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