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/blocker.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 = QEMU_ALIGN_DOWN(start, 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 } 378 379 --log->refcnt; 380 if (log->refcnt == 0) { 381 /* Sync only the range covered by the old log */ 382 if (dev->log_size && sync) { 383 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 384 } 385 386 if (vhost_log == log) { 387 g_free(log->log); 388 vhost_log = NULL; 389 } else if (vhost_log_shm == log) { 390 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 391 log->fd); 392 vhost_log_shm = NULL; 393 } 394 395 g_free(log); 396 } 397 398 dev->log = NULL; 399 dev->log_size = 0; 400 } 401 402 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 403 { 404 return dev->vhost_ops->vhost_requires_shm_log && 405 dev->vhost_ops->vhost_requires_shm_log(dev); 406 } 407 408 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 409 { 410 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 411 uint64_t log_base = (uintptr_t)log->log; 412 int r; 413 414 /* inform backend of log switching, this must be done before 415 releasing the current log, to ensure no logging is lost */ 416 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 417 if (r < 0) { 418 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 419 } 420 421 vhost_log_put(dev, true); 422 dev->log = log; 423 dev->log_size = size; 424 } 425 426 static int vhost_dev_has_iommu(struct vhost_dev *dev) 427 { 428 VirtIODevice *vdev = dev->vdev; 429 430 return virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 431 } 432 433 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 434 hwaddr *plen, int is_write) 435 { 436 if (!vhost_dev_has_iommu(dev)) { 437 return cpu_physical_memory_map(addr, plen, is_write); 438 } else { 439 return (void *)(uintptr_t)addr; 440 } 441 } 442 443 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 444 hwaddr len, int is_write, 445 hwaddr access_len) 446 { 447 if (!vhost_dev_has_iommu(dev)) { 448 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 449 } 450 } 451 452 static int vhost_verify_ring_part_mapping(struct vhost_dev *dev, 453 void *part, 454 uint64_t part_addr, 455 uint64_t part_size, 456 uint64_t start_addr, 457 uint64_t size) 458 { 459 hwaddr l; 460 void *p; 461 int r = 0; 462 463 if (!ranges_overlap(start_addr, size, part_addr, part_size)) { 464 return 0; 465 } 466 l = part_size; 467 p = vhost_memory_map(dev, part_addr, &l, 1); 468 if (!p || l != part_size) { 469 r = -ENOMEM; 470 } 471 if (p != part) { 472 r = -EBUSY; 473 } 474 vhost_memory_unmap(dev, p, l, 0, 0); 475 return r; 476 } 477 478 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 479 uint64_t start_addr, 480 uint64_t size) 481 { 482 int i, j; 483 int r = 0; 484 const char *part_name[] = { 485 "descriptor table", 486 "available ring", 487 "used ring" 488 }; 489 490 for (i = 0; i < dev->nvqs; ++i) { 491 struct vhost_virtqueue *vq = dev->vqs + i; 492 493 j = 0; 494 r = vhost_verify_ring_part_mapping(dev, vq->desc, vq->desc_phys, 495 vq->desc_size, start_addr, size); 496 if (!r) { 497 break; 498 } 499 500 j++; 501 r = vhost_verify_ring_part_mapping(dev, vq->avail, vq->avail_phys, 502 vq->avail_size, start_addr, size); 503 if (!r) { 504 break; 505 } 506 507 j++; 508 r = vhost_verify_ring_part_mapping(dev, vq->used, vq->used_phys, 509 vq->used_size, start_addr, size); 510 if (!r) { 511 break; 512 } 513 } 514 515 if (r == -ENOMEM) { 516 error_report("Unable to map %s for ring %d", part_name[j], i); 517 } else if (r == -EBUSY) { 518 error_report("%s relocated for ring %d", part_name[j], i); 519 } 520 return r; 521 } 522 523 static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, 524 uint64_t start_addr, 525 uint64_t size) 526 { 527 int i, n = dev->mem->nregions; 528 for (i = 0; i < n; ++i) { 529 struct vhost_memory_region *reg = dev->mem->regions + i; 