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 "hw/hw.h" 20 #include "qemu/atomic.h" 21 #include "qemu/range.h" 22 #include "qemu/error-report.h" 23 #include "qemu/memfd.h" 24 #include <linux/vhost.h> 25 #include "exec/address-spaces.h" 26 #include "hw/virtio/virtio-bus.h" 27 #include "hw/virtio/virtio-access.h" 28 #include "migration/blocker.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 vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys, 135 range_get_last(vq->used_phys, vq->used_size)); 136 } 137 return 0; 138 } 139 140 static void vhost_log_sync(MemoryListener *listener, 141 MemoryRegionSection *section) 142 { 143 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 144 memory_listener); 145 vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); 146 } 147 148 static void vhost_log_sync_range(struct vhost_dev *dev, 149 hwaddr first, hwaddr last) 150 { 151 int i; 152 /* FIXME: this is N^2 in number of sections */ 153 for (i = 0; i < dev->n_mem_sections; ++i) { 154 MemoryRegionSection *section = &dev->mem_sections[i]; 155 vhost_sync_dirty_bitmap(dev, section, first, last); 156 } 157 } 158 159 static uint64_t vhost_get_log_size(struct vhost_dev *dev) 160 { 161 uint64_t log_size = 0; 162 int i; 163 for (i = 0; i < dev->mem->nregions; ++i) { 164 struct vhost_memory_region *reg = dev->mem->regions + i; 165 uint64_t last = range_get_last(reg->guest_phys_addr, 166 reg->memory_size); 167 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 168 } 169 for (i = 0; i < dev->nvqs; ++i) { 170 struct vhost_virtqueue *vq = dev->vqs + i; 171 uint64_t last = vq->used_phys + vq->used_size - 1; 172 log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); 173 } 174 return log_size; 175 } 176 177 static struct vhost_log *vhost_log_alloc(uint64_t size, bool share) 178 { 179 Error *err = NULL; 180 struct vhost_log *log; 181 uint64_t logsize = size * sizeof(*(log->log)); 182 int fd = -1; 183 184 log = g_new0(struct vhost_log, 1); 185 if (share) { 186 log->log = qemu_memfd_alloc("vhost-log", logsize, 187 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, 188 &fd, &err); 189 if (err) { 190 error_report_err(err); 191 g_free(log); 192 return NULL; 193 } 194 memset(log->log, 0, logsize); 195 } else { 196 log->log = g_malloc0(logsize); 197 } 198 199 log->size = size; 200 log->refcnt = 1; 201 log->fd = fd; 202 203 return log; 204 } 205 206 static struct vhost_log *vhost_log_get(uint64_t size, bool share) 207 { 208 struct vhost_log *log = share ? vhost_log_shm : vhost_log; 209 210 if (!log || log->size != size) { 211 log = vhost_log_alloc(size, share); 212 if (share) { 213 vhost_log_shm = log; 214 } else { 215 vhost_log = log; 216 } 217 } else { 218 ++log->refcnt; 219 } 220 221 return log; 222 } 223 224 static void vhost_log_put(struct vhost_dev *dev, bool sync) 225 { 226 struct vhost_log *log = dev->log; 227 228 if (!log) { 229 return; 230 } 231 232 --log->refcnt; 233 if (log->refcnt == 0) { 234 /* Sync only the range covered by the old log */ 235 if (dev->log_size && sync) { 236 vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); 237 } 238 239 if (vhost_log == log) { 240 g_free(log->log); 241 vhost_log = NULL; 242 } else if (vhost_log_shm == log) { 243 qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), 244 log->fd); 245 vhost_log_shm = NULL; 246 } 247 248 g_free(log); 249 } 250 251 dev->log = NULL; 252 dev->log_size = 0; 253 } 254 255 static bool vhost_dev_log_is_shared(struct vhost_dev *dev) 256 { 257 return dev->vhost_ops->vhost_requires_shm_log && 258 dev->vhost_ops->vhost_requires_shm_log(dev); 259 } 260 261 static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 262 { 263 struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); 264 uint64_t log_base = (uintptr_t)log->log; 265 int r; 266 267 /* inform backend of log switching, this must be done before 268 releasing the current log, to ensure no logging is lost */ 269 r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); 270 if (r < 0) { 271 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 272 } 273 274 vhost_log_put(dev, true); 275 dev->log = log; 276 dev->log_size = size; 277 } 278 279 static int vhost_dev_has_iommu(struct vhost_dev *dev) 280 { 281 VirtIODevice *vdev = dev->vdev; 282 283 return virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); 284 } 285 286 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, 287 hwaddr *plen, int is_write) 288 { 289 if (!vhost_dev_has_iommu(dev)) { 290 return cpu_physical_memory_map(addr, plen, is_write); 291 } else { 292 return (void *)(uintptr_t)addr; 293 } 294 } 295 296 static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, 297 hwaddr len, int is_write, 298 hwaddr access_len) 299 { 300 if (!vhost_dev_has_iommu(dev)) { 301 cpu_physical_memory_unmap(buffer, len, is_write, access_len); 302 } 303 } 304 305 static int vhost_verify_ring_part_mapping(void *ring_hva, 306 uint64_t ring_gpa, 307 uint64_t ring_size, 308 void *reg_hva, 309 uint64_t reg_gpa, 310 uint64_t reg_size) 311 { 312 uint64_t hva_ring_offset; 313 uint64_t ring_last = range_get_last(ring_gpa, ring_size); 314 uint64_t reg_last = range_get_last(reg_gpa, reg_size); 315 316 if (ring_last < reg_gpa || ring_gpa > reg_last) { 317 