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 addr = virtio_queue_get_desc_addr(dev->vdev, idx); 890 if (!addr) { 891 continue; 892 } 893 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 894 dev->log_enabled); 895 } 896 vhost_dev_set_features(dev, dev->log_enabled); 897 err_features: 898 return r; 899 } 900 901 static int vhost_migration_log(MemoryListener *listener, bool enable) 902 { 903 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 904 memory_listener); 905 int r; 906 if (enable == dev->log_enabled) { 907 return 0; 908 } 909 if (!dev->started) { 910 dev->log_enabled = enable; 911 return 0; 912 } 913 914 r = 0; 915 if (!enable) { 916 r = vhost_dev_set_log(dev, false); 917 if (r < 0) { 918 goto check_dev_state; 919 } 920 vhost_log_put(dev, false); 921 } else { 922 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 923 r = vhost_dev_set_log(dev, true); 924 if (r < 0) { 925 goto check_dev_state; 926 } 927 } 928 929 check_dev_state: 930 dev->log_enabled = enable; 931 /* 932 * vhost-user-* devices could change their state during log 933 * initialization due to disconnect. So check dev state after 934 * vhost communication. 935 */ 936 if (!dev->started) { 937 /* 938 * Since device is in the stopped state, it is okay for 939 * migration. Return success. 940 */ 941 r = 0; 942 } 943 if (r) { 944 /* An error occurred. */ 945 dev->log_enabled = false; 946 } 947 948 return r; 949 } 950 951 static void vhost_log_global_start(MemoryListener *listener) 952 { 953 int r; 954 955 r = vhost_migration_log(listener, true); 956 if (r < 0) { 957 abort(); 958 } 959 } 960 961 static void vhost_log_global_stop(MemoryListener *listener) 962 { 963 int r; 964 965 r = vhost_migration_log(listener, false); 966 if (r < 0) { 967 abort(); 968 } 969 } 970 971 static void vhost_log_start(MemoryListener *listener, 972 MemoryRegionSection *section, 973 int old, int new) 974 { 975 /* FIXME: implement */ 976 } 977 978 static void vhost_log_stop(MemoryListener *listener, 979 MemoryRegionSection *section, 980 int old, int new) 981 { 982 /* FIXME: implement */ 983 } 984 985 /* The vhost driver natively knows how to handle the vrings of non 986 * cross-endian legacy devices and modern devices. Only legacy devices 987 * exposed to a bi-endian guest may require the vhost driver to use a 988 * specific endianness. 989 */ 990 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 991 { 992 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 993 return false; 994 } 995 #if HOST_BIG_ENDIAN 996 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 997 #else 998 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 999 #endif 1000 } 1001 1002 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 1003 bool is_big_endian, 1004 int vhost_vq_index) 1005 { 1006 int r; 1007 struct vhost_vring_state s = { 1008 .index = vhost_vq_index, 1009 .num = is_big_endian 1010 }; 1011 1012 r = dev->vhost_ops->vhost_set_vring_endian(dev, &s); 1013 if (r < 0) { 1014 VHOST_OPS_DEBUG(r, "vhost_set_vring_endian failed"); 1015 } 1016 return r; 1017 } 1018 1019 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 1020 uint64_t gpa, uint64_t *uaddr, 1021 uint64_t *len) 1022 { 1023 int i; 1024 1025 for (i = 0; i < hdev->mem->nregions; i++) { 1026 struct vhost_memory_region *reg = hdev->mem->regions + i; 1027 1028 if (gpa >= reg->guest_phys_addr && 1029 reg->guest_phys_addr + reg->memory_size > gpa) { 1030 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 1031 *len = reg->guest_phys_addr + reg->memory_size - gpa; 1032 return 0; 1033 } 1034 } 1035 1036 return -EFAULT; 1037 } 1038 1039 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 1040 { 1041 IOMMUTLBEntry iotlb; 1042 uint64_t uaddr, len; 1043 int ret = -EFAULT; 1044 1045 RCU_READ_LOCK_GUARD(); 1046 1047 trace_vhost_iotlb_miss(dev, 1); 1048 1049 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 1050 iova, write, 1051 