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 "qemu/atomic.h" 20 #include "qemu/range.h" 21 #include "qemu/error-report.h" 22 #include "qemu/memfd.h" 23 #include "qemu/log.h" 24 #include "standard-headers/linux/vhost_types.h" 25 #include "hw/virtio/virtio-bus.h" 26 #include "hw/mem/memory-device.h" 27 #include "migration/blocker.h" 28 #include "migration/qemu-file-types.h" 29 #include "sysemu/dma.h" 30 #include "trace.h" 31 32 /* enabled until disconnected backend stabilizes */ 33 #define _VHOST_DEBUG 1 34 35 #ifdef _VHOST_DEBUG 36 #define VHOST_OPS_DEBUG(retval, fmt, ...) \ 37 do { \ 38 error_report(fmt ": %s (%d)", ## __VA_ARGS__, \ 39 strerror(-retval), -retval); \ 40 } while (0) 41 #else 42 #define VHOST_OPS_DEBUG(retval, fmt, ...) \ 43 do { } while (0) 44 #endif 45 46 static struct vhost_log *vhost_log[VHOST_BACKEND_TYPE_MAX]; 47 static struct vhost_log *vhost_log_shm[VHOST_BACKEND_TYPE_MAX]; 48 49 /* Memslots used by backends that support private memslots (without an fd). */ 50 static unsigned int used_memslots; 51 52 /* Memslots used by backends that only support shared memslots (with an fd). */ 53 static unsigned int used_shared_memslots; 54 55 static QLIST_HEAD(, vhost_dev) vhost_devices = 56 QLIST_HEAD_INITIALIZER(vhost_devices); 57 58 unsigned int vhost_get_max_memslots(void) 59 { 60 unsigned int max = UINT_MAX; 61 struct vhost_dev *hdev; 62 63 QLIST_FOREACH(hdev, &vhost_devices, entry) { 64 max = MIN(max, hdev->vhost_ops->vhost_backend_memslots_limit(hdev)); 65 } 66 return max; 67 } 68 69 unsigned int vhost_get_free_memslots(void) 70 { 71 unsigned int free = UINT_MAX; 72 struct vhost_dev *hdev; 73 74 QLIST_FOREACH(hdev, &vhost_devices, entry) { 75 unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 76 unsigned int cur_free; 77 78 if (hdev->vhost_ops->vhost_backend_no_private_memslots && 79 hdev->vhost_ops->vhost_backend_no_private_memslots(hdev)) { 80 cur_free = r - used_shared_memslots; 81 } else { 82 cur_free = r - used_memslots; 83 } 84 free = MIN(free, cur_free); 85 } 86 return free; 87 } 88 89 static void vhost_dev_sync_region(struct vhost_dev *dev, 90 MemoryRegionSection *section, 91 uint64_t mfirst, uint64_t mlast, 92 uint64_t rfirst, uint64_t rlast) 93 { 94 vhost_log_chunk_t *dev_log = dev->log->log; 95 96 uint64_t start = MAX(mfirst, rfirst); 97 uint64_t end = MIN(mlast, rlast); 98 vhost_log_chunk_t *from = dev_log + start / VHOST_LOG_CHUNK; 99 vhost_log_chunk_t *to = dev_log + end / VHOST_LOG_CHUNK + 1; 100 uint64_t addr = QEMU_ALIGN_DOWN(start, VHOST_LOG_CHUNK); 101 102 if (end < start) { 103 return; 104 } 105 assert(end / VHOST_LOG_CHUNK < dev->log_size); 106 assert(start / VHOST_LOG_CHUNK < dev->log_size); 107 108 for (;from < to; ++from) { 109 vhost_log_chunk_t log; 110 /* We first check with non-atomic: much cheaper, 111 * and we expect non-dirty to be the common case. */ 112 if (!*from) { 113 addr += VHOST_LOG_CHUNK; 114 continue; 115 } 116 /* Data must be read atomically. We don't really need barrier semantics 117 * but it's easier to use atomic_* than roll our own. */ 118 log = qatomic_xchg(from, 0); 119 while (log) { 120 int bit = ctzl(log); 121 hwaddr page_addr; 122 hwaddr section_offset; 123 hwaddr mr_offset; 124 page_addr = addr + bit * VHOST_LOG_PAGE; 125 section_offset = page_addr - section->offset_within_address_space; 126 mr_offset = section_offset + section->offset_within_region; 127 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 128 log &= ~(0x1ull << bit); 129 } 130 addr += VHOST_LOG_CHUNK; 131 } 132 } 133 134 bool vhost_dev_has_iommu(struct vhost_dev *dev) 135 { 136 VirtIODevice *vdev = dev->vdev; 137 138 /* 139 * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support 140 * incremental memory mapping API via IOTLB API. For platform that 141 * does not have IOMMU, there's no need to enable this feature 142 * which may cause unnecessary IOTLB miss/update transactions. 143 */ 144 if (vdev) { 145 return virtio_bus_device_iommu_enabled(vdev) && 146 virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 147 } else { 148 return false; 149 } 150 } 151 152 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 153 MemoryRegionSection *section, 154 hwaddr first, 155 hwaddr last) 156 { 157 int i; 158 hwaddr start_addr; 159 hwaddr end_addr; 160 161 if (!dev->log_enabled || !dev->started) { 162 return 0; 163 } 164 start_addr = section->offset_within_address_space; 165 end_addr = range_get_last(start_addr, int128_get64(section->size)); 166 start_addr = MAX(first, start_addr); 167 end_addr = MIN(last, end_addr); 168 169 for (i = 0; i < dev->mem->nregions; ++i) { 170 struct vhost_memory_region *reg = dev->mem->regions + i; 171 vhost_dev_sync_region(dev, section, start_addr, end_addr, 172 reg->guest_phys_addr, 173 range_get_last(reg->guest_phys_addr, 174 reg->memory_size)); 175 } 176 for (i = 0; i < dev->nvqs; ++i) { 177 struct vhost_virtqueue *vq = dev->vqs + i; 178 179 if (!vq->used_phys && !vq->used_size) { 180 continue; 181 } 182 183 if (vhost_dev_has_iommu(dev)) { 184 IOMMUTLBEntry iotlb; 185 hwaddr used_phys = vq->used_phys, used_size = vq->used_size; 186 hwaddr phys, s, offset; 187 188 while (used_size) { 189 rcu_read_lock(); 190 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 191 used_phys, 192 true, 193 MEMTXATTRS_UNSPECIFIED); 194 rcu_read_unlock(); 195 196 if (!iotlb.target_as) { 197 qemu_log_mask(LOG_GUEST_ERROR, "translation " 198 "failure for used_iova %"PRIx64"\n", 199 used_phys); 200 return -EINVAL; 201 } 202 203 offset = used_phys & iotlb.addr_mask; 204 phys = iotlb.translated_addr + offset; 205 206 /* 207 * Distance from start of used ring until last byte of 208 * IOMMU page. 209 */ 210 s = iotlb.addr_mask - offset; 211 /* 212 * Size of used ring, or of the part of it until end 213 * of IOMMU page. To avoid zero result, do the adding 214 * outside of MIN(). 215 */ 216 s = MIN(s, used_size - 1) + 1; 217 218 vhost_dev_sync_region(dev, section, start_addr, end_addr, phys, 219 range_get_last(phys, s)); 220 used_size -= s; 221 used_phys += s; 222 } 223 } else { 224 vhost_dev_sync_region(dev, section, start_addr, 225 end_addr, vq->used_phys, 226 range_get_last(vq->used_phys, vq->used_size)); 227 } 228 } 229 return 0; 230 } 231 232 static void vhost_log_sync(MemoryListener *listener, 233 MemoryRegionSection *section) 234 { 235 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 236 memory_listener); 237 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 238 } 239 240 static void vhost_log_sync_range(struct vhost_dev *dev, 241 hwaddr first, hwaddr last) 242 { 243 int i; 244 /* FIXME: this is N^2 in number of sections */ 245 for (i = 0; i < dev->n_mem_sections; ++i) { 246 MemoryRegionSection *section = &dev->mem_sections[i]; 247 vhost_sync_dirty_bitmap(dev, section, first, last); 248 } 249 } 250 251 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 252 { 253 uint64_t log_size = 0; 254 int i; 255 for (i = 0; i < dev->mem->nregions; ++i) { 256 struct vhost_memory_region *reg = dev->mem->regions + i; 257 uint64_t last = range_get_last(reg->guest_phys_addr, 258 reg->memory_size); 259 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 260 } 261 return log_size; 262 } 263 264 static int vhost_set_backend_type(struct vhost_dev *dev, 265 VhostBackendType backend_type) 266 { 267 int r = 0; 268 269 switch (backend_type) { 270 #ifdef CONFIG_VHOST_KERNEL 271 case VHOST_BACKEND_TYPE_KERNEL: 272 dev->vhost_ops = &kernel_ops; 273 break; 274 #endif 275 #ifdef CONFIG_VHOST_USER 276 case VHOST_BACKEND_TYPE_USER: 277 dev->vhost_ops = &user_ops; 278 break; 279 #endif 280 #ifdef CONFIG_VHOST_VDPA 281 case VHOST_BACKEND_TYPE_VDPA: 282 dev->vhost_ops = &vdpa_ops; 283 break; 284 #endif 285 default: 286 error_report("Unknown vhost backend type"); 287 r = -1; 288 } 289 290 if (r == 0) { 291 assert(dev->vhost_ops->backend_type == backend_type); 292 } 293 294 return r; 295 } 296 297 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 298 { 299 Error *err = NULL; 300 struct vhost_log *log; 301 uint64_t logsize = size * sizeof(*(log->log)); 302 int fd = -1; 303 304 log = g_new0(struct vhost_log, 1); 305 if (share) { 306 log->log = qemu_memfd_alloc("vhost-log", logsize, 307 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 308 &fd, &err); 309 if (err) { 310 error_report_err(err); 311 g_free(log); 312 return NULL; 313 } 314 memset(log->log, 0, logsize); 315 } else { 316 log->log = g_malloc0(logsize); 317 } 318 319 log->size = size; 320 log->refcnt = 1; 321 log->fd = fd; 322 323 return log; 324 } 325 326 static struct vhost_log *vhost_log_get(VhostBackendType backend_type, 327 uint64_t size, bool share) 328 { 329 struct vhost_log *log; 330 331 assert(backend_type > VHOST_BACKEND_TYPE_NONE); 332 assert(backend_type < VHOST_BACKEND_TYPE_MAX); 333 334 log = share ? vhost_log_shm[backend_type] : vhost_log[backend_type]; 335 336 if (!log || log->size != size) { 337 log = vhost_log_alloc(size, share); 338 if (share) { 339 vhost_log_shm[backend_type] = log; 340 } else { 341 vhost_log[backend_type] = log; 342 } 343 } else { 344 ++log->refcnt; 345 } 346 347 return log; 348 } 349 350 static void vhost_log_put(struct vhost_dev *dev, bool sync) 351 { 352 struct vhost_log *log = dev->log; 353 VhostBackendType backend_type; 354 355 if (!log) { 356 return; 357 } 358 359 assert(dev->vhost_ops); 360 backend_type = dev->vhost_ops->backend_type; 361 362 if (backend_type == VHOST_BACKEND_TYPE_NONE || 363 backend_type >= VHOST_BACKEND_TYPE_MAX) { 364 return; 365 } 366 367 --log->refcnt; 368 if (log->refcnt == 0) { 369 /* Sync only the range covered by the old log */ 370 if (dev->log_size && sync) { 371 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 372 } 373 374 if (vhost_log[backend_type] == log) { 375 g_free(log->log); 376 vhost_log[backend_type] = NULL; 377 } else if (vhost_log_shm[backend_type] == log) { 378 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 379 log->fd); 380 vhost_log_shm[backend_type] = NULL; 381 } 382 383 g_free(log); 384 } 385 386 dev->log = NULL; 387 dev->log_size = 0; 388 } 389 390 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 391 { 392 return dev->vhost_ops->vhost_requires_shm_log && 393 dev->vhost_ops->vhost_requires_shm_log(dev); 394 } 395 396 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 397 { 398 struct vhost_log *log = vhost_log_get(dev->vhost_ops->backend_type, 399 size, vhost_dev_log_is_shared(dev)); 400 uint64_t log_base = (uintptr_t)log->log; 401 int r; 402 403 /* inform backend of log switching, this must be done before 404 releasing the current log, to ensure no logging is lost */ 405 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 406 if (r < 0) { 407 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 408 } 409 410 vhost_log_put(dev, true); 411 dev->log = log; 412 dev->log_size = size; 413 } 414 415 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 416 hwaddr *plen, bool is_write) 417 { 418 if (!vhost_dev_has_iommu(dev)) { 419 return cpu_physical_memory_map(addr, plen, is_write); 420 } else { 421 return (void *)(uintptr_t)addr; 422 } 423 } 424 425 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 426 hwaddr len, int is_write, 427 hwaddr access_len) 428 { 429 if (!vhost_dev_has_iommu(dev)) { 430 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 431 } 432 } 433 434 static int vhost_verify_ring_part_mapping(void *ring_hva, 435 uint64_t ring_gpa, 436 uint64_t ring_size, 437 void *reg_hva, 438 uint64_t reg_gpa, 439 uint64_t reg_size) 440 { 441 uint64_t hva_ring_offset; 442 uint64_t ring_last = range_get_last(ring_gpa, ring_size); 443 uint64_t reg_last = range_get_last(reg_gpa, reg_size); 444 445 if (ring_last < reg_gpa || ring_gpa > reg_last) { 446 return 0; 447 } 448 /* check that whole ring's is mapped */ 449 if (ring_last > reg_last) { 450 return -ENOMEM; 451 } 452 /* check that ring's MemoryRegion wasn't replaced */ 453 hva_ring_offset = ring_gpa - reg_gpa; 454 if (ring_hva != reg_hva + hva_ring_offset) { 455 return -EBUSY; 456 } 457 458 return 0; 459 } 460 461 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 462 void *reg_hva, 463 uint64_t reg_gpa, 464 uint64_t reg_size) 465 { 466 int i, j; 467 int r = 0; 468 const char *part_name[] = { 469 "descriptor table", 470 "available ring", 471 "used ring" 472 }; 473 474 if (vhost_dev_has_iommu(dev)) { 475 return 0; 476 } 477 478 for (i = 0; i < dev->nvqs; ++i) { 479 struct vhost_virtqueue *vq = dev->vqs + i; 480 481 if (vq->desc_phys == 0) { 482 continue; 483 } 484 485 j = 0; 486 r = vhost_verify_ring_part_mapping( 487 vq->desc, vq->desc_phys, vq->desc_size, 488 reg_hva, reg_gpa, reg_size); 489 if (r) { 490 break; 491 } 492 493 j++; 494 r = vhost_verify_ring_part_mapping( 495 vq->avail, vq->avail_phys, vq->avail_size, 496 reg_hva, reg_gpa, reg_size); 497 if (r) { 498 break; 499 } 500 501 j++; 502 r = vhost_verify_ring_part_mapping( 503 vq->used, vq->used_phys, vq->used_size, 504 reg_hva, reg_gpa, reg_size); 505 if (r) { 506 break; 507 } 508 } 509 510 if (r == -ENOMEM) { 511 error_report("Unable to map %s for ring %d", part_name[j], i); 512 } else if (r == -EBUSY) { 513 error_report("%s relocated for ring %d", part_name[j], i); 514 } 515 return r; 516 } 517 518 /* 519 * vhost_section: identify sections needed for vhost access 520 * 521 * We only care about RAM sections here (where virtqueue and guest 522 * internals accessed by virtio might live). 523 */ 524 static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section) 525 { 526 MemoryRegion *mr = section->mr; 527 528 if (memory_region_is_ram(mr) && !memory_region_is_rom(mr)) { 529 uint8_t dirty_mask = memory_region_get_dirty_log_mask(mr); 530 uint8_t handled_dirty; 531 532 /* 533 * Kernel based vhost doesn't handle any block which is doing 534 * dirty-tracking other than migration for which it has 535 * specific logging support. However for TCG the kernel never 536 * gets involved anyway so we can also ignore it's 537 * self-modiying code detection flags. However a vhost-user 538 * client could still confuse a TCG guest if it re-writes 539 * executable memory that has already been translated. 540 */ 541 handled_dirty = (1 << DIRTY_MEMORY_MIGRATION) | 542 (1 << DIRTY_MEMORY_CODE); 543 544 if (dirty_mask & ~handled_dirty) { 545 trace_vhost_reject_section(mr->name, 1); 546 return false; 547 } 548 549 /* 550 * Some backends (like vhost-user) can only handle memory regions 551 * that have an fd (can be mapped into a different process). Filter 552 * the ones without an fd out, if requested. 553 * 554 * TODO: we might have to limit to MAP_SHARED as well. 555 */ 556 if (memory_region_get_fd(section->mr) < 0 && 557 dev->vhost_ops->vhost_backend_no_private_memslots && 558 dev->vhost_ops->vhost_backend_no_private_memslots(dev)) { 559 trace_vhost_reject_section(mr->name, 2); 560 return false; 561 } 562 563 trace_vhost_section(mr->name); 564 return true; 565 } else { 566 trace_vhost_reject_section(mr->name, 3); 567 return false; 568 } 569 } 570 571 static void vhost_begin(MemoryListener *listener) 572 { 573 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 574 memory_listener); 575 dev->tmp_sections = NULL; 576 dev->n_tmp_sections = 0; 577 } 578 579 static void vhost_commit(MemoryListener *listener) 580 { 581 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 582 memory_listener); 583 MemoryRegionSection *old_sections; 584 int n_old_sections; 585 uint64_t log_size; 586 size_t regions_size; 587 int r; 588 int i; 589 bool changed = false; 590 591 /* Note we can be called before the device is started, but then 592 * starting the device calls set_mem_table, so we need to have 593 * built the data structures. 594 */ 595 old_sections = dev->mem_sections; 596 n_old_sections = dev->n_mem_sections; 597 dev->mem_sections = dev->tmp_sections; 598 dev->n_mem_sections = dev->n_tmp_sections; 599 600 if (dev->n_mem_sections != n_old_sections) { 601 changed = true; 602 } else { 603 /* Same size, lets check the contents */ 604 for (i = 0; i < n_old_sections; i++) { 605 if (!MemoryRegionSection_eq(&old_sections[i], 606 &dev->mem_sections[i])) { 607 changed = true; 608 break; 609 } 610 } 611 } 612 613 trace_vhost_commit(dev->started, changed); 614 if (!changed) { 615 goto out; 616 } 617 618 /* Rebuild the regions list from the new sections list */ 619 regions_size = offsetof(struct vhost_memory, regions) + 620 dev->n_mem_sections * sizeof dev->mem->regions[0]; 621 dev->mem = g_realloc(dev->mem, regions_size); 622 dev->mem->nregions = dev->n_mem_sections; 623 624 if (dev->vhost_ops->vhost_backend_no_private_memslots && 625 dev->vhost_ops->vhost_backend_no_private_memslots(dev)) { 626 used_shared_memslots = dev->mem->nregions; 627 } else { 628 used_memslots = dev->mem->nregions; 629 } 630 631 for (i = 0; i < dev->n_mem_sections; i++) { 632 struct vhost_memory_region *cur_vmr = dev->mem->regions + i; 633 struct MemoryRegionSection *mrs = dev->mem_sections + i; 634 635 cur_vmr->guest_phys_addr = mrs->offset_within_address_space; 636 cur_vmr->memory_size = int128_get64(mrs->size); 637 cur_vmr->userspace_addr = 638 (uintptr_t)memory_region_get_ram_ptr(mrs->mr) + 639 mrs->offset_within_region; 