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 "sysemu/tcg.h" 30 #include "trace.h" 31 32 /* enabled until disconnected backend stabilizes */ 33 #define _VHOST_DEBUG 1 34 35 #ifdef _VHOST_DEBUG 36 #define VHOST_OPS_DEBUG(retval, fmt, ...) \ 37 do { \ 38 error_report(fmt ": %s (%d)", ## __VA_ARGS__, \ 39 strerror(-retval), -retval); \ 40 } while (0) 41 #else 42 #define VHOST_OPS_DEBUG(retval, fmt, ...) \ 43 do { } while (0) 44 #endif 45 46 static struct vhost_log *vhost_log; 47 static struct vhost_log *vhost_log_shm; 48 49 static unsigned int used_memslots; 50 static QLIST_HEAD(, vhost_dev) vhost_devices = 51 QLIST_HEAD_INITIALIZER(vhost_devices); 52 53 bool vhost_has_free_slot(void) 54 { 55 unsigned int slots_limit = ~0U; 56 struct vhost_dev *hdev; 57 58 QLIST_FOREACH(hdev, &vhost_devices, entry) { 59 unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); 60 slots_limit = MIN(slots_limit, r); 61 } 62 return slots_limit > used_memslots; 63 } 64 65 static void vhost_dev_sync_region(struct vhost_dev *dev, 66 MemoryRegionSection *section, 67 uint64_t mfirst, uint64_t mlast, 68 uint64_t rfirst, uint64_t rlast) 69 { 70 vhost_log_chunk_t *log = dev->log->log; 71 72 uint64_t start = MAX(mfirst, rfirst); 73 uint64_t end = MIN(mlast, rlast); 74 vhost_log_chunk_t *from = log + start / VHOST_LOG_CHUNK; 75 vhost_log_chunk_t *to = log + end / VHOST_LOG_CHUNK + 1; 76 uint64_t addr = QEMU_ALIGN_DOWN(start, VHOST_LOG_CHUNK); 77 78 if (end < start) { 79 return; 80 } 81 assert(end / VHOST_LOG_CHUNK < dev->log_size); 82 assert(start / VHOST_LOG_CHUNK < dev->log_size); 83 84 for (;from < to; ++from) { 85 vhost_log_chunk_t log; 86 /* We first check with non-atomic: much cheaper, 87 * and we expect non-dirty to be the common case. */ 88 if (!*from) { 89 addr += VHOST_LOG_CHUNK; 90 continue; 91 } 92 /* Data must be read atomically. We don't really need barrier semantics 93 * but it's easier to use atomic_* than roll our own. */ 94 log = qatomic_xchg(from, 0); 95 while (log) { 96 int bit = ctzl(log); 97 hwaddr page_addr; 98 hwaddr section_offset; 99 hwaddr mr_offset; 100 page_addr = addr + bit * VHOST_LOG_PAGE; 101 section_offset = page_addr - section->offset_within_address_space; 102 mr_offset = section_offset + section->offset_within_region; 103 memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); 104 log &= ~(0x1ull << bit); 105 } 106 addr += VHOST_LOG_CHUNK; 107 } 108 } 109 110 static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, 111 MemoryRegionSection *section, 112 hwaddr first, 113 hwaddr last) 114 { 115 int i; 116 hwaddr start_addr; 117 hwaddr end_addr; 118 119 if (!dev->log_enabled || !dev->started) { 120 return 0; 121 } 122 start_addr = section->offset_within_address_space; 123 end_addr = range_get_last(start_addr, int128_get64(section->size)); 124 start_addr = MAX(first, start_addr); 125 end_addr = MIN(last, end_addr); 126 127 for (i = 0; i < dev->mem->nregions; ++i) { 128 struct vhost_memory_region *reg = dev->mem->regions + i; 129 vhost_dev_sync_region(dev, section, start_addr, end_addr, 130 reg->guest_phys_addr, 131 range_get_last(reg->guest_phys_addr, 132 reg->memory_size)); 133 } 134 for (i = 0; i < dev->nvqs; ++i) { 135 struct vhost_virtqueue *vq = dev->vqs + i; 136 137 if (!vq->used_phys && !vq->used_size) { 138 continue; 139 } 140 141 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 142 range_get_last(vq->used_phys, vq->used_size)); 143 } 144 return 0; 145 } 146 147 static void vhost_log_sync(MemoryListener *listener, 148 MemoryRegionSection *section) 149 { 150 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 151 memory_listener); 152 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 153 } 154 155 static void vhost_log_sync_range(struct vhost_dev *dev, 156 hwaddr first, hwaddr last) 157 { 158 int i; 159 /* FIXME: this is N^2 in number of sections */ 160 for (i = 0; i < dev->n_mem_sections; ++i) { 161 MemoryRegionSection *section = &dev->mem_sections[i]; 162 vhost_sync_dirty_bitmap(dev, section, first, last); 163 } 164 } 165 166 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 167 { 168 uint64_t log_size = 0; 169 int i; 170 for (i = 0; i < dev->mem->nregions; ++i) { 171 struct vhost_memory_region *reg = dev->mem->regions + i; 172 uint64_t last = range_get_last(reg->guest_phys_addr, 173 reg->memory_size); 174 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 175 } 176 return log_size; 177 } 178 179 static int vhost_set_backend_type(struct vhost_dev *dev, 180 VhostBackendType backend_type) 181 { 182 int r = 0; 183 184 switch (backend_type) { 185 #ifdef CONFIG_VHOST_KERNEL 186 case VHOST_BACKEND_TYPE_KERNEL: 187 dev->vhost_ops = &kernel_ops; 188 break; 189 #endif 190 #ifdef CONFIG_VHOST_USER 191 case VHOST_BACKEND_TYPE_USER: 192 dev->vhost_ops = &user_ops; 193 break; 194 #endif 195 #ifdef CONFIG_VHOST_VDPA 196 case VHOST_BACKEND_TYPE_VDPA: 197 dev->vhost_ops = &vdpa_ops; 198 break; 199 #endif 200 default: 201 error_report("Unknown vhost backend type"); 202 r = -1; 203 } 204 205 return r; 206 } 207 208 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 209 { 210 Error *err = NULL; 211 struct vhost_log *log; 212 uint64_t logsize = size * sizeof(*(log->log)); 213 int fd = -1; 214 215 log = g_new0(struct vhost_log, 1); 216 if (share) { 217 log->log = qemu_memfd_alloc("vhost-log", logsize, 218 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 219 &fd, &err); 220 if (err) { 221 error_report_err(err); 222 g_free(log); 223 return NULL; 224 } 225 memset(log->log, 0, logsize); 226 } else { 227 log->log = g_malloc0(logsize); 228 } 229 230 log->size = size; 231 log->refcnt = 1; 232 log->fd = fd; 233 234 return log; 235 } 236 237 static struct vhost_log *vhost_log_get(uint64_t size, bool share) 238 { 239 struct vhost_log *log = share ? vhost_log_shm : vhost_log; 240 241 if (!log || log->size != size) { 242 log = vhost_log_alloc(size, share); 243 if (share) { 244 vhost_log_shm = log; 245 } else { 246 vhost_log = log; 247 } 248 } else { 249 ++log->refcnt; 250 } 251 252 return log; 253 } 254 255 static void vhost_log_put(struct vhost_dev *dev, bool sync) 256 { 257 struct vhost_log *log = dev->log; 258 259 if (!log) { 260 return; 261 } 262 263 --log->refcnt; 264 if (log->refcnt == 0) { 265 /* Sync only the range covered by the old log */ 266 if (dev->log_size && sync) { 267 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 268 } 269 