return 0; 318 } 319 /* check that whole ring's is mapped */ 320 if (ring_last > reg_last) { 321 return -ENOMEM; 322 } 323 /* check that ring's MemoryRegion wasn't replaced */ 324 hva_ring_offset = ring_gpa - reg_gpa; 325 if (ring_hva != reg_hva + hva_ring_offset) { 326 return -EBUSY; 327 } 328 329 return 0; 330 } 331 332 static int vhost_verify_ring_mappings(struct vhost_dev *dev, 333 void *reg_hva, 334 uint64_t reg_gpa, 335 uint64_t reg_size) 336 { 337 int i, j; 338 int r = 0; 339 const char *part_name[] = { 340 "descriptor table", 341 "available ring", 342 "used ring" 343 }; 344 345 if (vhost_dev_has_iommu(dev)) { 346 return 0; 347 } 348 349 for (i = 0; i < dev->nvqs; ++i) { 350 struct vhost_virtqueue *vq = dev->vqs + i; 351 352 if (vq->desc_phys == 0) { 353 continue; 354 } 355 356 j = 0; 357 r = vhost_verify_ring_part_mapping( 358 vq->desc, vq->desc_phys, vq->desc_size, 359 reg_hva, reg_gpa, reg_size); 360 if (r) { 361 break; 362 } 363 364 j++; 365 r = vhost_verify_ring_part_mapping( 366 vq->avail, vq->avail_phys, vq->avail_size, 367 reg_hva, reg_gpa, reg_size); 368 if (r) { 369 break; 370 } 371 372 j++; 373 r = vhost_verify_ring_part_mapping( 374 vq->used, vq->used_phys, vq->used_size, 375 reg_hva, reg_gpa, reg_size); 376 if (r) { 377 break; 378 } 379 } 380 381 if (r == -ENOMEM) { 382 error_report("Unable to map %s for ring %d", part_name[j], i); 383 } else if (r == -EBUSY) { 384 error_report("%s relocated for ring %d", part_name[j], i); 385 } 386 return r; 387 } 388 389 static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section) 390 { 391 bool result; 392 bool log_dirty = memory_region_get_dirty_log_mask(section->mr) & 393 ~(1 << DIRTY_MEMORY_MIGRATION); 394 result = memory_region_is_ram(section->mr) && 395 !memory_region_is_rom(section->mr); 396 397 /* Vhost doesn't handle any block which is doing dirty-tracking other 398 * than migration; this typically fires on VGA areas. 399 */ 400 result &= !log_dirty; 401 402 if (result && dev->vhost_ops->vhost_backend_mem_section_filter) { 403 result &= 404 dev->vhost_ops->vhost_backend_mem_section_filter(dev, section); 405 } 406 407 trace_vhost_section(section->mr->name, result); 408 return result; 409 } 410 411 static void vhost_begin(MemoryListener *listener) 412 { 413 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 414 memory_listener); 415 dev->tmp_sections = NULL; 416 dev->n_tmp_sections = 0; 417 } 418 419 static void vhost_commit(MemoryListener *listener) 420 { 421 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 422 memory_listener); 423 MemoryRegionSection *old_sections; 424 int n_old_sections; 425 uint64_t log_size; 426 size_t regions_size; 427 int r; 428 int i; 429 bool changed = false; 430 431 /* Note we can be called before the device is started, but then 432 * starting the device calls set_mem_table, so we need to have 433 * built the data structures. 434 */ 435 old_sections = dev->mem_sections; 436 n_old_sections = dev->n_mem_sections; 437 dev->mem_sections = dev->tmp_sections; 438 dev->n_mem_sections = dev->n_tmp_sections; 439 440 if (dev->n_mem_sections != n_old_sections) { 441 changed = true; 442 } else { 443 /* Same size, lets check the contents */ 444 changed = n_old_sections && memcmp(dev->mem_sections, old_sections, 445 n_old_sections * sizeof(old_sections[0])) != 0; 446 } 447 448 trace_vhost_commit(dev->started, changed); 449 if (!changed) { 450 goto out; 451 } 452 453 /* Rebuild the regions list from the new sections list */ 454 regions_size = offsetof(struct vhost_memory, regions) + 455 dev->n_mem_sections * sizeof dev->mem->regions[0]; 456 dev->mem = g_realloc(dev->mem, regions_size); 457 dev->mem->nregions = dev->n_mem_sections; 458 used_memslots = dev->mem->nregions; 459 for (i = 0; i < dev->n_mem_sections; i++) { 460 struct vhost_memory_region *cur_vmr = dev->mem->regions + i; 461 struct MemoryRegionSection *mrs = dev->mem_sections + i; 462 463 cur_vmr->guest_phys_addr = mrs->offset_within_address_space; 464 cur_vmr->memory_size = int128_get64(mrs->size); 465 cur_vmr->userspace_addr = 466 (uintptr_t)memory_region_get_ram_ptr(mrs->mr) + 467 mrs->offset_within_region; 468 cur_vmr->flags_padding = 0; 469 } 470 471 if (!dev->started) { 472 goto out; 473 } 474 475 for (i = 0; i < dev->mem->nregions; i++) { 476 if (vhost_verify_ring_mappings(dev, 477 (void *)(uintptr_t)dev->mem->regions[i].userspace_addr, 478 dev->mem->regions[i].guest_phys_addr, 479 dev->mem->regions[i].memory_size)) { 480 error_report("Verify ring failure on region %d", i); 481 abort(); 482 } 483 } 484 485 if (!dev->log_enabled) { 486 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 487 if (r < 0) { 488 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 489 } 490 goto out; 491 } 492 log_size = vhost_get_log_size(dev); 493 /* We allocate an extra 4K bytes to log, 494 * to reduce the * number of reallocations. */ 495 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) 496 /* To log more, must increase log size before table update. */ 497 if (dev->log_size < log_size) { 498 vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); 499 } 500 r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); 501 if (r < 0) { 502 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 503 } 504 /* To log less, can only decrease log size after table update. */ 505 if (dev->log_size > log_size + VHOST_LOG_BUFFER) { 506 vhost_dev_log_resize(dev, log_size); 507 } 508 509 out: 510 /* Deref the old list of sections, this must happen _after_ the 511 * vhost_set_mem_table to ensure the client isn't still using the 512 * section we're about to unref. 