1 /* 2 * Virtio Support 3 * 4 * Copyright IBM, Corp. 2007 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.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 */ 13 14 #include "qemu/osdep.h" 15 #include "qapi/error.h" 16 #include "cpu.h" 17 #include "trace.h" 18 #include "qemu/error-report.h" 19 #include "qemu/log.h" 20 #include "qemu/main-loop.h" 21 #include "qemu/module.h" 22 #include "hw/virtio/virtio.h" 23 #include "migration/qemu-file-types.h" 24 #include "qemu/atomic.h" 25 #include "hw/virtio/virtio-bus.h" 26 #include "hw/qdev-properties.h" 27 #include "hw/virtio/virtio-access.h" 28 #include "sysemu/dma.h" 29 #include "sysemu/runstate.h" 30 #include "standard-headers/linux/virtio_ids.h" 31 32 /* 33 * The alignment to use between consumer and producer parts of vring. 34 * x86 pagesize again. This is the default, used by transports like PCI 35 * which don't provide a means for the guest to tell the host the alignment. 36 */ 37 #define VIRTIO_PCI_VRING_ALIGN 4096 38 39 typedef struct VRingDesc 40 { 41 uint64_t addr; 42 uint32_t len; 43 uint16_t flags; 44 uint16_t next; 45 } VRingDesc; 46 47 typedef struct VRingPackedDesc { 48 uint64_t addr; 49 uint32_t len; 50 uint16_t id; 51 uint16_t flags; 52 } VRingPackedDesc; 53 54 typedef struct VRingAvail 55 { 56 uint16_t flags; 57 uint16_t idx; 58 uint16_t ring[]; 59 } VRingAvail; 60 61 typedef struct VRingUsedElem 62 { 63 uint32_t id; 64 uint32_t len; 65 } VRingUsedElem; 66 67 typedef struct VRingUsed 68 { 69 uint16_t flags; 70 uint16_t idx; 71 VRingUsedElem ring[]; 72 } VRingUsed; 73 74 typedef struct VRingMemoryRegionCaches { 75 struct rcu_head rcu; 76 MemoryRegionCache desc; 77 MemoryRegionCache avail; 78 MemoryRegionCache used; 79 } VRingMemoryRegionCaches; 80 81 typedef struct VRing 82 { 83 unsigned int num; 84 unsigned int num_default; 85 unsigned int align; 86 hwaddr desc; 87 hwaddr avail; 88 hwaddr used; 89 VRingMemoryRegionCaches *caches; 90 } VRing; 91 92 typedef struct VRingPackedDescEvent { 93 uint16_t off_wrap; 94 uint16_t flags; 95 } VRingPackedDescEvent ; 96 97 struct VirtQueue 98 { 99 VRing vring; 100 VirtQueueElement *used_elems; 101 102 /* Next head to pop */ 103 uint16_t last_avail_idx; 104 bool last_avail_wrap_counter; 105 106 /* Last avail_idx read from VQ. */ 107 uint16_t shadow_avail_idx; 108 bool shadow_avail_wrap_counter; 109 110 uint16_t used_idx; 111 bool used_wrap_counter; 112 113 /* Last used index value we have signalled on */ 114 uint16_t signalled_used; 115 116 /* Last used index value we have signalled on */ 117 bool signalled_used_valid; 118 119 /* Notification enabled? */ 120 bool notification; 121 122 uint16_t queue_index; 123 124 unsigned int inuse; 125 126 uint16_t vector; 127 VirtIOHandleOutput handle_output; 128 VirtIOHandleAIOOutput handle_aio_output; 129 VirtIODevice *vdev; 130 EventNotifier guest_notifier; 131 EventNotifier host_notifier; 132 bool host_notifier_enabled; 133 QLIST_ENTRY(VirtQueue) node; 134 }; 135 136 /* Called within call_rcu(). */ 137 static void virtio_free_region_cache(VRingMemoryRegionCaches *caches) 138 { 139 assert(caches != NULL); 140 address_space_cache_destroy(&caches->desc); 141 address_space_cache_destroy(&caches->avail); 142 address_space_cache_destroy(&caches->used); 143 g_free(caches); 144 } 145 146 static void virtio_virtqueue_reset_region_cache(struct VirtQueue *vq) 147 { 148 VRingMemoryRegionCaches *caches; 149 150 caches = qatomic_read(&vq->vring.caches); 151 qatomic_rcu_set(&vq->vring.caches, NULL); 152 if (caches) { 153 call_rcu(caches, virtio_free_region_cache, rcu); 154 } 155 } 156 157 static void virtio_init_region_cache(VirtIODevice *vdev, int n) 158 { 159 VirtQueue *vq = &vdev->vq[n]; 160 VRingMemoryRegionCaches *old = vq->vring.caches; 161 VRingMemoryRegionCaches *new = NULL; 162 hwaddr addr, size; 163 int64_t len; 164 bool packed; 165 166 167 addr = vq->vring.desc; 168 if (!addr) { 169 goto out_no_cache; 170 } 171 new = g_new0(VRingMemoryRegionCaches, 1); 172 size = virtio_queue_get_desc_size(vdev, n); 173 packed = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ? 