dev, 942 struct VirtIODevice *vdev, 943 struct vhost_virtqueue *vq, 944 unsigned idx) 945 { 946 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 947 VirtioBusState *vbus = VIRTIO_BUS(qbus); 948 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 949 hwaddr s, l, a; 950 int r; 951 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 952 struct vhost_vring_file file = { 953 .index = vhost_vq_index 954 }; 955 struct vhost_vring_state state = { 956 .index = vhost_vq_index 957 }; 958 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 959 960 961 vq->num = state.num = virtio_queue_get_num(vdev, idx); 962 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 963 if (r) { 964 VHOST_OPS_DEBUG("vhost_set_vring_num failed"); 965 return -errno; 966 } 967 968 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 969 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 970 if (r) { 971 VHOST_OPS_DEBUG("vhost_set_vring_base failed"); 972 return -errno; 973 } 974 975 if (vhost_needs_vring_endian(vdev)) { 976 r = vhost_virtqueue_set_vring_endian_legacy(dev, 977 virtio_is_big_endian(vdev), 978 vhost_vq_index); 979 if (r) { 980 return -errno; 981 } 982 } 983 984 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 985 vq->desc_phys = a = virtio_queue_get_desc_addr(vdev, idx); 986 vq->desc = vhost_memory_map(dev, a, &l, 0); 987 if (!vq->desc || l != s) { 988 r = -ENOMEM; 989 goto fail_alloc_desc; 990 } 991 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 992 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 993 vq->avail = vhost_memory_map(dev, a, &l, 0); 994 if (!vq->avail || l != s) { 995 r = -ENOMEM; 996 goto fail_alloc_avail; 997 } 998 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 999 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1000 vq->used = vhost_memory_map(dev, a, &l, 1); 1001 if (!vq->used || l != s) { 1002 r = -ENOMEM; 1003 goto fail_alloc_used; 1004 } 1005 1006 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1007 if (r < 0) { 1008 r = -errno; 1009 goto fail_alloc; 1010 } 1011 1012 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1013 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1014 if (r) { 1015 VHOST_OPS_DEBUG("vhost_set_vring_kick failed"); 1016 r = -errno; 1017 goto fail_kick; 1018 } 1019 1020 /* Clear and discard previous events if any. */ 1021 event_notifier_test_and_clear(&vq->masked_notifier); 1022 1023 /* Init vring in unmasked state, unless guest_notifier_mask 1024 * will do it later. 1025 */ 1026 if (!vdev->use_guest_notifier_mask) { 1027 /* TODO: check and handle errors. */ 1028 vhost_virtqueue_mask(dev, vdev, idx, false); 1029 } 1030 1031 if (k->query_guest_notifiers && 1032 k->query_guest_notifiers(qbus->parent) && 1033 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1034 file.fd = -1; 1035 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1036 if (r) { 1037 goto fail_vector; 1038 } 1039 } 1040 1041 return 0; 1042 1043 fail_vector: 1044 fail_kick: 1045 fail_alloc: 1046 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1047 0, 0); 1048 fail_alloc_used: 1049 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1050 0, 0); 1051 fail_alloc_avail: 1052 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1053 0, 0); 1054 fail_alloc_desc: 1055 return r; 1056 } 1057 1058 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1059 struct VirtIODevice *vdev, 1060 struct vhost_virtqueue *vq, 1061 unsigned idx) 1062 { 1063 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1064 struct vhost_vring_state state = { 1065 .index = vhost_vq_index, 1066 }; 1067 int r; 1068 1069 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1070 if (r < 0) { 1071 VHOST_OPS_DEBUG("vhost VQ %d ring restore failed: %d", idx, r); 1072 } else { 1073 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1074 } 1075 virtio_queue_invalidate_signalled_used(vdev, idx); 1076 virtio_queue_update_used_idx(vdev, idx); 1077 1078 /* In the cross-endian case, we need to reset the vring endianness to 1079 * native as legacy devices expect so by default. 