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