MEMTXATTRS_UNSPECIFIED); 1052 if (iotlb.target_as != NULL) { 1053 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 1054 &uaddr, &len); 1055 if (ret) { 1056 trace_vhost_iotlb_miss(dev, 3); 1057 error_report("Fail to lookup the translated address " 1058 "%"PRIx64, iotlb.translated_addr); 1059 goto out; 1060 } 1061 1062 len = MIN(iotlb.addr_mask + 1, len); 1063 iova = iova & ~iotlb.addr_mask; 1064 1065 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 1066 len, iotlb.perm); 1067 if (ret) { 1068 trace_vhost_iotlb_miss(dev, 4); 1069 error_report("Fail to update device iotlb"); 1070 goto out; 1071 } 1072 } 1073 1074 trace_vhost_iotlb_miss(dev, 2); 1075 1076 out: 1077 return ret; 1078 } 1079 1080 static int vhost_virtqueue_start(struct vhost_dev *dev, 1081 struct VirtIODevice *vdev, 1082 struct vhost_virtqueue *vq, 1083 unsigned idx) 1084 { 1085 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1086 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1087 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1088 hwaddr s, l, a; 1089 int r; 1090 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1091 struct vhost_vring_file file = { 1092 .index = vhost_vq_index 1093 }; 1094 struct vhost_vring_state state = { 1095 .index = vhost_vq_index 1096 }; 1097 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1098 1099 a = virtio_queue_get_desc_addr(vdev, idx); 1100 if (a == 0) { 1101 /* Queue might not be ready for start */ 1102 return 0; 1103 } 1104 1105 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1106 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1107 if (r) { 1108 VHOST_OPS_DEBUG(r, "vhost_set_vring_num failed"); 1109 return r; 1110 } 1111 1112 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1113 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1114 if (r) { 1115 VHOST_OPS_DEBUG(r, "vhost_set_vring_base failed"); 1116 return r; 1117 } 1118 1119 if (vhost_needs_vring_endian(vdev)) { 1120 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1121 virtio_is_big_endian(vdev), 1122 vhost_vq_index); 1123 if (r) { 1124 return r; 1125 } 1126 } 1127 1128 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1129 vq->desc_phys = a; 1130 vq->desc = vhost_memory_map(dev, a, &l, false); 1131 if (!vq->desc || l != s) { 1132 r = -ENOMEM; 1133 goto fail_alloc_desc; 1134 } 1135 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1136 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1137 vq->avail = vhost_memory_map(dev, a, &l, false); 1138 if (!vq->avail || l != s) { 1139 r = -ENOMEM; 1140 goto fail_alloc_avail; 1141 } 1142 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1143 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1144 vq->used = vhost_memory_map(dev, a, &l, true); 1145 if (!vq->used || l != s) { 1146 r = -ENOMEM; 1147 goto fail_alloc_used; 1148 } 1149 1150 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1151 if (r < 0) { 1152 goto fail_alloc; 1153 } 1154 1155 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1156 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1157 if (r) { 1158 VHOST_OPS_DEBUG(r, "vhost_set_vring_kick failed"); 1159 goto fail_kick; 1160 } 1161 1162 /* Clear and discard previous events if any. */ 1163 event_notifier_test_and_clear(&vq->masked_notifier); 1164 1165 /* Init vring in unmasked state, unless guest_notifier_mask 1166 * will do it later. 