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 "standard-headers/linux/vhost_types.h" 24 #include "hw/virtio/virtio-bus.h" 25 #include "hw/virtio/virtio-access.h" 26 #include "migration/blocker.h" 27 #include "migration/qemu-file-types.h" 28 #include "sysemu/dma.h" 29 #include "trace.h" 30 31 /* enabled until disconnected backend stabilizes */ 32 #define _VHOST_DEBUG 1 33 34 #ifdef _VHOST_DEBUG 35 #define VHOST_OPS_DEBUG(retval, fmt, ...) \ 36 do { \ 37 error_report(fmt ": %s (%d)", ## __VA_ARGS__, \ 38 strerror(-retval), -retval); \ 39 } while (0) 40 #else 41 #define VHOST_OPS_DEBUG(retval, fmt, ...) \ 42 do { } while (0) 43 #endif 44 45 static struct vhost_log *vhost_log; 46 static struct vhost_log *vhost_log_shm; 47 48 static unsigned int used_memslots; 49 static QLIST_HEAD(, vhost_dev) vhost_devices = 50 QLIST_HEAD_INITIALIZER(vhost_devices); 51 52 bool vhost_has_free_slot(void) 53 { 54 unsigned int slots_limit = ~0U; 55 struct vhost_dev *hdev; 56 57 QLIST_FOREACH(hdev, &vhost_devices, entry) { 58 unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 59 slots_limit = MIN(slots_limit, r); 60 } 61 return slots_limit > used_memslots; 62 } 63 64 static void vhost_dev_sync_region(struct vhost_dev *dev, 65 MemoryRegionSection *section, 66 uint64_t mfirst, uint64_t mlast, 67 uint64_t rfirst, uint64_t rlast) 68 { 69 vhost_log_chunk_t *log = dev->log->log; 70 71 uint64_t start = MAX(mfirst, rfirst); 72 uint64_t end = MIN(mlast, rlast); 73 vhost_log_chunk_t *from = log + start / VHOST_LOG_CHUNK; 74 vhost_log_chunk_t *to = log + end / VHOST_LOG_CHUNK + 1; 75 uint64_t addr = QEMU_ALIGN_DOWN(start, VHOST_LOG_CHUNK); 76 77 if (end < start) { 78 return; 79 } 80 assert(end / VHOST_LOG_CHUNK < dev->log_size); 81 assert(start / VHOST_LOG_CHUNK < dev->log_size); 82 83 for (;from < to; ++from) { 84 vhost_log_chunk_t log; 85 /* We first check with non-atomic: much cheaper, 86 * and we expect non-dirty to be the common case. */ 87 if (!*from) { 88 addr += VHOST_LOG_CHUNK; 89 continue; 90 } 91 /* Data must be read atomically. We don't really need barrier semantics 92 * but it's easier to use atomic_* than roll our own. */ 93 log = qatomic_xchg(from, 0); 94 while (log) { 95 int bit = ctzl(log); 96 hwaddr page_addr; 97 hwaddr section_offset; 98 hwaddr mr_offset; 99 page_addr = addr + bit * VHOST_LOG_PAGE; 100 section_offset = page_addr - section->offset_within_address_space; 101 mr_offset = section_offset + section->offset_within_region; 102 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 103 log &= ~(0x1ull << bit); 104 } 105 addr += VHOST_LOG_CHUNK; 106 } 107 } 108 109 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 110 MemoryRegionSection *section, 111 hwaddr first, 112 hwaddr last) 113 { 114 int i; 115 hwaddr start_addr; 116 hwaddr end_addr; 117 118 if (!dev->log_enabled || !dev->started) { 119 return 0; 120 } 121 start_addr = section->offset_within_address_space; 122 end_addr = range_get_last(start_addr, int128_get64(section->size)); 123 start_addr = MAX(first, start_addr); 124 end_addr = MIN(last, end_addr); 125 126 for (i = 0; i < dev->mem->nregions; ++i) { 127 struct vhost_memory_region *reg = dev->mem->regions + i; 128 vhost_dev_sync_region(dev, section, start_addr, end_addr, 129 reg->guest_phys_addr, 130 range_get_last(reg->guest_phys_addr, 131 reg->memory_size)); 132 } 133 for (i = 0; i < dev->nvqs; ++i) { 134 struct vhost_virtqueue *vq = dev->vqs + i; 135 136 if (!vq->used_phys && !vq->used_size) { 137 continue; 138 } 139 140 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 141 range_get_last(vq->used_phys, vq->used_size)); 142 } 143 return 0; 144 } 145 146 static void vhost_log_sync(MemoryListener *listener, 147 MemoryRegionSection *section) 148 { 149 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 150 memory_listener); 151 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 152 } 153 154 static void vhost_log_sync_range(struct vhost_dev *dev, 155 hwaddr first, hwaddr last) 156 { 157 int i; 158 /* FIXME: this is N^2 in number of sections */ 159 for (i = 0; i < dev->n_mem_sections; ++i) { 160 MemoryRegionSection *section = &dev->mem_sections[i]; 161 vhost_sync_dirty_bitmap(dev, section, first, last); 162 } 163 } 164 165 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 166 { 167 uint64_t log_size = 0; 168 int i; 169 for (i = 0; i < dev->mem->nregions; ++i) { 170 struct vhost_memory_region *reg = dev->mem->regions + i; 171 uint64_t last = range_get_last(reg->guest_phys_addr, 172 reg->memory_size); 173 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 174 } 175 return log_size; 176 } 177 178 static int vhost_set_backend_type(struct vhost_dev *dev, 179 VhostBackendType backend_type) 180 { 181 int r = 0; 182 183 switch (backend_type) { 184 #ifdef CONFIG_VHOST_KERNEL 185 case VHOST_BACKEND_TYPE_KERNEL: 186 dev->vhost_ops = &kernel_ops; 187 break; 188 #endif 189 #ifdef CONFIG_VHOST_USER 190 case VHOST_BACKEND_TYPE_USER: 191 dev->vhost_ops = &user_ops; 192 break; 193 #endif 194 #ifdef CONFIG_VHOST_VDPA 195 case VHOST_BACKEND_TYPE_VDPA: 196 dev->vhost_ops = &vdpa_ops; 197 break; 198 #endif 199 default: 200 error_report("Unknown vhost backend type"); 201 r = -1; 202 } 203 204 return r; 205 } 206 207 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 208 { 209 Error *err = NULL; 210 struct vhost_log *log; 211 uint64_t logsize = size * sizeof(*(log->log)); 212 int fd = -1; 213 214 log = g_new0(struct vhost_log, 1); 215 if (share) { 216 log->log = qemu_memfd_alloc("vhost-log", logsize, 217 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 218 &fd, &err); 219 if (err) { 220 error_report_err(err); 221 g_free(log); 222 return NULL; 223 } 224 memset(log->log, 0, logsize); 225 } else { 226 log->log = g_malloc0(logsize); 227 } 228 229 log->size = size; 230 log->refcnt = 1; 231 log->fd = fd; 232 233 return log; 234 } 235 236 static struct vhost_log *vhost_log_get(uint64_t size, bool share) 237 { 238 struct vhost_log *log = share ? vhost_log_shm : vhost_log; 239 240 if (!log || log->size != size) { 241 log = vhost_log_alloc(size, share); 242 if (share) { 243 vhost_log_shm = log; 244 } else { 245 vhost_log = log; 246 } 247 } else { 248 ++log->refcnt; 249 } 250 251 return log; 252 } 253 254 static void vhost_log_put(struct vhost_dev *dev, bool sync) 255 { 256 struct vhost_log *log = dev->log; 257 258 if (!log) { 259 return; 260 } 261 262 --log->refcnt; 263 if (log->refcnt == 0) { 264 /* Sync only the range covered by the old log */ 265 if (dev->log_size && sync) { 266 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 267 } 268 269 if (vhost_log == log) { 270 g_free(log->log); 271 vhost_log = NULL; 272 } else if (vhost_log_shm == log) { 273 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 274 log->fd); 275 vhost_log_shm = NULL; 276 } 277 278 g_free(log); 279 } 280 281 dev->log = NULL; 282 dev->log_size = 0; 283 } 284 285 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 286 { 287 return dev->vhost_ops->vhost_requires_shm_log && 288 dev->vhost_ops->vhost_requires_shm_log(dev); 289 } 290 291 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 292 { 293 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 294 uint64_t log_base = (uintptr_t)log->log; 295 int r; 296 297 /* inform backend of log switching, this must be done before 298 releasing the current log, to ensure no logging is lost */ 299 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 300 if (r < 0) { 301 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 302 } 303 304 vhost_log_put(dev, true); 305 dev->log = log; 306 dev->log_size = size; 307 } 308 309 static int vhost_dev_has_iommu(struct vhost_dev *dev) 310 { 311 VirtIODevice *vdev = dev->vdev; 312 313 /* 314 * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support 315 * incremental memory mapping API via IOTLB API. For platform that 316 * does not have IOMMU, there's no need to enable this feature 317 * which may cause unnecessary IOTLB miss/update transactions. 318 */ 319 return virtio_bus_device_iommu_enabled(vdev) && 320 virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 321 } 322 323 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 324 hwaddr *plen, bool is_write) 325 { 326 if (!vhost_dev_has_iommu(dev)) { 327 return cpu_physical_memory_map(addr, plen, is_write); 328 } else { 329 return (void *)(uintptr_t)addr; 330 } 331 } 332 333 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 334 hwaddr len, int is_write, 335 hwaddr access_len) 336 { 337 if (!vhost_dev_has_iommu(dev)) { 338 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 339 } 340 } 341 342 static int vhost_verify_ring_part_mapping(void *ring_hva, 343 uint64_t ring_gpa, 344 uint64_t ring_size, 345 void *reg_hva, 346 uint64_t reg_gpa, 347 uint64_t reg_size) 348 { 349 uint64_t hva_ring_offset; 350 uint64_t ring_last = range_get_last(ring_gpa, ring_size); 351 uint64_t reg_last = range_get_last(reg_gpa, reg_size); 352 353 if (ring_last < reg_gpa || ring_gpa > reg_last) { 354 return 0; 355 } 356 /* check that whole ring's is mapped */ 357 if (ring_last > reg_last) { 358 return -ENOMEM; 359 } 360 /* check that ring's MemoryRegion wasn't replaced */ 361 hva_ring_offset = ring_gpa - reg_gpa; 362 if (ring_hva != reg_hva + hva_ring_offset) { 363 return -EBUSY; 364 } 365 366 return 0; 367 } 368 369 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 370 void *reg_hva, 371 uint64_t reg_gpa, 372 uint64_t reg_size) 373 { 374 int i, j; 375 int r = 0; 376 const char *part_name[] = { 377 "descriptor table", 378 "available ring", 379 "used ring" 380 }; 381 382 if (vhost_dev_has_iommu(dev)) { 383 return 0; 384 } 385 386 for (i = 0; i < dev->nvqs; ++i) { 387 struct vhost_virtqueue *vq = dev->vqs + i; 388 389 if (vq->desc_phys == 0) { 390 continue; 391 } 392 393 j = 0; 394 r = vhost_verify_ring_part_mapping( 395 vq->desc, vq->desc_phys, vq->desc_size, 396 reg_hva, reg_gpa, reg_size); 397 if (r) { 398 break; 399 } 400 401 j++; 402 r = vhost_verify_ring_part_mapping( 403 vq->avail, vq->avail_phys, vq->avail_size, 404 reg_hva, reg_gpa, reg_size); 405 if (r) { 406 break; 407 } 408 409 j++; 410 r = vhost_verify_ring_part_mapping( 411 vq->used, vq->used_phys, vq->used_size, 412 reg_hva, reg_gpa, reg_size); 413 if (r) { 414 break; 415 } 416 } 417 418 if (r == -ENOMEM) { 419 error_report("Unable to map %s for ring %d", part_name[j], i); 420 } else if (r == -EBUSY) { 421 error_report("%s relocated for ring %d", part_name[j], i); 422 } 423 return r; 424 } 425 426 /* 427 * vhost_section: identify sections needed for vhost access 428 * 429 * We only care about RAM sections here (where virtqueue and guest 430 * internals accessed by virtio might live). If we find one we still 431 * allow the backend to potentially filter it out of our list. 432 */ 433 static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section) 434 { 435 MemoryRegion *mr = section->mr; 436 437 if (memory_region_is_ram(mr) && !memory_region_is_rom(mr)) { 438 uint8_t dirty_mask = memory_region_get_dirty_log_mask(mr); 439 uint8_t handled_dirty; 440 441 /* 442 * Kernel based vhost doesn't handle any block which is doing 443 * dirty-tracking other than migration for which it has 444 * specific logging support. However for TCG the kernel never 445 * gets involved anyway so we can also ignore it's 446 * self-modiying code detection flags. However a vhost-user 447 * client could still confuse a TCG guest if it re-writes 448 * executable memory that has already been translated. 449 */ 450 handled_dirty = (1 << DIRTY_MEMORY_MIGRATION) | 451 (1 << DIRTY_MEMORY_CODE); 452 453 if (dirty_mask & ~handled_dirty) { 454 trace_vhost_reject_section(mr->name, 1); 455 return false; 456 } 457 458 if (dev->vhost_ops->vhost_backend_mem_section_filter && 459 !dev->vhost_ops->vhost_backend_mem_section_filter(dev, section)) { 460 trace_vhost_reject_section(mr->name, 2); 461 return false; 462 } 463 464 trace_vhost_section(mr->name); 465 return true; 466 } else { 467 trace_vhost_reject_section(mr->name, 3); 468 return false; 469 } 470 } 471 472 static void vhost_begin(MemoryListener *listener) 473 { 474 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 475 memory_listener); 476 dev->tmp_sections = NULL; 477 dev->n_tmp_sections = 0; 478 } 479 480 static void vhost_commit(MemoryListener *listener) 481 { 482 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 483 memory_listener); 484 MemoryRegionSection *old_sections; 485 int n_old_sections; 486 uint64_t log_size; 487 size_t regions_size; 488 int r; 489 int i; 490 bool changed = false; 491 492 /* Note we can be called before the device is started, but then 493 * starting the device calls set_mem_table, so we need to have 494 * built the data structures. 