1080 */ 1081 if (vhost_needs_vring_endian(vdev)) { 1082 vhost_virtqueue_set_vring_endian_legacy(dev, 1083 !virtio_is_big_endian(vdev), 1084 vhost_vq_index); 1085 } 1086 1087 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1088 1, virtio_queue_get_used_size(vdev, idx)); 1089 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1090 0, virtio_queue_get_avail_size(vdev, idx)); 1091 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1092 0, virtio_queue_get_desc_size(vdev, idx)); 1093 } 1094 1095 static void vhost_eventfd_add(MemoryListener *listener, 1096 MemoryRegionSection *section, 1097 bool match_data, uint64_t data, EventNotifier *e) 1098 { 1099 } 1100 1101 static void vhost_eventfd_del(MemoryListener *listener, 1102 MemoryRegionSection *section, 1103 bool match_data, uint64_t data, EventNotifier *e) 1104 { 1105 } 1106 1107 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1108 int n, uint32_t timeout) 1109 { 1110 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1111 struct vhost_vring_state state = { 1112 .index = vhost_vq_index, 1113 .num = timeout, 1114 }; 1115 int r; 1116 1117 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1118 return -EINVAL; 1119 } 1120 1121 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1122 if (r) { 1123 VHOST_OPS_DEBUG("vhost_set_vring_busyloop_timeout failed"); 1124 return r; 1125 } 1126 1127 return 0; 1128 } 1129 1130 static int vhost_virtqueue_init(struct vhost_dev *dev, 1131 struct vhost_virtqueue *vq, int n) 1132 { 1133 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1134 struct vhost_vring_file file = { 1135 .index = vhost_vq_index, 1136 }; 1137 int r = event_notifier_init(&vq->masked_notifier, 0); 1138 if (r < 0) { 1139 return r; 1140 } 1141 1142 file.fd = event_notifier_get_fd(&vq->masked_notifier); 1143 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1144 if (r) { 1145 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1146 r = -errno; 1147 goto fail_call; 1148 } 1149 1150 vq->dev = dev; 1151 1152 return 0; 1153 fail_call: 1154 event_notifier_cleanup(&vq->masked_notifier); 1155 return r; 1156 } 1157 1158 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1159 { 1160 event_notifier_cleanup(&vq->masked_notifier); 1161 } 1162 1163 static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 1164 { 1165 struct vhost_dev *hdev = container_of(n, struct vhost_dev, n); 1166 1167 if (hdev->vhost_ops->vhost_invalidate_device_iotlb(hdev, 1168 iotlb->iova, 1169 iotlb->addr_mask + 1)) { 1170 error_report("Fail to invalidate device iotlb"); 1171 } 1172 } 1173 1174 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1175 VhostBackendType backend_type, uint32_t busyloop_timeout) 1176 { 1177 uint64_t features; 1178 int i, r, n_initialized_vqs = 0; 1179 Error *local_err = NULL; 1180 1181 hdev->vdev = NULL; 1182 hdev->migration_blocker = NULL; 1183 1184 r = vhost_set_backend_type(hdev, backend_type); 1185 assert(r >= 0); 1186 1187 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque); 1188 if (r < 0) { 1189 goto fail; 1190 } 1191 1192 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1193 error_report("vhost backend memory slots limit is less" 1194 " than current number of present memory slots"); 1195 r = -1; 1196 goto fail; 1197 } 1198 1199 r = hdev->vhost_ops->vhost_set_owner(hdev); 1200 if (r < 0) { 1201 VHOST_OPS_DEBUG("vhost_set_owner failed"); 1202 goto fail; 1203 } 1204 1205 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1206 if (r < 0) { 1207 VHOST_OPS_DEBUG("vhost_get_features failed"); 1208 goto fail; 1209 } 1210 1211 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1212 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1213 if (r < 0) { 1214 goto fail; 1215 } 1216 } 1217 1218 if (busyloop_timeout) { 1219 for (i = 0; i < hdev->nvqs; ++i) { 1220 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1221 busyloop_timeout); 1222 if (r < 0) { 1223 goto fail_busyloop; 1224 } 1225 } 1226 } 1227 1228 hdev->features = features; 1229 1230 hdev->memory_listener = (MemoryListener) { 1231 .begin = vhost_begin, 1232 .commit = vhost_commit, 1233 .region_add = vhost_region_add, 1234 .region_del = vhost_region_del, 1235 .region_nop = vhost_region_nop, 1236 .log_start = vhost_log_start, 1237 .log_stop = vhost_log_stop, 1238 .log_sync = vhost_log_sync, 1239 .log_global_start = vhost_log_global_start, 1240 .log_global_stop = vhost_log_global_stop, 1241 .eventfd_add = vhost_eventfd_add, 1242 .eventfd_del = vhost_eventfd_del, 1243 .priority = 10 1244 }; 1245 1246 hdev->n.notify = vhost_iommu_unmap_notify; 1247 hdev->n.notifier_flags = IOMMU_NOTIFIER_UNMAP; 1248 1249 if (hdev->migration_blocker == NULL) { 1250 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1251 error_setg(&hdev->migration_blocker, 1252 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1253 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_check()) { 1254 error_setg(&hdev->migration_blocker, 1255 "Migration disabled: failed to allocate shared memory"); 1256 } 1257 } 1258 1259 if (hdev->migration_blocker != NULL) { 1260 r = migrate_add_blocker(hdev->migration_blocker, &local_err); 1261 if (local_err) { 1262 error_report_err(local_err); 1263 error_free(hdev->migration_blocker); 1264 goto fail_busyloop; 1265 } 1266 } 1267 1268 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1269 hdev->n_mem_sections = 0; 1270 hdev->mem_sections = NULL; 1271 hdev->log = NULL; 1272 hdev->log_size = 0; 1273 hdev->log_enabled = false; 1274 hdev->started = false; 1275 hdev->memory_changed = false; 1276 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1277 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1278 return 0; 1279 1280 fail_busyloop: 1281 while (--i >= 0) { 1282 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1283 } 1284 fail: 1285 hdev->nvqs = n_initialized_vqs; 1286 vhost_dev_cleanup(hdev); 1287 return r; 1288 } 1289 1290 void vhost_dev_cleanup(struct vhost_dev *hdev) 1291 { 1292 int i; 1293 1294 for (i = 0; i < hdev->nvqs; ++i) { 1295 vhost_virtqueue_cleanup(hdev->vqs + i); 1296 } 1297 if (hdev->mem) { 1298 /* those are only safe after successful init */ 1299 memory_listener_unregister(&hdev->memory_listener); 1300 QLIST_REMOVE(hdev, entry); 1301 } 1302 if (hdev->migration_blocker) { 1303 migrate_del_blocker(hdev->migration_blocker); 1304 error_free(hdev->migration_blocker); 1305 } 1306 g_free(hdev->mem); 1307 g_free(hdev->mem_sections); 1308 if (hdev->vhost_ops) { 1309 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1310 } 1311 assert(!hdev->log); 1312 1313 memset(hdev, 0, sizeof(struct vhost_dev)); 1314 } 1315 1316 /* Stop processing guest IO notifications in qemu. 1317 * Start processing them in vhost in kernel. 1318 */ 1319 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1320 { 1321 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1322 int i, r, e; 1323 1324 /* We will pass the notifiers to the kernel, make sure that QEMU 1325 * doesn't interfere. 1326 */ 1327 r = virtio_device_grab_ioeventfd(vdev); 1328 if (r < 0) { 1329 error_report("binding does not support host notifiers"); 1330 goto fail; 1331 } 1332 1333 for (i = 0; i < hdev->nvqs; ++i) { 1334 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1335 true); 1336 if (r < 0) { 1337 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1338 goto fail_vq; 1339 } 1340 } 1341 1342 return 0; 1343 fail_vq: 1344 while (--i >= 0) { 1345 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1346 false); 1347 if (e < 0) { 1348 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1349 } 1350 assert (e >= 0); 1351 } 1352 virtio_device_release_ioeventfd(vdev); 1353 fail: 1354 return r; 1355 } 1356 1357 /* Stop processing guest IO notifications in vhost. 1358 * Start processing them in qemu. 1359 * This might actually run the qemu handlers right away, 1360 * so virtio in qemu must be completely setup when this is called. 1361 */ 1362 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1363 { 1364 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1365 int i, r; 1366 1367 for (i = 0; i < hdev->nvqs; ++i) { 1368 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1369 false); 1370 if (r < 0) { 1371 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1372 } 1373 assert (r >= 0); 1374 } 1375 virtio_device_release_ioeventfd(vdev); 1376 } 1377 1378 /* Test and clear event pending status. 1379 * Should be called after unmask to avoid losing events. 