530 if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, 531 start_addr, size)) { 532 return reg; 533 } 534 } 535 return NULL; 536 } 537 538 static bool vhost_dev_cmp_memory(struct vhost_dev *dev, 539 uint64_t start_addr, 540 uint64_t size, 541 uint64_t uaddr) 542 { 543 struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); 544 uint64_t reglast; 545 uint64_t memlast; 546 547 if (!reg) { 548 return true; 549 } 550 551 reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); 552 memlast = range_get_last(start_addr, size); 553 554 /* Need to extend region? */ 555 if (start_addr < reg->guest_phys_addr || memlast > reglast) { 556 return true; 557 } 558 /* userspace_addr changed? */ 559 return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; 560 } 561 562 static void vhost_set_memory(MemoryListener *listener, 563 MemoryRegionSection *section, 564 bool add) 565 { 566 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 567 memory_listener); 568 hwaddr start_addr = section->offset_within_address_space; 569 ram_addr_t size = int128_get64(section->size); 570 bool log_dirty = 571 memory_region_get_dirty_log_mask(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); 572 int s = offsetof(struct vhost_memory, regions) + 573 (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; 574 void *ram; 575 576 dev->mem = g_realloc(dev->mem, s); 577 578 if (log_dirty) { 579 add = false; 580 } 581 582 assert(size); 583 584 /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ 585 ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; 586 if (add) { 587 if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { 588 /* Region exists with same address. Nothing to do. */ 589 return; 590 } 591 } else { 592 if (!vhost_dev_find_reg(dev, start_addr, size)) { 593 /* Removing region that we don't access. Nothing to do. */ 594 return; 595 } 596 } 597 598 vhost_dev_unassign_memory(dev, start_addr, size); 599 if (add) { 600 /* Add given mapping, merging adjacent regions if any */ 601 vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); 602 } else { 603 /* Remove old mapping for this memory, if any. */ 604 vhost_dev_unassign_memory(dev, start_addr, size); 605 } 606 dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr); 607 dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1); 608 dev->memory_changed = true; 609 used_memslots = dev->mem->nregions; 610 } 611 612 static bool vhost_section(MemoryRegionSection *section) 613 { 614 return memory_region_is_ram(section->mr) && 615 !memory_region_is_rom(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_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 723 { 724 struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n); 725 struct vhost_dev *hdev = iommu->hdev; 726 hwaddr iova = iotlb->iova + iommu->iommu_offset; 727 728 if (vhost_backend_invalidate_device_iotlb(hdev, iova, 729 iotlb->addr_mask + 1)) { 730 error_report("Fail to invalidate device iotlb"); 731 } 732 } 733 734 static void vhost_iommu_region_add(MemoryListener *listener, 735 MemoryRegionSection *section) 736 { 737 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 738 iommu_listener); 739 struct vhost_iommu *iommu; 740 Int128 end; 741 742 if (!memory_region_is_iommu(section->mr)) { 743 return; 744 } 745 746 iommu = g_malloc0(sizeof(*iommu)); 747 end = int128_add(int128_make64(section->offset_within_region), 748 section->size); 749 end = int128_sub(end, int128_one()); 750 iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, 751 IOMMU_NOTIFIER_UNMAP, 752 section->offset_within_region, 753 int128_get64(end)); 754 iommu->mr = section->mr; 755 iommu->iommu_offset = section->offset_within_address_space - 756 section->offset_within_region; 757 iommu->hdev = dev; 758 memory_region_register_iommu_notifier(section->mr, &iommu->n); 759 QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next); 760 /* TODO: can replay help performance here? */ 761 } 762 763 static void vhost_iommu_region_del(MemoryListener *listener, 764 MemoryRegionSection *section) 765 { 766 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 767 iommu_listener); 768 struct vhost_iommu *iommu; 769 770 if (!memory_region_is_iommu(section->mr)) { 771 return; 772 } 773 774 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 775 if (iommu->mr == section->mr && 776 iommu->n.start == section->offset_within_region) { 777 memory_region_unregister_iommu_notifier(iommu->mr, 778 &iommu->n); 779 QLIST_REMOVE(iommu, iommu_next); 780 g_free(iommu); 781 break; 782 } 783 } 784 } 785 786 static void vhost_region_nop(MemoryListener *listener, 787 MemoryRegionSection *section) 788 { 789 } 790 791 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 792 struct vhost_virtqueue *vq, 793 unsigned idx, bool enable_log) 794 { 795 struct vhost_vring_addr addr = { 796 .index = idx, 797 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 798 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 799 .used_user_addr = (uint64_t)(unsigned long)vq->used, 800 .log_guest_addr = vq->used_phys, 801 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 802 }; 803 int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 804 if (r < 0) { 805 VHOST_OPS_DEBUG("vhost_set_vring_addr failed"); 806 return -errno; 807 } 808 return 0; 809 } 810 811 static int vhost_dev_set_features(struct vhost_dev *dev, 812 bool enable_log) 813 { 814 uint64_t features = dev->acked_features; 815 int r; 816 if (enable_log) { 817 features |= 0x1ULL << VHOST_F_LOG_ALL; 818 } 819 r = dev->vhost_ops->vhost_set_features(dev, features); 820 if (r < 0) { 821 VHOST_OPS_DEBUG("vhost_set_features failed"); 822 } 823 return r < 0 ? -errno : 0; 824 } 825 826 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 827 { 828 int r, i, idx; 829 r = vhost_dev_set_features(dev, enable_log); 830 if (r < 0) { 831 goto err_features; 832 } 833 for (i = 0; i < dev->nvqs; ++i) { 834 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 835 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 836 enable_log); 837 if (r < 0) { 838 goto err_vq; 839 } 840 } 841 return 0; 842 err_vq: 843 for (; i >= 0; --i) { 844 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 845 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 846 dev->log_enabled); 847 } 848 vhost_dev_set_features(dev, dev->log_enabled); 849 err_features: 850 return r; 851 } 852 853 static int vhost_migration_log(MemoryListener *listener, int enable) 854 { 855 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 856 memory_listener); 857 int r; 858 if (!!enable == dev->log_enabled) { 859 return 0; 860 } 861 if (!dev->started) { 862 dev->log_enabled = enable; 863 return 0; 864 } 865 if (!enable) { 866 r = vhost_dev_set_log(dev, false); 867 if (r < 0) { 868 return r; 869 } 870 vhost_log_put(dev, false); 871 } else { 872 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 873 r = vhost_dev_set_log(dev, true); 874 if (r < 0) { 875 return r; 876 } 877 } 878 dev->log_enabled = enable; 879 return 0; 880 } 881 882 static void vhost_log_global_start(MemoryListener *listener) 883 { 884 int r; 885 886 r = vhost_migration_log(listener, true); 887 if (r < 0) { 888 abort(); 889 } 890 } 891 892 static void vhost_log_global_stop(MemoryListener *listener) 893 { 894 int r; 895 896 r = vhost_migration_log(listener, false); 897 if (r < 0) { 898 abort(); 899 } 900 } 901 902 static void vhost_log_start(MemoryListener *listener, 903 MemoryRegionSection *section, 904 int old, int new) 905 { 906 /* FIXME: implement */ 907 } 908 909 static void vhost_log_stop(MemoryListener *listener, 910 MemoryRegionSection *section, 911 int old, int new) 912 { 913 /* FIXME: implement */ 914 } 915 916 /* The vhost driver natively knows how to handle the vrings of non 917 * cross-endian legacy devices and modern devices. Only legacy devices 918 * exposed to a bi-endian guest may require the vhost driver to use a 919 * specific endianness. 