270 if (vhost_log == log) { 271 g_free(log->log); 272 vhost_log = NULL; 273 } else if (vhost_log_shm == log) { 274 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 275 log->fd); 276 vhost_log_shm = NULL; 277 } 278 279 g_free(log); 280 } 281 282 dev->log = NULL; 283 dev->log_size = 0; 284 } 285 286 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 287 { 288 return dev->vhost_ops->vhost_requires_shm_log && 289 dev->vhost_ops->vhost_requires_shm_log(dev); 290 } 291 292 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 293 { 294 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 295 uint64_t log_base = (uintptr_t)log->log; 296 int r; 297 298 /* inform backend of log switching, this must be done before 299 releasing the current log, to ensure no logging is lost */ 300 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 301 if (r < 0) { 302 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 303 } 304 305 vhost_log_put(dev, true); 306 dev->log = log; 307 dev->log_size = size; 308 } 309 310 static int vhost_dev_has_iommu(struct vhost_dev *dev) 311 { 312 VirtIODevice *vdev = dev->vdev; 313 314 /* 315 * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support 316 * incremental memory mapping API via IOTLB API. For platform that 317 * does not have IOMMU, there's no need to enable this feature 318 * which may cause unnecessary IOTLB miss/update transactions. 319 */ 320 return virtio_bus_device_iommu_enabled(vdev) && 321 virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 322 } 323 324 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 325 hwaddr *plen, bool is_write) 326 { 327 if (!vhost_dev_has_iommu(dev)) { 328 return cpu_physical_memory_map(addr, plen, is_write); 329 } else { 330 return (void *)(uintptr_t)addr; 331 } 332 } 333 334 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 335 hwaddr len, int is_write, 336 hwaddr access_len) 337 { 338 if (!vhost_dev_has_iommu(dev)) { 339 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 340 } 341 } 342 343 static int vhost_verify_ring_part_mapping(void *ring_hva, 344 uint64_t ring_gpa, 345 uint64_t ring_size, 346 void *reg_hva, 347 uint64_t reg_gpa, 348 uint64_t reg_size) 349 { 350 uint64_t hva_ring_offset; 351 uint64_t ring_last = range_get_last(ring_gpa, ring_size); 352 uint64_t reg_last = range_get_last(reg_gpa, reg_size); 353 354 if (ring_last < reg_gpa || ring_gpa > reg_last) { 355 return 0; 356 } 357 /* check that whole ring's is mapped */ 358 if (ring_last > reg_last) { 359 return -ENOMEM; 360 } 361 /* check that ring's MemoryRegion wasn't replaced */ 362 hva_ring_offset = ring_gpa - reg_gpa; 363 if (ring_hva != reg_hva + hva_ring_offset) { 364 return -EBUSY; 365 } 366 367 return 0; 368 } 369 370 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 371 void *reg_hva, 372 uint64_t reg_gpa, 373 uint64_t reg_size) 374 { 375 int i, j; 376 int r = 0; 377 const char *part_name[] = { 378 "descriptor table", 379 "available ring", 380 "used ring" 381 }; 382 383 if (vhost_dev_has_iommu(dev)) { 384 return 0; 385 } 386 387 for (i = 0; i < dev->nvqs; ++i) { 388 struct vhost_virtqueue *vq = dev->vqs + i; 389 390 if (vq->desc_phys == 0) { 391 continue; 392 } 393 394 j = 0; 395 r = vhost_verify_ring_part_mapping( 396 vq->desc, vq->desc_phys, vq->desc_size, 397 reg_hva, reg_gpa, reg_size); 398 if (r) { 399 break; 400 } 401 402 j++; 403 r = vhost_verify_ring_part_mapping( 404 vq->avail, vq->avail_phys, vq->avail_size, 405 reg_hva, reg_gpa, reg_size); 406 if (r) { 407 break; 408 } 409 410 j++; 411 r = vhost_verify_ring_part_mapping( 412 vq->used, vq->used_phys, vq->used_size, 413 reg_hva, reg_gpa, reg_size); 414 if (r) { 415 break; 416 } 417 } 418 419 if (r == -ENOMEM) { 420 error_report("Unable to map %s for ring %d", part_name[j], i); 421 } else if (r == -EBUSY) { 422 error_report("%s relocated for ring %d", part_name[j], i); 423 } 424 return r; 425 } 426 427 /* 428 * vhost_section: identify sections needed for vhost access 429 * 430 * We only care about RAM sections here (where virtqueue and guest 431 * internals accessed by virtio might live). If we find one we still 432 * allow the backend to potentially filter it out of our list. 433 */ 434 static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section) 435 { 436 MemoryRegion *mr = section->mr; 437 438 if (memory_region_is_ram(mr) && !memory_region_is_rom(mr)) { 439 uint8_t dirty_mask = memory_region_get_dirty_log_mask(mr); 440 uint8_t handled_dirty; 441 442 /* 443 * Kernel based vhost doesn't handle any block which is doing 444 * dirty-tracking other than migration for which it has 445 * specific logging support. However for TCG the kernel never 446 * gets involved anyway so we can also ignore it's 447 * self-modiying code detection flags. However a vhost-user 448 * client could still confuse a TCG guest if it re-writes 449 * executable memory that has already been translated. 450 */ 451 handled_dirty = (1 << DIRTY_MEMORY_MIGRATION) | 452 (1 << DIRTY_MEMORY_CODE); 453 454 if (dirty_mask & ~handled_dirty) { 455 trace_vhost_reject_section(mr->name, 1); 456 return false; 457 } 458 459 if (dev->vhost_ops->vhost_backend_mem_section_filter && 460 !dev->vhost_ops->vhost_backend_mem_section_filter(dev, section)) { 461 trace_vhost_reject_section(mr->name, 2); 462 return false; 463 } 464 465 trace_vhost_section(mr->name); 466 return true; 467 } else { 468 trace_vhost_reject_section(mr->name, 3); 469 return false; 470 } 471 } 472 473 static void vhost_begin(MemoryListener *listener) 474 { 475 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 476 memory_listener); 477 dev->tmp_sections = NULL; 478 dev->n_tmp_sections = 0; 479 } 480 481 static void vhost_commit(MemoryListener *listener) 482 { 483 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 484 memory_listener); 485 MemoryRegionSection *old_sections; 486 int n_old_sections; 487 uint64_t log_size; 488 size_t regions_size; 489 int r; 490 int i; 491 bool changed = false; 492 493 /* Note we can be called before the device is started, but then 494 * starting the device calls set_mem_table, so we need to have 495 * built the data structures. 