495 */ 496 old_sections = dev->mem_sections; 497 n_old_sections = dev->n_mem_sections; 498 dev->mem_sections = dev->tmp_sections; 499 dev->n_mem_sections = dev->n_tmp_sections; 500 501 if (dev->n_mem_sections != n_old_sections) { 502 changed = true; 503 } else { 504 /* Same size, lets check the contents */ 505 for (int i = 0; i < n_old_sections; i++) { 506 if (!MemoryRegionSection_eq(&old_sections[i], 507 &dev->mem_sections[i])) { 508 changed = true; 509 break; 510 } 511 } 512 } 513 514 trace_vhost_commit(dev->started, changed); 515 if (!changed) { 516 goto out; 517 } 518 519 /* Rebuild the regions list from the new sections list */ 520 regions_size = offsetof(struct vhost_memory, regions) + 521 dev->n_mem_sections * sizeof dev->mem->regions[0]; 522 dev->mem = g_realloc(dev->mem, regions_size); 523 dev->mem->nregions = dev->n_mem_sections; 524 used_memslots = dev->mem->nregions; 525 for (i = 0; i < dev->n_mem_sections; i++) { 526 struct vhost_memory_region *cur_vmr = dev->mem->regions + i; 527 struct MemoryRegionSection *mrs = dev->mem_sections + i; 528 529 cur_vmr->guest_phys_addr = mrs->offset_within_address_space; 530 cur_vmr->memory_size = int128_get64(mrs->size); 531 cur_vmr->userspace_addr = 532 (uintptr_t)memory_region_get_ram_ptr(mrs->mr) + 533 mrs->offset_within_region; 534 cur_vmr->flags_padding = 0; 535 } 536 537 if (!dev->started) { 538 goto out; 539 } 540 541 for (i = 0; i < dev->mem->nregions; i++) { 542 if (vhost_verify_ring_mappings(dev, 543 (void *)(uintptr_t)dev->mem->regions[i].userspace_addr, 544 dev->mem->regions[i].guest_phys_addr, 545 dev->mem->regions[i].memory_size)) { 546 error_report("Verify ring failure on region %d", i); 547 abort(); 548 } 549 } 550 551 if (!dev->log_enabled) { 552 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 553 if (r < 0) { 554 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 555 } 556 goto out; 557 } 558 log_size = vhost_get_log_size(dev); 559 /* We allocate an extra 4K bytes to log, 560 * to reduce the * number of reallocations. */ 561 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 562 /* To log more, must increase log size before table update. */ 563 if (dev->log_size < log_size) { 564 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 565 } 566 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 567 if (r < 0) { 568 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 569 } 570 /* To log less, can only decrease log size after table update. */ 571 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 572 vhost_dev_log_resize(dev, log_size); 573 } 574 575 out: 576 /* Deref the old list of sections, this must happen _after_ the 577 * vhost_set_mem_table to ensure the client isn't still using the 578 * section we're about to unref. 579 */ 580 while (n_old_sections--) { 581 memory_region_unref(old_sections[n_old_sections].mr); 582 } 583 g_free(old_sections); 584 return; 585 } 586 587 /* Adds the section data to the tmp_section structure. 588 * It relies on the listener calling us in memory address order 589 * and for each region (via the _add and _nop methods) to 590 * join neighbours. 591 */ 592 static void vhost_region_add_section(struct vhost_dev *dev, 593 MemoryRegionSection *section) 594 { 595 bool need_add = true; 596 uint64_t mrs_size = int128_get64(section->size); 597 uint64_t mrs_gpa = section->offset_within_address_space; 598 uintptr_t mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) + 599 section->offset_within_region; 600 RAMBlock *mrs_rb = section->mr->ram_block; 601 602 trace_vhost_region_add_section(section->mr->name, mrs_gpa, mrs_size, 603 mrs_host); 604 605 if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) { 606 /* Round the section to it's page size */ 607 /* First align the start down to a page boundary */ 608 size_t mrs_page = qemu_ram_pagesize(mrs_rb); 609 uint64_t alignage = mrs_host & (mrs_page - 1); 610 if (alignage) { 611 mrs_host -= alignage; 612 mrs_size += alignage; 613 mrs_gpa -= alignage; 614 } 615 /* Now align the size up to a page boundary */ 616 alignage = mrs_size & (mrs_page - 1); 617 if (alignage) { 618 mrs_size += mrs_page - alignage; 619 } 620 trace_vhost_region_add_section_aligned(section->mr->name, mrs_gpa, 621 mrs_size, mrs_host); 622 } 623 624 if (dev->n_tmp_sections) { 625 /* Since we already have at least one section, lets see if 626 * this extends it; since we're scanning in order, we only 627 * have to look at the last one, and the FlatView that calls 628 * us shouldn't have overlaps. 629 */ 630 MemoryRegionSection *prev_sec = dev->tmp_sections + 631 (dev->n_tmp_sections - 1); 632 uint64_t prev_gpa_start = prev_sec->offset_within_address_space; 633 uint64_t prev_size = int128_get64(prev_sec->size); 634 uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size); 635 uint64_t prev_host_start = 636 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) + 637 prev_sec->offset_within_region; 638 uint64_t prev_host_end = range_get_last(prev_host_start, prev_size); 639 640 if (mrs_gpa <= (prev_gpa_end + 1)) { 641 /* OK, looks like overlapping/intersecting - it's possible that 642 * the rounding to page sizes has made them overlap, but they should 643 * match up in the same RAMBlock if they do. 644 */ 645 if (mrs_gpa < prev_gpa_start) { 646 error_report("%s:Section '%s' rounded to %"PRIx64 647 " prior to previous '%s' %"PRIx64, 648 __func__, section->mr->name, mrs_gpa, 649 prev_sec->mr->name, prev_gpa_start); 650 /* A way to cleanly fail here would be better */ 651 return; 652 } 653 /* Offset from the start of the previous GPA to this GPA */ 654 size_t offset = mrs_gpa - prev_gpa_start; 655 656 if (prev_host_start + offset == mrs_host && 657 section->mr == prev_sec->mr && 658 (!dev->vhost_ops->vhost_backend_can_merge || 659 dev->vhost_ops->vhost_backend_can_merge(dev, 660 mrs_host, mrs_size, 661 prev_host_start, prev_size))) { 662 uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size); 663 need_add = false; 664 prev_sec->offset_within_address_space = 665 MIN(prev_gpa_start, mrs_gpa); 666 prev_sec->offset_within_region = 667 MIN(prev_host_start, mrs_host) - 668 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr); 669 prev_sec->size = int128_make64(max_end - MIN(prev_host_start, 670 mrs_host)); 671 trace_vhost_region_add_section_merge(section->mr->name, 672 int128_get64(prev_sec->size), 673 prev_sec->offset_within_address_space, 674 prev_sec->offset_within_region); 675 } else { 676 /* adjoining regions are fine, but overlapping ones with 677 * different blocks/offsets