920 */ 921 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 922 { 923 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 924 return false; 925 } 926 #ifdef HOST_WORDS_BIGENDIAN 927 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 928 #else 929 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 930 #endif 931 } 932 933 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 934 bool is_big_endian, 935 int vhost_vq_index) 936 { 937 struct vhost_vring_state s = { 938 .index = vhost_vq_index, 939 .num = is_big_endian 940 }; 941 942 if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { 943 return 0; 944 } 945 946 VHOST_OPS_DEBUG("vhost_set_vring_endian failed"); 947 if (errno == ENOTTY) { 948 error_report("vhost does not support cross-endian"); 949 return -ENOSYS; 950 } 951 952 return -errno; 953 } 954 955 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 956 uint64_t gpa, uint64_t *uaddr, 957 uint64_t *len) 958 { 959 int i; 960 961 for (i = 0; i < hdev->mem->nregions; i++) { 962 struct vhost_memory_region *reg = hdev->mem->regions + i; 963 964 if (gpa >= reg->guest_phys_addr && 965 reg->guest_phys_addr + reg->memory_size > gpa) { 966 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 967 *len = reg->guest_phys_addr + reg->memory_size - gpa; 968 return 0; 969 } 970 } 971 972 return -EFAULT; 973 } 974 975 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 976 { 977 IOMMUTLBEntry iotlb; 978 uint64_t uaddr, len; 979 int ret = -EFAULT; 980 981 rcu_read_lock(); 982 983 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 984 iova, write); 985 if (iotlb.target_as != NULL) { 986 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 987 &uaddr, &len); 988 if (ret) { 989 error_report("Fail to lookup the translated address " 990 "%"PRIx64, iotlb.translated_addr); 991 goto out; 992 } 993 994 len = MIN(iotlb.addr_mask + 1, len); 995 iova = iova & ~iotlb.addr_mask; 996 997 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 998 len, iotlb.perm); 999 if (ret) { 1000 error_report("Fail to update device iotlb"); 1001 goto out; 1002 } 1003 } 1004 out: 1005 rcu_read_unlock(); 1006 1007 return ret; 1008 } 1009 1010 static int vhost_virtqueue_start(struct vhost_dev *dev, 1011 struct VirtIODevice *vdev, 1012 struct vhost_virtqueue *vq, 1013 unsigned idx) 1014 { 1015 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1016 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1017 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1018 hwaddr s, l, a; 1019 int r; 1020 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1021 struct vhost_vring_file file = { 1022 .index = vhost_vq_index 1023 }; 1024 struct vhost_vring_state state = { 1025 .index = vhost_vq_index 1026 }; 1027 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1028 1029 1030 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1031 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1032 if (r) { 1033 VHOST_OPS_DEBUG("vhost_set_vring_num failed"); 1034 return -errno; 1035 } 1036 1037 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1038 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1039 if (r) { 1040 VHOST_OPS_DEBUG("vhost_set_vring_base failed"); 1041 return -errno; 1042 } 1043 1044 if (vhost_needs_vring_endian(vdev)) { 1045 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1046 virtio_is_big_endian(vdev), 1047 vhost_vq_index); 1048 if (r) { 1049 return -errno; 1050 } 1051 } 1052 1053 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1054 vq->desc_phys = a = virtio_queue_get_desc_addr(vdev, idx); 1055 vq->desc = vhost_memory_map(dev, a, &l, 0); 1056 if (!vq->desc || l != s) { 1057 r = -ENOMEM; 1058 goto fail_alloc_desc; 1059 } 1060 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1061 