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 } 822 return r < 0 ? -errno : 0; 823 } 824 825 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 826 { 827 int r, i, idx; 828 r = vhost_dev_set_features(dev, enable_log); 829 if (r < 0) { 830 goto err_features; 831 } 832 for (i = 0; i < dev->nvqs; ++i) { 833 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 834 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 835 enable_log); 836 if (r < 0) { 837 goto err_vq; 838 } 839 } 840 return 0; 841 err_vq: 842 for (; i >= 0; --i) { 843 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 844 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 845 dev->log_enabled); 846 } 847 vhost_dev_set_features(dev, dev->log_enabled); 848 err_features: 849 return r; 850 } 851 852 static int vhost_migration_log(MemoryListener *listener, bool enable) 853 { 854 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 855 memory_listener); 856 int r; 857 if (enable == dev->log_enabled) { 858 return 0; 859 } 860 if (!dev->started) { 861 dev->log_enabled = enable; 862 return 0; 863 } 864 if (!enable) { 865 r = vhost_dev_set_log(dev, false); 866 if (r < 0) { 867 return r; 868 } 869 vhost_log_put(dev, false); 870 } else { 871 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 872 r = vhost_dev_set_log(dev, true); 873 if (r < 0) { 874 return r; 875 } 876 } 877 dev->log_enabled = enable; 878 return 0; 879 } 880 881 static void vhost_log_global_start(MemoryListener *listener) 882 { 883 int r; 884 885 r = vhost_migration_log(listener, true); 886 if (r < 0) { 887 abort(); 888 } 889 } 890 891 static void vhost_log_global_stop(MemoryListener *listener) 892 { 893 int r; 894 895 r = vhost_migration_log(listener, false); 896 if (r < 0) { 897 abort(); 898 } 899 } 900 901 static void vhost_log_start(MemoryListener *listener, 902 MemoryRegionSection *section, 903 int old, int new) 904 { 905 /* FIXME: implement */ 906 } 907 908 static void vhost_log_stop(MemoryListener *listener, 909 MemoryRegionSection *section, 910 int old, int new) 911 { 912 /* FIXME: implement */ 913 } 914 915 /* The vhost driver natively knows how to handle the vrings of non 916 * cross-endian legacy devices and modern devices. Only legacy devices 917 * exposed to a bi-endian guest may require the vhost driver to use a 918 * specific endianness. 919 */ 920 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 921 { 922 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 923 return false; 924 } 925 #ifdef HOST_WORDS_BIGENDIAN 926 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 927 #else 928 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 929 #endif 930 } 931 932 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 933 bool is_big_endian, 934 int vhost_vq_index) 935 { 936 struct vhost_vring_state s = { 937 .index = vhost_vq_index, 938 .num = is_big_endian 939 }; 940 941 if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { 942 return 0; 943 } 944 945 VHOST_OPS_DEBUG("vhost_set_vring_endian failed"); 946 if (errno == ENOTTY) { 947 error_report("vhost does not support cross-endian"); 948 return -ENOSYS; 949 } 950 951 return -errno; 952 } 953 954 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 955 uint64_t gpa, uint64_t *uaddr, 956 uint64_t *len) 957 { 958 int i; 959 960 for (i = 0; i < hdev->mem->nregions; i++) { 961 struct vhost_memory_region *reg = hdev->mem->regions + i; 962 963 if (gpa >= reg->guest_phys_addr && 964 reg->guest_phys_addr + reg->memory_size > gpa) { 965 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 966 *len = reg->guest_phys_addr + reg->memory_size - gpa; 967 return 0; 968 } 969 } 970 971 return -EFAULT; 972 } 973 974 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 975 { 976 IOMMUTLBEntry iotlb; 977 uint64_t uaddr, len; 978 int ret = -EFAULT; 979 980 RCU_READ_LOCK_GUARD(); 981 982 trace_vhost_iotlb_miss(dev, 1); 983 984 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 985 iova, write, 986 MEMTXATTRS_UNSPECIFIED); 987 if (iotlb.target_as != NULL) { 988 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 989 &uaddr, &len); 990 if (ret) { 991 trace_vhost_iotlb_miss(dev, 3); 992 error_report("Fail to lookup the translated address " 993 "%"PRIx64, iotlb.translated_addr); 