174 true : false; 175 len = address_space_cache_init(&new->desc, vdev->dma_as, 176 addr, size, packed); 177 if (len < size) { 178 virtio_error(vdev, "Cannot map desc"); 179 goto err_desc; 180 } 181 182 size = virtio_queue_get_used_size(vdev, n); 183 len = address_space_cache_init(&new->used, vdev->dma_as, 184 vq->vring.used, size, true); 185 if (len < size) { 186 virtio_error(vdev, "Cannot map used"); 187 goto err_used; 188 } 189 190 size = virtio_queue_get_avail_size(vdev, n); 191 len = address_space_cache_init(&new->avail, vdev->dma_as, 192 vq->vring.avail, size, false); 193 if (len < size) { 194 virtio_error(vdev, "Cannot map avail"); 195 goto err_avail; 196 } 197 198 qatomic_rcu_set(&vq->vring.caches, new); 199 if (old) { 200 call_rcu(old, virtio_free_region_cache, rcu); 201 } 202 return; 203 204 err_avail: 205 address_space_cache_destroy(&new->avail); 206 err_used: 207 address_space_cache_destroy(&new->used); 208 err_desc: 209 address_space_cache_destroy(&new->desc); 210 out_no_cache: 211 g_free(new); 212 virtio_virtqueue_reset_region_cache(vq); 213 } 214 215 /* virt queue functions */ 216 void virtio_queue_update_rings(VirtIODevice *vdev, int n) 217 { 218 VRing *vring = &vdev->vq[n].vring; 219 220 if (!vring->num || !vring->desc || !vring->align) { 221 /* not yet setup -> nothing to do */ 222 return; 223 } 224 vring->avail = vring->desc + vring->num * sizeof(VRingDesc); 225 vring->used = vring_align(vring->avail + 226 offsetof(VRingAvail, ring[vring->num]), 227 vring->align); 228 virtio_init_region_cache(vdev, n); 229 } 230 231 /* Called within rcu_read_lock(). */ 232 static void vring_split_desc_read(VirtIODevice *vdev, VRingDesc *desc, 233 MemoryRegionCache *cache, int i) 234 { 235 address_space_read_cached(cache, i * sizeof(VRingDesc), 236 desc, sizeof(VRingDesc)); 237 virtio_tswap64s(vdev, &desc->addr); 238 virtio_tswap32s(vdev, &desc->len); 239 virtio_tswap16s(vdev, &desc->flags); 240 virtio_tswap16s(vdev, &desc->next); 241 } 242 243 static void vring_packed_event_read(VirtIODevice *vdev, 244 MemoryRegionCache *cache, 245 VRingPackedDescEvent *e) 246 { 247 hwaddr off_off = offsetof(VRingPackedDescEvent, off_wrap); 248 hwaddr off_flags = offsetof(VRingPackedDescEvent, flags); 249 250 e->flags = virtio_lduw_phys_cached(vdev, cache, off_flags); 251 /* Make sure flags is seen before off_wrap */ 252 smp_rmb(); 253 e->off_wrap = virtio_lduw_phys_cached(vdev, cache, off_off); 254 virtio_tswap16s(vdev, &e->flags); 255 } 256 257 static void vring_packed_off_wrap_write(VirtIODevice *vdev, 258 MemoryRegionCache *cache, 259 uint16_t off_wrap) 260 { 261 hwaddr off = offsetof(VRingPackedDescEvent, off_wrap); 262 263 virtio_stw_phys_cached(vdev, cache, off, off_wrap); 264 address_space_cache_invalidate(cache, off, sizeof(off_wrap)); 265 } 266 267 static void vring_packed_flags_write(VirtIODevice *vdev, 268 MemoryRegionCache *cache, uint16_t flags) 269 { 270 hwaddr off = offsetof(VRingPackedDescEvent, flags); 271 272 virtio_stw_phys_cached(vdev, cache, off, flags); 273 address_space_cache_invalidate(cache, off, sizeof(flags)); 274 } 275 276 /* Called within rcu_read_lock(). */ 277 static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq) 278 { 279 return qatomic_rcu_read(&vq->vring.caches); 280 } 281 282 /* Called within rcu_read_lock(). */ 283 static inline uint16_t vring_avail_flags(VirtQueue *vq) 284 { 285 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 286 hwaddr pa = offsetof(VRingAvail, flags); 287 288 if (!caches) { 289 return 0; 290 } 291 292 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 293 } 294 295 /* Called within rcu_read_lock(). */ 296 static inline uint16_t vring_avail_idx(VirtQueue *vq) 297 { 298 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 299 hwaddr pa = offsetof(VRingAvail, idx); 300 301 if (!caches) { 302 return 0; 303 } 304 305 vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 306 return vq->shadow_avail_idx; 307 } 308 309 /* Called within rcu_read_lock(). */ 310 static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) 