513 */ 514 while (n_old_sections--) { 515 memory_region_unref(old_sections[n_old_sections].mr); 516 } 517 g_free(old_sections); 518 return; 519 } 520 521 /* Adds the section data to the tmp_section structure. 522 * It relies on the listener calling us in memory address order 523 * and for each region (via the _add and _nop methods) to 524 * join neighbours. 525 */ 526 static void vhost_region_add_section(struct vhost_dev *dev, 527 MemoryRegionSection *section) 528 { 529 bool need_add = true; 530 uint64_t mrs_size = int128_get64(section->size); 531 uint64_t mrs_gpa = section->offset_within_address_space; 532 uintptr_t mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) + 533 section->offset_within_region; 534 RAMBlock *mrs_rb = section->mr->ram_block; 535 size_t mrs_page = qemu_ram_pagesize(mrs_rb); 536 537 trace_vhost_region_add_section(section->mr->name, mrs_gpa, mrs_size, 538 mrs_host); 539 540 /* Round the section to it's page size */ 541 /* First align the start down to a page boundary */ 542 uint64_t alignage = mrs_host & (mrs_page - 1); 543 if (alignage) { 544 mrs_host -= alignage; 545 mrs_size += alignage; 546 mrs_gpa -= alignage; 547 } 548 /* Now align the size up to a page boundary */ 549 alignage = mrs_size & (mrs_page - 1); 550 if (alignage) { 551 mrs_size += mrs_page - alignage; 552 } 553 trace_vhost_region_add_section_aligned(section->mr->name, mrs_gpa, mrs_size, 554 mrs_host); 555 556 if (dev->n_tmp_sections) { 557 /* Since we already have at least one section, lets see if 558 * this extends it; since we're scanning in order, we only 559 * have to look at the last one, and the FlatView that calls 560 * us shouldn't have overlaps. 561 */ 562 MemoryRegionSection *prev_sec = dev->tmp_sections + 563 (dev->n_tmp_sections - 1); 564 uint64_t prev_gpa_start = prev_sec->offset_within_address_space; 565 uint64_t prev_size = int128_get64(prev_sec->size); 566 uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size); 567 uint64_t prev_host_start = 568 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) + 569 prev_sec->offset_within_region; 570 uint64_t prev_host_end = range_get_last(prev_host_start, prev_size); 571 572 if (mrs_gpa <= (prev_gpa_end + 1)) { 573 /* OK, looks like overlapping/intersecting - it's possible that 574 * the rounding to page sizes has made them overlap, but they should 575 * match up in the same RAMBlock if they do. 576 */ 577 if (mrs_gpa < prev_gpa_start) { 578 error_report("%s:Section rounded to %"PRIx64 579 " prior to previous %"PRIx64, 580 __func__, mrs_gpa, prev_gpa_start); 581 /* A way to cleanly fail here would be better */ 582 return; 583 } 584 /* Offset from the start of the previous GPA to this GPA */ 585 size_t offset = mrs_gpa - prev_gpa_start; 586 587 if (prev_host_start + offset == mrs_host && 588 section->mr == prev_sec->mr && 589 (!dev->vhost_ops->vhost_backend_can_merge || 590 dev->vhost_ops->vhost_backend_can_merge(dev, 591 mrs_host, mrs_size, 592 prev_host_start, prev_size))) { 593 uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size); 594 need_add = false; 595 prev_sec->offset_within_address_space = 596 MIN(prev_gpa_start, mrs_gpa); 597 prev_sec->offset_within_region = 598 MIN(prev_host_start, mrs_host) - 599 (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr); 600 prev_sec->size = int128_make64(max_end - MIN(prev_host_start, 601 mrs_host)); 602 trace_vhost_region_add_section_merge(section->mr->name, 603 int128_get64(prev_sec->size), 604 prev_sec->offset_within_address_space, 605 prev_sec->offset_within_region); 606 } else { 607 /* adjoining regions are fine, but overlapping ones with 608 * different blocks/offsets shouldn't happen 609 */ 610 if (mrs_gpa != prev_gpa_end + 1) { 611 error_report("%s: Overlapping but not coherent sections " 612 "at %"PRIx64, 613 __func__, mrs_gpa); 614 return; 615 } 616 } 617 } 618 } 619 620 if (need_add) { 621 ++dev->n_tmp_sections; 622 dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections, 623 dev->n_tmp_sections); 624 dev->tmp_sections[dev->n_tmp_sections - 1] = *section; 625 /* The flatview isn't stable and we don't use it, making it NULL 626 * means we can memcmp the list. 627 */ 628 dev->tmp_sections[dev->n_tmp_sections - 1].fv = NULL; 629 memory_region_ref(section->mr); 630 } 631 } 632 633 /* Used for both add and nop callbacks */ 634 static void vhost_region_addnop(MemoryListener *listener, 635 MemoryRegionSection *section) 636 { 637 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 638 memory_listener); 639 640 if (!vhost_section(dev, section)) { 641 return; 642 } 643 vhost_region_add_section(dev, section); 644 } 645 646 static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) 647 { 648 struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n); 649 struct vhost_dev *hdev = iommu->hdev; 650 hwaddr iova = iotlb->iova + iommu->iommu_offset; 