496 */ 497 old_sections = dev->mem_sections; 498 n_old_sections = dev->n_mem_sections; 499 dev->mem_sections = dev->tmp_sections; 500 dev->n_mem_sections = dev->n_tmp_sections; 501 502 if (dev->n_mem_sections != n_old_sections) { 503 changed = true; 504 } else { 505 /* Same size, lets check the contents */ 506 for (int i = 0; i < n_old_sections; i++) { 507 if (!MemoryRegionSection_eq(&old_sections[i], 508 &dev->mem_sections[i])) { 509 changed = true; 510 break; 511 } 512 } 513 } 514 515 trace_vhost_commit(dev->started, changed); 516 if (!changed) { 517 goto out; 518 } 519 520 /* Rebuild the regions list from the new sections list */ 521 regions_size = offsetof(struct vhost_memory, regions) + 522 dev->n_mem_sections * sizeof dev->mem->regions[0]; 523 dev->mem = g_realloc(dev->mem, regions_size); 524 dev->mem->nregions = dev->n_mem_sections; 525 used_memslots = dev->mem->nregions; 526 for (i = 0; i < dev->n_mem_sections; i++) { 527 struct vhost_memory_region *cur_vmr = dev->mem->regions + i; 528 struct MemoryRegionSection *mrs = dev->mem_sections + i; 529 530 cur_vmr->guest_phys_addr = mrs->offset_within_address_space; 531 cur_vmr->memory_size = int128_get64(mrs->size); 532 cur_vmr->userspace_addr = 533 (uintptr_t)memory_region_get_ram_ptr(mrs->mr) + 534 mrs->offset_within_region; 535 cur_vmr->flags_padding = 0; 536 } 537 538 if (!dev->started) { 539 goto out; 540 } 541 542 for (i = 0; i < dev->mem->nregions; i++) { 543 if (vhost_verify_ring_mappings(dev, 544 (void *)(uintptr_t)dev->mem->regions[i].userspace_addr, 545 dev->mem->regions[i].guest_phys_addr, 546 dev->mem->regions[i].memory_size)) { 547 error_report("Verify ring failure on region %d", i); 548 abort(); 549 } 550 } 551 552 if (!dev->log_enabled) { 553 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 554 if (r < 0) { 555 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 556 } 557 goto out; 558 } 559 log_size = vhost_get_log_size(dev); 560 /* We allocate an extra 4K bytes to log, 561 * to reduce the * number of reallocations. */ 562 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 563 /* To log more, must increase log size before table update. */ 564 if (dev->log_size < log_size) { 565 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 566 } 567 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 568 if (r < 0) { 569 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 570 } 571 /* To log less, can only decrease log size after table update. */ 572 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 573 vhost_dev_log_resize(dev, log_size); 574 } 575 576 out: 577 /* Deref the old list of sections, this must happen _after_ the 578 * vhost_set_mem_table to ensure the client isn't still using the 579 * section we're about to unref. 580 */ 581 while (n_old_sections--) { 582 memory_region_unref(old_sections[n_old_sections].mr); 583 } 584 g_free(old_sections); 585 return; 586 } 587 588 /* Adds the section data to the tmp_section structure. 589 * It relies on the listener calling us in memory address order 590 * and for each region (via the _add and _nop methods) to 591 * join neighbours. 592 */ 593 static void vhost_region_add_section(struct vhost_dev *dev, 594 MemoryRegionSection *section) 595 { 596 bool need_add = true; 597 uint64_t mrs_size = int128_get64(section->size); 598 uint64_t mrs_gpa = section->offset_within_address_space; 599 uintptr_t mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) + 600 section->offset_within_region; 601 RAMBlock *mrs_rb = section->mr->ram_block; 602 603 trace_vhost_region_add_section(section->mr->name, mrs_gpa, mrs_size, 604 mrs_host); 605 606 if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) { 607 /* Round the section to it's page size */ 608 /* First align the start down to a page boundary */ 609 size_t mrs_page = qemu_ram_pagesize(mrs_rb); 610 uint64_t alignage = mrs_host & (mrs_page - 1); 611 if (alignage) { 612 mrs_host -= alignage; 613 mrs_size += alignage; 614 mrs_gpa -= alignage; 615 } 616 /* Now align the size up to a page boundary */ 617 alignage = mrs_size & (mrs_page - 1); 618 if (alignage) { 619 mrs_size += mrs_page - alignage; 620 } 621 trace_vhost_region_add_section_aligned(section->mr->name, mrs_gpa, 622 mrs_size, mrs_host); 623 } 624 625 if (dev->n_tmp_sections) { 626 /* Since we already have at least one section, lets see if 627 * this extends it; since we're scanning in order, we only 628 * have to look at the last one, and the FlatView that calls 629 * us shouldn't have overlaps. 630 */ 631 MemoryRegionSection *prev_sec = dev->tmp_sections + 632 (dev->n_tmp_sections - 1); 633 uint64_t prev_gpa_start = prev_sec->offset_within_address_space; 634 uint64_t prev_size = int128_get64(prev_sec->size); 635 uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size); 636 uint64_t prev_host_start = 637 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) + 638 prev_sec->offset_within_region; 639 uint64_t prev_host_end = range_get_last(prev_host_start, prev_size); 640 641 if (mrs_gpa <= (prev_gpa_end + 1)) { 642 /* OK, looks like overlapping/intersecting - it's possible that 643 * the rounding to page sizes has made them overlap, but they should 644 * match up in the same RAMBlock if they do. 645 */ 646 if (mrs_gpa < prev_gpa_start) { 647 error_report("%s:Section '%s' rounded to %"PRIx64 648 " prior to previous '%s' %"PRIx64, 649 __func__, section->mr->name, mrs_gpa, 650 prev_sec->mr->name, prev_gpa_start); 651 /* A way to cleanly fail here would be better */ 652 return; 653 } 654 /* Offset from the start of the previous GPA to this GPA */ 655 size_t offset = mrs_gpa - prev_gpa_start; 656 657 if (prev_host_start + offset == mrs_host && 658 section->mr == prev_sec->mr && 659 (!dev->vhost_ops->vhost_backend_can_merge || 660 dev->vhost_ops->vhost_backend_can_merge(dev, 661 mrs_host, mrs_size, 662 prev_host_start, prev_size))) { 663 uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size); 664 need_add = false; 665 prev_sec->offset_within_address_space = 666 MIN(prev_gpa_start, mrs_gpa); 667 prev_sec->offset_within_region = 668 MIN(prev_host_start, mrs_host) - 669 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr); 670 prev_sec->size = int128_make64(max_end - MIN(prev_host_start, 671 mrs_host)); 672 trace_vhost_region_add_section_merge(section->mr->name, 673 int128_get64(prev_sec->size), 674 prev_sec->offset_within_address_space, 675 prev_sec->offset_within_region); 676 } else { 677 /* adjoining regions are fine, but overlapping ones with 678 * different blocks/offsets shouldn't happen 679 */ 680 if (mrs_gpa != prev_gpa_end + 1) { 681 error_report("%s: Overlapping but not coherent