311 { 312 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 313 hwaddr pa = offsetof(VRingAvail, ring[i]); 314 315 if (!caches) { 316 return 0; 317 } 318 319 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 320 } 321 322 /* Called within rcu_read_lock(). */ 323 static inline uint16_t vring_get_used_event(VirtQueue *vq) 324 { 325 return vring_avail_ring(vq, vq->vring.num); 326 } 327 328 /* Called within rcu_read_lock(). */ 329 static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, 330 int i) 331 { 332 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 333 hwaddr pa = offsetof(VRingUsed, ring[i]); 334 335 if (!caches) { 336 return; 337 } 338 339 virtio_tswap32s(vq->vdev, &uelem->id); 340 virtio_tswap32s(vq->vdev, &uelem->len); 341 address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem)); 342 address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem)); 343 } 344 345 /* Called within rcu_read_lock(). */ 346 static uint16_t vring_used_idx(VirtQueue *vq) 347 { 348 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 349 hwaddr pa = offsetof(VRingUsed, idx); 350 351 if (!caches) { 352 return 0; 353 } 354 355 return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 356 } 357 358 /* Called within rcu_read_lock(). */ 359 static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val) 360 { 361 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 362 hwaddr pa = offsetof(VRingUsed, idx); 363 364 if (caches) { 365 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 366 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 367 } 368 369 vq->used_idx = val; 370 } 371 372 /* Called within rcu_read_lock(). */ 373 static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) 374 { 375 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 376 VirtIODevice *vdev = vq->vdev; 377 hwaddr pa = offsetof(VRingUsed, flags); 378 uint16_t flags; 379 380 if (!caches) { 381 return; 382 } 383 384 flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 385 virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask); 386 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 387 } 388 389 /* Called within rcu_read_lock(). */ 390 static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) 391 { 392 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 393 VirtIODevice *vdev = vq->vdev; 394 hwaddr pa = offsetof(VRingUsed, flags); 395 uint16_t flags; 396 397 if (!caches) { 398 return; 399 } 400 401 flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 402 virtio_stw_phys_cached(vdev, &caches->used, pa, flags & ~mask); 403 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 404 } 405 406 /* Called within rcu_read_lock(). */ 407 static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) 408 { 409 VRingMemoryRegionCaches *caches; 410 hwaddr pa; 411 if (!vq->notification) { 412 return; 413 } 414 415 caches = vring_get_region_caches(vq); 416 if (!caches) { 417 return; 418 } 419 420 pa = offsetof(VRingUsed, ring[vq->vring.num]); 421 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 422 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 423 } 424 425 static void virtio_queue_split_set_notification(VirtQueue *vq, int enable) 426 { 427 RCU_READ_LOCK_GUARD(); 428 429 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 430 vring_set_avail_event(vq, vring_avail_idx(vq)); 431 } else if (enable) { 432 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); 433 } else { 434 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); 435 } 436 if (enable) { 437 /* Expose avail event/used flags before caller checks the avail idx. */ 438 smp_mb(); 439 } 440 } 441 442 static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) 443 { 444 uint16_t off_wrap; 445 VRingPackedDescEvent e; 446 VRingMemoryRegionCaches *caches; 447 448 RCU_READ_LOCK_GUARD(); 449 caches = vring_get_region_caches(vq); 450 if (!caches) { 451 return; 452 } 453 454 vring_packed_event_read(vq->vdev, &caches->used, &e); 455 456 if (!enable) { 457 e.flags = VRING_PACKED_EVENT_FLAG_DISABLE; 458 } else