1167 */ 1168 if (!vdev->use_guest_notifier_mask) { 1169 /* TODO: check and handle errors. */ 1170 vhost_virtqueue_mask(dev, vdev, idx, false); 1171 } 1172 1173 if (k->query_guest_notifiers && 1174 k->query_guest_notifiers(qbus->parent) && 1175 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1176 file.fd = -1; 1177 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1178 if (r) { 1179 goto fail_vector; 1180 } 1181 } 1182 1183 return 0; 1184 1185 fail_vector: 1186 fail_kick: 1187 fail_alloc: 1188 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1189 0, 0); 1190 fail_alloc_used: 1191 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1192 0, 0); 1193 fail_alloc_avail: 1194 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1195 0, 0); 1196 fail_alloc_desc: 1197 return r; 1198 } 1199 1200 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1201 struct VirtIODevice *vdev, 1202 struct vhost_virtqueue *vq, 1203 unsigned idx) 1204 { 1205 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1206 struct vhost_vring_state state = { 1207 .index = vhost_vq_index, 1208 }; 1209 int r; 1210 1211 if (virtio_queue_get_desc_addr(vdev, idx) == 0) { 1212 /* Don't stop the virtqueue which might have not been started */ 1213 return; 1214 } 1215 1216 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1217 if (r < 0) { 1218 VHOST_OPS_DEBUG(r, "vhost VQ %u ring restore failed: %d", idx, r); 1219 /* Connection to the backend is broken, so let's sync internal 1220 * last avail idx to the device used idx. 1221 */ 1222 virtio_queue_restore_last_avail_idx(vdev, idx); 1223 } else { 1224 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1225 } 1226 virtio_queue_invalidate_signalled_used(vdev, idx); 1227 virtio_queue_update_used_idx(vdev, idx); 1228 1229 /* In the cross-endian case, we need to reset the vring endianness to 1230 * native as legacy devices expect so by default. 1231 */ 1232 if (vhost_needs_vring_endian(vdev)) { 1233 vhost_virtqueue_set_vring_endian_legacy(dev, 1234 !virtio_is_big_endian(vdev), 1235 vhost_vq_index); 1236 } 1237 1238 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1239 1, virtio_queue_get_used_size(vdev, idx)); 1240 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1241 0, virtio_queue_get_avail_size(vdev, idx)); 1242 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1243 0, virtio_queue_get_desc_size(vdev, idx)); 1244 } 1245 1246 static void vhost_eventfd_add(MemoryListener *listener, 1247 MemoryRegionSection *section, 1248 bool match_data, uint64_t data, EventNotifier *e) 1249 { 1250 } 1251 1252 static void vhost_eventfd_del(MemoryListener *listener, 1253 MemoryRegionSection *section, 1254 bool match_data, uint64_t data, EventNotifier *e) 1255 { 1256 } 1257 1258 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1259 int n, uint32_t timeout) 1260 { 1261 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1262 struct vhost_vring_state state = { 1263 .index = vhost_vq_index, 1264 .num = timeout, 1265 }; 1266 int r; 1267 1268 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1269 return -EINVAL; 1270 } 1271 1272 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1273 if (r) { 1274 VHOST_OPS_DEBUG(r, "vhost_set_vring_busyloop_timeout failed"); 1275 return r; 1276 } 1277 1278 return 0; 1279 } 1280 1281 static void vhost_virtqueue_error_notifier(EventNotifier *n) 1282 { 1283 struct vhost_virtqueue *vq = container_of(n, struct vhost_virtqueue, 1284 error_notifier); 1285 struct vhost_dev *dev = vq->dev; 1286 int index = vq - dev->vqs; 1287 1288 if (event_notifier_test_and_clear(n) && dev->vdev) { 1289 VHOST_OPS_DEBUG(-EINVAL, "vhost vring error in virtqueue %d", 1290 dev->vq_index + index); 1291 } 1292 } 1293 1294 static int vhost_virtqueue_init(struct vhost_dev *dev, 1295 struct vhost_virtqueue *vq, int n) 1296 { 1297 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1298 struct vhost_vring_file file = { 1299 .index = vhost_vq_index, 1300 }; 1301 int r = event_notifier_init(&vq->masked_notifier, 0); 1302 if (r < 0) { 1303 return r; 1304 } 1305 1306 file.fd = event_notifier_get_wfd(&vq->masked_notifier); 1307 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1308 if (r) { 1309 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1310 goto fail_call; 1311 } 1312 1313 vq->dev = dev; 1314 1315 if (dev->vhost_ops->vhost_set_vring_err) { 1316 r = event_notifier_init(&vq->error_notifier, 0); 1317 if (r < 0) { 1318 goto fail_call; 