sections " 682 "at %"PRIx64, 683 __func__, mrs_gpa); 684 return; 685 } 686 } 687 } 688 } 689 690 if (need_add) { 691 ++dev->n_tmp_sections; 692 dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections, 693 dev->n_tmp_sections); 694 dev->tmp_sections[dev->n_tmp_sections - 1] = *section; 695 /* The flatview isn't stable and we don't use it, making it NULL 696 * means we can memcmp the list. 697 */ 698 dev->tmp_sections[dev->n_tmp_sections - 1].fv = NULL; 699 memory_region_ref(section->mr); 700 } 701 } 702 703 /* Used for both add and nop callbacks */ 704 static void vhost_region_addnop(MemoryListener *listener, 705 MemoryRegionSection *section) 706 { 707 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 708 memory_listener); 709 710 if (!vhost_section(dev, section)) { 711 return; 712 } 713 vhost_region_add_section(dev, section); 714 } 715 716 static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 717 { 718 struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n); 719 struct vhost_dev *hdev = iommu->hdev; 720 hwaddr iova = iotlb->iova + iommu->iommu_offset; 721 722 if (vhost_backend_invalidate_device_iotlb(hdev, iova, 723 iotlb->addr_mask + 1)) { 724 error_report("Fail to invalidate device iotlb"); 725 } 726 } 727 728 static void vhost_iommu_region_add(MemoryListener *listener, 729 MemoryRegionSection *section) 730 { 731 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 732 iommu_listener); 733 struct vhost_iommu *iommu; 734 Int128 end; 735 int iommu_idx; 736 IOMMUMemoryRegion *iommu_mr; 737 int ret; 738 739 if (!memory_region_is_iommu(section->mr)) { 740 return; 741 } 742 743 iommu_mr = IOMMU_MEMORY_REGION(section->mr); 744 745 iommu = g_malloc0(sizeof(*iommu)); 746 end = int128_add(int128_make64(section->offset_within_region), 747 section->size); 748 end = int128_sub(end, int128_one()); 749 iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr, 750 MEMTXATTRS_UNSPECIFIED); 751 iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, 752 IOMMU_NOTIFIER_DEVIOTLB_UNMAP, 753 section->offset_within_region, 754 int128_get64(end), 755 iommu_idx); 756 iommu->mr = section->mr; 757 iommu->iommu_offset = section->offset_within_address_space - 758 section->offset_within_region; 759 iommu->hdev = dev; 760 ret = memory_region_register_iommu_notifier(section->mr, &iommu->n, NULL); 761 if (ret) { 762 /* 763 * Some vIOMMUs do not support dev-iotlb yet. If so, try to use the 764 * UNMAP legacy message 765 */ 766 iommu->n.notifier_flags = IOMMU_NOTIFIER_UNMAP; 767 memory_region_register_iommu_notifier(section->mr, &iommu->n, 768 &error_fatal); 769 } 770 QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next); 771 /* TODO: can replay help performance here? */ 772 } 773 774 static void vhost_iommu_region_del(MemoryListener *listener, 775 MemoryRegionSection *section) 776 { 777 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 778 iommu_listener); 779 struct vhost_iommu *iommu; 780 781 if (!memory_region_is_iommu(section->mr)) { 782 return; 783 } 784 785 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 786 if (iommu->mr == section->mr && 787 iommu->n.start == section->offset_within_region) { 788 memory_region_unregister_iommu_notifier(iommu->mr, 789 &iommu->n); 790 QLIST_REMOVE(iommu, iommu_next); 791 g_free(iommu); 792 break; 793 } 794 } 795 } 796 797 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 798 struct vhost_virtqueue *vq, 799 unsigned idx, bool enable_log) 800 { 801 struct vhost_vring_addr addr; 802 int r; 803 memset(&addr, 0, sizeof(struct vhost_vring_addr)); 804 805 if (dev->vhost_ops->vhost_vq_get_addr) { 806 r = dev->vhost_ops->vhost_vq_get_addr(dev, &addr, vq); 807 if (r < 0) { 808 VHOST_OPS_DEBUG(r, "vhost_vq_get_addr failed"); 809 return r; 810 } 811 } else { 812 addr.desc_user_addr = (uint64_t)(unsigned long)vq->desc; 813 addr.avail_user_addr = (uint64_t)(unsigned long)vq->avail; 814 addr.used_user_addr = (uint64_t)(unsigned long)vq->used; 815 } 816 addr.index = idx; 817 addr.log_guest_addr = vq->used_phys; 818 addr.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0; 819 r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 820 if (r < 0) { 821 VHOST_OPS_DEBUG(r, "vhost_set_vring_addr failed"); 822 } 823 return r; 824 } 825 826 static int vhost_dev_set_features(struct vhost_dev *dev, 827 bool enable_log) 828 { 829 uint64_t features = dev->acked_features; 830 int r; 831 if (enable_log) { 832 features |= 0x1ULL << VHOST_F_LOG_ALL; 833 } 834 if (!vhost_dev_has_iommu(dev)) { 835 features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM); 836 } 837 if (dev->vhost_ops->vhost_force_iommu) { 838 if (dev->vhost_ops->vhost_force_iommu(dev) == true) { 839 features |= 0x1ULL << VIRTIO_F_IOMMU_PLATFORM; 840 } 841 } 842 r = dev->vhost_ops->vhost_set_features(dev, features); 843 if (r < 0) { 844 VHOST_OPS_DEBUG(r, "vhost_set_features failed"); 845 goto out; 846 } 847 if (dev->vhost_ops->vhost_set_backend_cap) { 848 r = dev->vhost_ops->vhost_set_backend_cap(dev); 849 if (r < 0) { 850 VHOST_OPS_DEBUG(r, "vhost_set_backend_cap failed"); 851 goto out; 852 } 853 } 854 855 out: 856 return r; 857 } 858 859 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 860 { 861 int r, i, idx; 862 hwaddr addr; 863 864 r = vhost_dev_set_features(dev, enable_log); 865 if (r < 0) { 866 goto err_features; 867 } 868 for (i = 0; i < dev->nvqs; ++i) { 869 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 870 addr = virtio_queue_get_desc_addr(dev->vdev, idx); 871 if (!addr) { 872 /* 873 * The queue might not be ready for start. If this 874 * is the case there is no reason to continue the process. 875 * The similar logic is used by the vhost_virtqueue_start() 876 * routine. 877 */ 878 continue; 879 } 880 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 881 enable_log); 882 if (r < 0) { 883 goto err_vq; 884 } 885 } 886 return 0; 887 err_vq: 888 for (; i >= 0; --i) { 889 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 890 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 891 dev->log_enabled); 892 } 893 vhost_dev_set_features(dev, dev->log_enabled); 894 err_features: 895 return r; 896 } 897 898 static int vhost_migration_log(MemoryListener *listener, bool enable) 899 { 900 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 901 memory_listener); 902 int r; 903 if (enable == dev->log_enabled) { 904 return 0; 905 } 906 if (!dev->started) { 907 dev->log_enabled = enable; 908 return 0; 909 } 910 911 r = 0; 912 if (!enable) { 913 r = vhost_dev_set_log(dev, false); 914 if (r < 0) { 915 goto check_dev_state; 916 } 917 vhost_log_put(dev, false); 918 } else { 919 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 920 r = vhost_dev_set_log(dev, true); 921 if (r < 0) { 922 goto check_dev_state; 923 } 924 } 925 926 check_dev_state: 927 dev->log_enabled = enable; 928 /* 929 * vhost-user-* devices could change their state during log 930 * initialization due to disconnect. So check dev state after 931 * vhost communication. 