994 goto out; 995 } 996 997 len = MIN(iotlb.addr_mask + 1, len); 998 iova = iova & ~iotlb.addr_mask; 999 1000 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 1001 len, iotlb.perm); 1002 if (ret) { 1003 trace_vhost_iotlb_miss(dev, 4); 1004 error_report("Fail to update device iotlb"); 1005 goto out; 1006 } 1007 } 1008 1009 trace_vhost_iotlb_miss(dev, 2); 1010 1011 out: 1012 return ret; 1013 } 1014 1015 static int vhost_virtqueue_start(struct vhost_dev *dev, 1016 struct VirtIODevice *vdev, 1017 struct vhost_virtqueue *vq, 1018 unsigned idx) 1019 { 1020 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1021 VirtioBusState *vbus = VIRTIO_BUS(qbus); 1022 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 1023 hwaddr s, l, a; 1024 int r; 1025 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1026 struct vhost_vring_file file = { 1027 .index = vhost_vq_index 1028 }; 1029 struct vhost_vring_state state = { 1030 .index = vhost_vq_index 1031 }; 1032 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 1033 1034 a = virtio_queue_get_desc_addr(vdev, idx); 1035 if (a == 0) { 1036 /* Queue might not be ready for start */ 1037 return 0; 1038 } 1039 1040 vq->num = state.num = virtio_queue_get_num(vdev, idx); 1041 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 1042 if (r) { 1043 VHOST_OPS_DEBUG("vhost_set_vring_num failed"); 1044 return -errno; 1045 } 1046 1047 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 1048 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 1049 if (r) { 1050 VHOST_OPS_DEBUG("vhost_set_vring_base failed"); 1051 return -errno; 1052 } 1053 1054 if (vhost_needs_vring_endian(vdev)) { 1055 r = vhost_virtqueue_set_vring_endian_legacy(dev, 1056 virtio_is_big_endian(vdev), 1057 vhost_vq_index); 1058 if (r) { 1059 return -errno; 1060 } 1061 } 1062 1063 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 1064 vq->desc_phys = a; 1065 vq->desc = vhost_memory_map(dev, a, &l, false); 1066 if (!vq->desc || l != s) { 1067 r = -ENOMEM; 1068 goto fail_alloc_desc; 1069 } 1070 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1071 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1072 vq->avail = vhost_memory_map(dev, a, &l, false); 1073 if (!vq->avail || l != s) { 1074 r = -ENOMEM; 1075 goto fail_alloc_avail; 1076 } 1077 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1078 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1079 vq->used = vhost_memory_map(dev, a, &l, true); 1080 if (!vq->used || l != s) { 1081 r = -ENOMEM; 1082 goto fail_alloc_used; 1083 } 1084 1085 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1086 if (r < 0) { 1087 r = -errno; 1088 goto fail_alloc; 1089 } 1090 1091 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1092 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1093 if (r) { 1094 VHOST_OPS_DEBUG("vhost_set_vring_kick failed"); 1095 r = -errno; 1096 goto fail_kick; 1097 } 1098 1099 /* Clear and discard previous events if any. */ 1100 event_notifier_test_and_clear(&vq->masked_notifier); 1101 1102 /* Init vring in unmasked state, unless guest_notifier_mask 1103 * will do it later. 1104 */ 1105 if (!vdev->use_guest_notifier_mask) { 1106 /* TODO: check and handle errors. */ 1107 vhost_virtqueue_mask(dev, vdev, idx, false); 1108 } 1109 1110 if (k->query_guest_notifiers && 1111 k->query_guest_notifiers(qbus->parent) && 1112 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1113 file.fd = -1; 1114 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1115 if (r) { 1116 goto fail_vector; 1117 } 1118 } 1119 1120 return 0; 1121 1122 fail_vector: 1123 fail_kick: 1124 fail_alloc: 1125 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1126 0, 0); 1127 fail_alloc_used: 1128 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1129 0, 0); 1130 fail_alloc_avail: 1131 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1132 0, 0); 1133 fail_alloc_desc: 1134 return r; 1135 } 1136 1137 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1138 struct VirtIODevice *vdev, 1139 struct vhost_virtqueue *vq, 1140 unsigned idx) 1141 { 1142 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1143 struct vhost_vring_state state = { 1144 .index = vhost_vq_index, 1145 }; 1146 int r; 1147 1148 if (virtio_queue_get_desc_addr(vdev, idx) == 