651 652 if (vhost_backend_invalidate_device_iotlb(hdev, iova, 653 iotlb->addr_mask + 1)) { 654 error_report("Fail to invalidate device iotlb"); 655 } 656 } 657 658 static void vhost_iommu_region_add(MemoryListener *listener, 659 MemoryRegionSection *section) 660 { 661 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 662 iommu_listener); 663 struct vhost_iommu *iommu; 664 Int128 end; 665 int iommu_idx; 666 IOMMUMemoryRegion *iommu_mr; 667 668 if (!memory_region_is_iommu(section->mr)) { 669 return; 670 } 671 672 iommu_mr = IOMMU_MEMORY_REGION(section->mr); 673 674 iommu = g_malloc0(sizeof(*iommu)); 675 end = int128_add(int128_make64(section->offset_within_region), 676 section->size); 677 end = int128_sub(end, int128_one()); 678 iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr, 679 MEMTXATTRS_UNSPECIFIED); 680 iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, 681 IOMMU_NOTIFIER_UNMAP, 682 section->offset_within_region, 683 int128_get64(end), 684 iommu_idx); 685 iommu->mr = section->mr; 686 iommu->iommu_offset = section->offset_within_address_space - 687 section->offset_within_region; 688 iommu->hdev = dev; 689 memory_region_register_iommu_notifier(section->mr, &iommu->n); 690 QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next); 691 /* TODO: can replay help performance here? */ 692 } 693 694 static void vhost_iommu_region_del(MemoryListener *listener, 695 MemoryRegionSection *section) 696 { 697 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 698 iommu_listener); 699 struct vhost_iommu *iommu; 700 701 if (!memory_region_is_iommu(section->mr)) { 702 return; 703 } 704 705 QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) { 706 if (iommu->mr == section->mr && 707 iommu->n.start == section->offset_within_region) { 708 memory_region_unregister_iommu_notifier(iommu->mr, 709 &iommu->n); 710 QLIST_REMOVE(iommu, iommu_next); 711 g_free(iommu); 712 break; 713 } 714 } 715 } 716 717 static int vhost_virtqueue_set_addr(struct vhost_dev *dev, 718 struct vhost_virtqueue *vq, 719 unsigned idx, bool enable_log) 720 { 721 struct vhost_vring_addr addr = { 722 .index = idx, 723 .desc_user_addr = (uint64_t)(unsigned long)vq->desc, 724 .avail_user_addr = (uint64_t)(unsigned long)vq->avail, 725 .used_user_addr = (uint64_t)(unsigned long)vq->used, 726 .log_guest_addr = vq->used_phys, 727 .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, 728 }; 729 int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr); 730 if (r < 0) { 731 VHOST_OPS_DEBUG("vhost_set_vring_addr failed"); 732 return -errno; 733 } 734 return 0; 735 } 736 737 static int vhost_dev_set_features(struct vhost_dev *dev, 738 bool enable_log) 739 { 740 uint64_t features = dev->acked_features; 741 int r; 742 if (enable_log) { 743 features |= 0x1ULL << VHOST_F_LOG_ALL; 744 } 745 r = dev->vhost_ops->vhost_set_features(dev, features); 746 if (r < 0) { 747 VHOST_OPS_DEBUG("vhost_set_features failed"); 748 } 749 return r < 0 ? -errno : 0; 750 } 751 752 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) 753 { 754 int r, i, idx; 755 r = vhost_dev_set_features(dev, enable_log); 756 if (r < 0) { 757 goto err_features; 758 } 759 for (i = 0; i < dev->nvqs; ++i) { 760 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 761 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 762 enable_log); 763 if (r < 0) { 764 goto err_vq; 765 } 766 } 767 return 0; 768 err_vq: 769 for (; i >= 0; --i) { 770 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); 771 vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, 772 dev->log_enabled); 773 } 774 vhost_dev_set_features(dev, dev->log_enabled); 775 err_features: 776 return r; 777 } 778 779 static int vhost_migration_log(MemoryListener *listener, int enable) 780 { 781 struct vhost_dev *dev = container_of(listener, struct vhost_dev, 782 memory_listener); 783 int r; 784 if (!!enable == dev->log_enabled) { 785 return 0; 786 } 787 if (!dev->started) { 788 dev->log_enabled = enable; 789 return 0; 790 } 791 if (!enable) { 792 r = vhost_dev_set_log(dev, false); 793 if (r < 0) { 794 return r; 795 } 796 vhost_log_put(dev, false); 797 } else { 798 vhost_dev_log_resize(dev, vhost_get_log_size(dev)); 799 r = vhost_dev_set_log(dev, true); 800 if (r < 0) { 801 return r; 802 } 803 } 804 dev->log_enabled = enable; 805 return 0; 806 } 807 808 static void vhost_log_global_start(MemoryListener *listener) 809 { 810 int r; 811 812 r = vhost_migration_log(listener, true); 813 if (r < 0) { 814 abort(); 815 } 816 } 817 818 static void vhost_log_global_stop(MemoryListener *listener) 819 { 820 int r; 821 822 r = vhost_migration_log(listener, false); 823 if (r < 0) { 824 abort(); 825 } 826 } 827 828 static void vhost_log_start(MemoryListener *listener, 829 MemoryRegionSection *section, 830 int old, int new) 831 { 832 /* FIXME: implement */ 833 } 834 835 static void vhost_log_stop(MemoryListener *listener, 836 MemoryRegionSection *section, 837 int old, int new) 838 { 839 /* FIXME: implement */ 840 } 841 842 /* The vhost driver natively knows how to handle the vrings of non 843 * cross-endian legacy devices and modern devices. Only legacy devices 844 * exposed to a bi-endian guest may require the vhost driver to use a 845 * specific endianness. 