640 cur_vmr->flags_padding = 0; 641 } 642 643 if (!dev->started) { 644 goto out; 645 } 646 647 for (i = 0; i < dev->mem->nregions; i++) { 648 if (vhost_verify_ring_mappings(dev, 649 (void *)(uintptr_t)dev->mem->regions[i].userspace_addr, 650 dev->mem->regions[i].guest_phys_addr, 651 dev->mem->regions[i].memory_size)) { 652 error_report("Verify ring failure on region %d", i); 653 abort(); 654 } 655 } 656 657 if (!dev->log_enabled) { 658 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 659 if (r < 0) { 660 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 661 } 662 goto out; 663 } 664 log_size = vhost_get_log_size(dev); 665 /* We allocate an extra 4K bytes to log, 666 * to reduce the * number of reallocations. */ 667 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 668 /* To log more, must increase log size before table update. */ 669 if (dev->log_size < log_size) { 670 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 671 } 672 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 673 if (r < 0) { 674 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 675 } 676 /* To log less, can only decrease log size after table update. */ 677 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 678 vhost_dev_log_resize(dev, log_size); 679 } 680 681 out: 682 /* Deref the old list of sections, this must happen _after_ the 683 * vhost_set_mem_table to ensure the client isn't still using the 684 * section we're about to unref. 685 */ 686 while (n_old_sections--) { 687 memory_region_unref(old_sections[n_old_sections].mr); 688 } 689 g_free(old_sections); 690 return; 691 } 692 693 /* Adds the section data to the tmp_section structure. 694 * It relies on the listener calling us in memory address order 695 * and for each region (via the _add and _nop methods) to 696 * join neighbours. 697 */ 698 static void vhost_region_add_section(struct vhost_dev *dev, 699 MemoryRegionSection *section) 700 { 701 bool need_add = true; 702 uint64_t mrs_size = int128_get64(section->size); 703 uint64_t mrs_gpa = section->offset_within_address_space; 704 uintptr_t mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) + 705 section->offset_within_region; 706 RAMBlock *mrs_rb = section->mr->ram_block; 707 708 trace_vhost_region_add_section(section->mr->name, mrs_gpa, mrs_size, 709 mrs_host); 710 711 if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) { 712 /* Round the section to it's page size */ 713 /* First align the start down to a page boundary */ 714 size_t mrs_page = qemu_ram_pagesize(mrs_rb); 715 uint64_t alignage = mrs_host & (mrs_page - 1); 716 if (alignage) { 717 mrs_host -= alignage; 718 mrs_size += alignage; 719 mrs_gpa -= alignage; 720 } 721 /* Now align the size up to a page boundary */ 722 alignage = mrs_size & (mrs_page - 1); 723 if (alignage) { 724 mrs_size += mrs_page - alignage; 725 } 726 trace_vhost_region_add_section_aligned(section->mr->name, mrs_gpa, 727 mrs_size, mrs_host); 728 } 729 730 if (dev->n_tmp_sections && !section->unmergeable) { 731 /* Since we already have at least one section, lets see if 732 * this extends it; since we're scanning in order, we only 733 * have to look at the last one, and the FlatView that calls 734 * us shouldn't have overlaps. 735 */ 736 MemoryRegionSection *prev_sec = dev->tmp_sections + 737 (dev->n_tmp_sections - 1); 738 uint64_t prev_gpa_start = prev_sec->offset_within_address_space; 739 uint64_t prev_size = int128_get64(prev_sec->size); 740 uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size); 741 uint64_t prev_host_start = 742 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) + 743 prev_sec->offset_within_region; 744 uint64_t prev_host_end = range_get_last(prev_host_start, prev_size); 745 746 if (mrs_gpa <= (prev_gpa_end + 1)) { 747 /* OK, looks like overlapping/intersecting - it's possible that 748 * the rounding to page sizes has made them overlap, but they should 749 * match up in the same RAMBlock if they do. 750 */ 751 if (mrs_gpa < prev_gpa_start) { 752 error_report("%s:Section '%s' rounded to %"PRIx64 753 " prior to previous '%s' %"PRIx64, 754 __func__, section->mr->name, mrs_gpa, 755 prev_sec->mr->name, prev_gpa_start); 756 /* A way to cleanly fail here would be better */ 757 return; 758 } 759 /* Offset from the start of the previous GPA to this GPA */ 760 size_t offset = mrs_gpa - prev_gpa_start; 761 762 if (prev_host_start + offset == mrs_host && 763 section->mr == prev_sec->mr && !prev_sec->unmergeable) { 764 uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size); 765 need_add = false; 766 prev_sec->offset_within_address_space = 767 MIN(prev_gpa_start, mrs_gpa); 768 prev_sec->offset_within_region = 769 MIN(prev_host_start, mrs_host) - 770 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr); 771 prev_sec->size = int128_make64(max_end - MIN(prev_host_start, 772 mrs_host)); 773 trace_vhost_region_add_section_merge(section->mr->name, 774 int128_get64(prev_sec->size), 775 prev_sec->offset_within_address_space, 776 prev_sec->offset_within_region); 777 } else { 778 /* adjoining regions are fine, but overlapping ones with 779 * different blocks/offsets shouldn't happen 780 */ 781 if (mrs_gpa != prev_gpa_end + 1) { 782 error_report("%s: Overlapping but not coherent sections " 783 "at %"PRIx64, 784 __func__, mrs_gpa); 785 return; 786 } 787 } 788 } 789 } 790 791 if (need_add) { 792 ++dev->n_tmp_sections; 793 dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections, 794 dev->n_tmp_sections); 795 dev->tmp_sections[dev->n_tmp_sections - 1] = *section; 796 /* The flatview isn't stable and we don't use it, making it NULL 797 * means we can memcmp the list. 798 */ 799 dev->tmp_sections[dev->n_tmp_sections - 1].fv = NULL; 800 memory_region_ref(section->mr); 801 } 802 } 803 804 /* Used for both add and nop callbacks */ 805 static void vhost_region_addnop(MemoryListener *listener, 806 MemoryRegionSection *section) 807 { 808 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 809 memory_listener); 810 811 if (!vhost_section(dev, section)) { 812 return; 813 } 814 vhost_region_add_section(dev, section); 815 } 816 817 static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 818 { 819 struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n); 820 struct vhost_dev *hdev = iommu->hdev; 821 hwaddr iova = iotlb->iova + iommu->iommu_offset; 822 823 if (vhost_backend_invalidate_device_iotlb(hdev, iova, 824 iotlb->addr_mask + 1)) { 825 error_report("Fail to invalidate device iotlb"); 826 } 827 } 828 829 static void vhost_iommu_region_add(MemoryListener *listener, 830 MemoryRegionSection *section) 831 { 832 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 833 iommu_listener); 834 struct vhost_iommu *iommu; 835 Int128 end; 836 int iommu_idx; 837 IOMMUMemoryRegion *iommu_mr; 838 839 if (!memory_region_is_iommu(section->mr)) { 840 return; 841 } 842 843 iommu_mr = IOMMU_MEMORY_REGION(section->mr); 844 845 iommu = g_malloc0(sizeof(*iommu)); 846 end = int128_add(int128_make64(section->offset_within_region), 847 section->size); 848 end = int128_sub(end, int128_one()); 849 iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr, 850 MEMTXATTRS_UNSPECIFIED); 851 iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, 852 dev->vdev->device_iotlb_enabled ? 853 IOMMU_NOTIFIER_DEVIOTLB_UNMAP : 854 IOMMU_NOTIFIER_UNMAP, 855 section->offset_within_region, 856 int128_get64(end), 857 iommu_idx); 858 iommu->mr = section->mr; 859 iommu->iommu_offset = section->offset_within_address_space - 860 section->offset_within_region; 861 iommu->hdev = dev; 862 memory_region_register_iommu_notifier(section->mr, &iommu->n, 863 &error_fatal); 864 QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next); 865 /* TODO: can replay help performance here? */ 866 } 867 868 static void vhost_iommu_region_del(MemoryListener *listener, 869 MemoryRegionSection *section) 870 { 871 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 872 iommu_listener); 873 struct vhost_iommu *iommu; 874 875 if (!memory_region_is_iommu(section->mr)) { 876 return; 877 } 878 879 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 880 if (iommu->mr == section->mr && 881 iommu->n.start == section->offset_within_region) { 882 memory_region_unregister_iommu_notifier(iommu->mr, 883 &iommu->n); 884 QLIST_REMOVE(iommu, iommu_next); 885 g_free(iommu); 886 break; 887 } 888 } 889 } 890 891 void vhost_toggle_device_iotlb(VirtIODevice *vdev) 892 { 893 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 894 struct vhost_dev *dev; 895 struct vhost_iommu *iommu; 896 897 if (vdev->vhost_started) { 898 dev = vdc->get_vhost(vdev); 899 } else { 900 return; 901 } 902 903 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 904 memory_region_unregister_iommu_notifier(iommu->mr, &iommu->n); 905 iommu->n.notifier_flags = vdev->device_iotlb_enabled ? 