shouldn't happen 678 */ 679 if (mrs_gpa != prev_gpa_end + 1) { 680 error_report("%s: Overlapping but not coherent sections " 681 "at %"PRIx64, 682 __func__, mrs_gpa); 683 return; 684 } 685 } 686 } 687 } 688 689 if (need_add) { 690 ++dev->n_tmp_sections; 691 dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections, 692 dev->n_tmp_sections); 693 dev->tmp_sections[dev->n_tmp_sections - 1] = *section; 694 /* The flatview isn't stable and we don't use it, making it NULL 695 * means we can memcmp the list. 696 */ 697 dev->tmp_sections[dev->n_tmp_sections - 1].fv = NULL; 698 memory_region_ref(section->mr); 699 } 700 } 701 702 /* Used for both add and nop callbacks */ 703 static void vhost_region_addnop(MemoryListener *listener, 704 MemoryRegionSection *section) 705 { 706 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 707 memory_listener); 708 709 if (!vhost_section(dev, section)) { 710 return; 711 } 712 vhost_region_add_section(dev, section); 713 } 714 715 static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 716 { 717 struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n); 718 struct vhost_dev *hdev = iommu->hdev; 719 hwaddr iova = iotlb->iova + iommu->iommu_offset; 720 721 if (vhost_backend_invalidate_device_iotlb(hdev, iova, 722 iotlb->addr_mask + 1)) { 723 error_report("Fail to invalidate device iotlb"); 724 } 725 } 726 727 static void vhost_iommu_region_add(MemoryListener *listener, 728 MemoryRegionSection *section) 729 { 730 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 731 iommu_listener); 732 struct vhost_iommu *iommu; 733 Int128 end; 734 int iommu_idx; 735 IOMMUMemoryRegion *iommu_mr; 736 int ret; 737 738 if (!memory_region_is_iommu(section->mr)) { 739 return; 740 } 741 742 iommu_mr = IOMMU_MEMORY_REGION(section->mr); 743 744 iommu = g_malloc0(sizeof(*iommu)); 745 end = int128_add(int128_make64(section->offset_within_region), 746 section->size); 747 end = int128_sub(end, int128_one()); 748 iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr, 749 MEMTXATTRS_UNSPECIFIED); 750 iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, 751 IOMMU_NOTIFIER_DEVIOTLB_UNMAP, 752 section->offset_within_region, 753 int128_get64(end), 754 iommu_idx); 755 iommu->mr = section->mr; 756 iommu->iommu_offset = section->offset_within_address_space - 757 section->offset_within_region; 758 iommu->hdev = dev; 759 ret = memory_region_register_iommu_notifier(section->mr, &iommu->n, NULL); 760 if (ret) { 761 /* 762 * Some vIOMMUs do not support dev-iotlb yet. If so, try to use the 763 * UNMAP legacy message 764 */ 765 iommu->n.notifier_flags = IOMMU_NOTIFIER_UNMAP; 766 memory_region_register_iommu_notifier(section->mr, &iommu->n, 767 &error_fatal); 768 } 769 QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next); 770 /* TODO: can replay help performance here? */ 771 } 772 773 static void vhost_iommu_region_del(MemoryListener *listener, 774 MemoryRegionSection *section) 775 { 776 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 777 iommu_listener); 778 struct vhost_iommu *iommu; 779 780 if (!memory_region_is_iommu(section->mr)) { 781 return; 782 } 783 784 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 785 if (iommu->mr == section->mr && 786 iommu->n.start == section->offset_within_region) { 787 memory_region_unregister_iommu_notifier(iommu->mr, 788 &iommu->n); 789 QLIST_REMOVE(iommu, iommu_next); 790 g_free(iommu); 791 break; 792 } 793 } 794 } 795 796 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 797 struct vhost_virtqueue *vq, 798 unsigned idx, bool enable_log) 799 { 800 struct vhost_vring_addr addr; 801 int r; 802 memset(&addr, 0, sizeof(struct vhost_vring_addr)); 803 804 if (dev->vhost_ops->vhost_vq_get_addr) { 805 r = dev->vhost_ops->vhost_vq_get_addr(dev, &addr, vq); 806 if (r < 0) { 807 VHOST_OPS_DEBUG(r, "vhost_vq_get_addr failed"); 808 return r; 809 } 810 } else { 811 addr.desc_user_addr = (uint64_t)(unsigned long)vq->desc; 812 addr.avail_user_addr = (uint64_t)(unsigned long)vq->avail; 813 addr.used_user_addr = (uint64_t)(unsigned long)vq->used; 814 } 815 addr.index = idx; 816 addr.log_guest_addr = vq->used_phys; 817 addr.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0; 818 r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 819 if (r < 0) { 820 VHOST_OPS_DEBUG(r, "vhost_set_vring_addr failed"); 821 } 822 return r; 823 } 824 825 static int vhost_dev_set_features(struct vhost_dev *dev, 826 bool enable_log) 827 { 828 uint64_t features = dev->acked_features; 829 int r; 830 if (enable_log) { 831 features |= 0x1ULL << VHOST_F_LOG_ALL; 832 } 833 if (!vhost_dev_has_iommu(dev)) { 834 features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM); 835 } 836 if (dev->vhost_ops->vhost_force_iommu) { 837 if (dev->vhost_ops->vhost_force_iommu(dev) == true) { 838 features |= 0x1ULL << VIRTIO_F_IOMMU_PLATFORM; 839 } 840 } 841 r = dev->vhost_ops->vhost_set_features(dev, features); 842 if (r < 0) { 843 VHOST_OPS_DEBUG(r, "vhost_set_features failed"); 844 goto out; 845 } 846 if (dev->vhost_ops->vhost_set_backend_cap) { 847 r = dev->vhost_ops->vhost_set_backend_cap(dev); 848 if (r < 0) { 849 VHOST_OPS_DEBUG(r, "vhost_set_backend_cap failed"); 850 goto out; 851 } 852 } 853 854 out: 855 return r; 856 } 857 858 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 859 { 860 int r, i, idx; 861 hwaddr addr; 862 863 r = vhost_dev_set_features(dev, enable_log); 864 if (r < 0) { 865 goto err_features; 866 } 867 for (i = 0; i < dev->nvqs; ++i) { 868 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 869 addr = virtio_queue_get_desc_addr(dev->vdev, idx); 870 if (!addr) { 871 /* 872 * The queue might not be ready for start. If this 873 * is the case there is no reason to continue the process. 874 * The similar logic is used by the vhost_virtqueue_start() 875 * routine. 