932 */ 933 if (!dev->started) { 934 /* 935 * Since device is in the stopped state, it is okay for 936 * migration. Return success. 937 */ 938 r = 0; 939 } 940 if (r) { 941 /* An error occurred. */ 942 dev->log_enabled = false; 943 } 944 945 return r; 946 } 947 948 static void vhost_log_global_start(MemoryListener *listener) 949 { 950 int r; 951 952 r = vhost_migration_log(listener, true); 953 if (r < 0) { 954 abort(); 955 } 956 } 957 958 static void vhost_log_global_stop(MemoryListener *listener) 959 { 960 int r; 961 962 r = vhost_migration_log(listener, false); 963 if (r < 0) { 964 abort(); 965 } 966 } 967 968 static void vhost_log_start(MemoryListener *listener, 969 MemoryRegionSection *section, 970 int old, int new) 971 { 972 /* FIXME: implement */ 973 } 974 975 static void vhost_log_stop(MemoryListener *listener, 976 MemoryRegionSection *section, 977 int old, int new) 978 { 979 /* FIXME: implement */ 980 } 981 982 /* The vhost driver natively knows how to handle the vrings of non 983 * cross-endian legacy devices and modern devices. Only legacy devices 984 * exposed to a bi-endian guest may require the vhost driver to use a 985 * specific endianness. 986 */ 987 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 988 { 989 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 990 return false; 991 } 992 #ifdef HOST_WORDS_BIGENDIAN 993 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 994 #else 995 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 996 #endif 997 } 998 999 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 1000 bool is_big_endian, 1001 int vhost_vq_index) 1002 { 1003 int r; 1004 struct vhost_vring_state s = { 1005 .index = vhost_vq_index, 1006 .num = is_big_endian 1007 }; 1008 1009 r = dev->vhost_ops->vhost_set_vring_endian(dev, &s); 1010 if (r < 0) { 1011 VHOST_OPS_DEBUG(r, "vhost_set_vring_endian failed"); 1012 } 1013 return r; 1014 } 1015 1016 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 1017 uint64_t gpa, uint64_t *uaddr, 1018 uint64_t *len) 1019 { 1020 int i; 1021 1022 for (i = 0; i < hdev->mem->nregions; i++) { 1023 struct vhost_memory_region *reg = hdev->mem->regions + i; 1024 1025 if (gpa >= reg->guest_phys_addr && 1026 reg->guest_phys_addr + reg->memory_size > gpa) { 1027 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 1028 *len = reg->guest_phys_addr + reg->memory_size - gpa; 1029 return 0; 1030 } 1031 } 1032 1033 return -EFAULT; 1034 } 1035 1036 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 1037 { 1038 IOMMUTLBEntry iotlb; 1039 uint64_t uaddr, len; 1040 int ret = -EFAULT; 1041 1042 RCU_READ_LOCK_GUARD(); 1043 1044 trace_vhost_iotlb_miss(dev, 1); 1045 1046 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 1047 iova, write, 1048 MEMTXATTRS_UNSPECIFIED); 1049 if (iotlb.target_as != NULL) { 1050 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 1051 &uaddr, &len); 1052 if (ret) { 1053 trace_vhost_iotlb_miss(dev, 3); 1054 error_report("Fail to lookup the translated address " 1055 "%"PRIx64, iotlb.translated_addr); 1056 goto out; 1057 } 1058 1059 len = MIN(iotlb.addr_mask + 1, len); 1060 iova = iova & ~iotlb.addr_mask; 1061 1062 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 1063 len, iotlb.perm); 1064 if (ret) { 1065 trace_vhost_iotlb_miss(dev, 4); 1066 error_report("Fail to update device iotlb"); 1067 goto out; 1068 } 1069 } 1070 1071 trace_vhost_iotlb_miss(dev, 2); 1072 1073 out: 1074 return ret; 1075 } 1076 1077 static int vhost_virtqueue_start(struct vhost_dev *dev, 1078 struct VirtIODevice *vdev, 1079 struct vhost_virtqueue *vq, 1080 unsigned idx) 1081 { 1082 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1083 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1084 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1085 hwaddr s, l, a; 1086 int r; 1087 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1088 struct vhost_vring_file file = { 1089 .index = vhost_vq_index 1090 }; 1091 struct vhost_vring_state state = { 1092 .index = vhost_vq_index 1093 }; 1094 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1095 1096 a = virtio_queue_get_desc_addr(vdev, idx); 1097 if (a == 0) { 1098 /* Queue might not be ready for start */ 1099 return 0; 1100 } 1101 1102 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1103 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1104 if (r) { 1105 VHOST_OPS_DEBUG(r, "vhost_set_vring_num failed"); 1106 return r; 1107 } 1108 1109 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1110 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1111 if (r) { 1112 VHOST_OPS_DEBUG(r, "vhost_set_vring_base failed"); 1113 return r; 1114 } 1115 1116 if (vhost_needs_vring_endian(vdev)) { 1117 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1118 virtio_is_big_endian(vdev), 1119 vhost_vq_index); 1120 if (r) { 1121 return r; 1122 } 1123 } 1124 1125 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1126 vq->desc_phys = a; 1127 vq->desc = vhost_memory_map(dev, a, &l, false); 1128 if (!vq->desc || l != s) { 1129 r = -ENOMEM; 1130 goto fail_alloc_desc; 1131 } 1132 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1133 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1134 vq->avail = vhost_memory_map(dev, a, &l, false); 1135 if (!vq->avail || l != s) { 1136 r = -ENOMEM; 1137 goto fail_alloc_avail; 1138 } 1139 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1140 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1141 vq->used = vhost_memory_map(dev, a, &l, true); 1142 if (!vq->used || l != s) { 1143 r = -ENOMEM; 1144 goto fail_alloc_used; 1145 } 1146 1147 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1148 if (r < 0) { 1149 goto fail_alloc; 1150 } 1151 1152 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1153 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1154 if (r) { 1155 VHOST_OPS_DEBUG(r, "vhost_set_vring_kick failed"); 1156 goto fail_kick; 1157 } 1158 1159 /* Clear and discard previous events if any. */ 1160 event_notifier_test_and_clear(&vq->masked_notifier); 1161 1162 /* Init vring in unmasked state, unless guest_notifier_mask 1163 * will do it later. 