0) { 1149 /* Don't stop the virtqueue which might have not been started */ 1150 return; 1151 } 1152 1153 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1154 if (r < 0) { 1155 VHOST_OPS_DEBUG("vhost VQ %u ring restore failed: %d", idx, r); 1156 /* Connection to the backend is broken, so let's sync internal 1157 * last avail idx to the device used idx. 1158 */ 1159 virtio_queue_restore_last_avail_idx(vdev, idx); 1160 } else { 1161 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1162 } 1163 virtio_queue_invalidate_signalled_used(vdev, idx); 1164 virtio_queue_update_used_idx(vdev, idx); 1165 1166 /* In the cross-endian case, we need to reset the vring endianness to 1167 * native as legacy devices expect so by default. 1168 */ 1169 if (vhost_needs_vring_endian(vdev)) { 1170 vhost_virtqueue_set_vring_endian_legacy(dev, 1171 !virtio_is_big_endian(vdev), 1172 vhost_vq_index); 1173 } 1174 1175 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1176 1, virtio_queue_get_used_size(vdev, idx)); 1177 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1178 0, virtio_queue_get_avail_size(vdev, idx)); 1179 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1180 0, virtio_queue_get_desc_size(vdev, idx)); 1181 } 1182 1183 static void vhost_eventfd_add(MemoryListener *listener, 1184 MemoryRegionSection *section, 1185 bool match_data, uint64_t data, EventNotifier *e) 1186 { 1187 } 1188 1189 static void vhost_eventfd_del(MemoryListener *listener, 1190 MemoryRegionSection *section, 1191 bool match_data, uint64_t data, EventNotifier *e) 1192 { 1193 } 1194 1195 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1196 int n, uint32_t timeout) 1197 { 1198 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1199 struct vhost_vring_state state = { 1200 .index = vhost_vq_index, 1201 .num = timeout, 1202 }; 1203 int r; 1204 1205 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1206 return -EINVAL; 1207 } 1208 1209 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1210 if (r) { 1211 VHOST_OPS_DEBUG("vhost_set_vring_busyloop_timeout failed"); 1212 return r; 1213 } 1214 1215 return 0; 1216 } 1217 1218 static int vhost_virtqueue_init(struct vhost_dev *dev, 1219 struct vhost_virtqueue *vq, int n) 1220 { 1221 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1222 struct vhost_vring_file file = { 1223 .index = vhost_vq_index, 1224 }; 1225 int r = event_notifier_init(&vq->masked_notifier, 0); 1226 if (r < 0) { 1227 return r; 1228 } 1229 1230 file.fd = event_notifier_get_fd(&vq->masked_notifier); 1231 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1232 if (r) { 1233 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1234 r = -errno; 1235 goto fail_call; 1236 } 1237 1238 vq->dev = dev; 1239 1240 return 0; 1241 fail_call: 1242 event_notifier_cleanup(&vq->masked_notifier); 1243 return r; 1244 } 1245 1246 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1247 { 1248 event_notifier_cleanup(&vq->masked_notifier); 1249 } 1250 1251 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1252 VhostBackendType backend_type, uint32_t busyloop_timeout) 1253 { 1254 uint64_t features; 1255 int i, r, n_initialized_vqs = 0; 1256 Error *local_err = NULL; 1257 1258 hdev->vdev = NULL; 1259 hdev->migration_blocker = NULL; 1260 1261 r = vhost_set_backend_type(hdev, backend_type); 1262 assert(r >= 0); 1263 1264 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque); 1265 if (r < 0) { 1266 goto fail; 1267 } 1268 1269 r = hdev->vhost_ops->vhost_set_owner(hdev); 1270 if (r < 0) { 1271 VHOST_OPS_DEBUG("vhost_set_owner failed"); 1272 goto fail; 1273 } 1274 1275 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1276 if (r < 0) { 1277 VHOST_OPS_DEBUG("vhost_get_features failed"); 1278 goto fail; 1279 } 1280 1281 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1282 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1283 if (r < 0) { 1284 goto fail; 1285 } 1286 } 1287 1288 if (busyloop_timeout) { 1289 for (i = 0; i < hdev->nvqs; ++i) { 1290 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1291 busyloop_timeout); 1292 if (r < 0) { 1293 goto fail_busyloop; 1294 } 1295 } 1296 } 1297 1298 hdev->features = features; 1299 1300 hdev->memory_listener = (MemoryListener) { 1301 .begin = vhost_begin, 1302 .commit = vhost_commit, 1303 .region_add = vhost_region_addnop, 1304 .region_nop = vhost_region_addnop, 1305 .log_start = vhost_log_start, 1306 .log_stop = vhost_log_stop, 1307 .log_sync = vhost_log_sync, 1308 .log_global_start = vhost_log_global_start, 1309 .log_global_stop = vhost_log_global_stop, 1310 .eventfd_add = vhost_eventfd_add, 1311 .eventfd_del = vhost_eventfd_del, 1312 .priority = 10 1313 }; 1314 1315 hdev->iommu_listener = (MemoryListener) { 1316 .region_add = vhost_iommu_region_add, 1317 .region_del = vhost_iommu_region_del, 1318 }; 1319 1320 if (hdev->migration_blocker == NULL) { 1321 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1322 error_setg(&hdev->migration_blocker, 1323 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1324 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) { 1325 error_setg(&hdev->migration_blocker, 1326 "Migration disabled: failed to allocate shared memory"); 1327 } 1328 } 1329 1330 if (hdev->migration_blocker != NULL) { 1331 r = migrate_add_blocker(hdev->migration_blocker, &local_err); 1332 if (local_err) { 1333 error_report_err(local_err); 1334 error_free(hdev->migration_blocker); 1335 goto fail_busyloop; 1336 } 1337 } 1338 1339 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1340 hdev->n_mem_sections = 0; 1341 hdev->mem_sections = NULL; 1342 hdev->log = NULL; 1343 hdev->log_size = 0; 1344 hdev->log_enabled = false; 1345 hdev->started = false; 1346 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1347 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1348 1349 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1350 error_report("vhost backend memory slots limit is less" 1351 " than current number of present memory slots"); 1352 r = -1; 1353 if (busyloop_timeout) { 1354 goto fail_busyloop; 1355 } else { 1356 goto fail; 1357 } 1358 } 1359 1360 return 0; 1361 1362 fail_busyloop: 1363 while (--i >= 0) { 1364 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1365 } 1366 fail: 1367 hdev->nvqs = n_initialized_vqs; 1368 vhost_dev_cleanup(hdev); 1369 return r; 1370 } 1371 1372 void vhost_dev_cleanup(struct vhost_dev *hdev) 1373 { 1374 int i; 1375 1376 for (i = 0; i < hdev->nvqs; ++i) { 1377 vhost_virtqueue_cleanup(hdev->vqs + i); 1378 } 1379 if (hdev->mem) { 1380 /* those are only safe after successful init */ 1381 memory_listener_unregister(&hdev->memory_listener); 1382 QLIST_REMOVE(hdev, entry); 1383 } 1384 if (hdev->migration_blocker) { 1385 migrate_del_blocker(hdev->migration_blocker); 1386 error_free(hdev->migration_blocker); 1387 } 1388 g_free(hdev->mem); 1389 g_free(hdev->mem_sections); 1390 if (hdev->vhost_ops) { 1391 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1392 } 1393 assert(!hdev->log); 1394 1395 memset(hdev, 0, sizeof(struct vhost_dev)); 1396 } 1397 1398 /* Stop processing guest IO notifications in qemu. 1399 * Start processing them in vhost in kernel. 1400 */ 1401 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1402 { 1403 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1404 int i, r, e; 1405 1406 /* We will pass the notifiers to the kernel, make sure that QEMU 1407 * doesn't interfere. 1408 */ 1409 r = virtio_device_grab_ioeventfd(vdev); 1410 if (r < 0) { 1411 error_report("binding does not support host notifiers"); 1412 goto fail; 1413 } 1414 1415 for (i = 0; i < hdev->nvqs; ++i) { 1416 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1417 true); 1418 if (r < 0) { 1419 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1420 goto fail_vq; 1421 } 1422 } 1423 1424 return 0; 1425 fail_vq: 1426 while (--i >= 0) { 1427 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1428 false); 1429 if (e < 0) { 1430 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1431 } 1432 assert (e >= 0); 1433 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1434 } 1435 virtio_device_release_ioeventfd(vdev); 1436 fail: 1437 return r; 1438 } 1439 1440 /* Stop processing guest IO notifications in vhost. 1441 * Start processing them in qemu. 1442 * This might actually run the qemu handlers right away, 1443 * so virtio in qemu must be completely setup when this is called. 