846 */ 847 static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) 848 { 849 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 850 return false; 851 } 852 #ifdef HOST_WORDS_BIGENDIAN 853 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; 854 #else 855 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 856 #endif 857 } 858 859 static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, 860 bool is_big_endian, 861 int vhost_vq_index) 862 { 863 struct vhost_vring_state s = { 864 .index = vhost_vq_index, 865 .num = is_big_endian 866 }; 867 868 if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { 869 return 0; 870 } 871 872 VHOST_OPS_DEBUG("vhost_set_vring_endian failed"); 873 if (errno == ENOTTY) { 874 error_report("vhost does not support cross-endian"); 875 return -ENOSYS; 876 } 877 878 return -errno; 879 } 880 881 static int vhost_memory_region_lookup(struct vhost_dev *hdev, 882 uint64_t gpa, uint64_t *uaddr, 883 uint64_t *len) 884 { 885 int i; 886 887 for (i = 0; i < hdev->mem->nregions; i++) { 888 struct vhost_memory_region *reg = hdev->mem->regions + i; 889 890 if (gpa >= reg->guest_phys_addr && 891 reg->guest_phys_addr + reg->memory_size > gpa) { 892 *uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr; 893 *len = reg->guest_phys_addr + reg->memory_size - gpa; 894 return 0; 895 } 896 } 897 898 return -EFAULT; 899 } 900 901 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write) 902 { 903 IOMMUTLBEntry iotlb; 904 uint64_t uaddr, len; 905 int ret = -EFAULT; 906 907 rcu_read_lock(); 908 909 trace_vhost_iotlb_miss(dev, 1); 910 911 iotlb = address_space_get_iotlb_entry(dev->vdev->dma_as, 912 iova, write, 913 MEMTXATTRS_UNSPECIFIED); 914 if (iotlb.target_as != NULL) { 915 ret = vhost_memory_region_lookup(dev, iotlb.translated_addr, 916 &uaddr, &len); 917 if (ret) { 918 trace_vhost_iotlb_miss(dev, 3); 919 error_report("Fail to lookup the translated address " 920 "%"PRIx64, iotlb.translated_addr); 921 goto out; 922 } 923 924 len = MIN(iotlb.addr_mask + 1, len); 925 iova = iova & ~iotlb.addr_mask; 926 927 ret = vhost_backend_update_device_iotlb(dev, iova, uaddr, 928 len, iotlb.perm); 929 if (ret) { 930 trace_vhost_iotlb_miss(dev, 4); 931 error_report("Fail to update device iotlb"); 932 goto out; 933 } 934 } 935 936 trace_vhost_iotlb_miss(dev, 2); 937 938 out: 939 rcu_read_unlock(); 940 941 return ret; 942 } 943 944 static int vhost_virtqueue_start(struct vhost_dev *dev, 945 struct VirtIODevice *vdev, 946 struct vhost_virtqueue *vq, 947 unsigned idx) 948 { 949 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 950 VirtioBusState *vbus = VIRTIO_BUS(qbus); 951 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); 952 hwaddr s, l, a; 953 int r; 954 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 955 struct vhost_vring_file file = { 956 .index = vhost_vq_index 957 }; 958 struct vhost_vring_state state = { 959 .index = vhost_vq_index 960 }; 961 struct VirtQueue *vvq = virtio_get_queue(vdev, idx); 962 963 a = virtio_queue_get_desc_addr(vdev, idx); 964 if (a == 0) { 965 /* Queue might not be ready for start */ 966 return 0; 967 } 968 969 vq->num = state.num = virtio_queue_get_num(vdev, idx); 970 r = dev->vhost_ops->vhost_set_vring_num(dev, &state); 971 if (r) { 972 VHOST_OPS_DEBUG("vhost_set_vring_num failed"); 973 return -errno; 974 } 975 976 state.num = virtio_queue_get_last_avail_idx(vdev, idx); 977 r = dev->vhost_ops->vhost_set_vring_base(dev, &state); 978 if (r) { 979 VHOST_OPS_DEBUG("vhost_set_vring_base failed"); 980 return -errno; 981 } 982 983 if (vhost_needs_vring_endian(vdev)) { 984 r = vhost_virtqueue_set_vring_endian_legacy(dev, 985 virtio_is_big_endian(vdev), 986 vhost_vq_index); 987 if (r) { 988 return -errno; 989 } 990 } 991 992 vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); 993 vq->desc_phys = a; 994 vq->desc = vhost_memory_map(dev, a, &l, 0); 995 if (!vq->desc || l != s) { 996 r = -ENOMEM; 997 goto fail_alloc_desc; 998 } 999 vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx); 1000 vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx); 1001 vq->avail = vhost_memory_map(dev, a, &l, 0); 1002 if (!vq->avail || l != s) { 1003 r = -ENOMEM; 1004 goto fail_alloc_avail; 1005 } 1006 vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); 1007 vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); 1008 vq->used = vhost_memory_map(dev, a, &l, 1); 1009 if (!vq->used || l != s) { 1010 r = -ENOMEM; 1011 goto fail_alloc_used; 1012 } 1013 1014 r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); 1015 if (r < 0) { 1016 r = -errno; 1017 goto fail_alloc; 1018 } 1019 1020 file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); 1021 r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); 1022 if (r) { 1023 VHOST_OPS_DEBUG("vhost_set_vring_kick failed"); 1024 r = -errno; 1025 goto fail_kick; 1026 } 1027 1028 /* Clear and discard previous events if any. */ 1029 event_notifier_test_and_clear(&vq->masked_notifier); 1030 1031 /* Init vring in unmasked state, unless guest_notifier_mask 1032 * will do it later. 