1319 } 1320 1321 file.fd = event_notifier_get_fd(&vq->error_notifier); 1322 r = dev->vhost_ops->vhost_set_vring_err(dev, &file); 1323 if (r) { 1324 VHOST_OPS_DEBUG(r, "vhost_set_vring_err failed"); 1325 goto fail_err; 1326 } 1327 1328 event_notifier_set_handler(&vq->error_notifier, 1329 vhost_virtqueue_error_notifier); 1330 } 1331 1332 return 0; 1333 1334 fail_err: 1335 event_notifier_cleanup(&vq->error_notifier); 1336 fail_call: 1337 event_notifier_cleanup(&vq->masked_notifier); 1338 return r; 1339 } 1340 1341 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1342 { 1343 event_notifier_cleanup(&vq->masked_notifier); 1344 if (vq->dev->vhost_ops->vhost_set_vring_err) { 1345 event_notifier_set_handler(&vq->error_notifier, NULL); 1346 event_notifier_cleanup(&vq->error_notifier); 1347 } 1348 } 1349 1350 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1351 VhostBackendType backend_type, uint32_t busyloop_timeout, 1352 Error **errp) 1353 { 1354 uint64_t features; 1355 int i, r, n_initialized_vqs = 0; 1356 1357 hdev->vdev = NULL; 1358 hdev->migration_blocker = NULL; 1359 1360 r = vhost_set_backend_type(hdev, backend_type); 1361 assert(r >= 0); 1362 1363 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque, errp); 1364 if (r < 0) { 1365 goto fail; 1366 } 1367 1368 r = hdev->vhost_ops->vhost_set_owner(hdev); 1369 if (r < 0) { 1370 error_setg_errno(errp, -r, "vhost_set_owner failed"); 1371 goto fail; 1372 } 1373 1374 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1375 if (r < 0) { 1376 error_setg_errno(errp, -r, "vhost_get_features failed"); 1377 goto fail; 1378 } 1379 1380 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1381 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1382 if (r < 0) { 1383 error_setg_errno(errp, -r, "Failed to initialize virtqueue %d", i); 1384 goto fail; 1385 } 1386 } 1387 1388 if (busyloop_timeout) { 1389 for (i = 0; i < hdev->nvqs; ++i) { 1390 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1391 busyloop_timeout); 1392 if (r < 0) { 1393 error_setg_errno(errp, -r, "Failed to set busyloop timeout"); 1394 goto fail_busyloop; 1395 } 1396 } 1397 } 1398 1399 hdev->features = features; 1400 1401 hdev->memory_listener = (MemoryListener) { 1402 .name = "vhost", 1403 .begin = vhost_begin, 1404 .commit = vhost_commit, 1405 .region_add = vhost_region_addnop, 1406 .region_nop = vhost_region_addnop, 1407 .log_start = vhost_log_start, 1408 .log_stop = vhost_log_stop, 1409 .log_sync = vhost_log_sync, 1410 .log_global_start = vhost_log_global_start, 1411 .log_global_stop = vhost_log_global_stop, 1412 .eventfd_add = vhost_eventfd_add, 1413 .eventfd_del = vhost_eventfd_del, 1414 .priority = 10 1415 }; 1416 1417 hdev->iommu_listener = (MemoryListener) { 1418 .name = "vhost-iommu", 1419 .region_add = vhost_iommu_region_add, 1420 .region_del = vhost_iommu_region_del, 1421 }; 1422 1423 if (hdev->migration_blocker == NULL) { 1424 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1425 error_setg(&hdev->migration_blocker, 1426 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1427 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) { 1428 error_setg(&hdev->migration_blocker, 1429 "Migration disabled: failed to allocate shared memory"); 1430 } 1431 } 1432 1433 if (hdev->migration_blocker != NULL) { 1434 r = migrate_add_blocker(hdev->migration_blocker, errp); 1435 if (r < 0) { 1436 error_free(hdev->migration_blocker); 1437 goto fail_busyloop; 1438 } 1439 } 1440 1441 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1442 hdev->n_mem_sections = 0; 1443 hdev->mem_sections = NULL; 1444 hdev->log = NULL; 1445 hdev->log_size = 0; 1446 hdev->log_enabled = false; 1447 hdev->started = false; 1448 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1449 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1450 1451 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1452 error_setg(errp, "vhost backend memory