906 IOMMU_NOTIFIER_DEVIOTLB_UNMAP : IOMMU_NOTIFIER_UNMAP; 907 memory_region_register_iommu_notifier(iommu->mr, &iommu->n, 908 &error_fatal); 909 } 910 } 911 912 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 913 struct vhost_virtqueue *vq, 914 unsigned idx, bool enable_log) 915 { 916 struct vhost_vring_addr addr; 917 int r; 918 memset(&addr, 0, sizeof(struct vhost_vring_addr)); 919 920 if (dev->vhost_ops->vhost_vq_get_addr) { 921 r = dev->vhost_ops->vhost_vq_get_addr(dev, &addr, vq); 922 if (r < 0) { 923 VHOST_OPS_DEBUG(r, "vhost_vq_get_addr failed"); 924 return r; 925 } 926 } else { 927 addr.desc_user_addr = (uint64_t)(unsigned long)vq->desc; 928 addr.avail_user_addr = (uint64_t)(unsigned long)vq->avail; 929 addr.used_user_addr = (uint64_t)(unsigned long)vq->used; 930 } 931 addr.index = idx; 932 addr.log_guest_addr = vq->used_phys; 933 addr.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0; 934 r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 935 if (r < 0) { 936 VHOST_OPS_DEBUG(r, "vhost_set_vring_addr failed"); 937 } 938 return r; 939 } 940 941 static int vhost_dev_set_features(struct vhost_dev *dev, 942 bool enable_log) 943 { 944 uint64_t features = dev->acked_features; 945 int r; 946 if (enable_log) { 947 features |= 0x1ULL << VHOST_F_LOG_ALL; 948 } 949 if (!vhost_dev_has_iommu(dev)) { 950 features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM); 951 } 952 if (dev->vhost_ops->vhost_force_iommu) { 953 if (dev->vhost_ops->vhost_force_iommu(dev) == true) { 954 features |= 0x1ULL << VIRTIO_F_IOMMU_PLATFORM; 955 } 956 } 957 r = dev->vhost_ops->vhost_set_features(dev, features); 958 if (r < 0) { 959 VHOST_OPS_DEBUG(r, "vhost_set_features failed"); 960 goto out; 961 } 962 if (dev->vhost_ops->vhost_set_backend_cap) { 963 r = dev->vhost_ops->vhost_set_backend_cap(dev); 964 if (r < 0) { 965 VHOST_OPS_DEBUG(r, "vhost_set_backend_cap failed"); 966 goto out; 967 } 968 } 969 970 out: 971 return r; 972 } 973 974 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 975 { 976 int r, i, idx; 977 hwaddr addr; 978 979 r = vhost_dev_set_features(dev, enable_log); 980 if (r < 0) { 981 goto err_features; 982 } 983 for (i = 0; i < dev->nvqs; ++i) { 984 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 985 addr = virtio_queue_get_desc_addr(dev->vdev, idx); 986 if (!addr) { 987 /* 988 * The queue might not be ready for start. If this 989 * is the case there is no reason to continue the process. 990 * The similar logic is used by the vhost_virtqueue_start() 991 * routine. 992 */ 993 continue; 994 } 995 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 996 enable_log); 997 if (r < 0) { 998 goto err_vq; 999 } 1000 } 1001 return 0; 1002 err_vq: 1003 for (; i >= 0; --i) { 1004 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 1005 addr = virtio_queue_get_desc_addr(dev->vdev, idx); 1006 if (!addr) { 1007 continue; 1008 } 1009 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 1010 dev->log_enabled); 1011 } 1012 vhost_dev_set_features(dev, dev->log_enabled); 1013 err_features: 1014 return r; 1015 } 1016 1017 static int vhost_migration_log(MemoryListener *listener, bool enable) 1018 { 1019 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 1020 memory_listener); 1021 int r; 1022 if (enable == dev->log_enabled) { 1023 return 0; 1024 } 1025 if (!dev->started) { 1026 dev->log_enabled = enable; 1027 return 0; 1028 } 1029 1030 r = 0; 1031 if (!enable) { 1032 r = vhost_dev_set_log(dev, false); 1033 if (r < 0) { 1034 goto check_dev_state; 1035 } 1036 vhost_log_put(dev, false); 1037 } else { 1038 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 1039 r = vhost_dev_set_log(dev, true); 1040 if (r < 0) { 1041 goto check_dev_state; 1042 } 1043 } 1044 1045 check_dev_state: 1046 dev->log_enabled = enable; 1047 /* 1048 * vhost-user-* devices could change their state during log 1049 * initialization due to disconnect. So check dev state after 1050 * vhost communication. 1051 */ 1052 if (!dev->started) { 1053 /* 1054 * Since device is in the stopped state, it is okay for 1055 * migration. Return success. 1056 */ 1057 r = 0; 1058 } 1059 if (r) { 1060 /* An error occurred. */ 1061 dev->log_enabled = false; 1062 } 1063 1064 return r; 1065 } 1066 1067 static bool vhost_log_global_start(MemoryListener *listener, Error **errp) 1068 { 1069 int r; 1070 1071 r = vhost_migration_log(listener, true); 1072 if (r < 0) { 1073 abort(); 1074 } 1075 return true; 1076 } 1077 1078 static void vhost_log_global_stop(MemoryListener *listener) 1079 { 1080 int r; 1081 1082 r = vhost_migration_log(listener, false); 1083 if (r < 0) { 1084 abort(); 1085 } 1086 } 1087 1088 static void vhost_log_start(MemoryListener *listener, 1089 MemoryRegionSection *section, 1090 int old, int new) 1091 { 1092 /* FIXME: implement */ 1093 } 1094 1095 static void vhost_log_stop(MemoryListener *listener, 1096 MemoryRegionSection *section, 1097 int old, int new) 1098 { 1099 /* FIXME: implement */ 1100 } 1101 1102 /* The vhost driver natively knows how to handle the vrings of non 1103 * cross-endian legacy devices and modern devices. Only legacy devices 1104 * exposed to a bi-endian guest may require the vhost driver to use a 1105 * specific endianness. 1106 */ 1107 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 1108 { 1109 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1110 return false; 1111 } 1112 #if HOST_BIG_ENDIAN 1113 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 1114 #else 1115 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 1116 #endif 1117 } 1118 1119 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 1120 bool is_big_endian, 1121 int vhost_vq_index) 1122 { 1123 int r; 1124 struct vhost_vring_state s = { 1125 .index = vhost_vq_index, 1126 .num = is_big_endian 1127 }; 1128 1129 r = dev->vhost_ops->vhost_set_vring_endian(dev, &s); 1130 if (r < 0) { 1131 VHOST_OPS_DEBUG(r, "vhost_set_vring_endian failed"); 1132 } 1133 return r; 1134 } 1135 1136 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 1137 uint64_t gpa, uint64_t *uaddr, 1138 uint64_t *len) 1139 { 1140 int i; 1141 1142 for (i = 0; i < hdev->mem->nregions; i++) { 1143 struct vhost_memory_region *reg = hdev->mem->regions + i; 1144 1145 if (gpa >= reg->guest_phys_addr && 1146 reg->guest_phys_addr + reg->memory_size > gpa) { 1147 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 1148 *len = reg->guest_phys_addr + reg->memory_size - gpa; 1149 return 0; 1150 } 1151 } 1152 1153 return -EFAULT; 1154 } 1155 1156 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 1157 { 1158 IOMMUTLBEntry iotlb; 1159 uint64_t uaddr, len; 1160 int ret = -EFAULT; 1161 1162 RCU_READ_LOCK_GUARD(); 1163 1164 trace_vhost_iotlb_miss(dev, 1); 1165 1166 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 1167 iova, write, 1168 MEMTXATTRS_UNSPECIFIED); 1169 if (iotlb.target_as != NULL) { 1170 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 1171 &uaddr, &len); 1172 if (ret) { 1173 trace_vhost_iotlb_miss(dev, 3); 1174 error_report("Fail to lookup the translated address " 1175 "%"PRIx64, iotlb.translated_addr); 1176 goto out; 1177 } 1178 1179 len = MIN(iotlb.addr_mask + 1, len); 1180 iova = iova & ~iotlb.addr_mask; 1181 1182 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 1183 len, iotlb.perm); 1184 if (ret) { 1185 trace_vhost_iotlb_miss(dev, 4); 1186 error_report("Fail to update device iotlb"); 1187 goto out; 1188 } 1189 } 1190 1191 trace_vhost_iotlb_miss(dev, 2); 1192 1193 out: 1194 return ret; 1195 } 1196 1197 int vhost_virtqueue_start(struct vhost_dev *dev, 1198 struct VirtIODevice *vdev, 1199 struct vhost_virtqueue *vq, 1200 unsigned idx) 1201 { 1202 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1203 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1204 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1205 hwaddr s, l, a; 1206 int r; 1207 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1208 struct vhost_vring_file file = { 1209 .index = vhost_vq_index 1210 }; 1211 struct vhost_vring_state state = { 1212 .index = vhost_vq_index 1213 }; 1214 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1215 1216 a = virtio_queue_get_desc_addr(vdev, idx); 1217 if (a == 0) { 1218 /* Queue might not be ready for start */ 1219 return 0; 1220 } 1221 1222 