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1062 vq->avail = vhost_memory_map(dev, a, &l, 0); 1063 if (!vq->avail || l != s) { 1064 r = -ENOMEM; 1065 goto fail_alloc_avail; 1066 } 1067 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1068 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1069 vq->used = vhost_memory_map(dev, a, &l, 1); 1070 if (!vq->used || l != s) { 1071 r = -ENOMEM; 1072 goto fail_alloc_used; 1073 } 1074 1075 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1076 if (r < 0) { 1077 r = -errno; 1078 goto fail_alloc; 1079 } 1080 1081 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1082 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1083 if (r) { 1084 VHOST_OPS_DEBUG("vhost_set_vring_kick failed"); 1085 r = -errno; 1086 goto fail_kick; 1087 } 1088 1089 /* Clear and discard previous events if any. */ 1090 event_notifier_test_and_clear(&vq->masked_notifier); 1091 1092 /* Init vring in unmasked state, unless guest_notifier_mask 1093 * will do it later. 1094 */ 1095 if (!vdev->use_guest_notifier_mask) { 1096 /* TODO: check and handle errors. */ 1097 vhost_virtqueue_mask(dev, vdev, idx, false); 1098 } 1099 1100 if (k->query_guest_notifiers && 1101 k->query_guest_notifiers(qbus->parent) && 1102 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1103 file.fd = -1; 1104 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1105 if (r) { 1106 goto fail_vector; 1107 } 1108 } 1109 1110 return 0; 1111 1112 fail_vector: 1113 fail_kick: 1114 fail_alloc: 1115 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1116 0, 0); 1117 fail_alloc_used: 1118 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1119 0, 0); 1120 fail_alloc_avail: 1121 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1122 0, 0); 1123 fail_alloc_desc: 1124 return r; 1125 } 1126 1127 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1128 struct VirtIODevice *vdev, 1129 struct vhost_virtqueue *vq, 1130 unsigned idx) 1131 { 1132 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1133 struct vhost_vring_state state = { 1134 .index = vhost_vq_index, 1135 }; 1136 int r; 1137 1138 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1139 if (r < 0) { 1140 VHOST_OPS_DEBUG("vhost VQ %d ring restore failed: %d", idx, r); 1141 } else { 1142 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1143 } 1144 virtio_queue_invalidate_signalled_used(vdev, idx); 1145 virtio_queue_update_used_idx(vdev, idx); 1146 1147 /* In the cross-endian case, we need to reset the vring endianness to 1148 * native as legacy devices expect so by default. 1149 */ 1150 if (vhost_needs_vring_endian(vdev)) { 1151 vhost_virtqueue_set_vring_endian_legacy(dev, 1152 !virtio_is_big_endian(vdev), 1153 vhost_vq_index); 1154 } 1155 1156 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1157 1, virtio_queue_get_used_size(vdev, idx)); 1158 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1159 0, virtio_queue_get_avail_size(vdev, idx)); 1160 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1161 0, virtio_queue_get_desc_size(vdev, idx)); 1162 } 1163 1164 static void vhost_eventfd_add(MemoryListener *listener, 1165 MemoryRegionSection *section, 1166 bool match_data, uint64_t data, EventNotifier *e) 1167 { 1168 } 1169 1170 static void vhost_eventfd_del(MemoryListener *listener, 1171 MemoryRegionSection *section, 1172 bool match_data, uint64_t data, EventNotifier *e) 1173 { 1174 } 1175 1176 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1177 int n, uint32_t timeout) 1178 { 1179 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1180 struct vhost_vring_state state = { 1181 .index = vhost_vq_index, 1182 .num = timeout, 1183 }; 1184 int r; 1185 1186 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1187 return -EINVAL; 1188 } 1189 1190 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1191 if (r) { 1192 