if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 459 off_wrap = vq->shadow_avail_idx | vq->shadow_avail_wrap_counter << 15; 460 vring_packed_off_wrap_write(vq->vdev, &caches->used, off_wrap); 461 /* Make sure off_wrap is wrote before flags */ 462 smp_wmb(); 463 e.flags = VRING_PACKED_EVENT_FLAG_DESC; 464 } else { 465 e.flags = VRING_PACKED_EVENT_FLAG_ENABLE; 466 } 467 468 vring_packed_flags_write(vq->vdev, &caches->used, e.flags); 469 if (enable) { 470 /* Expose avail event/used flags before caller checks the avail idx. */ 471 smp_mb(); 472 } 473 } 474 475 bool virtio_queue_get_notification(VirtQueue *vq) 476 { 477 return vq->notification; 478 } 479 480 void virtio_queue_set_notification(VirtQueue *vq, int enable) 481 { 482 vq->notification = enable; 483 484 if (!vq->vring.desc) { 485 return; 486 } 487 488 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 489 virtio_queue_packed_set_notification(vq, enable); 490 } else { 491 virtio_queue_split_set_notification(vq, enable); 492 } 493 } 494 495 int virtio_queue_ready(VirtQueue *vq) 496 { 497 return vq->vring.avail != 0; 498 } 499 500 static void vring_packed_desc_read_flags(VirtIODevice *vdev, 501 uint16_t *flags, 502 MemoryRegionCache *cache, 503 int i) 504 { 505 hwaddr off = i * sizeof(VRingPackedDesc) + offsetof(VRingPackedDesc, flags); 506 507 *flags = virtio_lduw_phys_cached(vdev, cache, off); 508 } 509 510 static void vring_packed_desc_read(VirtIODevice *vdev, 511 VRingPackedDesc *desc, 512 MemoryRegionCache *cache, 513 int i, bool strict_order) 514 { 515 hwaddr off = i * sizeof(VRingPackedDesc); 516 517 vring_packed_desc_read_flags(vdev, &desc->flags, cache, i); 518 519 if (strict_order) { 520 /* Make sure flags is read before the rest fields. */ 521 smp_rmb(); 522 } 523 524 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, addr), 525 &desc->addr, sizeof(desc->addr)); 526 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, id), 527 &desc->id, sizeof(desc->id)); 528 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, len), 529 &desc->len, sizeof(desc->len)); 530 virtio_tswap64s(vdev, &desc->addr); 531 virtio_tswap16s(vdev, &desc->id); 532 virtio_tswap32s(vdev, &desc->len); 533 } 534 535 static void vring_packed_desc_write_data(VirtIODevice *vdev, 536 VRingPackedDesc *desc, 537 MemoryRegionCache *cache, 538 int i) 539 { 540 hwaddr off_id = i * sizeof(VRingPackedDesc) + 541 offsetof(VRingPackedDesc, id); 542 hwaddr off_len = i * sizeof(VRingPackedDesc) + 543 offsetof(VRingPackedDesc, len); 544 545 virtio_tswap32s(vdev, &desc->len); 546 virtio_tswap16s(vdev, &desc->id); 547 address_space_write_cached(cache, off_id, &desc->id, sizeof(desc->id)); 548 address_space_cache_invalidate(cache, off_id, sizeof(desc->id)); 549 address_space_write_cached(cache, off_len, &desc->len, sizeof(desc->len)); 550 address_space_cache_invalidate(cache, off_len, sizeof(desc->len)); 551 } 552 553 static void vring_packed_desc_write_flags(VirtIODevice *vdev, 554 VRingPackedDesc *desc, 555 MemoryRegionCache *cache, 556 int i) 557 { 558 hwaddr off = i * sizeof(VRingPackedDesc) + offsetof(VRingPackedDesc, flags); 559 560 virtio_stw_phys_cached(vdev, cache, off, desc->flags); 561 address_space_cache_invalidate(cache, off, sizeof(desc->flags)); 562 } 563 564 static void vring_packed_desc_write(VirtIODevice *vdev, 565 VRingPackedDesc *desc, 566 MemoryRegionCache *cache, 567 int i, bool strict_order) 568 { 569 vring_packed_desc_write_data(vdev, desc, cache, i); 570 if (strict_order) { 571 /* Make sure data is wrote before flags. */ 572 smp_wmb(); 573 } 574 vring_packed_desc_write_flags(vdev, desc, cache, i); 575 } 576 577 static inline bool is_desc_avail(uint16_t flags, bool wrap_counter) 578 { 579 bool avail, used; 580 581 avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL)); 582 used = !!(flags & (1 << VRING_PACKED_DESC_F_USED)); 583 return (avail != used) && (avail == wrap_counter); 584 } 585 586 /* Fetch avail_idx from VQ memory only when we really need to know if 587 * guest has added some buffers. 