876 */ 877 continue; 878 } 879 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 880 enable_log); 881 if (r < 0) { 882 goto err_vq; 883 } 884 } 885 return 0; 886 err_vq: 887 for (; i >= 0; --i) { 888 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 889 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 890 dev->log_enabled); 891 } 892 vhost_dev_set_features(dev, dev->log_enabled); 893 err_features: 894 return r; 895 } 896 897 static int vhost_migration_log(MemoryListener *listener, bool enable) 898 { 899 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 900 memory_listener); 901 int r; 902 if (enable == dev->log_enabled) { 903 return 0; 904 } 905 if (!dev->started) { 906 dev->log_enabled = enable; 907 return 0; 908 } 909 910 r = 0; 911 if (!enable) { 912 r = vhost_dev_set_log(dev, false); 913 if (r < 0) { 914 goto check_dev_state; 915 } 916 vhost_log_put(dev, false); 917 } else { 918 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 919 r = vhost_dev_set_log(dev, true); 920 if (r < 0) { 921 goto check_dev_state; 922 } 923 } 924 925 check_dev_state: 926 dev->log_enabled = enable; 927 /* 928 * vhost-user-* devices could change their state during log 929 * initialization due to disconnect. So check dev state after 930 * vhost communication. 931 */ 932 if (!dev->started) { 933 /* 934 * Since device is in the stopped state, it is okay for 935 * migration. Return success. 936 */ 937 r = 0; 938 } 939 if (r) { 940 /* An error occurred. */ 941 dev->log_enabled = false; 942 } 943 944 return r; 945 } 946 947 static void vhost_log_global_start(MemoryListener *listener) 948 { 949 int r; 950 951 r = vhost_migration_log(listener, true); 952 if (r < 0) { 953 abort(); 954 } 955 } 956 957 static void vhost_log_global_stop(MemoryListener *listener) 958 { 959 int r; 960 961 r = vhost_migration_log(listener, false); 962 if (r < 0) { 963 abort(); 964 } 965 } 966 967 static void vhost_log_start(MemoryListener *listener, 968 MemoryRegionSection *section, 969 int old, int new) 970 { 971 /* FIXME: implement */ 972 } 973 974 static void vhost_log_stop(MemoryListener *listener, 975 MemoryRegionSection *section, 976 int old, int new) 977 { 978 /* FIXME: implement */ 979 } 980 981 /* The vhost driver natively knows how to handle the vrings of non 982 * cross-endian legacy devices and modern devices. Only legacy devices 983 * exposed to a bi-endian guest may require the vhost driver to use a 984 * specific endianness. 985 */ 986 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 987 { 988 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 989 return false; 990 } 991 #if HOST_BIG_ENDIAN 992 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 993 #else 994 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 995 #endif 996 } 997 998 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 999 bool is_big_endian, 1000 int vhost_vq_index) 1001 { 1002 int r; 1003 struct vhost_vring_state s = { 1004 .index = vhost_vq_index, 1005 .num = is_big_endian 1006 }; 1007 1008 r = dev->vhost_ops->vhost_set_vring_endian(dev, &s); 1009 if (r < 0) { 1010 VHOST_OPS_DEBUG(r, "vhost_set_vring_endian failed"); 1011 } 1012 return r; 1013 } 1014 1015 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 1016 uint64_t gpa, uint64_t *uaddr, 1017 uint64_t *len) 1018 { 1019 int i; 1020 1021 for (i = 0; i < hdev->mem->nregions; i++) { 1022 struct vhost_memory_region *reg = hdev->mem->regions + i; 1023 1024 if (gpa >= reg->guest_phys_addr && 1025 reg->guest_phys_addr + reg->memory_size > gpa) { 1026 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 1027 *len = reg->guest_phys_addr + reg->memory_size - gpa; 1028 return 0; 1029 } 1030 } 1031 1032 return -EFAULT; 1033 } 1034 1035 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 1036 { 1037 IOMMUTLBEntry iotlb; 1038 uint64_t uaddr, len; 1039 int ret = -EFAULT; 1040 1041 RCU_READ_LOCK_GUARD(); 1042 1043 trace_vhost_iotlb_miss(dev, 1); 1044 1045 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 1046 iova, write, 1047 MEMTXATTRS_UNSPECIFIED); 1048 if (iotlb.target_as != NULL) { 1049 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 1050 &uaddr, &len); 1051 if (ret) { 1052 trace_vhost_iotlb_miss(dev, 3); 1053 error_report("Fail to lookup the translated address " 1054 "%"PRIx64, iotlb.translated_addr); 1055 goto out; 1056 } 1057 1058 len = MIN(iotlb.addr_mask + 1, len); 1059 iova = iova & ~iotlb.addr_mask; 1060 1061 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 1062 len, iotlb.perm); 1063 if (ret) { 1064 trace_vhost_iotlb_miss(dev, 4); 1065 error_report("Fail to update device iotlb"); 1066 goto out; 1067 } 1068 } 1069 1070 trace_vhost_iotlb_miss(dev, 2); 1071 1072 out: 1073 return ret; 1074 } 1075 1076 static int vhost_virtqueue_start(struct vhost_dev *dev, 1077 struct VirtIODevice *vdev, 1078 struct vhost_virtqueue *vq, 1079 unsigned idx) 1080 { 1081 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1082 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1083 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1084 hwaddr s, l, a; 1085 int r; 1086 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1087 struct vhost_vring_file file = { 1088 .index = vhost_vq_index 1089 }; 1090 struct vhost_vring_state state = { 1091 .index = vhost_vq_index 1092 }; 1093 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1094 1095 a = virtio_queue_get_desc_addr(vdev, idx); 1096 if (a == 0) { 1097 /* Queue might not be ready for start */ 1098 return 0; 1099 } 1100 1101 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1102 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1103 if (r) { 1104 VHOST_OPS_DEBUG(r, "vhost_set_vring_num failed"); 1105 return r; 1106 } 1107 1108 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1109 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1110 if (r) { 1111 VHOST_OPS_DEBUG(r, "vhost_set_vring_base failed"); 1112 return r; 1113 } 1114 1115 if (vhost_needs_vring_endian(vdev)) { 1116 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1117 virtio_is_big_endian(vdev), 1118 vhost_vq_index); 1119 if (r) { 1120 return r; 1121 } 1122 } 1123 1124 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1125 vq->desc_phys = a; 1126 vq->desc = vhost_memory_map(dev, a, &l, false); 1127 if (!vq->desc || l != s) { 1128 r = -ENOMEM; 1129 goto fail_alloc_desc; 1130 } 1131 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1132 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1133 vq->avail = vhost_memory_map(dev, a, &l, false); 1134 if (!vq->avail || l != s) { 1135 r = -ENOMEM; 1136 goto fail_alloc_avail; 1137 } 1138 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1139 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1140 vq->used = vhost_memory_map(dev, a, &l, true); 1141 if (!vq->used || l != s) { 1142 r = -ENOMEM; 1143 goto fail_alloc_used; 1144 } 1145 1146 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1147 if (r < 0) { 1148 goto fail_alloc; 1149 } 1150 1151 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1152 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1153 if (r) { 1154 VHOST_OPS_DEBUG(r, "vhost_set_vring_kick failed"); 1155 goto fail_kick; 1156 } 1157 1158 /* Clear and discard previous events if any. */ 1159 event_notifier_test_and_clear(&vq->masked_notifier); 1160 1161 /* Init vring in unmasked state, unless guest_notifier_mask 1162 * will do it later. 