slots limit is less" 1453 " than current number of present memory slots"); 1454 r = -EINVAL; 1455 goto fail_busyloop; 1456 } 1457 1458 return 0; 1459 1460 fail_busyloop: 1461 if (busyloop_timeout) { 1462 while (--i >= 0) { 1463 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1464 } 1465 } 1466 fail: 1467 hdev->nvqs = n_initialized_vqs; 1468 vhost_dev_cleanup(hdev); 1469 return r; 1470 } 1471 1472 void vhost_dev_cleanup(struct vhost_dev *hdev) 1473 { 1474 int i; 1475 1476 for (i = 0; i < hdev->nvqs; ++i) { 1477 vhost_virtqueue_cleanup(hdev->vqs + i); 1478 } 1479 if (hdev->mem) { 1480 /* those are only safe after successful init */ 1481 memory_listener_unregister(&hdev->memory_listener); 1482 QLIST_REMOVE(hdev, entry); 1483 } 1484 if (hdev->migration_blocker) { 1485 migrate_del_blocker(hdev->migration_blocker); 1486 error_free(hdev->migration_blocker); 1487 } 1488 g_free(hdev->mem); 1489 g_free(hdev->mem_sections); 1490 if (hdev->vhost_ops) { 1491 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1492 } 1493 assert(!hdev->log); 1494 1495 memset(hdev, 0, sizeof(struct vhost_dev)); 1496 } 1497 1498 /* Stop processing guest IO notifications in qemu. 1499 * Start processing them in vhost in kernel. 1500 */ 1501 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1502 { 1503 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1504 int i, r, e; 1505 1506 /* We will pass the notifiers to the kernel, make sure that QEMU 1507 * doesn't interfere. 1508 */ 1509 r = virtio_device_grab_ioeventfd(vdev); 1510 if (r < 0) { 1511 error_report("binding does not support host notifiers"); 1512 goto fail; 1513 } 1514 1515 for (i = 0; i < hdev->nvqs; ++i) { 1516 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1517 true); 1518 if (r < 0) { 1519 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1520 goto fail_vq; 1521 } 1522 } 1523 1524 return 0; 1525 fail_vq: 1526 while (--i >= 0) { 1527 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1528 false); 1529 if (e < 0) { 1530 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1531 } 1532 assert (e >= 0); 1533 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1534 } 1535 virtio_device_release_ioeventfd(vdev); 1536 fail: 1537 return r; 1538 } 1539 1540 /* Stop processing guest IO notifications in vhost. 1541 * Start processing them in qemu. 1542 * This might actually run the qemu handlers right away, 1543 * so virtio in qemu must be completely setup when this is called. 1544 */ 1545 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1546 { 1547 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1548 int i, r; 1549 1550 for (i = 0; i < hdev->nvqs; ++i) { 1551 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1552 false); 1553 if (r < 0) { 1554 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1555 } 1556 assert (r >= 0); 1557 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1558 } 1559 virtio_device_release_ioeventfd(vdev); 1560 } 1561 1562 /* Test and clear event pending status. 1563 * Should be called after unmask to avoid losing events. 1564 */ 1565 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1566 { 1567 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1568 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1569 return event_notifier_test_and_clear(&vq->masked_notifier); 1570 } 1571 1572 /* Mask/unmask events from this vq. */ 1573 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1574 bool mask) 1575 { 1576 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1577 int r, index = n - hdev->vq_index; 1578 struct vhost_vring_file file; 1579 1580 /* should only be called after backend is connected */ 1581 assert(hdev->vhost_ops); 1582 1583 if (mask) { 1584 assert(vdev->use_guest_notifier_mask); 1585 file.fd = event_notifier_get_wfd(&hdev->vqs[index].masked_notifier); 1586 } else { 1587 file.fd = event_notifier_get_wfd(virtio_queue_get_guest_notifier(vvq)); 1588 } 1589 1590 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1591 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1592 if (r < 0) { 1593 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1594 } 1595 } 1596 1597 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1598 uint64_t features) 1599 { 1600 const int *bit = feature_bits; 1601 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1602 uint64_t bit_mask = (1ULL << *bit); 1603 if (!