588 * Called within rcu_read_lock(). */ 589 static int virtio_queue_empty_rcu(VirtQueue *vq) 590 { 591 if (virtio_device_disabled(vq->vdev)) { 592 return 1; 593 } 594 595 if (unlikely(!vq->vring.avail)) { 596 return 1; 597 } 598 599 if (vq->shadow_avail_idx != vq->last_avail_idx) { 600 return 0; 601 } 602 603 return vring_avail_idx(vq) == vq->last_avail_idx; 604 } 605 606 static int virtio_queue_split_empty(VirtQueue *vq) 607 { 608 bool empty; 609 610 if (virtio_device_disabled(vq->vdev)) { 611 return 1; 612 } 613 614 if (unlikely(!vq->vring.avail)) { 615 return 1; 616 } 617 618 if (vq->shadow_avail_idx != vq->last_avail_idx) { 619 return 0; 620 } 621 622 RCU_READ_LOCK_GUARD(); 623 empty = vring_avail_idx(vq) == vq->last_avail_idx; 624 return empty; 625 } 626 627 /* Called within rcu_read_lock(). */ 628 static int virtio_queue_packed_empty_rcu(VirtQueue *vq) 629 { 630 struct VRingPackedDesc desc; 631 VRingMemoryRegionCaches *cache; 632 633 if (unlikely(!vq->vring.desc)) { 634 return 1; 635 } 636 637 cache = vring_get_region_caches(vq); 638 if (!cache) { 639 return 1; 640 } 641 642 vring_packed_desc_read_flags(vq->vdev, &desc.flags, &cache->desc, 643 vq->last_avail_idx); 644 645 return !is_desc_avail(desc.flags, vq->last_avail_wrap_counter); 646 } 647 648 static int virtio_queue_packed_empty(VirtQueue *vq) 649 { 650 RCU_READ_LOCK_GUARD(); 651 return virtio_queue_packed_empty_rcu(vq); 652 } 653 654 int virtio_queue_empty(VirtQueue *vq) 655 { 656 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 657 return virtio_queue_packed_empty(vq); 658 } else { 659 return virtio_queue_split_empty(vq); 660 } 661 } 662 663 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 664 unsigned int len) 665 { 666 AddressSpace *dma_as = vq->vdev->dma_as; 667 unsigned int offset; 668 int i; 669 670 offset = 0; 671 for (i = 0; i < elem->in_num; i++) { 672 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 673 674 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 675 elem->in_sg[i].iov_len, 676 DMA_DIRECTION_FROM_DEVICE, size); 677 678 offset += size; 679 } 680 681 for (i = 0; i < elem->out_num; i++) 682 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 683 elem->out_sg[i].iov_len, 684 DMA_DIRECTION_TO_DEVICE, 685 elem->out_sg[i].iov_len); 686 } 687 688 /* virtqueue_detach_element: 689 * @vq: The #VirtQueue 690 * @elem: The #VirtQueueElement 691 * @len: number of bytes written 692 * 693 * Detach the element from the virtqueue. This function is suitable for device 694 * reset or other situations where a #VirtQueueElement is simply freed and will 695 * not be pushed or discarded. 696 */ 697 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 698 unsigned int len) 699 { 700 vq->inuse -= elem->ndescs; 701 virtqueue_unmap_sg(vq, elem, len); 702 } 703 704 static void virtqueue_split_rewind(VirtQueue *vq, unsigned int num) 705 { 706 vq->last_avail_idx -= num; 707 } 708 709 static void virtqueue_packed_rewind(VirtQueue *vq, unsigned int num) 710 { 711 if (vq->last_avail_idx < num) { 712 vq->last_avail_idx = vq->vring.num + vq->last_avail_idx - num; 713 vq->last_avail_wrap_counter ^= 1; 714 } else { 715 vq->last_avail_idx -= num; 716 } 717 } 718 719 /* virtqueue_unpop: 720 * @vq: The #VirtQueue 721 * @elem: The #VirtQueueElement 722 * @len: number of bytes written 723 * 724 * Pretend the most recent element wasn't popped from the virtqueue. The next 725 * call to virtqueue_pop() will refetch the element. 726 */ 727 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 728 unsigned int len) 729 { 730 731 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 732 virtqueue_packed_rewind(vq, 1); 733 } else { 734 virtqueue_split_rewind(vq, 1); 735 } 736 737 virtqueue_detach_element(vq, elem, len); 738 } 739 740 /* virtqueue_rewind: 741 * @vq: The #VirtQueue 742 * @num: Number of elements to push back 743 * 744 * Pretend that elements weren't popped from the virtqueue. The next 745 * virtqueue_pop() will refetch the oldest element. 746 * 747 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 748 * 749 * Returns: true on success, false if @num is greater than the number of in use 750 * elements. 