1033 */ 1034 if (!vdev->use_guest_notifier_mask) { 1035 /* TODO: check and handle errors. */ 1036 vhost_virtqueue_mask(dev, vdev, idx, false); 1037 } 1038 1039 if (k->query_guest_notifiers && 1040 k->query_guest_notifiers(qbus->parent) && 1041 virtio_queue_vector(vdev, idx) == VIRTIO_NO_VECTOR) { 1042 file.fd = -1; 1043 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1044 if (r) { 1045 goto fail_vector; 1046 } 1047 } 1048 1049 return 0; 1050 1051 fail_vector: 1052 fail_kick: 1053 fail_alloc: 1054 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1055 0, 0); 1056 fail_alloc_used: 1057 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1058 0, 0); 1059 fail_alloc_avail: 1060 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1061 0, 0); 1062 fail_alloc_desc: 1063 return r; 1064 } 1065 1066 static void vhost_virtqueue_stop(struct vhost_dev *dev, 1067 struct VirtIODevice *vdev, 1068 struct vhost_virtqueue *vq, 1069 unsigned idx) 1070 { 1071 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); 1072 struct vhost_vring_state state = { 1073 .index = vhost_vq_index, 1074 }; 1075 int r; 1076 1077 if (virtio_queue_get_desc_addr(vdev, idx) == 0) { 1078 /* Don't stop the virtqueue which might have not been started */ 1079 return; 1080 } 1081 1082 r = dev->vhost_ops->vhost_get_vring_base(dev, &state); 1083 if (r < 0) { 1084 VHOST_OPS_DEBUG("vhost VQ %d ring restore failed: %d", idx, r); 1085 /* Connection to the backend is broken, so let's sync internal 1086 * last avail idx to the device used idx. 1087 */ 1088 virtio_queue_restore_last_avail_idx(vdev, idx); 1089 } else { 1090 virtio_queue_set_last_avail_idx(vdev, idx, state.num); 1091 } 1092 virtio_queue_invalidate_signalled_used(vdev, idx); 1093 virtio_queue_update_used_idx(vdev, idx); 1094 1095 /* In the cross-endian case, we need to reset the vring endianness to 1096 * native as legacy devices expect so by default. 1097 */ 1098 if (vhost_needs_vring_endian(vdev)) { 1099 vhost_virtqueue_set_vring_endian_legacy(dev, 1100 !virtio_is_big_endian(vdev), 1101 vhost_vq_index); 1102 } 1103 1104 vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx), 1105 1, virtio_queue_get_used_size(vdev, idx)); 1106 vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, idx), 1107 0, virtio_queue_get_avail_size(vdev, idx)); 1108 vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx), 1109 0, virtio_queue_get_desc_size(vdev, idx)); 1110 } 1111 1112 static void vhost_eventfd_add(MemoryListener *listener, 1113 MemoryRegionSection *section, 1114 bool match_data, uint64_t data, EventNotifier *e) 1115 { 1116 } 1117 1118 static void vhost_eventfd_del(MemoryListener *listener, 1119 MemoryRegionSection *section, 1120 bool match_data, uint64_t data, EventNotifier *e) 1121 { 1122 } 1123 1124 static int vhost_virtqueue_set_busyloop_timeout(struct vhost_dev *dev, 1125 int n, uint32_t timeout) 1126 { 1127 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1128 struct vhost_vring_state state = { 1129 .index = vhost_vq_index, 1130 .num = timeout, 1131 }; 1132 int r; 1133 1134 if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { 1135 return -EINVAL; 1136 } 1137 1138 r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); 1139 if (r) { 1140 VHOST_OPS_DEBUG("vhost_set_vring_busyloop_timeout failed"); 1141 return r; 1142 } 1143 1144 return 0; 1145 } 1146 1147 static int vhost_virtqueue_init(struct vhost_dev *dev, 1148 struct vhost_virtqueue *vq, int n) 1149 { 1150 int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); 1151 struct vhost_vring_file file = { 1152 .index = vhost_vq_index, 1153 }; 1154 int r = event_notifier_init(&vq->masked_notifier, 0); 1155 if (r < 0) { 1156 return r; 1157 } 1158 1159 file.fd = event_notifier_get_fd(&vq->masked_notifier); 1160 r = dev->vhost_ops->vhost_set_vring_call(dev, &file); 1161 if (r) { 1162 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1163 r = -errno; 1164 goto fail_call; 1165 } 1166 1167 vq->dev = dev; 1168 1169 return 0; 1170 fail_call: 1171 event_notifier_cleanup(&vq->masked_notifier); 1172 return r; 1173 } 1174 1175 static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 1176 { 1177 event_notifier_cleanup(&vq->masked_notifier); 1178 } 1179 1180 int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 1181 VhostBackendType backend_type, uint32_t busyloop_timeout) 1182 { 1183 uint64_t features; 1184 int i, r, n_initialized_vqs = 0; 1185 Error *local_err = NULL; 1186 1187 hdev->vdev = NULL; 1188 hdev->migration_blocker = NULL; 1189 1190 r = vhost_set_backend_type(hdev, backend_type); 1191 assert(r >= 0); 1192 1193 r = hdev->vhost_ops->vhost_backend_init(hdev, opaque); 1194 if (r < 0) { 1195 goto fail; 1196 } 1197 1198 r = hdev->vhost_ops->vhost_set_owner(hdev); 1199 if (r < 0) { 1200 VHOST_OPS_DEBUG("vhost_set_owner failed"); 1201 goto fail; 1202 } 1203 1204 r = hdev->vhost_ops->vhost_get_features(hdev, &features); 1205 if (r < 0) { 1206 VHOST_OPS_DEBUG("vhost_get_features failed"); 1207 goto fail; 1208 } 1209 1210 for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) { 1211 r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); 1212 if (r < 0) { 1213 goto fail; 1214 } 1215 } 1216 1217 if (busyloop_timeout) { 1218 for (i = 0; i < hdev->nvqs; ++i) { 1219 r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 1220 busyloop_timeout); 1221 if (r < 0) { 1222 goto fail_busyloop; 1223 } 