1444 */ 1445 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1446 { 1447 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1448 int i, r; 1449 1450 for (i = 0; i < hdev->nvqs; ++i) { 1451 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1452 false); 1453 if (r < 0) { 1454 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1455 } 1456 assert (r >= 0); 1457 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1458 } 1459 virtio_device_release_ioeventfd(vdev); 1460 } 1461 1462 /* Test and clear event pending status. 1463 * Should be called after unmask to avoid losing events. 1464 */ 1465 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1466 { 1467 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1468 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1469 return event_notifier_test_and_clear(&vq->masked_notifier); 1470 } 1471 1472 /* Mask/unmask events from this vq. */ 1473 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1474 bool mask) 1475 { 1476 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1477 int r, index = n - hdev->vq_index; 1478 struct vhost_vring_file file; 1479 1480 /* should only be called after backend is connected */ 1481 assert(hdev->vhost_ops); 1482 1483 if (mask) { 1484 assert(vdev->use_guest_notifier_mask); 1485 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1486 } else { 1487 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1488 } 1489 1490 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1491 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1492 if (r < 0) { 1493 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1494 } 1495 } 1496 1497 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1498 uint64_t features) 1499 { 1500 const int *bit = feature_bits; 1501 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1502 uint64_t bit_mask = (1ULL << *bit); 1503 if (!(hdev->features & bit_mask)) { 1504 features &= ~bit_mask; 1505 } 1506 bit++; 1507 } 1508 return features; 1509 } 1510 1511 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1512 uint64_t features) 1513 { 1514 const int *bit = feature_bits; 1515 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1516 uint64_t bit_mask = (1ULL << *bit); 1517 if (features & bit_mask) { 1518 hdev->acked_features |= bit_mask; 1519 } 1520 bit++; 1521 } 1522 } 1523 1524 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1525 uint32_t config_len) 1526 { 1527 assert(hdev->vhost_ops); 1528 1529 if (hdev->vhost_ops->vhost_get_config) { 1530 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len); 1531 } 1532 1533 return -1; 1534 } 1535 1536 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1537 uint32_t offset, uint32_t size, uint32_t flags) 1538 { 1539 assert(hdev->vhost_ops); 1540 1541 if (hdev->vhost_ops->vhost_set_config) { 1542 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1543 size, flags); 1544 } 1545 1546 return -1; 1547 } 1548 1549 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1550 const VhostDevConfigOps *ops) 1551 { 1552 hdev->config_ops = ops; 1553 } 1554 1555 void vhost_dev_free_inflight(struct vhost_inflight *inflight) 1556 { 1557 if (inflight && inflight->addr) { 1558 qemu_memfd_free(inflight->addr, inflight->size, inflight->fd); 1559 inflight->addr = NULL; 1560 inflight->fd = -1; 1561 } 1562 } 1563 1564 static int vhost_dev_resize_inflight(struct vhost_inflight *inflight, 1565 uint64_t new_size) 1566 { 1567 Error *err = NULL; 1568 int fd = -1; 1569 void *addr = qemu_memfd_alloc("vhost-inflight", new_size, 1570 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 1571 &fd, &err); 1572 1573 if (err) { 1574 error_report_err(err); 1575 return -1; 1576 } 1577 1578 vhost_dev_free_inflight(inflight); 1579 inflight->offset = 0; 1580 inflight->addr = addr; 1581 inflight->fd = fd; 1582 inflight->size = new_size; 1583 1584 return 0; 1585 } 1586 1587 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1588 { 1589 if (inflight->addr) { 1590 qemu_put_be64(f, inflight->size); 1591 qemu_put_be16(f, inflight->queue_size); 1592 qemu_put_buffer(f, inflight->addr, inflight->size); 1593 } else { 1594 qemu_put_be64(f, 0); 1595 } 1596 } 1597 1598 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f) 1599 { 1600 uint64_t size; 1601 1602 size = qemu_get_be64(f); 1603 if (!size) { 1604 return 0; 1605 } 1606 1607 if (inflight->size != size) { 