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