751 */ 752 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 753 { 754 if (num > vq->inuse) { 755 return false; 756 } 757 758 vq->inuse -= num; 759 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 760 virtqueue_packed_rewind(vq, num); 761 } else { 762 virtqueue_split_rewind(vq, num); 763 } 764 return true; 765 } 766 767 static void virtqueue_split_fill(VirtQueue *vq, const VirtQueueElement *elem, 768 unsigned int len, unsigned int idx) 769 { 770 VRingUsedElem uelem; 771 772 if (unlikely(!vq->vring.used)) { 773 return; 774 } 775 776 idx = (idx + vq->used_idx) % vq->vring.num; 777 778 uelem.id = elem->index; 779 uelem.len = len; 780 vring_used_write(vq, &uelem, idx); 781 } 782 783 static void virtqueue_packed_fill(VirtQueue *vq, const VirtQueueElement *elem, 784 unsigned int len, unsigned int idx) 785 { 786 vq->used_elems[idx].index = elem->index; 787 vq->used_elems[idx].len = len; 788 vq->used_elems[idx].ndescs = elem->ndescs; 789 } 790 791 static void virtqueue_packed_fill_desc(VirtQueue *vq, 792 const VirtQueueElement *elem, 793 unsigned int idx, 794 bool strict_order) 795 { 796 uint16_t head; 797 VRingMemoryRegionCaches *caches; 798 VRingPackedDesc desc = { 799 .id = elem->index, 800 .len = elem->len, 801 }; 802 bool wrap_counter = vq->used_wrap_counter; 803 804 if (unlikely(!vq->vring.desc)) { 805 return; 806 } 807 808 head = vq->used_idx + idx; 809 if (head >= vq->vring.num) { 810 head -= vq->vring.num; 811 wrap_counter ^= 1; 812 } 813 if (wrap_counter) { 814 desc.flags |= (1 << VRING_PACKED_DESC_F_AVAIL); 815 desc.flags |= (1 << VRING_PACKED_DESC_F_USED); 816 } else { 817 desc.flags &= ~(1 << VRING_PACKED_DESC_F_AVAIL); 818 desc.flags &= ~(1 << VRING_PACKED_DESC_F_USED); 819 } 820 821 caches = vring_get_region_caches(vq); 822 if (!caches) { 823 return; 824 } 825 826 vring_packed_desc_write(vq->vdev, &desc, &caches->desc, head, strict_order); 827 } 828 829 /* Called within rcu_read_lock(). */ 830 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 831 unsigned int len, unsigned int idx) 832 { 833 trace_virtqueue_fill(vq, elem, len, idx); 834 835 virtqueue_unmap_sg(vq, elem, len); 836 837 if (virtio_device_disabled(vq->vdev)) { 838 return; 839 } 840 841 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 842 virtqueue_packed_fill(vq, elem, len, idx); 843 } else { 844 virtqueue_split_fill(vq, elem, len, idx); 845 } 846 } 847 848 /* Called within rcu_read_lock(). */ 849 static void virtqueue_split_flush(VirtQueue *vq, unsigned int count) 850 { 851 uint16_t old, new; 852 853 if (unlikely(!vq->vring.used)) { 854 return; 855 } 856 857 /* Make sure buffer is written before we update index. */ 858 smp_wmb(); 859 trace_virtqueue_flush(vq, count); 860 old = vq->used_idx; 861 new = old + count; 862 vring_used_idx_set(vq, new); 863 vq->inuse -= count; 864 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 865 vq->signalled_used_valid = false; 866 } 867 868 static void virtqueue_packed_flush(VirtQueue *vq, unsigned int count) 869 { 870 unsigned int i, ndescs = 0; 871 872 if (unlikely(!vq->vring.desc)) { 873 return; 874 } 875 876 for (i = 1; i < count; i++) { 877 virtqueue_packed_fill_desc(vq, &vq->used_elems[i], i, false); 878 ndescs += vq->used_elems[i].ndescs; 879 } 880 virtqueue_packed_fill_desc(vq, &vq->used_elems[0], 0, true); 881 ndescs += vq->used_elems[0].ndescs; 882 883 vq->inuse -= ndescs; 884 vq->used_idx += ndescs; 885 if (vq->used_idx >= vq->vring.num) { 886 vq->used_idx -= vq->vring.num; 887 vq->used_wrap_counter ^= 1; 888 } 889 } 890 891 void virtqueue_flush(VirtQueue *vq, unsigned int count) 892 { 893 if (virtio_device_disabled(vq->vdev)) { 894 vq->inuse -= count; 895 return; 896 } 897 898 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 899 virtqueue_packed_flush(vq, count); 900 } else { 901 virtqueue_split_flush(vq, count); 902 } 903 } 904 905 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 906 unsigned int len) 907 { 908 RCU_READ_LOCK_GUARD(); 909 virtqueue_fill(vq, elem, len, 0); 910 virtqueue_flush(vq, 1); 