1164 */ 1165 if (!vdev->use_guest_notifier_mask) { 1166 /* TODO: check and handle errors. */ 1167 vhost_virtqueue_mask(dev, vdev, idx, false); 1168 } 1169 1170 if (k->query_guest_notifiers && 1171 k->query_guest_notifiers(qbus->parent) && 1172 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1173 file.fd = -1; 1174 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1175 if (r) { 1176 goto fail_vector; 1177 } 1178 } 1179 1180 return 0; 1181 1182 fail_vector: 1183 fail_kick: 1184 fail_alloc: 1185 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1186 0, 0); 1187 fail_alloc_used: 1188 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1189 0, 0); 1190 fail_alloc_avail: 1191 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1192 0, 0); 1193 fail_alloc_desc: 1194 return r; 1195 } 1196 1197 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1198 struct VirtIODevice *vdev, 1199 struct vhost_virtqueue *vq, 1200 unsigned idx) 1201 { 1202 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1203 struct vhost_vring_state state = { 1204 .index = vhost_vq_index, 1205 }; 1206 int r; 1207 1208 if (virtio_queue_get_desc_addr(vdev, idx) == 0) { 1209 /* Don't stop the virtqueue which might have not been started */ 1210 return; 1211 } 1212 1213 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1214 if (r < 0) { 1215 VHOST_OPS_DEBUG(r, "vhost VQ %u ring restore failed: %d", idx, r); 1216 /* Connection to the backend is broken, so let's sync internal 1217 * last avail idx to the device used idx. 1218 */ 1219 virtio_queue_restore_last_avail_idx(vdev, idx); 1220 } else { 1221 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1222 } 1223 virtio_queue_invalidate_signalled_used(vdev, idx); 1224 virtio_queue_update_used_idx(vdev, idx); 1225 1226 /* In the cross-endian case, we need to reset the vring endianness to 1227 * native as legacy devices expect so by default. 1228 */ 1229 if (vhost_needs_vring_endian(vdev)) { 1230 vhost_virtqueue_set_vring_endian_legacy(dev, 1231 !virtio_is_big_endian(vdev), 1232 vhost_vq_index); 1233 } 1234 1235 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1236 1, virtio_queue_get_used_size(vdev, idx)); 1237 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1238 0, virtio_queue_get_avail_size(vdev, idx)); 1239 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1240 0, virtio_queue_get_desc_size(vdev, idx)); 1241 } 1242 1243 static void vhost_eventfd_add(MemoryListener *listener, 1244 MemoryRegionSection *section, 1245 bool match_data, uint64_t data, EventNotifier *e) 1246 { 1247 } 1248 1249 static void vhost_eventfd_del(MemoryListener *listener, 1250 MemoryRegionSection *section, 1251 bool match_data, uint64_t data, EventNotifier *e) 1252 { 1253 } 1254 1255 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1256 int n, uint32_t timeout) 1257 { 1258 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1259 struct vhost_vring_state state = { 1260 .index = vhost_vq_index, 1261 .num = timeout, 1262 }; 1263 int r; 1264 1265 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1266 return -EINVAL; 1267 } 1268 1269 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1270 if (r) { 1271 VHOST_OPS_DEBUG(r, "vhost_set_vring_busyloop_timeout failed"); 1272 return r; 1273 } 1274 1275 return 0; 1276 } 1277 1278 static int vhost_virtqueue_init(struct vhost_dev *dev, 1279 struct vhost_virtqueue *vq, int n) 1280 { 1281 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1282 struct vhost_vring_file file = { 1283 .index = vhost_vq_index, 1284 }; 1285 int r = event_notifier_init(&vq->masked_notifier, 0); 1286 if (r < 0) { 1287 return r; 1288 } 1289 1290 file.fd = event_notifier_get_wfd(&vq->masked_notifier); 1291 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1292 if (r) { 1293 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1294 goto fail_call; 1295 } 1296 1297 vq->dev = dev; 1298 1299 return 0; 1300 fail_call: 1301 event_notifier_cleanup(&vq->masked_notifier); 1302 return r; 1303 } 1304 1305 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1306 { 1307 event_notifier_cleanup(&vq->masked_notifier); 1308 } 1309 1310 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1311 VhostBackendType backend_type, uint32_t busyloop_timeout, 1312 Error **errp) 1313 { 1314 uint64_t features; 1315 int i, r, n_initialized_vqs = 0; 1316 1317 hdev->vdev = NULL; 1318 hdev->migration_blocker = NULL; 1319 1320 r = vhost_set_backend_type(hdev, backend_type); 1321 assert(r >= 0); 1322 1323 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque, errp); 1324 if (r < 0) { 1325 goto fail; 1326 } 1327 1328 r = hdev->vhost_ops->vhost_set_owner(hdev); 1329 if (r < 0) { 1330 error_setg_errno(errp, -r, "vhost_set_owner failed"); 1331 goto fail; 1332 } 1333 1334 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1335 if (r < 0) { 1336 error_setg_errno(errp, -r, "vhost_get_features failed"); 1337 goto fail; 1338 } 1339 1340 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1341 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1342 if (r < 0) { 1343 error_setg_errno(errp, -r, "Failed to initialize virtqueue %d", i); 1344 goto fail; 1345 } 1346 } 1347 1348 if (busyloop_timeout) { 1349 for (i = 0; i < hdev->nvqs; ++i) { 1350 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1351 busyloop_timeout); 1352 if (r < 0) { 1353 error_setg_errno(errp, -r, "Failed to set busyloop timeout"); 1354 goto fail_busyloop; 1355 } 1356 } 1357 } 1358 1359 hdev->features = features; 1360 1361 hdev->memory_listener = (MemoryListener) { 1362 .name = "vhost", 1363 .begin = vhost_begin, 1364 .commit = vhost_commit, 1365 .region_add = vhost_region_addnop, 1366 .region_nop = vhost_region_addnop, 1367 .log_start = vhost_log_start, 1368 .log_stop = vhost_log_stop, 1369 .log_sync = vhost_log_sync, 1370 .log_global_start = vhost_log_global_start, 1371 .log_global_stop = vhost_log_global_stop, 1372 .eventfd_add = vhost_eventfd_add, 1373 .eventfd_del = vhost_eventfd_del, 1374 .priority = 10 1375 }; 1376 1377 hdev->iommu_listener = (MemoryListener) { 1378 .name = "vhost-iommu", 