1224 } 1225 } 1226 1227 hdev->features = features; 1228 1229 hdev->memory_listener = (MemoryListener) { 1230 .begin = vhost_begin, 1231 .commit = vhost_commit, 1232 .region_add = vhost_region_addnop, 1233 .region_nop = vhost_region_addnop, 1234 .log_start = vhost_log_start, 1235 .log_stop = vhost_log_stop, 1236 .log_sync = vhost_log_sync, 1237 .log_global_start = vhost_log_global_start, 1238 .log_global_stop = vhost_log_global_stop, 1239 .eventfd_add = vhost_eventfd_add, 1240 .eventfd_del = vhost_eventfd_del, 1241 .priority = 10 1242 }; 1243 1244 hdev->iommu_listener = (MemoryListener) { 1245 .region_add = vhost_iommu_region_add, 1246 .region_del = vhost_iommu_region_del, 1247 }; 1248 1249 if (hdev->migration_blocker == NULL) { 1250 if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { 1251 error_setg(&hdev->migration_blocker, 1252 "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); 1253 } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_alloc_check()) { 1254 error_setg(&hdev->migration_blocker, 1255 "Migration disabled: failed to allocate shared memory"); 1256 } 1257 } 1258 1259 if (hdev->migration_blocker != NULL) { 1260 r = migrate_add_blocker(hdev->migration_blocker, &local_err); 1261 if (local_err) { 1262 error_report_err(local_err); 1263 error_free(hdev->migration_blocker); 1264 goto fail_busyloop; 1265 } 1266 } 1267 1268 hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); 1269 hdev->n_mem_sections = 0; 1270 hdev->mem_sections = NULL; 1271 hdev->log = NULL; 1272 hdev->log_size = 0; 1273 hdev->log_enabled = false; 1274 hdev->started = false; 1275 memory_listener_register(&hdev->memory_listener, &address_space_memory); 1276 QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); 1277 1278 if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { 1279 error_report("vhost backend memory slots limit is less" 1280 " than current number of present memory slots"); 1281 r = -1; 1282 if (busyloop_timeout) { 1283 goto fail_busyloop; 1284 } else { 1285 goto fail; 1286 } 1287 } 1288 1289 return 0; 1290 1291 fail_busyloop: 1292 while (--i >= 0) { 1293 vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); 1294 } 1295 fail: 1296 hdev->nvqs = n_initialized_vqs; 1297 vhost_dev_cleanup(hdev); 1298 return r; 1299 } 1300 1301 void vhost_dev_cleanup(struct vhost_dev *hdev) 1302 { 1303 int i; 1304 1305 for (i = 0; i < hdev->nvqs; ++i) { 1306 vhost_virtqueue_cleanup(hdev->vqs + i); 1307 } 1308 if (hdev->mem) { 1309 /* those are only safe after successful init */ 1310 memory_listener_unregister(&hdev->memory_listener); 1311 QLIST_REMOVE(hdev, entry); 1312 } 1313 if (hdev->migration_blocker) { 1314 migrate_del_blocker(hdev->migration_blocker); 1315 error_free(hdev->migration_blocker); 1316 } 1317 g_free(hdev->mem); 1318 g_free(hdev->mem_sections); 1319 if (hdev->vhost_ops) { 1320 hdev->vhost_ops->vhost_backend_cleanup(hdev); 1321 } 1322 assert(!hdev->log); 1323 1324 memset(hdev, 0, sizeof(struct vhost_dev)); 1325 } 1326 1327 /* Stop processing guest IO notifications in qemu. 1328 * Start processing them in vhost in kernel. 1329 */ 1330 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1331 { 1332 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1333 int i, r, e; 1334 1335 /* We will pass the notifiers to the kernel, make sure that QEMU 1336 * doesn't interfere. 1337 */ 1338 r = virtio_device_grab_ioeventfd(vdev); 1339 if (r < 0) { 1340 error_report("binding does not support host notifiers"); 1341 goto fail; 1342 } 1343 1344 for (i = 0; i < hdev->nvqs; ++i) { 1345 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1346 true); 1347 if (r < 0) { 1348 error_report("vhost VQ %d notifier binding failed: %d", i, -r); 1349 goto fail_vq; 1350 } 1351 } 1352 1353 return 0; 1354 fail_vq: 1355 while (--i >= 0) { 1356 e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1357 false); 1358 if (e < 0) { 1359 error_report("vhost VQ %d notifier cleanup error: %d", i, -r); 1360 } 1361 assert (e >= 0); 1362 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1363 } 1364 virtio_device_release_ioeventfd(vdev); 1365 fail: 1366 return r; 1367 } 1368 1369 /* Stop processing guest IO notifications in vhost. 1370 * Start processing them in qemu. 1371 * This might actually run the qemu handlers right away, 1372 * so virtio in qemu must be completely setup when this is called. 1373 */ 1374 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) 1375 { 1376 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 1377 int i, r; 1378 1379 for (i = 0; i < hdev->nvqs; ++i) { 1380 r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, 1381 false); 1382 if (r < 0) { 1383 error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); 1384 } 1385 assert (r >= 0); 1386 virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); 1387 } 1388 virtio_device_release_ioeventfd(vdev); 1389 } 1390 1391 /* Test and clear event pending status. 1392 * Should be called after unmask to avoid losing events. 