(hdev->features & bit_mask)) { 1604 features &= ~bit_mask; 1605 } 1606 bit++; 1607 } 1608 return features; 1609 } 1610 1611 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1612 uint64_t features) 1613 { 1614 const int *bit = feature_bits; 1615 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1616 uint64_t bit_mask = (1ULL << *bit); 1617 if (features & bit_mask) { 1618 hdev->acked_features |= bit_mask; 1619 } 1620 bit++; 1621 } 1622 } 1623 1624 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1625 uint32_t config_len, Error **errp) 1626 { 1627 assert(hdev->vhost_ops); 1628 1629 if (hdev->vhost_ops->vhost_get_config) { 1630 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len, 1631 errp); 1632 } 1633 1634 error_setg(errp, "vhost_get_config not implemented"); 1635 return -ENOSYS; 1636 } 1637 1638 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1639 uint32_t offset, uint32_t size, uint32_t flags) 1640 { 1641 assert(hdev->vhost_ops); 1642 1643 if (hdev->vhost_ops->vhost_set_config) { 1644 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1645 size, flags); 1646 } 1647 1648 return -ENOSYS; 1649 } 1650 1651 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1652 const VhostDevConfigOps *ops) 1653 { 1654 hdev->config_ops = ops; 1655 } 1656 1657 void vhost_dev_free_inflight(struct vhost_inflight *inflight) 1658 { 1659 if (inflight && inflight->addr) { 1660 qemu_memfd_free(inflight->addr, inflight->size, inflight->fd); 1661 inflight->addr = NULL; 1662 inflight->fd = -1; 1663 } 1664 } 1665 1666 static int vhost_dev_resize_inflight(struct vhost_inflight *inflight, 1667 uint64_t new_size) 1668 { 1669 Error *err = NULL; 1670 int fd = -1; 1671 void *addr = qemu_memfd_alloc("vhost-inflight", new_size, 1672 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 1673 &fd, &err); 1674 1675 if (err) { 1676 error_report_err(err); 1677 return -ENOMEM; 1678 } 1679 1680 vhost_dev_free_inflight(inflight); 1681 inflight->offset = 0; 1682 inflight->addr = addr; 1683 inflight->fd = fd; 1684 inflight->size = new_size; 1685 1686 return 0; 1687 } 1688 1689 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1690 { 1691 if (inflight->addr) { 1692 qemu_put_be64(f, inflight->size); 1693 qemu_put_be16(f, inflight->queue_size); 1694 qemu_put_buffer(f, inflight->addr, inflight->size); 1695 } else { 1696 qemu_put_be64(f, 0); 1697 } 1698 } 1699 1700 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1701 { 1702 uint64_t size; 1703 1704 size = qemu_get_be64(f); 1705 if (!size) { 1706 return 0; 1707 } 1708 1709 if (inflight->size != size) { 1710 int ret = vhost_dev_resize_inflight(inflight, size); 1711 if (ret < 0) { 1712 return ret; 1713 } 1714 } 1715 inflight->queue_size = qemu_get_be16(f); 1716 1717 qemu_get_buffer(f, inflight->addr, size); 1718 1719 return 0; 1720 } 1721 1722 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev) 1723 { 1724 int r; 1725 1726 if (hdev->vhost_ops->vhost_get_inflight_fd == NULL || 1727 hdev->vhost_ops->vhost_set_inflight_fd == NULL) { 1728 return 0; 1729 } 1730 1731 hdev->vdev = vdev; 1732 1733 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1734 if (r < 0) { 1735 VHOST_OPS_DEBUG(r, "vhost_dev_prepare_inflight failed"); 1736 return r; 1737 } 1738 1739 return 0; 1740 } 1741 1742 int vhost_dev_set_inflight(struct vhost_dev *dev, 1743 struct vhost_inflight *inflight) 1744 { 1745 int r; 1746 1747 if (dev->vhost_ops->vhost_set_inflight_fd && inflight->addr) { 