VHOST_OPS_DEBUG("vhost_set_vring_busyloop_timeout failed"); 1193 return r; 1194 } 1195 1196 return 0; 1197 } 1198 1199 static int vhost_virtqueue_init(struct vhost_dev *dev, 1200 struct vhost_virtqueue *vq, int n) 1201 { 1202 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1203 struct vhost_vring_file file = { 1204 .index = vhost_vq_index, 1205 }; 1206 int r = event_notifier_init(&vq->masked_notifier, 0); 1207 if (r < 0) { 1208 return r; 1209 } 1210 1211 file.fd = event_notifier_get_fd(&vq->masked_notifier); 1212 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1213 if (r) { 1214 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1215 r = -errno; 1216 goto fail_call; 1217 } 1218 1219 vq->dev = dev; 1220 1221 return 0; 1222 fail_call: 1223 event_notifier_cleanup(&vq->masked_notifier); 1224 return r; 1225 } 1226 1227 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1228 { 1229 event_notifier_cleanup(&vq->masked_notifier); 1230 } 1231 1232 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1233 VhostBackendType backend_type, uint32_t busyloop_timeout) 1234 { 1235 uint64_t features; 1236 int i, r, n_initialized_vqs = 0; 1237 Error *local_err = NULL; 1238 1239 hdev->vdev = NULL; 1240 hdev->migration_blocker = NULL; 1241 1242 r = vhost_set_backend_type(hdev, backend_type); 1243 assert(r >= 0); 1244 1245 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque); 1246 if (r < 0) { 1247 goto fail; 1248 } 1249 1250 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1251 error_report("vhost backend memory slots limit is less" 1252 " than current number of present memory slots"); 1253 r = -1; 1254 goto fail; 1255 } 1256 1257 r = hdev->vhost_ops->vhost_set_owner(hdev); 1258 if (r < 0) { 1259 VHOST_OPS_DEBUG("vhost_set_owner failed"); 1260 goto fail; 1261 } 1262 1263 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1264 if (r < 0) { 1265 VHOST_OPS_DEBUG("vhost_get_features failed"); 1266 goto fail; 1267 } 1268 1269 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1270 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1271 if (r < 0) { 1272 goto fail; 1273 } 1274 } 1275 1276 if (busyloop_timeout) { 1277 for (i = 0; i < hdev->nvqs; ++i) { 1278 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1279 busyloop_timeout); 1280 if (r < 0) { 1281 goto fail_busyloop; 1282 } 1283 } 1284 } 1285 1286 hdev->features = features; 1287 1288 hdev->memory_listener = (MemoryListener) { 1289 .begin = vhost_begin, 1290 .commit = vhost_commit, 1291 .region_add = vhost_region_add, 1292 .region_del = vhost_region_del, 1293 .region_nop = vhost_region_nop, 1294 .log_start = vhost_log_start, 1295 .log_stop = vhost_log_stop, 1296 .log_sync = vhost_log_sync, 1297 .log_global_start = vhost_log_global_start, 1298 .log_global_stop = vhost_log_global_stop, 1299 .eventfd_add = vhost_eventfd_add, 1300 .eventfd_del = vhost_eventfd_del, 1301 .priority = 10 1302 }; 1303 1304 hdev->iommu_listener = (MemoryListener) { 1305 .region_add = vhost_iommu_region_add, 1306 .region_del = vhost_iommu_region_del, 1307 }; 1308 1309 if (hdev->migration_blocker == NULL) { 1310 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1311 error_setg(&hdev->migration_blocker, 1312 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1313 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_check()) { 1314 error_setg(&hdev->migration_blocker, 1315 "Migration disabled: failed to allocate shared memory"); 1316 } 1317 } 1318 1319 if (hdev->migration_blocker != NULL) { 1320 r = migrate_add_blocker(hdev->migration_blocker, &local_err); 1321 if (local_err) { 1322 error_report_err(local_err); 1323 error_free(hdev->migration_blocker); 1324 goto fail_busyloop; 1325 } 1326 } 1327 1328 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1329 hdev->n_mem_sections = 0; 1330 hdev->mem_sections = NULL; 1331 hdev->log = NULL; 1332 hdev->log_size = 0; 1333 hdev->log_enabled = false; 