1380 */ 1381 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1382 { 1383 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1384 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1385 return event_notifier_test_and_clear(&vq->masked_notifier); 1386 } 1387 1388 /* Mask/unmask events from this vq. */ 1389 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1390 bool mask) 1391 { 1392 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1393 int r, index = n - hdev->vq_index; 1394 struct vhost_vring_file file; 1395 1396 /* should only be called after backend is connected */ 1397 assert(hdev->vhost_ops); 1398 1399 if (mask) { 1400 assert(vdev->use_guest_notifier_mask); 1401 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1402 } else { 1403 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1404 } 1405 1406 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1407 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1408 if (r < 0) { 1409 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1410 } 1411 } 1412 1413 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1414 uint64_t features) 1415 { 1416 const int *bit = feature_bits; 1417 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1418 uint64_t bit_mask = (1ULL << *bit); 1419 if (!(hdev->features & bit_mask)) { 1420 features &= ~bit_mask; 1421 } 1422 bit++; 1423 } 1424 return features; 1425 } 1426 1427 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1428 uint64_t features) 1429 { 1430 const int *bit = feature_bits; 1431 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1432 uint64_t bit_mask = (1ULL << *bit); 1433 if (features & bit_mask) { 1434 hdev->acked_features |= bit_mask; 1435 } 1436 bit++; 1437 } 1438 } 1439 1440 /* Host notifiers must be enabled at this point. */ 1441 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1442 { 1443 int i, r; 1444 1445 /* should only be called after backend is connected */ 1446 assert(hdev->vhost_ops); 1447 1448 hdev->started = true; 1449 hdev->vdev = vdev; 1450 1451 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1452 if (r < 0) { 1453 goto fail_features; 1454 } 1455 1456 if (vhost_dev_has_iommu(hdev)) { 1457 memory_region_register_iommu_notifier(vdev->dma_as->root, 1458 &hdev->n); 1459 } 1460 1461 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1462 if (r < 0) { 1463 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 1464 r = -errno; 1465 goto fail_mem; 1466 } 1467 for (i = 0; i < hdev->nvqs; ++i) { 1468 r = vhost_virtqueue_start(hdev, 1469 vdev, 1470 hdev->vqs + i, 1471 hdev->vq_index + i); 1472 if (r < 0) { 1473 goto fail_vq; 1474 } 1475 } 1476 1477 if (hdev->log_enabled) { 1478 uint64_t log_base; 1479 1480 hdev->log_size = vhost_get_log_size(hdev); 1481 hdev->log = vhost_log_get(hdev->log_size, 1482 vhost_dev_log_is_shared(hdev)); 1483 log_base = (uintptr_t)hdev->log->log; 1484 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1485 hdev->log_size ? log_base : 0, 1486 hdev->log); 1487 if (r < 0) { 1488 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 1489 r = -errno; 1490 goto fail_log; 1491 } 1492 } 1493 1494 if (vhost_dev_has_iommu(hdev)) { 1495 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1496 1497 /* Update used ring information for IOTLB to work correctly, 1498 * vhost-kernel code requires for this.*/ 1499 for (i = 0; i < hdev->nvqs; ++i) { 1500 struct vhost_virtqueue *vq = hdev->vqs + i; 1501 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1502 } 1503 } 1504 return 0; 1505 fail_log: 1506 vhost_log_put(hdev, false); 1507 fail_vq: 1508 while (--i >= 0) { 1509 vhost_virtqueue_stop(hdev, 1510 vdev, 1511 hdev->vqs + i, 1512 hdev->vq_index + i); 1513 } 1514 i = hdev->nvqs; 1515 1516 fail_mem: 1517 fail_features: 1518 1519 hdev->started = false; 1520 return r; 1521 } 1522 1523 /* Host notifiers must be enabled at this point. */ 1524 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1525 { 1526 int i; 1527 1528 /* should only be called after backend is connected */ 1529 assert(hdev->vhost_ops); 1530 1531 for (i = 0; i < hdev->nvqs; ++i) { 1532 vhost_virtqueue_stop(hdev, 1533 vdev, 1534 hdev->vqs + i, 1535 hdev->vq_index + i); 1536 } 1537 1538 if (vhost_dev_has_iommu(hdev)) { 1539 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1540 memory_region_unregister_iommu_notifier(vdev->dma_as->root, 1541 &hdev->n); 1542 } 1543 vhost_log_put(hdev, true); 1544 hdev->started = false; 1545 hdev->vdev = NULL; 1546 } 1547 1548 int vhost_net_set_backend(struct vhost_dev *hdev, 1549 struct vhost_vring_file *file) 1550 { 1551 if (hdev->vhost_ops->vhost_net_set_backend) { 1552 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1553 } 1554 1555 return -1; 1556 } 1557