1748 r = dev->vhost_ops->vhost_set_inflight_fd(dev, inflight); 1749 if (r) { 1750 VHOST_OPS_DEBUG(r, "vhost_set_inflight_fd failed"); 1751 return r; 1752 } 1753 } 1754 1755 return 0; 1756 } 1757 1758 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, 1759 struct vhost_inflight *inflight) 1760 { 1761 int r; 1762 1763 if (dev->vhost_ops->vhost_get_inflight_fd) { 1764 r = dev->vhost_ops->vhost_get_inflight_fd(dev, queue_size, inflight); 1765 if (r) { 1766 VHOST_OPS_DEBUG(r, "vhost_get_inflight_fd failed"); 1767 return r; 1768 } 1769 } 1770 1771 return 0; 1772 } 1773 1774 /* Host notifiers must be enabled at this point. */ 1775 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1776 { 1777 int i, r; 1778 1779 /* should only be called after backend is connected */ 1780 assert(hdev->vhost_ops); 1781 1782 vdev->vhost_started = true; 1783 hdev->started = true; 1784 hdev->vdev = vdev; 1785 1786 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1787 if (r < 0) { 1788 goto fail_features; 1789 } 1790 1791 if (vhost_dev_has_iommu(hdev)) { 1792 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1793 } 1794 1795 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1796 if (r < 0) { 1797 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 1798 goto fail_mem; 1799 } 1800 for (i = 0; i < hdev->nvqs; ++i) { 1801 r = vhost_virtqueue_start(hdev, 1802 vdev, 1803 hdev->vqs + i, 1804 hdev->vq_index + i); 1805 if (r < 0) { 1806 goto fail_vq; 1807 } 1808 } 1809 1810 if (hdev->log_enabled) { 1811 uint64_t log_base; 1812 1813 hdev->log_size = vhost_get_log_size(hdev); 1814 hdev->log = vhost_log_get(hdev->log_size, 1815 vhost_dev_log_is_shared(hdev)); 1816 log_base = (uintptr_t)hdev->log->log; 1817 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1818 hdev->log_size ? log_base : 0, 1819 hdev->log); 1820 if (r < 0) { 1821 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 1822 goto fail_log; 1823 } 1824 } 1825 if (hdev->vhost_ops->vhost_dev_start) { 1826 r = hdev->vhost_ops->vhost_dev_start(hdev, true); 1827 if (r) { 1828 goto fail_log; 1829 } 1830 } 1831 if (vhost_dev_has_iommu(hdev) && 1832 hdev->vhost_ops->vhost_set_iotlb_callback) { 1833 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1834 1835 /* Update used ring information for IOTLB to work correctly, 1836 * vhost-kernel code requires for this.*/ 1837 for (i = 0; i < hdev->nvqs; ++i) { 1838 struct vhost_virtqueue *vq = hdev->vqs + i; 1839 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1840 } 1841 } 1842 return 0; 1843 fail_log: 1844 vhost_log_put(hdev, false); 1845 fail_vq: 1846 while (--i >= 0) { 1847 vhost_virtqueue_stop(hdev, 1848 vdev, 1849 hdev->vqs + i, 1850 hdev->vq_index + i); 1851 } 1852 1853 fail_mem: 1854 fail_features: 1855 vdev->vhost_started = false; 1856 hdev->started = false; 1857 return r; 1858 } 1859 1860 /* Host notifiers must be enabled at this point. */ 1861 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1862 { 1863 int i; 1864 1865 /* should only be called after backend is connected */ 1866 assert(hdev->vhost_ops); 1867 1868 if (hdev->vhost_ops->vhost_dev_start) { 1869 hdev->vhost_ops->vhost_dev_start(hdev, false); 1870 } 1871 for (i = 0; i < hdev->nvqs; ++i) { 1872 vhost_virtqueue_stop(hdev, 1873 vdev, 1874 hdev->vqs + i, 1875 hdev->vq_index + i); 1876 } 1877 1878 if (vhost_dev_has_iommu(hdev)) { 1879 if (hdev->vhost_ops->vhost_set_iotlb_callback) { 1880 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1881 } 1882 memory_listener_unregister(&hdev->iommu_listener); 1883 } 1884 vhost_log_put(hdev, true); 1885 hdev->started = false; 1886 vdev->vhost_started = false; 1887 hdev->vdev = NULL; 1888 } 1889 1890 int vhost_net_set_backend(struct vhost_dev *hdev, 1891 struct vhost_vring_file *file) 1892 { 1893 if (hdev->vhost_ops->vhost_net_set_backend) { 1894 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1895 } 1896 1897 return -ENOSYS; 1898 } 1899