1334 hdev->started = false; 1335 hdev->memory_changed = false; 1336 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1337 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1338 return 0; 1339 1340 fail_busyloop: 1341 while (--i >= 0) { 1342 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1343 } 1344 fail: 1345 hdev->nvqs = n_initialized_vqs; 1346 vhost_dev_cleanup(hdev); 1347 return r; 1348 } 1349 1350 void vhost_dev_cleanup(struct vhost_dev *hdev) 1351 { 1352 int i; 1353 1354 for (i = 0; i < hdev->nvqs; ++i) { 1355 vhost_virtqueue_cleanup(hdev->vqs + i); 1356 } 1357 if (hdev->mem) { 1358 /* those are only safe after successful init */ 1359 memory_listener_unregister(&hdev->memory_listener); 1360 for (i = 0; i < hdev->n_mem_sections; ++i) { 1361 MemoryRegionSection *section = &hdev->mem_sections[i]; 1362 memory_region_unref(section->mr); 1363 } 1364 QLIST_REMOVE(hdev, entry); 1365 } 1366 if (hdev->migration_blocker) { 1367 migrate_del_blocker(hdev->migration_blocker); 1368 error_free(hdev->migration_blocker); 1369 } 1370 g_free(hdev->mem); 1371 g_free(hdev->mem_sections); 1372 if (hdev->vhost_ops) { 1373 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1374 } 1375 assert(!hdev->log); 1376 1377 memset(hdev, 0, sizeof(struct vhost_dev)); 1378 } 1379 1380 /* Stop processing guest IO notifications in qemu. 1381 * Start processing them in vhost in kernel. 1382 */ 1383 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1384 { 1385 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1386 int i, r, e; 1387 1388 /* We will pass the notifiers to the kernel, make sure that QEMU 1389 * doesn't interfere. 1390 */ 1391 r = virtio_device_grab_ioeventfd(vdev); 1392 if (r < 0) { 1393 error_report("binding does not support host notifiers"); 1394 goto fail; 1395 } 1396 1397 for (i = 0; i < hdev->nvqs; ++i) { 1398 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1399 true); 1400 if (r < 0) { 1401 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1402 goto fail_vq; 1403 } 1404 } 1405 1406 return 0; 1407 fail_vq: 1408 while (--i >= 0) { 1409 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1410 false); 1411 if (e < 0) { 1412 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1413 } 1414 assert (e >= 0); 1415 } 1416 virtio_device_release_ioeventfd(vdev); 1417 fail: 1418 return r; 1419 } 1420 1421 /* Stop processing guest IO notifications in vhost. 1422 * Start processing them in qemu. 1423 * This might actually run the qemu handlers right away, 1424 * so virtio in qemu must be completely setup when this is called. 1425 */ 1426 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1427 { 1428 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1429 int i, r; 1430 1431 for (i = 0; i < hdev->nvqs; ++i) { 1432 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1433 false); 1434 if (r < 0) { 1435 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1436 } 1437 assert (r >= 0); 1438 } 1439 virtio_device_release_ioeventfd(vdev); 1440 } 1441 1442 /* Test and clear event pending status. 1443 * Should be called after unmask to avoid losing events. 1444 */ 1445 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1446 { 1447 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1448 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1449 return event_notifier_test_and_clear(&vq->masked_notifier); 1450 } 1451 1452 /* Mask/unmask events from this vq. */ 1453 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1454 bool mask) 1455 { 1456 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1457 int r, index = n - hdev->vq_index; 1458 struct vhost_vring_file file; 1459 1460 /* should only be called after backend is connected */ 1461 assert(hdev->vhost_ops); 1462 1463 if (mask) { 1464 assert(vdev->use_guest_notifier_mask); 1465 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1466 } else { 1467 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1468 } 1469 1470 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1471 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1472 if (r < 0) { 1473 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1474 } 1475 } 1476 1477 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1478 uint64_t features) 1479 { 1480 const int *bit = feature_bits; 1481 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1482 uint64_t bit_mask = (1ULL << *bit); 1483 if (!