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1223 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1224 if (r) { 1225 VHOST_OPS_DEBUG(r, "vhost_set_vring_num failed"); 1226 return r; 1227 } 1228 1229 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1230 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1231 if (r) { 1232 VHOST_OPS_DEBUG(r, "vhost_set_vring_base failed"); 1233 return r; 1234 } 1235 1236 if (vhost_needs_vring_endian(vdev)) { 1237 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1238 virtio_is_big_endian(vdev), 1239 vhost_vq_index); 1240 if (r) { 1241 return r; 1242 } 1243 } 1244 1245 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1246 vq->desc_phys = a; 1247 vq->desc = vhost_memory_map(dev, a, &l, false); 1248 if (!vq->desc || l != s) { 1249 r = -ENOMEM; 1250 goto fail_alloc_desc; 1251 } 1252 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1253 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1254 vq->avail = vhost_memory_map(dev, a, &l, false); 1255 if (!vq->avail || l != s) { 1256 r = -ENOMEM; 1257 goto fail_alloc_avail; 1258 } 1259 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1260 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1261 vq->used = vhost_memory_map(dev, a, &l, true); 1262 if (!vq->used || l != s) { 1263 r = -ENOMEM; 1264 goto fail_alloc_used; 1265 } 1266 1267 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1268 if (r < 0) { 1269 goto fail_alloc; 1270 } 1271 1272 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1273 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1274 if (r) { 1275 VHOST_OPS_DEBUG(r, "vhost_set_vring_kick failed"); 1276 goto fail_kick; 1277 } 1278 1279 /* Clear and discard previous events if any. */ 1280 event_notifier_test_and_clear(&vq->masked_notifier); 1281 1282 /* Init vring in unmasked state, unless guest_notifier_mask 1283 * will do it later. 1284 */ 1285 if (!vdev->use_guest_notifier_mask) { 1286 /* TODO: check and handle errors. */ 1287 vhost_virtqueue_mask(dev, vdev, idx, false); 1288 } 1289 1290 if (k->query_guest_notifiers && 1291 k->query_guest_notifiers(qbus->parent) && 1292 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1293 file.fd = -1; 1294 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1295 if (r) { 1296 goto fail_vector; 1297 } 1298 } 1299 1300 return 0; 1301 1302 fail_vector: 1303 fail_kick: 1304 fail_alloc: 1305 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1306 0, 0); 1307 fail_alloc_used: 1308 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1309 0, 0); 1310 fail_alloc_avail: 1311 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1312 0, 0); 1313 fail_alloc_desc: 1314 return r; 1315 } 1316 1317 void vhost_virtqueue_stop(struct vhost_dev *dev, 1318 struct VirtIODevice *vdev, 1319 struct vhost_virtqueue *vq, 1320 unsigned idx) 1321 { 1322 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1323 struct vhost_vring_state state = { 1324 .index = vhost_vq_index, 1325 }; 1326 int r; 1327 1328 if (virtio_queue_get_desc_addr(vdev, idx) == 0) { 1329 /* Don't stop the virtqueue which might have not been started */ 1330 return; 1331 } 1332 1333 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1334 if (r < 0) { 1335 VHOST_OPS_DEBUG(r, "vhost VQ %u ring restore failed: %d", idx, r); 1336 /* Connection to the backend is broken, so let's sync internal 1337 * last avail idx to the device used idx. 1338 */ 1339 virtio_queue_restore_last_avail_idx(vdev, idx); 1340 } else { 1341 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1342 } 1343 virtio_queue_invalidate_signalled_used(vdev, idx); 1344 virtio_queue_update_used_idx(vdev, idx); 1345 1346 /* In the cross-endian case, we need to reset the vring endianness to 1347 * native as legacy devices expect so by default. 1348 */ 1349 if (vhost_needs_vring_endian(vdev)) { 1350 vhost_virtqueue_set_vring_endian_legacy(dev, 1351 !virtio_is_big_endian(vdev), 1352 vhost_vq_index); 1353 } 1354 1355 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1356 1, virtio_queue_get_used_size(vdev, idx)); 1357 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1358 0, virtio_queue_get_avail_size(vdev, idx)); 1359 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1360 0, virtio_queue_get_desc_size(vdev, idx)); 1361 } 1362 1363 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1364 int n, uint32_t timeout) 1365 { 1366 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1367 struct vhost_vring_state state = { 1368 .index = vhost_vq_index, 1369 .num = timeout, 1370 }; 1371 int r; 1372 1373 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1374 return -EINVAL; 1375 } 1376 1377 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1378 if (r) { 1379 VHOST_OPS_DEBUG(r, "vhost_set_vring_busyloop_timeout failed"); 1380 return r; 1381 } 1382 1383 return 0; 1384 } 1385 1386 static void vhost_virtqueue_error_notifier(EventNotifier *n) 1387 { 1388 struct vhost_virtqueue *vq = container_of(n, struct vhost_virtqueue, 1389 error_notifier); 1390 struct vhost_dev *dev = vq->dev; 1391 int index = vq - dev->vqs; 1392 1393 if (event_notifier_test_and_clear(n) && dev->vdev) { 1394 VHOST_OPS_DEBUG(-EINVAL, "vhost vring error in virtqueue %d", 1395 dev->vq_index + index); 1396 } 1397 } 1398 1399 static int vhost_virtqueue_init(struct vhost_dev *dev, 1400 struct vhost_virtqueue *vq, int n) 1401 { 1402 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1403 struct vhost_vring_file file = { 1404 .index = vhost_vq_index, 1405 }; 1406 int r = event_notifier_init(&vq->masked_notifier, 0); 1407 if (r < 0) { 1408 return r; 1409 } 1410 1411 file.fd = event_notifier_get_wfd(&vq->masked_notifier); 1412 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1413 if (r) { 1414 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1415 goto fail_call; 1416 } 1417 1418 vq->dev = dev; 1419 1420 if (dev->vhost_ops->vhost_set_vring_err) { 1421 r = event_notifier_init(&vq->error_notifier, 0); 1422 if (r < 0) { 1423 goto fail_call; 1424 } 1425 1426 file.fd = event_notifier_get_fd(&vq->error_notifier); 1427 r = dev->vhost_ops->vhost_set_vring_err(dev, &file); 1428 if (r) { 1429 VHOST_OPS_DEBUG(r, "vhost_set_vring_err failed"); 1430 goto fail_err; 1431 } 1432 1433 event_notifier_set_handler(&vq->error_notifier, 1434 vhost_virtqueue_error_notifier); 1435 } 1436 1437 return 0; 1438 1439 fail_err: 1440 event_notifier_cleanup(&vq->error_notifier); 1441 fail_call: 1442 event_notifier_cleanup(&vq->masked_notifier); 1443 return r; 1444 } 1445 1446 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1447 { 1448 event_notifier_cleanup(&vq->masked_notifier); 1449 if (vq->dev->vhost_ops->vhost_set_vring_err) { 1450 event_notifier_set_handler(&vq->error_notifier, NULL); 1451 event_notifier_cleanup(&vq->error_notifier); 1452 } 1453 } 1454 1455 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1456 VhostBackendType backend_type, uint32_t busyloop_timeout, 1457 Error **errp) 1458 { 1459 unsigned int used, reserved, limit; 1460 uint64_t features; 1461 int i, r, n_initialized_vqs = 0; 1462 1463 hdev->vdev = NULL; 1464 hdev->migration_blocker = NULL; 1465 1466 r = vhost_set_backend_type(hdev, backend_type); 1467 assert(r >= 0); 1468 1469 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque, errp); 1470 if (r < 0) { 1471 goto fail; 1472 } 1473 1474 r = hdev->vhost_ops->vhost_set_owner(hdev); 1475 if (r < 0) { 1476 error_setg_errno(errp, -r, "vhost_set_owner failed"); 1477 goto fail; 1478 } 1479 1480 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1481 if (r < 0) { 1482 error_setg_errno(errp, -r, "vhost_get_features failed"); 1483 goto fail; 1484 } 1485 1486 limit = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 1487 if (limit < MEMORY_DEVICES_SAFE_MAX_MEMSLOTS && 1488 memory_devices_memslot_auto_decision_active()) { 1489 error_setg(errp, "some memory device (like virtio-mem)" 1490 " decided how many memory slots to use based on the overall" 1491 " number of memory slots; this vhost backend would further" 1492 " restricts the overall number of memory slots"); 1493 error_append_hint(errp, "Try plugging this vhost backend before" 1494 " plugging such memory devices.