1379 .region_add = vhost_iommu_region_add, 1380 .region_del = vhost_iommu_region_del, 1381 }; 1382 1383 if (hdev->migration_blocker == NULL) { 1384 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1385 error_setg(&hdev->migration_blocker, 1386 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1387 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) { 1388 error_setg(&hdev->migration_blocker, 1389 "Migration disabled: failed to allocate shared memory"); 1390 } 1391 } 1392 1393 if (hdev->migration_blocker != NULL) { 1394 r = migrate_add_blocker(hdev->migration_blocker, errp); 1395 if (r < 0) { 1396 error_free(hdev->migration_blocker); 1397 goto fail_busyloop; 1398 } 1399 } 1400 1401 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1402 hdev->n_mem_sections = 0; 1403 hdev->mem_sections = NULL; 1404 hdev->log = NULL; 1405 hdev->log_size = 0; 1406 hdev->log_enabled = false; 1407 hdev->started = false; 1408 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1409 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1410 1411 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1412 error_setg(errp, "vhost backend memory slots limit is less" 1413 " than current number of present memory slots"); 1414 r = -EINVAL; 1415 goto fail_busyloop; 1416 } 1417 1418 return 0; 1419 1420 fail_busyloop: 1421 if (busyloop_timeout) { 1422 while (--i >= 0) { 1423 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1424 } 1425 } 1426 fail: 1427 hdev->nvqs = n_initialized_vqs; 1428 vhost_dev_cleanup(hdev); 1429 return r; 1430 } 1431 1432 void vhost_dev_cleanup(struct vhost_dev *hdev) 1433 { 1434 int i; 1435 1436 for (i = 0; i < hdev->nvqs; ++i) { 1437 vhost_virtqueue_cleanup(hdev->vqs + i); 1438 } 1439 if (hdev->mem) { 1440 /* those are only safe after successful init */ 1441 memory_listener_unregister(&hdev->memory_listener); 1442 QLIST_REMOVE(hdev, entry); 1443 } 1444 if (hdev->migration_blocker) { 1445 migrate_del_blocker(hdev->migration_blocker); 1446 error_free(hdev->migration_blocker); 1447 } 1448 g_free(hdev->mem); 1449 g_free(hdev->mem_sections); 1450 if (hdev->vhost_ops) { 1451 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1452 } 1453 assert(!hdev->log); 1454 1455 memset(hdev, 0, sizeof(struct vhost_dev)); 1456 } 1457 1458 /* Stop processing guest IO notifications in qemu. 1459 * Start processing them in vhost in kernel. 1460 */ 1461 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1462 { 1463 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1464 int i, r, e; 1465 1466 /* We will pass the notifiers to the kernel, make sure that QEMU 1467 * doesn't interfere. 1468 */ 1469 r = virtio_device_grab_ioeventfd(vdev); 1470 if (r < 0) { 1471 error_report("binding does not support host notifiers"); 1472 goto fail; 1473 } 1474 1475 for (i = 0; i < hdev->nvqs; ++i) { 1476 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1477 true); 1478 if (r < 0) { 1479 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1480 goto fail_vq; 1481 } 1482 } 1483 1484 return 0; 1485 fail_vq: 1486 while (--i >= 0) { 1487 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1488 false); 1489 if (e < 0) { 1490 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1491 } 1492 assert (e >= 0); 1493 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1494 } 1495 virtio_device_release_ioeventfd(vdev); 1496 fail: 1497 return r; 1498 } 1499 1500 /* Stop processing guest IO notifications in vhost. 1501 * Start processing them in qemu. 1502 * This might actually run the qemu handlers right away, 1503 * so virtio in qemu must be completely setup when this is called. 1504 */ 1505 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1506 { 1507 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1508 int i, r; 1509 1510 for (i = 0; i < hdev->nvqs; ++i) { 1511 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1512 false); 1513 if (r < 0) { 1514 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1515 } 1516 assert (r >= 0); 1517 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1518 } 1519 virtio_device_release_ioeventfd(vdev); 1520 } 1521 1522 /* Test and clear event pending status. 1523 * Should be called after unmask to avoid losing events. 1524 */ 1525 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1526 { 1527 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1528 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1529 return event_notifier_test_and_clear(&vq->masked_notifier); 1530 } 1531 1532 /* Mask/unmask events from this vq. */ 1533 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1534 bool mask) 1535 { 1536 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1537 int r, index = n - hdev->vq_index; 1538 struct vhost_vring_file file; 1539 1540 /* should only be called after backend is connected */ 1541 assert(hdev->vhost_ops); 1542 1543 if (mask) { 1544 assert(vdev->use_guest_notifier_mask); 1545 file.fd = event_notifier_get_wfd(&hdev->vqs[index].masked_notifier); 1546 } else { 1547 file.fd = event_notifier_get_wfd(virtio_queue_get_guest_notifier(vvq)); 1548 } 1549 1550 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1551 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1552 if (r < 0) { 1553 VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); 1554 } 1555 } 1556 1557 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1558 uint64_t features) 1559 { 1560 const int *bit = feature_bits; 1561 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1562 uint64_t bit_mask = (1ULL << *bit); 1563 if (!