(hdev->features & bit_mask)) { 1484 features &= ~bit_mask; 1485 } 1486 bit++; 1487 } 1488 return features; 1489 } 1490 1491 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1492 uint64_t features) 1493 { 1494 const int *bit = feature_bits; 1495 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1496 uint64_t bit_mask = (1ULL << *bit); 1497 if (features & bit_mask) { 1498 hdev->acked_features |= bit_mask; 1499 } 1500 bit++; 1501 } 1502 } 1503 1504 /* Host notifiers must be enabled at this point. */ 1505 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1506 { 1507 int i, r; 1508 1509 /* should only be called after backend is connected */ 1510 assert(hdev->vhost_ops); 1511 1512 hdev->started = true; 1513 hdev->vdev = vdev; 1514 1515 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1516 if (r < 0) { 1517 goto fail_features; 1518 } 1519 1520 if (vhost_dev_has_iommu(hdev)) { 1521 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1522 } 1523 1524 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1525 if (r < 0) { 1526 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 1527 r = -errno; 1528 goto fail_mem; 1529 } 1530 for (i = 0; i < hdev->nvqs; ++i) { 1531 r = vhost_virtqueue_start(hdev, 1532 vdev, 1533 hdev->vqs + i, 1534 hdev->vq_index + i); 1535 if (r < 0) { 1536 goto fail_vq; 1537 } 1538 } 1539 1540 if (hdev->log_enabled) { 1541 uint64_t log_base; 1542 1543 hdev->log_size = vhost_get_log_size(hdev); 1544 hdev->log = vhost_log_get(hdev->log_size, 1545 vhost_dev_log_is_shared(hdev)); 1546 log_base = (uintptr_t)hdev->log->log; 1547 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1548 hdev->log_size ? log_base : 0, 1549 hdev->log); 1550 if (r < 0) { 1551 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 1552 r = -errno; 1553 goto fail_log; 1554 } 1555 } 1556 1557 if (vhost_dev_has_iommu(hdev)) { 1558 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1559 1560 /* Update used ring information for IOTLB to work correctly, 1561 * vhost-kernel code requires for this.*/ 1562 for (i = 0; i < hdev->nvqs; ++i) { 1563 struct vhost_virtqueue *vq = hdev->vqs + i; 1564 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1565 } 1566 } 1567 return 0; 1568 fail_log: 1569 vhost_log_put(hdev, false); 1570 fail_vq: 1571 while (--i >= 0) { 1572 vhost_virtqueue_stop(hdev, 1573 vdev, 1574 hdev->vqs + i, 1575 hdev->vq_index + i); 1576 } 1577 i = hdev->nvqs; 1578 1579 fail_mem: 1580 fail_features: 1581 1582 hdev->started = false; 1583 return r; 1584 } 1585 1586 /* Host notifiers must be enabled at this point. */ 1587 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1588 { 1589 int i; 1590 1591 /* should only be called after backend is connected */ 1592 assert(hdev->vhost_ops); 1593 1594 for (i = 0; i < hdev->nvqs; ++i) { 1595 vhost_virtqueue_stop(hdev, 1596 vdev, 1597 hdev->vqs + i, 1598 hdev->vq_index + i); 1599 } 1600 1601 if (vhost_dev_has_iommu(hdev)) { 1602 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1603 memory_listener_unregister(&hdev->iommu_listener); 1604 } 1605 vhost_log_put(hdev, true); 1606 hdev->started = false; 1607 hdev->vdev = NULL; 1608 } 1609 1610 int vhost_net_set_backend(struct vhost_dev *hdev, 1611 struct vhost_vring_file *file) 1612 { 1613 if (hdev->vhost_ops->vhost_net_set_backend) { 1614 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1615 } 1616 1617 return -1; 1618 } 1619