\n"); 1495 r = -EINVAL; 1496 goto fail; 1497 } 1498 1499 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1500 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1501 if (r < 0) { 1502 error_setg_errno(errp, -r, "Failed to initialize virtqueue %d", i); 1503 goto fail; 1504 } 1505 } 1506 1507 if (busyloop_timeout) { 1508 for (i = 0; i < hdev->nvqs; ++i) { 1509 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1510 busyloop_timeout); 1511 if (r < 0) { 1512 error_setg_errno(errp, -r, "Failed to set busyloop timeout"); 1513 goto fail_busyloop; 1514 } 1515 } 1516 } 1517 1518 hdev->features = features; 1519 1520 hdev->memory_listener = (MemoryListener) { 1521 .name = "vhost", 1522 .begin = vhost_begin, 1523 .commit = vhost_commit, 1524 .region_add = vhost_region_addnop, 1525 .region_nop = vhost_region_addnop, 1526 .log_start = vhost_log_start, 1527 .log_stop = vhost_log_stop, 1528 .log_sync = vhost_log_sync, 1529 .log_global_start = vhost_log_global_start, 1530 .log_global_stop = vhost_log_global_stop, 1531 .priority = MEMORY_LISTENER_PRIORITY_DEV_BACKEND 1532 }; 1533 1534 hdev->iommu_listener = (MemoryListener) { 1535 .name = "vhost-iommu", 1536 .region_add = vhost_iommu_region_add, 1537 .region_del = vhost_iommu_region_del, 1538 }; 1539 1540 if (hdev->migration_blocker == NULL) { 1541 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1542 error_setg(&hdev->migration_blocker, 1543 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1544 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) { 1545 error_setg(&hdev->migration_blocker, 1546 "Migration disabled: failed to allocate shared memory"); 1547 } 1548 } 1549 1550 if (hdev->migration_blocker != NULL) { 1551 r = migrate_add_blocker_normal(&hdev->migration_blocker, errp); 1552 if (r < 0) { 1553 goto fail_busyloop; 1554 } 1555 } 1556 1557 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1558 hdev->n_mem_sections = 0; 1559 hdev->mem_sections = NULL; 1560 hdev->log = NULL; 1561 hdev->log_size = 0; 1562 hdev->log_enabled = false; 1563 hdev->started = false; 1564 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1565 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1566 1567 /* 1568 * The listener we registered properly updated the corresponding counter. 1569 * So we can trust that these values are accurate. 1570 */ 1571 if (hdev->vhost_ops->vhost_backend_no_private_memslots && 1572 hdev->vhost_ops->vhost_backend_no_private_memslots(hdev)) { 1573 used = used_shared_memslots; 1574 } else { 1575 used = used_memslots; 1576 } 1577 /* 1578 * We assume that all reserved memslots actually require a real memslot 1579 * in our vhost backend. This might not be true, for example, if the 1580 * memslot would be ROM. If ever relevant, we can optimize for that -- 1581 * but we'll need additional information about the reservations. 1582 */ 1583 reserved = memory_devices_get_reserved_memslots(); 1584 if (used + reserved > limit) { 1585 error_setg(errp, "vhost backend memory slots limit (%d) is less" 1586 " than current number of used (%d) and reserved (%d)" 1587 " memory slots for memory devices.", limit, used, reserved); 1588 r = -EINVAL; 1589 goto fail_busyloop; 1590 } 1591 1592 return 0; 1593 1594 fail_busyloop: 1595 if (busyloop_timeout) { 1596 while (--i >= 0) { 1597 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1598 } 1599 } 1600 fail: 1601 hdev->nvqs = n_initialized_vqs; 1602 vhost_dev_cleanup(hdev); 1603 return r; 1604 } 1605 1606 void vhost_dev_cleanup(struct vhost_dev *hdev) 1607 { 1608 int i; 1609 1610 trace_vhost_dev_cleanup(hdev); 1611 1612 for (i = 0; i < hdev->nvqs; ++i) { 1613 vhost_virtqueue_cleanup(hdev->vqs + i); 1614 } 1615 if (hdev->mem) { 1616 /* those are only safe after successful init */ 1617 memory_listener_unregister(&hdev->memory_listener); 1618 QLIST_REMOVE(hdev, entry); 1619 } 1620 migrate_del_blocker(&hdev->migration_blocker); 1621 g_free(hdev->mem); 1622 g_free(hdev->mem_sections); 1623 if (hdev->vhost_ops) { 1624 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1625 } 1626 assert(!hdev->log); 1627 1628 memset(hdev, 0, sizeof(struct vhost_dev)); 1629 } 1630 1631 static void vhost_dev_disable_notifiers_nvqs(struct vhost_dev *hdev, 1632 VirtIODevice *vdev, 1633 unsigned int nvqs) 1634 { 1635 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1636 int i, r; 1637 1638 /* 1639 * Batch all the host notifiers in a single transaction to avoid 1640 * quadratic time complexity in address_space_update_ioeventfds(). 1641 */ 1642 memory_region_transaction_begin(); 1643 1644 for (i = 0; i < nvqs; ++i) { 1645 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1646 false); 1647 if (r < 0) { 1648 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1649 } 1650 assert(r >= 0); 1651 } 1652 1653 /* 1654 * The transaction expects the ioeventfds to be open when it 1655 * commits. Do it now, before the cleanup loop. 1656 */ 1657 memory_region_transaction_commit(); 1658 1659 for (i = 0; i < nvqs; ++i) { 1660 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1661 } 1662 virtio_device_release_ioeventfd(vdev); 1663 } 1664 1665 /* Stop processing guest IO notifications in qemu. 1666 * Start processing them in vhost in kernel. 1667 */ 1668 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1669 { 1670 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1671 int i, r; 1672 1673 /* We will pass the notifiers to the kernel, make sure that QEMU 1674 * doesn't interfere. 1675 */ 1676 r = virtio_device_grab_ioeventfd(vdev); 1677 if (r < 0) { 1678 error_report("binding does not support host notifiers"); 1679 return r; 1680 } 1681 1682 /* 1683 * Batch all the host notifiers in a single transaction to avoid 1684 * quadratic time complexity in address_space_update_ioeventfds(). 1685 */ 1686 memory_region_transaction_begin(); 1687 1688 for (i = 0; i < hdev->nvqs; ++i) { 1689 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1690 true); 1691 if (r < 0) { 1692 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1693 memory_region_transaction_commit(); 1694 vhost_dev_disable_notifiers_nvqs(hdev, vdev, i); 1695 return r; 1696 } 1697 } 1698 1699 memory_region_transaction_commit(); 1700 1701 return 0; 1702 } 1703 1704 /* Stop processing guest IO notifications in vhost. 1705 * Start processing them in qemu. 1706 * This might actually run the qemu handlers right away, 1707 * so virtio in qemu must be completely setup when this is called. 1708 */ 1709 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1710 { 1711 vhost_dev_disable_notifiers_nvqs(hdev, vdev, hdev->nvqs); 1712 } 1713 1714 /* Test and clear event pending status. 1715 * Should be called after unmask to avoid losing events. 1716 */ 1717 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1718 { 1719 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1720 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1721 return event_notifier_test_and_clear(&vq->masked_notifier); 1722 } 1723 1724 /* Mask/unmask events from this vq. */ 1725 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1726 bool mask) 1727 { 1728 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1729 int r, index = n - hdev->vq_index; 1730 struct vhost_vring_file file; 1731 1732 /* should only be called after backend is connected */ 1733 assert(hdev->vhost_ops); 1734 1735 if (mask) { 1736 assert(vdev->use_guest_notifier_mask); 1737 file.fd = event_notifier_get_wfd(&hdev->vqs[index].masked_notifier); 1738 } else { 1739 file.fd = event_notifier_get_wfd(virtio_queue_get_guest_notifier(vvq)); 1740 } 1741 1742 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1743 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1744 if (r < 0) { 1745 error_report("vhost_set_vring_call failed %d", -r); 1746 } 1747 } 1748 1749 bool vhost_config_pending(struct vhost_dev *hdev) 1750 { 1751 assert(hdev->vhost_ops); 1752 if ((hdev->started == false) || 1753 (hdev->vhost_ops->vhost_set_config_call == NULL)) { 1754 return false; 1755 } 1756 1757 EventNotifier *notifier = 1758 &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier; 1759 return event_notifier_test_and_clear(notifier); 1760 } 1761 1762 void vhost_config_mask(struct vhost_dev *hdev, VirtIODevice *vdev, bool mask) 1763 { 1764 int fd; 1765 int r; 1766 EventNotifier *notifier = 1767 &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier; 1768 EventNotifier *config_notifier = &vdev->config_notifier; 1769 assert(hdev->vhost_ops); 1770 1771 if ((hdev->started == false) || 1772 (hdev->vhost_ops->vhost_set_config_call == NULL)) { 1773 return; 1774 } 1775 if (mask) { 1776 assert(vdev->use_guest_notifier_mask); 1777 fd = event_notifier_get_fd(notifier); 1778 } else { 1779 fd = event_notifier_get_fd(config_notifier); 1780 } 1781 r = hdev->vhost_ops->vhost_set_config_call(hdev, fd); 1782 if (r < 0) { 1783 error_report("vhost_set_config_call failed %d", -r); 1784 } 1785 } 1786 1787 static void vhost_stop_config_intr(struct vhost_dev *dev) 1788 { 1789 int fd = -1; 1790 assert(dev->vhost_ops); 1791 if (dev->vhost_ops->vhost_set_config_call) { 1792 dev->vhost_ops->vhost_set_config_call(dev, fd); 1793 } 1794 } 1795 1796 static void vhost_start_config_intr(struct vhost_dev *dev) 1797 { 1798 int r; 1799 1800 assert(dev->vhost_ops); 1801 int fd = event_notifier_get_fd(&dev->vdev->config_notifier); 1802 if (dev->vhost_ops->vhost_set_config_call) { 1803 r = dev->vhost_ops->vhost_set_config_call(dev, fd); 1804 if (!r) { 1805 event_notifier_set(&dev->vdev->config_notifier); 1806 } 1807 } 1808 } 1809 1810 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1811 uint64_t features) 1812 { 1813 const int *bit = feature_bits; 1814 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1815 uint64_t bit_mask = (1ULL << *bit); 1816 if (!