1608 if (vhost_dev_resize_inflight(inflight, size)) { 1609 return -1; 1610 } 1611 } 1612 inflight->queue_size = qemu_get_be16(f); 1613 1614 qemu_get_buffer(f, inflight->addr, size); 1615 1616 return 0; 1617 } 1618 1619 int vhost_dev_set_inflight(struct vhost_dev *dev, 1620 struct vhost_inflight *inflight) 1621 { 1622 int r; 1623 1624 if (dev->vhost_ops->vhost_set_inflight_fd && inflight->addr) { 1625 r = dev->vhost_ops->vhost_set_inflight_fd(dev, inflight); 1626 if (r) { 1627 VHOST_OPS_DEBUG("vhost_set_inflight_fd failed"); 1628 return -errno; 1629 } 1630 } 1631 1632 return 0; 1633 } 1634 1635 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, 1636 struct vhost_inflight *inflight) 1637 { 1638 int r; 1639 1640 if (dev->vhost_ops->vhost_get_inflight_fd) { 1641 r = dev->vhost_ops->vhost_get_inflight_fd(dev, queue_size, inflight); 1642 if (r) { 1643 VHOST_OPS_DEBUG("vhost_get_inflight_fd failed"); 1644 return -errno; 1645 } 1646 } 1647 1648 return 0; 1649 } 1650 1651 /* Host notifiers must be enabled at this point. */ 1652 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1653 { 1654 int i, r; 1655 1656 /* should only be called after backend is connected */ 1657 assert(hdev->vhost_ops); 1658 1659 hdev->started = true; 1660 hdev->vdev = vdev; 1661 1662 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1663 if (r < 0) { 1664 goto fail_features; 1665 } 1666 1667 if (vhost_dev_has_iommu(hdev)) { 1668 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1669 } 1670 1671 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1672 if (r < 0) { 1673 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 1674 r = -errno; 1675 goto fail_mem; 1676 } 1677 for (i = 0; i < hdev->nvqs; ++i) { 1678 r = vhost_virtqueue_start(hdev, 1679 vdev, 1680 hdev->vqs + i, 1681 hdev->vq_index + i); 1682 if (r < 0) { 1683 goto fail_vq; 1684 } 1685 } 1686 1687 if (hdev->log_enabled) { 1688 uint64_t log_base; 1689 1690 hdev->log_size = vhost_get_log_size(hdev); 1691 hdev->log = vhost_log_get(hdev->log_size, 1692 vhost_dev_log_is_shared(hdev)); 1693 log_base = (uintptr_t)hdev->log->log; 1694 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1695 hdev->log_size ? log_base : 0, 1696 hdev->log); 1697 if (r < 0) { 1698 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 1699 r = -errno; 1700 goto fail_log; 1701 } 1702 } 1703 if (hdev->vhost_ops->vhost_dev_start) { 1704 r = hdev->vhost_ops->vhost_dev_start(hdev, true); 1705 if (r) { 1706 goto fail_log; 1707 } 1708 } 1709 if (vhost_dev_has_iommu(hdev) && 1710 hdev->vhost_ops->vhost_set_iotlb_callback) { 1711 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1712 1713 /* Update used ring information for IOTLB to work correctly, 1714 * vhost-kernel code requires for this.*/ 1715 for (i = 0; i < hdev->nvqs; ++i) { 1716 struct vhost_virtqueue *vq = hdev->vqs + i; 1717 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1718 } 1719 } 1720 return 0; 1721 fail_log: 1722 vhost_log_put(hdev, false); 1723 fail_vq: 1724 while (--i >= 0) { 1725 vhost_virtqueue_stop(hdev, 1726 vdev, 1727 hdev->vqs + i, 1728 hdev->vq_index + i); 1729 } 1730 1731 fail_mem: 1732 fail_features: 1733 1734 hdev->started = false; 1735 return r; 1736 } 1737 1738 /* Host notifiers must be enabled at this point. */ 1739 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1740 { 1741 int i; 1742 1743 /* should only be called after backend is connected */ 1744 assert(hdev->vhost_ops); 1745 1746 if (hdev->vhost_ops->vhost_dev_start) { 1747 hdev->vhost_ops->vhost_dev_start(hdev, false); 1748 } 1749 for (i = 0; i < hdev->nvqs; ++i) { 1750 vhost_virtqueue_stop(hdev, 1751 vdev, 1752 hdev->vqs + i, 1753 hdev->vq_index + i); 1754 } 1755 1756 if (vhost_dev_has_iommu(hdev)) { 1757 if (hdev->vhost_ops->vhost_set_iotlb_callback) { 1758 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1759 } 1760 memory_listener_unregister(&hdev->iommu_listener); 1761 } 1762 vhost_log_put(hdev, true); 1763 hdev->started = false; 1764 hdev->vdev = NULL; 1765 } 1766 1767 int vhost_net_set_backend(struct vhost_dev *hdev, 1768 struct vhost_vring_file *file) 1769 { 1770 if (hdev->vhost_ops->vhost_net_set_backend) { 1771 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1772 } 1773 1774 return -1; 1775 } 1776