1393 */ 1394 bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) 1395 { 1396 struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; 1397 assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); 1398 return event_notifier_test_and_clear(&vq->masked_notifier); 1399 } 1400 1401 /* Mask/unmask events from this vq. */ 1402 void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, 1403 bool mask) 1404 { 1405 struct VirtQueue *vvq = virtio_get_queue(vdev, n); 1406 int r, index = n - hdev->vq_index; 1407 struct vhost_vring_file file; 1408 1409 /* should only be called after backend is connected */ 1410 assert(hdev->vhost_ops); 1411 1412 if (mask) { 1413 assert(vdev->use_guest_notifier_mask); 1414 file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); 1415 } else { 1416 file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); 1417 } 1418 1419 file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); 1420 r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); 1421 if (r < 0) { 1422 VHOST_OPS_DEBUG("vhost_set_vring_call failed"); 1423 } 1424 } 1425 1426 uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, 1427 uint64_t features) 1428 { 1429 const int *bit = feature_bits; 1430 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1431 uint64_t bit_mask = (1ULL << *bit); 1432 if (!(hdev->features & bit_mask)) { 1433 features &= ~bit_mask; 1434 } 1435 bit++; 1436 } 1437 return features; 1438 } 1439 1440 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, 1441 uint64_t features) 1442 { 1443 const int *bit = feature_bits; 1444 while (*bit != VHOST_INVALID_FEATURE_BIT) { 1445 uint64_t bit_mask = (1ULL << *bit); 1446 if (features & bit_mask) { 1447 hdev->acked_features |= bit_mask; 1448 } 1449 bit++; 1450 } 1451 } 1452 1453 int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, 1454 uint32_t config_len) 1455 { 1456 assert(hdev->vhost_ops); 1457 1458 if (hdev->vhost_ops->vhost_get_config) { 1459 return hdev->vhost_ops->vhost_get_config(hdev, config, config_len); 1460 } 1461 1462 return -1; 1463 } 1464 1465 int vhost_dev_set_config(struct vhost_dev *hdev, const uint8_t *data, 1466 uint32_t offset, uint32_t size, uint32_t flags) 1467 { 1468 assert(hdev->vhost_ops); 1469 1470 if (hdev->vhost_ops->vhost_set_config) { 1471 return hdev->vhost_ops->vhost_set_config(hdev, data, offset, 1472 size, flags); 1473 } 1474 1475 return -1; 1476 } 1477 1478 void vhost_dev_set_config_notifier(struct vhost_dev *hdev, 1479 const VhostDevConfigOps *ops) 1480 { 1481 hdev->config_ops = ops; 1482 } 1483 1484 /* Host notifiers must be enabled at this point. */ 1485 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 1486 { 1487 int i, r; 1488 1489 /* should only be called after backend is connected */ 1490 assert(hdev->vhost_ops); 1491 1492 hdev->started = true; 1493 hdev->vdev = vdev; 1494 1495 r = vhost_dev_set_features(hdev, hdev->log_enabled); 1496 if (r < 0) { 1497 goto fail_features; 1498 } 1499 1500 if (vhost_dev_has_iommu(hdev)) { 1501 memory_listener_register(&hdev->iommu_listener, vdev->dma_as); 1502 } 1503 1504 r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); 1505 if (r < 0) { 1506 VHOST_OPS_DEBUG("vhost_set_mem_table failed"); 1507 r = -errno; 1508 goto fail_mem; 1509 } 1510 for (i = 0; i < hdev->nvqs; ++i) { 1511 r = vhost_virtqueue_start(hdev, 1512 vdev, 1513 hdev->vqs + i, 1514 hdev->vq_index + i); 1515 if (r < 0) { 1516 goto fail_vq; 1517 } 1518 } 1519 1520 if (hdev->log_enabled) { 1521 uint64_t log_base; 1522 1523 hdev->log_size = vhost_get_log_size(hdev); 1524 hdev->log = vhost_log_get(hdev->log_size, 1525 vhost_dev_log_is_shared(hdev)); 1526 log_base = (uintptr_t)hdev->log->log; 1527 r = hdev->vhost_ops->vhost_set_log_base(hdev, 1528 hdev->log_size ? log_base : 0, 1529 hdev->log); 1530 if (r < 0) { 1531 VHOST_OPS_DEBUG("vhost_set_log_base failed"); 1532 r = -errno; 1533 goto fail_log; 1534 } 1535 } 1536 1537 if (vhost_dev_has_iommu(hdev)) { 1538 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true); 1539 1540 /* Update used ring information for IOTLB to work correctly, 1541 * vhost-kernel code requires for this.*/ 1542 for (i = 0; i < hdev->nvqs; ++i) { 1543 struct vhost_virtqueue *vq = hdev->vqs + i; 1544 vhost_device_iotlb_miss(hdev, vq->used_phys, true); 1545 } 1546 } 1547 return 0; 1548 fail_log: 1549 vhost_log_put(hdev, false); 1550 fail_vq: 1551 while (--i >= 0) { 1552 vhost_virtqueue_stop(hdev, 1553 vdev, 1554 hdev->vqs + i, 1555 hdev->vq_index + i); 1556 } 1557 i = hdev->nvqs; 1558 1559 fail_mem: 1560 fail_features: 1561 1562 hdev->started = false; 1563 return r; 1564 } 1565 1566 /* Host notifiers must be enabled at this point. */ 1567 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 1568 { 1569 int i; 1570 1571 /* should only be called after backend is connected */ 1572 assert(hdev->vhost_ops); 1573 1574 for (i = 0; i < hdev->nvqs; ++i) { 1575 vhost_virtqueue_stop(hdev, 1576 vdev, 1577 hdev->vqs + i, 1578 hdev->vq_index + i); 1579 } 1580 1581 if (vhost_dev_has_iommu(hdev)) { 1582 hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false); 1583 memory_listener_unregister(&hdev->iommu_listener); 1584 } 1585 vhost_log_put(hdev, true); 1586 hdev->started = false; 1587 hdev->vdev = NULL; 1588 } 1589 1590 int vhost_net_set_backend(struct vhost_dev *hdev, 1591 struct vhost_vring_file *file) 1592 { 1593 if (hdev->vhost_ops->vhost_net_set_backend) { 1594 return hdev->vhost_ops->vhost_net_set_backend(hdev, file); 1595 } 1596 1597 return -1; 1598 } 1599