911 } 912 913 /* Called within rcu_read_lock(). */ 914 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 915 { 916 uint16_t num_heads = vring_avail_idx(vq) - idx; 917 918 /* Check it isn't doing very strange things with descriptor numbers. */ 919 if (num_heads > vq->vring.num) { 920 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 921 idx, vq->shadow_avail_idx); 922 return -EINVAL; 923 } 924 /* On success, callers read a descriptor at vq->last_avail_idx. 925 * Make sure descriptor read does not bypass avail index read. */ 926 if (num_heads) { 927 smp_rmb(); 928 } 929 930 return num_heads; 931 } 932 933 /* Called within rcu_read_lock(). */ 934 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 935 unsigned int *head) 936 { 937 /* Grab the next descriptor number they're advertising, and increment 938 * the index we've seen. */ 939 *head = vring_avail_ring(vq, idx % vq->vring.num); 940 941 /* If their number is silly, that's a fatal mistake. */ 942 if (*head >= vq->vring.num) { 943 virtio_error(vq->vdev, "Guest says index %u is available", *head); 944 return false; 945 } 946 947 return true; 948 } 949 950 enum { 951 VIRTQUEUE_READ_DESC_ERROR = -1, 952 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 953 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 954 }; 955 956 static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 957 MemoryRegionCache *desc_cache, 958 unsigned int max, unsigned int *next) 959 { 960 /* If this descriptor says it doesn't chain, we're done. */ 961 if (!(desc->flags & VRING_DESC_F_NEXT)) { 962 return VIRTQUEUE_READ_DESC_DONE; 963 } 964 965 /* Check they're not leading us off end of descriptors. */ 966 *next = desc->next; 967 /* Make sure compiler knows to grab that: we don't want it changing! */ 968 smp_wmb(); 969 970 if (*next >= max) { 971 virtio_error(vdev, "Desc next is %u", *next); 972 return VIRTQUEUE_READ_DESC_ERROR; 973 } 974 975 vring_split_desc_read(vdev, desc, desc_cache, *next); 976 return VIRTQUEUE_READ_DESC_MORE; 977 } 978 979 /* Called within rcu_read_lock(). */ 980 static void virtqueue_split_get_avail_bytes(VirtQueue *vq, 981 unsigned int *in_bytes, unsigned int *out_bytes, 982 unsigned max_in_bytes, unsigned max_out_bytes, 983 VRingMemoryRegionCaches *caches) 984 { 985 VirtIODevice *vdev = vq->vdev; 986 unsigned int max, idx; 987 unsigned int total_bufs, in_total, out_total; 988 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 989 int64_t len = 0; 990 int rc; 991 992 idx = vq->last_avail_idx; 993 total_bufs = in_total = out_total = 0; 994 995 max = vq->vring.num; 996 997 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 998 MemoryRegionCache *desc_cache = &caches->desc; 999 unsigned int num_bufs; 1000 VRingDesc desc; 1001 unsigned int i; 1002 1003 num_bufs = total_bufs; 1004 1005 if (!virtqueue_get_head(vq, idx++, &i)) { 1006 goto err; 1007 } 1008 1009 vring_split_desc_read(vdev, &desc, desc_cache, i); 1010 1011 if (desc.flags & VRING_DESC_F_INDIRECT) { 1012 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1013 virtio_error(vdev, "Invalid size for indirect buffer table"); 1014 goto err; 1015 } 1016 1017 /* If we've got too many, that implies a descriptor loop. */ 1018 if (num_bufs >= max) { 1019 virtio_error(vdev, "Looped descriptor"); 1020 goto err; 1021 } 1022 1023 /* loop over the indirect descriptor table */ 1024 len = address_space_cache_init(&indirect_desc_cache, 1025 vdev->dma_as, 1026 desc.addr, desc.len, false); 1027 desc_cache = &indirect_desc_cache; 1028 if (len < desc.len) { 1029 virtio_error(vdev, "Cannot map indirect buffer"); 1030 goto err; 1031 } 1032 1033 max = desc.len / sizeof(VRingDesc); 1034 num_bufs = i = 0; 1035 vring_split_desc_read(vdev, &desc, desc_cache, i); 1036 } 1037 1038 do { 1039 /* If we've got too many, that implies a descriptor loop. */ 1040 if (++num_bufs > max) { 1041 virtio_error(vdev, "Looped descriptor"); 1042 goto err; 1043 } 1044 1045 if (desc.flags & VRING_DESC_F_WRITE) { 1046 in_total += desc.len; 1047 } else { 1048 out_total += desc.len; 1049 } 1050 