1163 */ 1164 if (!vdev->use_guest_notifier_mask) { 1165 /* TODO: check and handle errors. */ 1166 vhost_virtqueue_mask(dev, vdev, idx, false); 1167 } 1168 1169 if (k->query_guest_notifiers && 1170 k->query_guest_notifiers(qbus->parent) && 1171 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1172 file.fd = -1; 1173 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1174 if (r) { 1175 goto fail_vector; 1176 } 1177 } 1178 1179 return 0; 1180 1181 fail_vector: 1182 fail_kick: 1183 fail_alloc: 1184 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1185 0, 0); 1186 fail_alloc_used: 1187 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1188 0, 0); 1189 fail_alloc_avail: 1190 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1191 0, 0); 1192 fail_alloc_desc: 1193 return r; 1194 } 1195 1196 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1197 struct VirtIODevice *vdev, 1198 struct vhost_virtqueue *vq, 1199 unsigned idx) 1200 { 1201 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1202 struct vhost_vring_state state = { 1203 .index = vhost_vq_index, 1204 }; 1205 int r; 1206 1207 if (virtio_queue_get_desc_addr(vdev, idx) == 0) { 1208 /* Don't stop the virtqueue which might have not been started */ 1209 return; 1210 } 1211 1212 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1213 if (r < 0) { 1214 VHOST_OPS_DEBUG(r, "vhost VQ %u ring restore failed: %d", idx, r); 1215 /* Connection to the backend is broken, so let's sync internal 1216 * last avail idx to the device used idx. 1217 */ 1218 virtio_queue_restore_last_avail_idx(vdev, idx); 1219 } else { 1220 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1221 } 1222 virtio_queue_invalidate_signalled_used(vdev, idx); 1223 virtio_queue_update_used_idx(vdev, idx); 1224 1225 /* In the cross-endian case, we need to reset the vring endianness to 1226 * native as legacy devices expect so by default. 1227 */ 1228 if (vhost_needs_vring_endian(vdev)) { 1229 vhost_virtqueue_set_vring_endian_legacy(dev, 1230 !virtio_is_big_endian(vdev), 1231 vhost_vq_index); 1232 } 1233 1234 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1235 1, virtio_queue_get_used_size(vdev, idx)); 1236 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1237 0, virtio_queue_get_avail_size(vdev, idx)); 1238 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1239 0, virtio_queue_get_desc_size(vdev, idx)); 1240 } 1241 1242 static void vhost_eventfd_add(MemoryListener *listener, 1243 MemoryRegionSection *section, 1244 bool match_data, uint64_t data, EventNotifier *e) 1245 { 1246 } 1247 1248 static void vhost_eventfd_del(MemoryListener *listener, 1249 MemoryRegionSection *section, 1250 bool match_data, uint64_t data, EventNotifier *e) 1251 { 1252 } 1253 1254 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1255 int n, uint32_t timeout) 1256 { 1257 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1258 struct vhost_vring_state state = { 1259 .index = vhost_vq_index, 1260 .num = timeout, 1261 }; 1262 int r; 1263 1264 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1265 return -EINVAL; 1266 } 1267 1268 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1269 if (r) { 1270 VHOST_OPS_DEBUG(r, "vhost_set_vring_busyloop_timeout failed"); 1271 return r; 1272 } 1273 1274 return 0; 1275 } 1276 1277 static int vhost_virtqueue_init(struct vhost_dev *dev, 1278 struct vhost_virtqueue *vq, int n) 1279 { 1280 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1281 struct vhost_vring_file file = { 1282 .index = vhost_vq_index, 1283 }; 1284 int r = event_notifier_init(&vq->masked_notifier, 0); 1285 if (r < 0) { 1286 return r; 1287 } 1288 1289 file.fd = event_notifier_get_wfd(&vq->masked_notifier); 1290 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1291 if (r) { 1292 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1293 goto fail_call; 1294 } 1295 1296 vq->dev = dev; 1297 1298 return 0; 1299 fail_call: 1300 event_notifier_cleanup(&vq->masked_notifier); 1301 return r; 1302 } 1303 1304 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1305 { 1306 event_notifier_cleanup(&vq->masked_notifier); 1307 } 1308 1309 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1310 VhostBackendType backend_type, uint32_t busyloop_timeout, 1311 Error **errp) 1312 { 1313 uint64_t features; 1314 int i, r, n_initialized_vqs = 0; 1315 1316 hdev->vdev = NULL; 1317 hdev->migration_blocker = NULL; 1318 1319 r = vhost_set_backend_type(hdev, backend_type); 1320 assert(r >= 0); 1321 1322 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque, errp); 1323 if (r < 0) { 1324 goto fail; 1325 } 1326 1327 r = hdev->vhost_ops->vhost_set_owner(hdev); 1328 if (r < 0) { 1329 error_setg_errno(errp, -r, "vhost_set_owner failed"); 1330 goto fail; 1331 } 1332 1333 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1334 if (r < 0) { 1335 error_setg_errno(errp, -r, "vhost_get_features failed"); 1336 goto fail; 1337 } 1338 1339 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1340 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1341 if (r < 0) { 1342 error_setg_errno(errp, -r, "Failed to initialize virtqueue %d", i); 1343 goto fail; 1344 } 1345 } 1346 1347 if (busyloop_timeout) { 1348 for (i = 0; i < hdev->nvqs; ++i) { 1349 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1350 busyloop_timeout); 1351 if (r < 0) { 1352 error_setg_errno(errp, -r, "Failed to set busyloop timeout"); 1353 goto fail_busyloop; 1354 } 1355 } 1356 } 1357 1358 hdev->features = features; 1359 1360 hdev->memory_listener = (MemoryListener) { 1361 .name = "vhost", 1362 .begin = vhost_begin, 1363 .commit = vhost_commit, 1364 .region_add = vhost_region_addnop, 1365 .region_nop = vhost_region_addnop, 1366 .log_start = vhost_log_start, 1367 .log_stop = vhost_log_stop, 1368 .log_sync = vhost_log_sync, 1369 .log_global_start = vhost_log_global_start, 1370 .log_global_stop = vhost_log_global_stop, 1371 .eventfd_add = vhost_eventfd_add, 1372 .eventfd_del = vhost_eventfd_del, 1373 .priority = 10 1374 }; 1375 1376 hdev->iommu_listener = (MemoryListener) { 1377 .name = "vhost-iommu", 1378 .region_add = vhost_iommu_region_add, 1379 .region_del = vhost_iommu_region_del, 1380 }; 1381 1382 if (hdev->migration_blocker == NULL) { 1383 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1384 error_setg(&hdev->migration_blocker, 1385 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1386 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) { 1387 error_setg(&hdev->migration_blocker, 1388 "Migration disabled: failed to allocate shared memory"); 1389 } 1390 } 1391 1392 if (hdev->migration_blocker != NULL) { 1393 r = migrate_add_blocker(hdev->migration_blocker, errp); 1394 if (r < 0) { 1395 error_free(hdev->migration_blocker); 1396 goto fail_busyloop; 1397 } 1398 } 1399 1400 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1401 hdev->n_mem_sections = 0; 1402 hdev->mem_sections = NULL; 1403 hdev->log = NULL; 1404 hdev->log_size = 0; 1405 hdev->log_enabled = false; 1406 hdev->started = false; 1407 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1408 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1409 1410 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1411 error_setg(errp, "vhost backend memory slots limit is less" 1412 " than current number of present memory slots"); 1413 r = -EINVAL; 1414 goto fail_busyloop; 1415 } 1416 1417 return 0; 1418 1419 fail_busyloop: 1420 if (busyloop_timeout) { 1421 while (--i >= 0) { 1422 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1423 } 1424 } 1425 fail: 1426 hdev->nvqs = n_initialized_vqs; 1427 vhost_dev_cleanup(hdev); 1428 return r; 1429 } 1430 1431 void vhost_dev_cleanup(struct vhost_dev *hdev) 1432 { 1433 int i; 1434 1435 for (i = 0; i < hdev->nvqs; ++i) { 1436 vhost_virtqueue_cleanup(hdev->vqs + i); 1437 } 1438 if (hdev->mem) { 1439 /* those are only safe after successful init */ 1440 memory_listener_unregister(&hdev->memory_listener); 1441 QLIST_REMOVE(hdev, entry); 1442 } 1443 if (hdev->migration_blocker) { 1444 migrate_del_blocker(hdev->migration_blocker); 1445 error_free(hdev->migration_blocker); 1446 } 1447 g_free(hdev->mem); 1448 g_free(hdev->mem_sections); 1449 if (hdev->vhost_ops) { 1450 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1451 } 1452 assert(!hdev->log); 1453 1454 memset(hdev, 0, sizeof(struct vhost_dev)); 1455 } 1456 1457 /* Stop processing guest IO notifications in qemu. 1458 * Start processing them in vhost in kernel. 1459 */ 1460 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1461 { 1462 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1463 int i, r, e; 1464 1465 /* We will pass the notifiers to the kernel, make sure that QEMU 1466 * doesn't interfere. 1467 */ 1468 r = virtio_device_grab_ioeventfd(vdev); 1469 if (r < 0) { 1470 error_report("binding does not support host notifiers"); 1471 goto fail; 1472 } 1473 1474 for (i = 0; i < hdev->nvqs; ++i) { 1475 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1476 true); 1477 if (r < 0) { 1478 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1479 goto fail_vq; 1480 } 1481 } 1482 1483 return 0; 1484 fail_vq: 1485 while (--i >= 0) { 1486 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1487 false); 1488 if (e < 0) { 1489 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1490 } 1491 assert (e >= 0); 1492 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1493 } 1494 virtio_device_release_ioeventfd(vdev); 1495 fail: 1496 return r; 1497 } 1498 1499 /* Stop processing guest IO notifications in vhost. 1500 * Start processing them in qemu. 1501 * This might actually run the qemu handlers right away, 1502 * so virtio in qemu must be completely setup when this is called. 1503 */ 1504 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1505 { 1506 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1507 int i, r; 1508 1509 for (i = 0; i < hdev->nvqs; ++i) { 1510 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1511 false); 1512 if (r < 0) { 1513 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1514 } 1515 assert (r >= 0); 1516 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1517 } 1518 virtio_device_release_ioeventfd(vdev); 1519 } 1520 1521 /* Test and clear event pending status. 1522 * Should be called after unmask to avoid losing events. 1523 */ 1524 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1525 { 1526 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1527 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1528 return event_notifier_test_and_clear(&vq->masked_notifier); 1529 } 1530 1531 /* Mask/unmask events from this vq. */ 1532 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1533 bool mask) 1534 { 1535 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1536 int r, index = n - hdev->vq_index; 1537 struct vhost_vring_file file; 1538 1539 /* should only be called after backend is connected */ 1540 assert(hdev->vhost_ops); 1541 1542 if (mask) { 1543 assert(vdev->use_guest_notifier_mask); 1544 file.fd = event_notifier_get_wfd(&hdev->vqs[index].masked_notifier); 1545 } else { 1546 file.fd = event_notifier_get_wfd(virtio_queue_get_guest_notifier(vvq)); 1547 } 1548 1549 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1550 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1551 if (r < 0) { 1552 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1553 } 1554 } 1555 1556 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1557 uint64_t features) 1558 { 1559 const int *bit = feature_bits; 1560 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1561 uint64_t bit_mask = (1ULL << *bit); 1562 if (!