(hdev->features & bit_mask)) { 1817 features &= ~bit_mask; 1818 } 1819 bit++; 1820 } 1821 return features; 1822 } 1823 1824 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1825 uint64_t features) 1826 { 1827 const int *bit = feature_bits; 1828 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1829 uint64_t bit_mask = (1ULL << *bit); 1830 if (features & bit_mask) { 1831 hdev->acked_features |= bit_mask; 1832 } 1833 bit++; 1834 } 1835 } 1836 1837 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1838 uint32_t config_len, Error **errp) 1839 { 1840 assert(hdev->vhost_ops); 1841 1842 if (hdev->vhost_ops->vhost_get_config) { 1843 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len, 1844 errp); 1845 } 1846 1847 error_setg(errp, "vhost_get_config not implemented"); 1848 return -ENOSYS; 1849 } 1850 1851 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1852 uint32_t offset, uint32_t size, uint32_t flags) 1853 { 1854 assert(hdev->vhost_ops); 1855 1856 if (hdev->vhost_ops->vhost_set_config) { 1857 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1858 size, flags); 1859 } 1860 1861 return -ENOSYS; 1862 } 1863 1864 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1865 const VhostDevConfigOps *ops) 1866 { 1867 hdev->config_ops = ops; 1868 } 1869 1870 void vhost_dev_free_inflight(struct vhost_inflight *inflight) 1871 { 1872 if (inflight && inflight->addr) { 1873 qemu_memfd_free(inflight->addr, inflight->size, inflight->fd); 1874 inflight->addr = NULL; 1875 inflight->fd = -1; 1876 } 1877 } 1878 1879 static int vhost_dev_resize_inflight(struct vhost_inflight *inflight, 1880 uint64_t new_size) 1881 { 1882 Error *err = NULL; 1883 int fd = -1; 1884 void *addr = qemu_memfd_alloc("vhost-inflight", new_size, 1885 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 1886 &fd, &err); 1887 1888 if (err) { 1889 error_report_err(err); 1890 return -ENOMEM; 1891 } 1892 1893 vhost_dev_free_inflight(inflight); 1894 inflight->offset = 0; 1895 inflight->addr = addr; 1896 inflight->fd = fd; 1897 inflight->size = new_size; 1898 1899 return 0; 1900 } 1901 1902 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1903 { 1904 if (inflight->addr) { 1905 qemu_put_be64(f, inflight->size); 1906 qemu_put_be16(f, inflight->queue_size); 1907 qemu_put_buffer(f, inflight->addr, inflight->size); 1908 } else { 1909 qemu_put_be64(f, 0); 1910 } 1911 } 1912 1913 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1914 { 1915 uint64_t size; 1916 1917 size = qemu_get_be64(f); 1918 if (!size) { 1919 return 0; 1920 } 1921 1922 if (inflight->size != size) { 1923 int ret = vhost_dev_resize_inflight(inflight, size); 1924 if (ret < 0) { 1925 return ret; 1926 } 1927 } 1928 inflight->queue_size = qemu_get_be16(f); 1929 1930 qemu_get_buffer(f, inflight->addr, size); 1931 1932 return 0; 1933 } 1934 1935 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev) 1936 { 1937 int r; 1938 1939 if (hdev->vhost_ops->vhost_get_inflight_fd == NULL || 1940 hdev->vhost_ops->vhost_set_inflight_fd == NULL) { 1941 return 0; 1942 } 1943 1944 hdev->vdev = vdev; 1945 1946 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1947 if (r < 0) { 1948 VHOST_OPS_DEBUG(r, "vhost_dev_prepare_inflight failed"); 1949 return r; 1950 } 1951 1952 return 0; 1953 } 1954 1955 int vhost_dev_set_inflight(struct vhost_dev *dev, 1956 struct vhost_inflight *inflight) 1957 { 1958 int r; 1959 1960 if (dev->vhost_ops->vhost_set_inflight_fd && inflight->addr) { 1961 r = dev->vhost_ops->vhost_set_inflight_fd(dev, inflight); 1962 if (r) { 1963 VHOST_OPS_DEBUG(r, "vhost_set_inflight_fd failed"); 1964 return r; 1965 } 1966 } 1967 1968 return 0; 1969 } 1970 1971 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, 1972 struct vhost_inflight *inflight) 1973 { 1974 int r; 1975 1976 if (dev->vhost_ops->vhost_get_inflight_fd) { 1977 r = dev->vhost_ops->vhost_get_inflight_fd(dev, queue_size, inflight); 1978 if (r) { 1979 VHOST_OPS_DEBUG(r, "vhost_get_inflight_fd failed"); 1980 return r; 1981 } 1982 } 1983 1984 return 0; 1985 } 1986 1987 static int vhost_dev_set_vring_enable(struct vhost_dev *hdev, int enable) 1988 { 1989 if (!hdev->vhost_ops->vhost_set_vring_enable) { 1990 return 0; 1991 } 1992 1993 /* 1994 * For vhost-user devices, if VHOST_USER_F_PROTOCOL_FEATURES has not 1995 * been negotiated, the rings start directly in the enabled state, and 1996 * .vhost_set_vring_enable callback will fail since 1997 * VHOST_USER_SET_VRING_ENABLE is not supported. 1998 */ 1999 if (hdev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER && 2000 !virtio_has_feature(hdev->backend_features, 2001 VHOST_USER_F_PROTOCOL_FEATURES)) { 2002 return 0; 2003 } 2004 2005 return hdev->vhost_ops->vhost_set_vring_enable(hdev, enable); 2006 } 2007 2008 /* 2009 * Host notifiers must be enabled at this point. 2010 * 2011 * If @vrings is true, this function will enable all vrings before starting the 2012 * device. If it is false, the vring initialization is left to be done by the 2013 * caller. 2014 */ 2015 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) 2016 { 2017 int i, r; 2018 2019 /* should only be called after backend is connected */ 2020 assert(hdev->vhost_ops); 2021 2022 trace_vhost_dev_start(hdev, vdev->name, vrings); 2023 2024 vdev->vhost_started = true; 2025 hdev->started = true; 2026 hdev->vdev = vdev; 2027 2028 r = vhost_dev_set_features(hdev, hdev->log_enabled); 2029 if (r < 0) { 2030 goto fail_features; 2031 } 2032 2033 if (vhost_dev_has_iommu(hdev)) { 2034 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 2035 } 2036 2037 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 2038 if (r < 0) { 2039 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 2040 goto fail_mem; 2041 } 2042 for (i = 0; i < hdev->nvqs; ++i) { 2043 r = vhost_virtqueue_start(hdev, 2044 vdev, 2045 hdev->vqs + i, 2046 hdev->vq_index + i); 2047 if (r < 0) { 2048 goto fail_vq; 2049 } 2050 } 2051 2052 r = event_notifier_init( 2053 &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier, 0); 2054 if (r < 0) { 2055 VHOST_OPS_DEBUG(r, "event_notifier_init failed"); 2056 goto fail_vq; 2057 } 2058 event_notifier_test_and_clear( 2059 &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier); 2060 if (!vdev->use_guest_notifier_mask) { 2061 vhost_config_mask(hdev, vdev, true); 2062 } 2063 if (hdev->log_enabled) { 2064 uint64_t log_base; 2065 2066 hdev->log_size = vhost_get_log_size(hdev); 2067 hdev->log = vhost_log_get(hdev->vhost_ops->backend_type, 2068 hdev->log_size, 2069 vhost_dev_log_is_shared(hdev)); 2070 log_base = (uintptr_t)hdev->log->log; 2071 r = hdev->vhost_ops->vhost_set_log_base(hdev, 2072 hdev->log_size ? log_base : 0, 2073 hdev->log); 2074 if (r < 0) { 2075 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 2076 goto fail_log; 2077 } 2078 } 2079 if (vrings) { 2080 r = vhost_dev_set_vring_enable(hdev, true); 2081 if (r) { 2082 goto fail_log; 2083 } 2084 } 2085 if (hdev->vhost_ops->vhost_dev_start) { 2086 r = hdev->vhost_ops->vhost_dev_start(hdev, true); 2087 if (r) { 2088 goto fail_start; 2089 } 2090 } 2091 if (vhost_dev_has_iommu(hdev) && 2092 hdev->vhost_ops->vhost_set_iotlb_callback) { 2093 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 2094 2095 /* Update used ring information for IOTLB to work correctly, 2096 * vhost-kernel code requires for this.