(hdev->features & bit_mask)) { 1564 features &= ~bit_mask; 1565 } 1566 bit++; 1567 } 1568 return features; 1569 } 1570 1571 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1572 uint64_t features) 1573 { 1574 const int *bit = feature_bits; 1575 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1576 uint64_t bit_mask = (1ULL << *bit); 1577 if (features & bit_mask) { 1578 hdev->acked_features |= bit_mask; 1579 } 1580 bit++; 1581 } 1582 } 1583 1584 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1585 uint32_t config_len, Error **errp) 1586 { 1587 assert(hdev->vhost_ops); 1588 1589 if (hdev->vhost_ops->vhost_get_config) { 1590 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len, 1591 errp); 1592 } 1593 1594 error_setg(errp, "vhost_get_config not implemented"); 1595 return -ENOSYS; 1596 } 1597 1598 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1599 uint32_t offset, uint32_t size, uint32_t flags) 1600 { 1601 assert(hdev->vhost_ops); 1602 1603 if (hdev->vhost_ops->vhost_set_config) { 1604 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1605 size, flags); 1606 } 1607 1608 return -ENOSYS; 1609 } 1610 1611 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1612 const VhostDevConfigOps *ops) 1613 { 1614 hdev->config_ops = ops; 1615 } 1616 1617 void vhost_dev_free_inflight(struct vhost_inflight *inflight) 1618 { 1619 if (inflight && inflight->addr) { 1620 qemu_memfd_free(inflight->addr, inflight->size, inflight->fd); 1621 inflight->addr = NULL; 1622 inflight->fd = -1; 1623 } 1624 } 1625 1626 static int vhost_dev_resize_inflight(struct vhost_inflight *inflight, 1627 uint64_t new_size) 1628 { 1629 Error *err = NULL; 1630 int fd = -1; 1631 void *addr = qemu_memfd_alloc("vhost-inflight", new_size, 1632 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 1633 &fd, &err); 1634 1635 if (err) { 1636 error_report_err(err); 1637 return -ENOMEM; 1638 } 1639 1640 vhost_dev_free_inflight(inflight); 1641 inflight->offset = 0; 1642 inflight->addr = addr; 1643 inflight->fd = fd; 1644 inflight->size = new_size; 1645 1646 return 0; 1647 } 1648 1649 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1650 { 1651 if (inflight->addr) { 1652 qemu_put_be64(f, inflight->size); 1653 qemu_put_be16(f, inflight->queue_size); 1654 qemu_put_buffer(f, inflight->addr, inflight->size); 1655 } else { 1656 qemu_put_be64(f, 0); 1657 } 1658 } 1659 1660 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1661 { 1662 uint64_t size; 1663 1664 size = qemu_get_be64(f); 1665 if (!size) { 1666 return 0; 1667 } 1668 1669 if (inflight->size != size) { 1670 int ret = vhost_dev_resize_inflight(inflight, size); 1671 if (ret < 0) { 1672 return ret; 1673 } 1674 } 1675 inflight->queue_size = qemu_get_be16(f); 1676 1677 qemu_get_buffer(f, inflight->addr, size); 1678 1679 return 0; 1680 } 1681 1682 int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev) 1683 { 1684 int r; 1685 1686 if (hdev->vhost_ops->vhost_get_inflight_fd == NULL || 1687 hdev->vhost_ops->vhost_set_inflight_fd == NULL) { 1688 return 0; 1689 } 1690 1691 hdev->vdev = vdev; 1692 1693 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1694 if (r < 0) { 1695 VHOST_OPS_DEBUG(r, "vhost_dev_prepare_inflight failed"); 1696 return r; 1697 } 1698 1699 return 0; 1700 } 1701 1702 int vhost_dev_set_inflight(struct vhost_dev *dev, 1703 struct vhost_inflight *inflight) 1704 { 1705 int r; 1706 1707 if (dev->vhost_ops->vhost_set_inflight_fd && inflight->addr) { 1708 r = dev->vhost_ops->vhost_set_inflight_fd(dev, inflight); 1709 if (r) { 1710 VHOST_OPS_DEBUG(r, "vhost_set_inflight_fd failed"); 1711 return r; 1712 } 1713 } 1714 1715 return 0; 1716 } 1717 1718 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, 1719 struct vhost_inflight *inflight) 1720 { 1721 int r; 1722 1723 if (dev->vhost_ops->vhost_get_inflight_fd) { 1724 r = dev->vhost_ops->vhost_get_inflight_fd(dev, queue_size, inflight); 1725 if (r) { 1726 VHOST_OPS_DEBUG(r, "vhost_get_inflight_fd failed"); 1727 return r; 1728 } 1729 } 1730 1731 return 0; 1732 } 1733 1734 /* Host notifiers must be enabled at this point. */ 1735 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1736 { 1737 int i, r; 1738 1739 /* should only be called after backend is connected */ 1740 assert(hdev->vhost_ops); 1741 1742 hdev->started = true; 1743 hdev->vdev = vdev; 1744 1745 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1746 if (r < 0) { 1747 goto fail_features; 1748 } 1749 1750 if (vhost_dev_has_iommu(hdev)) { 1751 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1752 } 1753 1754 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1755 if (r < 0) { 1756 VHOST_OPS_DEBUG(r, "vhost_set_mem_table failed"); 1757 goto fail_mem; 1758 } 1759 for (i = 0; i < hdev->nvqs; ++i) { 1760 r = vhost_virtqueue_start(hdev, 1761 vdev, 1762 hdev->vqs + i, 1763 hdev->vq_index + i); 1764 if (r < 0) { 1765 goto fail_vq; 1766 } 1767 } 1768 1769 if (hdev->log_enabled) { 1770 uint64_t log_base; 1771 1772 hdev->log_size = vhost_get_log_size(hdev); 1773 hdev->log = vhost_log_get(hdev->log_size, 1774 vhost_dev_log_is_shared(hdev)); 1775 log_base = (uintptr_t)hdev->log->log; 1776 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1777 hdev->log_size ? log_base : 0, 1778 hdev->log); 1779 if (r < 0) { 1780 VHOST_OPS_DEBUG(r, "vhost_set_log_base failed"); 1781 goto fail_log; 1782 } 1783 } 1784 if (hdev->vhost_ops->vhost_dev_start) { 1785 r = hdev->vhost_ops->vhost_dev_start(hdev, true); 1786 if (r) { 1787 goto fail_log; 1788 } 1789 } 1790 if (vhost_dev_has_iommu(hdev) && 1791 hdev->vhost_ops->vhost_set_iotlb_callback) { 1792 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1793 1794 /* Update used ring information for IOTLB to work correctly, 1795 * vhost-kernel code requires for this.*/ 1796 for (i = 0; i < hdev->nvqs; ++i) { 1797 struct vhost_virtqueue *vq = hdev->vqs + i; 1798 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1799 } 1800 } 1801 return 0; 1802 fail_log: 1803 vhost_log_put(hdev, false); 1804 fail_vq: 1805 while (--i >= 0) { 1806 vhost_virtqueue_stop(hdev, 1807 vdev, 1808 hdev->vqs + i, 1809 hdev->vq_index + i); 1810 } 1811 1812 fail_mem: 1813 fail_features: 1814 1815 hdev->started = false; 1816 return r; 1817 } 1818 1819 /* Host notifiers must be enabled at this point. */ 1820 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1821 { 1822 int i; 1823 1824 /* should only be called after backend is connected */ 1825 assert(hdev->vhost_ops); 1826 1827 if (hdev->vhost_ops->vhost_dev_start) { 1828 hdev->vhost_ops->vhost_dev_start(hdev, false); 1829 } 1830 for (i = 0; i < hdev->nvqs; ++i) { 1831 vhost_virtqueue_stop(hdev, 1832 vdev, 1833 hdev->vqs + i, 1834 hdev->vq_index + i); 1835 } 1836 1837 if (vhost_dev_has_iommu(hdev)) { 1838 if (hdev->vhost_ops->vhost_set_iotlb_callback) { 1839 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1840 } 1841 memory_listener_unregister(&hdev->iommu_listener); 1842 } 1843 vhost_log_put(hdev, true); 1844 hdev->started = false; 1845 hdev->vdev = NULL; 1846 } 1847 1848 int vhost_net_set_backend(struct vhost_dev *hdev, 1849 struct vhost_vring_file *file) 1850 { 1851 if (hdev->vhost_ops->vhost_net_set_backend) { 1852 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1853 } 1854 1855 return -ENOSYS; 1856 } 1857