(hdev->features & bit_mask)) { 1563 features &= ~bit_mask; 1564 } 1565 bit++; 1566 } 1567 return features; 1568 } 1569 1570 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1571 uint64_t features) 1572 { 1573 const int *bit = feature_bits; 1574 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1575 uint64_t bit_mask = (1ULL << *bit); 1576 if (features & bit_mask) { 1577 hdev->acked_features |= bit_mask; 1578 } 1579 bit++; 1580 } 1581 } 1582 1583 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1584 uint32_t config_len, Error **errp) 1585 { 1586 assert(hdev->vhost_ops); 1587 1588 if (hdev->vhost_ops->vhost_get_config) { 1589 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len, 1590 errp); 1591 } 1592 1593 error_setg(errp, "vhost_get_config not implemented"); 1594 return -ENOSYS; 1595 } 1596 1597 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1598 uint32_t offset, uint32_t size, uint32_t flags) 1599 { 1600 assert(hdev->vhost_ops); 1601 1602 if (hdev->vhost_ops->vhost_set_config) { 1603 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1604 size, flags); 1605 } 1606 1607 return -ENOSYS; 1608 } 1609 1610 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1611 const VhostDevConfigOps *ops) 1612 { 1613 hdev->config_ops = ops; 1614 } 1615 1616 void vhost_dev_free_inflight(struct vhost_inflight *inflight) 1617 { 1618 if (inflight && inflight->addr) { 1619 qemu_memfd_free(inflight->addr, inflight->size, inflight->fd); 1620 inflight->addr = NULL; 1621 inflight->fd = -1; 1622 } 1623 } 1624 1625 static int vhost_dev_resize_inflight(struct vhost_inflight *inflight, 1626 uint64_t new_size) 1627 { 1628 Error *err = NULL; 1629 int fd = -1; 1630 void *addr = qemu_memfd_alloc("vhost-inflight", new_size, 1631 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 1632 &fd, &err); 1633 1634 if (err) { 1635 error_report_err(err); 1636 return -ENOMEM; 1637 } 1638 1639 vhost_dev_free_inflight(inflight); 1640 inflight->offset = 0; 1641 inflight->addr = addr; 1642 inflight->fd = fd; 1643 inflight->size = new_size; 1644 1645 return 0; 1646 } 1647 1648 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1649 { 1650 if (inflight->addr) { 1651 qemu_put_be64(f, inflight->size); 1652 qemu_put_be16(f, inflight->queue_size); 1653 qemu_put_buffer(f, inflight->addr, inflight->size); 1654 } else { 1655 qemu_put_be64(f, 0); 1656 } 1657 } 1658 1659 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1660 { 1661 uint64_t size; 1662 1663 size = qemu_get_be64(f); 1664 if (!size) { 1665 return 0; 1666 } 1667 1668 if (inflight->size != size) { 1669 int ret = vhost_dev_resize_inflight(inflight, size); 1670 if (ret < 0) { 1671 return ret; 1672 } 1673 } 1674 inflight->queue_size = qemu_get_be16(f); 1675 1676 qemu_get_buffer(f, inflight->addr, size); 1677 1678 return 0; 1679 } 1680 1681 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev) 1682 { 1683 int r; 1684 1685 if (hdev->vhost_ops->vhost_get_inflight_fd == NULL || 1686 hdev->vhost_ops->vhost_set_inflight_fd == NULL) { 1687 return 0; 1688 } 1689 1690 hdev->vdev = vdev; 1691 1692 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1693 if (r < 0) { 1694 VHOST_OPS_DEBUG(r, "vhost_dev_prepare_inflight failed"); 1695 return r; 1696 } 1697 1698 return 0; 1699 } 1700 1701 int vhost_dev_set_inflight(struct vhost_dev *dev, 1702 struct vhost_inflight *inflight) 1703 { 1704 int r; 1705 1706 if (dev->vhost_ops->vhost_set_inflight_fd && inflight->addr) { 1707 r = dev->vhost_ops->vhost_set_inflight_fd(dev, inflight); 1708 if (r) { 1709 VHOST_OPS_DEBUG(r, "vhost_set_inflight_fd failed"); 1710 return r; 1711 } 1712 } 1713 1714 return 0; 1715 } 1716 1717 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, 1718 struct vhost_inflight *inflight) 1719 { 1720 int r; 1721 1722 if (dev->vhost_ops->vhost_get_inflight_fd) { 1723 r = dev->vhost_ops->vhost_get_inflight_fd(dev, queue_size, inflight); 1724 if (r) { 1725 VHOST_OPS_DEBUG(r, "vhost_get_inflight_fd failed"); 1726 return r; 1727 } 1728 } 1729 1730 return 0; 1731 } 1732 1733 /* Host notifiers must be enabled at this point. */ 1734 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1735 { 1736 int i, r; 1737 1738 /* should only be called after backend is connected */ 1739 assert(hdev->vhost_ops); 1740 1741 hdev->started = true; 1742 hdev->vdev = vdev; 1743 1744 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1745 if (r < 0) { 1746 goto fail_features; 1747 } 1748 1749 if (vhost_dev_has_iommu(hdev)) { 1750 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1751 } 1752 1753 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1754 if (r < 0) { 1755 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 1756 goto fail_mem; 1757 } 1758 for (i = 0; i < hdev->nvqs; ++i) { 1759 r = vhost_virtqueue_start(hdev, 1760 vdev, 1761 hdev->vqs + i, 1762 hdev->vq_index + i); 1763 if (r < 0) { 1764 goto fail_vq; 1765 } 1766 } 1767 1768 if (hdev->log_enabled) { 1769 uint64_t log_base; 1770 1771 hdev->log_size = vhost_get_log_size(hdev); 1772 hdev->log = vhost_log_get(hdev->log_size, 1773 vhost_dev_log_is_shared(hdev)); 1774 log_base = (uintptr_t)hdev->log->log; 1775 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1776 hdev->log_size ? log_base : 0, 1777 hdev->log); 1778 if (r < 0) { 1779 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 1780 goto fail_log; 1781 } 1782 } 1783 if (hdev->vhost_ops->vhost_dev_start) { 1784 r = hdev->vhost_ops->vhost_dev_start(hdev, true); 1785 if (r) { 1786 goto fail_log; 1787 } 1788 } 1789 if (vhost_dev_has_iommu(hdev) && 1790 hdev->vhost_ops->vhost_set_iotlb_callback) { 1791 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1792 1793 /* Update used ring information for IOTLB to work correctly, 1794 * vhost-kernel code requires for this.*/ 1795 for (i = 0; i < hdev->nvqs; ++i) { 1796 struct vhost_virtqueue *vq = hdev->vqs + i; 1797 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1798 } 1799 } 1800 return 0; 1801 fail_log: 1802 vhost_log_put(hdev, false); 1803 fail_vq: 1804 while (--i >= 0) { 1805 vhost_virtqueue_stop(hdev, 1806 vdev, 1807 hdev->vqs + i, 1808 hdev->vq_index + i); 1809 } 1810 1811 fail_mem: 1812 fail_features: 1813 1814 hdev->started = false; 1815 return r; 1816 } 1817 1818 /* Host notifiers must be enabled at this point. */ 1819 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1820 { 1821 int i; 1822 1823 /* should only be called after backend is connected */ 1824 assert(hdev->vhost_ops); 1825 1826 if (hdev->vhost_ops->vhost_dev_start) { 1827 hdev->vhost_ops->vhost_dev_start(hdev, false); 1828 } 1829 for (i = 0; i < hdev->nvqs; ++i) { 1830 vhost_virtqueue_stop(hdev, 1831 vdev, 1832 hdev->vqs + i, 1833 hdev->vq_index + i); 1834 } 1835 1836 if (vhost_dev_has_iommu(hdev)) { 1837 if (hdev->vhost_ops->vhost_set_iotlb_callback) { 1838 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1839 } 1840 memory_listener_unregister(&hdev->iommu_listener); 1841 } 1842 vhost_log_put(hdev, true); 1843 hdev->started = false; 1844 hdev->vdev = NULL; 1845 } 1846 1847 int vhost_net_set_backend(struct vhost_dev *hdev, 1848 struct vhost_vring_file *file) 1849 { 1850 if (hdev->vhost_ops->vhost_net_set_backend) { 1851 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1852 } 1853 1854 return -ENOSYS; 1855 } 1856