*/ 2097 for (i = 0; i < hdev->nvqs; ++i) { 2098 struct vhost_virtqueue *vq = hdev->vqs + i; 2099 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 2100 } 2101 } 2102 vhost_start_config_intr(hdev); 2103 return 0; 2104 fail_start: 2105 if (vrings) { 2106 vhost_dev_set_vring_enable(hdev, false); 2107 } 2108 fail_log: 2109 vhost_log_put(hdev, false); 2110 fail_vq: 2111 while (--i >= 0) { 2112 vhost_virtqueue_stop(hdev, 2113 vdev, 2114 hdev->vqs + i, 2115 hdev->vq_index + i); 2116 } 2117 2118 fail_mem: 2119 if (vhost_dev_has_iommu(hdev)) { 2120 memory_listener_unregister(&hdev->iommu_listener); 2121 } 2122 fail_features: 2123 vdev->vhost_started = false; 2124 hdev->started = false; 2125 return r; 2126 } 2127 2128 /* Host notifiers must be enabled at this point. */ 2129 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) 2130 { 2131 int i; 2132 2133 /* should only be called after backend is connected */ 2134 assert(hdev->vhost_ops); 2135 event_notifier_test_and_clear( 2136 &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier); 2137 event_notifier_test_and_clear(&vdev->config_notifier); 2138 event_notifier_cleanup( 2139 &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier); 2140 2141 trace_vhost_dev_stop(hdev, vdev->name, vrings); 2142 2143 if (hdev->vhost_ops->vhost_dev_start) { 2144 hdev->vhost_ops->vhost_dev_start(hdev, false); 2145 } 2146 if (vrings) { 2147 vhost_dev_set_vring_enable(hdev, false); 2148 } 2149 for (i = 0; i < hdev->nvqs; ++i) { 2150 vhost_virtqueue_stop(hdev, 2151 vdev, 2152 hdev->vqs + i, 2153 hdev->vq_index + i); 2154 } 2155 if (hdev->vhost_ops->vhost_reset_status) { 2156 hdev->vhost_ops->vhost_reset_status(hdev); 2157 } 2158 2159 if (vhost_dev_has_iommu(hdev)) { 2160 if (hdev->vhost_ops->vhost_set_iotlb_callback) { 2161 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 2162 } 2163 memory_listener_unregister(&hdev->iommu_listener); 2164 } 2165 vhost_stop_config_intr(hdev); 2166 vhost_log_put(hdev, true); 2167 hdev->started = false; 2168 vdev->vhost_started = false; 2169 hdev->vdev = NULL; 2170 } 2171 2172 int vhost_net_set_backend(struct vhost_dev *hdev, 2173 struct vhost_vring_file *file) 2174 { 2175 if (hdev->vhost_ops->vhost_net_set_backend) { 2176 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 2177 } 2178 2179 return -ENOSYS; 2180 } 2181 2182 int vhost_reset_device(struct vhost_dev *hdev) 2183 { 2184 if (hdev->vhost_ops->vhost_reset_device) { 2185 return hdev->vhost_ops->vhost_reset_device(hdev); 2186 } 2187 2188 return -ENOSYS; 2189 } 2190 2191 bool vhost_supports_device_state(struct vhost_dev *dev) 2192 { 2193 if (dev->vhost_ops->vhost_supports_device_state) { 2194 return dev->vhost_ops->vhost_supports_device_state(dev); 2195 } 2196 2197 return false; 2198 } 2199 2200 int vhost_set_device_state_fd(struct vhost_dev *dev, 2201 VhostDeviceStateDirection direction, 2202 VhostDeviceStatePhase phase, 2203 int fd, 2204 int *reply_fd, 2205 Error **errp) 2206 { 2207 if (dev->vhost_ops->vhost_set_device_state_fd) { 2208 return dev->vhost_ops->vhost_set_device_state_fd(dev, direction, phase, 2209 fd, reply_fd, errp); 2210 } 2211 2212 error_setg(errp, 2213 "vhost transport does not support migration state transfer"); 2214 return -ENOSYS; 2215 } 2216 2217 int vhost_check_device_state(struct vhost_dev *dev, Error **errp) 2218 { 2219 if (dev->vhost_ops->vhost_check_device_state) { 2220 return dev->vhost_ops->vhost_check_device_state(dev, errp); 2221 } 2222 2223 error_setg(errp, 2224 "vhost transport does not support migration state transfer"); 2225 return -ENOSYS; 2226 } 2227 2228 int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp) 2229 { 2230 ERRP_GUARD(); 2231 /* Maximum chunk size in which to transfer the state */ 2232 const size_t chunk_size = 1 * 1024 * 1024; 2233 g_autofree void *transfer_buf = NULL; 2234 g_autoptr(GError) g_err = NULL; 2235 int pipe_fds[2], read_fd = -1, write_fd = -1, reply_fd = -1; 2236 int ret; 2237 2238 /* [0] for reading (our end), [1] for writing (back-end's end) */ 2239 if (!g_unix_open_pipe(pipe_fds, FD_CLOEXEC, &g_err)) { 2240 error_setg(errp, "Failed to set up state transfer pipe: %s", 2241 g_err->message); 2242 ret = -EINVAL; 2243 goto fail; 2244 } 2245 2246 read_fd = pipe_fds[0]; 2247 write_fd = pipe_fds[1]; 2248 2249 /* 2250 * VHOST_TRANSFER_STATE_PHASE_STOPPED means the device must be stopped. 2251 * Ideally, it is suspended, but SUSPEND/RESUME currently do not exist for 2252 * vhost-user, so just check that it is stopped at all. 2253 */ 2254 assert(!dev->started); 2255 2256 /* Transfer ownership of write_fd to the back-end */ 2257 ret = vhost_set_device_state_fd(dev, 2258 VHOST_TRANSFER_STATE_DIRECTION_SAVE, 2259 VHOST_TRANSFER_STATE_PHASE_STOPPED, 2260 write_fd, 2261 &reply_fd, 2262 errp); 2263 if (ret < 0) { 2264 error_prepend(errp, "Failed to initiate state transfer: "); 2265 goto fail; 2266 } 2267 2268 /* If the back-end wishes to use a different pipe, switch over */ 2269 if (reply_fd >= 0) { 2270 close(read_fd); 2271 read_fd = reply_fd; 2272 } 2273 2274 transfer_buf = g_malloc(chunk_size); 2275 2276 while (true) { 2277 ssize_t read_ret; 2278 2279 read_ret = RETRY_ON_EINTR(read(read_fd, transfer_buf, chunk_size)); 2280 if (read_ret < 0) { 2281 ret = -errno; 2282 error_setg_errno(errp, -ret, "Failed to receive state"); 2283 goto fail; 2284 } 2285 2286 assert(read_ret <= chunk_size); 2287 qemu_put_be32(f, read_ret); 2288 2289 if (read_ret == 0) { 2290 /* EOF */ 2291 break; 2292 } 2293 2294 qemu_put_buffer(f, transfer_buf, read_ret); 2295 } 2296 2297 /* 2298 * Back-end will not really care, but be clean and close our end of the pipe 2299 * before inquiring the back-end about whether transfer was successful 2300 */ 2301 close(read_fd); 2302 read_fd = -1; 2303 2304 /* Also, verify that the device is still stopped */ 2305 assert(!dev->started); 2306 2307 ret = vhost_check_device_state(dev, errp); 2308 if (ret < 0) { 2309 goto fail; 2310 } 2311 2312 ret = 0; 2313 fail: 2314 if (read_fd >= 0) { 2315 close(read_fd); 2316 } 2317 2318 return ret; 2319 } 2320 2321 int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp) 2322 { 2323 ERRP_GUARD(); 2324 size_t transfer_buf_size = 0; 2325 g_autofree void *transfer_buf = NULL; 2326 g_autoptr(GError) g_err = NULL; 2327 int pipe_fds[2], read_fd = -1, write_fd = -1, reply_fd = -1; 2328 int ret; 2329 2330 /* [0] for reading (back-end's end), [1] for writing (our end) */ 2331 if (!g_unix_open_pipe(pipe_fds, FD_CLOEXEC, &g_err)) { 2332 error_setg(errp, "Failed to set up state transfer pipe: %s", 2333 g_err->message); 2334 ret = -EINVAL; 2335 goto fail; 2336 } 2337 2338 read_fd = pipe_fds[0]; 2339 write_fd = pipe_fds[1]; 2340 2341 /* 2342 * VHOST_TRANSFER_STATE_PHASE_STOPPED means the device must be stopped. 2343 * Ideally, it is suspended, but SUSPEND/RESUME currently do not exist for 2344 * vhost-user, so just check that it is stopped at all. 2345 */ 2346 assert(!dev->started); 2347 2348 /* Transfer ownership of read_fd to the back-end */ 2349 ret = vhost_set_device_state_fd(dev, 2350 VHOST_TRANSFER_STATE_DIRECTION_LOAD, 2351 VHOST_TRANSFER_STATE_PHASE_STOPPED, 2352 read_fd, 2353 &reply_fd, 2354 errp); 2355 if (ret < 0) { 2356 error_prepend(errp, "Failed to initiate state transfer: "); 2357 goto fail; 2358 } 2359 2360 /* If the back-end wishes to use a different pipe, switch over */ 2361 if (reply_fd >= 0) { 2362 close(write_fd); 2363 write_fd = reply_fd; 2364 } 2365 2366 while (true) { 2367 size_t this_chunk_size = qemu_get_be32(f); 2368 ssize_t write_ret; 2369 const uint8_t *transfer_pointer; 2370 2371 if (this_chunk_size == 0) { 2372 /* End of state */ 2373 break; 2374 } 2375 2376 if (transfer_buf_size < this_chunk_size) { 2377 transfer_buf = g_realloc(transfer_buf, this_chunk_size); 2378 transfer_buf_size = this_chunk_size; 2379 } 2380 2381 if (qemu_get_buffer(f, transfer_buf, this_chunk_size) < 2382 this_chunk_size) 2383 { 2384 error_setg(errp, "Failed to read state"); 2385 ret = -EINVAL; 2386 goto fail; 2387 } 2388 2389 transfer_pointer = transfer_buf; 2390 while (this_chunk_size > 0) { 2391 write_ret = RETRY_ON_EINTR( 2392 write(write_fd, transfer_pointer, this_chunk_size) 2393 ); 2394 if (write_ret < 0) { 2395 ret = -errno; 2396 error_setg_errno(errp, -ret, "Failed to send state"); 2397 goto fail; 2398 } else if (write_ret == 0) { 2399 error_setg(errp, "Failed to send state: Connection is closed"); 2400 ret = -ECONNRESET; 2401 goto fail; 2402 } 2403 2404 assert(write_ret <= this_chunk_size); 2405 this_chunk_size -= write_ret; 2406 transfer_pointer += write_ret; 2407 } 2408 } 2409 2410 /* 2411 * Close our end, thus ending transfer, before inquiring the back-end about 2412 * whether transfer was successful 2413 */ 2414 close(write_fd); 2415 write_fd = -1; 2416 2417 /* Also, verify that the device is still stopped */ 2418 assert(!dev->started); 2419 2420 ret = vhost_check_device_state(dev, errp); 2421 if (ret < 0) { 2422 goto fail; 2423 } 2424 2425 ret = 0; 2426 fail: 2427 if (write_fd >= 0) { 2428 close(write_fd); 2429 } 2430 2431 return ret; 2432 } 2433