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1051 goto done; 1052 } 1053 1054 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); 1055 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1056 1057 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1058 goto err; 1059 } 1060 1061 if (desc_cache == &indirect_desc_cache) { 1062 address_space_cache_destroy(&indirect_desc_cache); 1063 total_bufs++; 1064 } else { 1065 total_bufs = num_bufs; 1066 } 1067 } 1068 1069 if (rc < 0) { 1070 goto err; 1071 } 1072 1073 done: 1074 address_space_cache_destroy(&indirect_desc_cache); 1075 if (in_bytes) { 1076 *in_bytes = in_total; 1077 } 1078 if (out_bytes) { 1079 *out_bytes = out_total; 1080 } 1081 return; 1082 1083 err: 1084 in_total = out_total = 0; 1085 goto done; 1086 } 1087 1088 static int virtqueue_packed_read_next_desc(VirtQueue *vq, 1089 VRingPackedDesc *desc, 1090 MemoryRegionCache 1091 *desc_cache, 1092 unsigned int max, 1093 unsigned int *next, 1094 bool indirect) 1095 { 1096 /* If this descriptor says it doesn't chain, we're done. */ 1097 if (!indirect && !(desc->flags & VRING_DESC_F_NEXT)) { 1098 return VIRTQUEUE_READ_DESC_DONE; 1099 } 1100 1101 ++*next; 1102 if (*next == max) { 1103 if (indirect) { 1104 return VIRTQUEUE_READ_DESC_DONE; 1105 } else { 1106 (*next) -= vq->vring.num; 1107 } 1108 } 1109 1110 vring_packed_desc_read(vq->vdev, desc, desc_cache, *next, false); 1111 return VIRTQUEUE_READ_DESC_MORE; 1112 } 1113 1114 /* Called within rcu_read_lock(). */ 1115 static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, 1116 unsigned int *in_bytes, 1117 unsigned int *out_bytes, 1118 unsigned max_in_bytes, 1119 unsigned max_out_bytes, 1120 VRingMemoryRegionCaches *caches) 1121 { 1122 VirtIODevice *vdev = vq->vdev; 1123 unsigned int max, idx; 1124 unsigned int total_bufs, in_total, out_total; 1125 MemoryRegionCache *desc_cache; 1126 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1127 int64_t len = 0; 1128 VRingPackedDesc desc; 1129 bool wrap_counter; 1130 1131 idx = vq->last_avail_idx; 1132 wrap_counter = vq->last_avail_wrap_counter; 1133 total_bufs = in_total = out_total = 0; 1134 1135 max = vq->vring.num; 1136 1137 for (;;) { 1138 unsigned int num_bufs = total_bufs; 1139 unsigned int i = idx; 1140 int rc; 1141 1142 desc_cache = &caches->desc; 1143 vring_packed_desc_read(vdev, &desc, desc_cache, idx, true); 1144 if (!is_desc_avail(desc.flags, wrap_counter)) { 1145 break; 1146 } 1147 1148 if (desc.flags & VRING_DESC_F_INDIRECT) { 1149 if (desc.len % sizeof(VRingPackedDesc)) { 1150 virtio_error(vdev, "Invalid size for indirect buffer table"); 1151 goto err; 1152 } 1153 1154 /* If we've got too many, that implies a descriptor loop. */ 1155 if (num_bufs >= max) { 1156 virtio_error(vdev, "Looped descriptor"); 1157 goto err; 1158 } 1159 1160 /* loop over the indirect descriptor table */ 1161 len = address_space_cache_init(&indirect_desc_cache, 1162 vdev->dma_as, 1163 desc.addr, desc.len, false); 1164 desc_cache = &indirect_desc_cache; 1165 if (len < desc.len) { 1166 virtio_error(vdev, "Cannot map indirect buffer"); 1167 goto err; 1168 } 1169 1170 max = desc.len / sizeof(VRingPackedDesc); 1171 num_bufs = i = 0; 1172 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1173 } 1174 1175 do { 1176 /* If we've got too many, that implies a descriptor loop. */ 1177 if (++num_bufs > max) { 1178 virtio_error(vdev, "Looped descriptor"); 1179 goto err; 1180 } 1181 1182 if (desc.flags & VRING_DESC_F_WRITE) { 1183 in_total += desc.len; 1184 } else { 1185 out_total += desc.len; 1186 } 1187 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1188 goto done; 1189 } 1190 1191 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, 1192 &i, desc_cache == 1193 &indirect_desc_cache); 1194 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1195 1196 if (desc_cache == &indirect_desc_cache) { 1197 address_space_cache_destroy(&indirect_desc_cache); 1198 total_bufs++; 1199 idx++; 1200 } else { 1201 idx += num_bufs - total_bufs; 1202 total_bufs = num_bufs; 1203 } 1204 1205 if (idx >= vq->vring.num) { 1206 idx -= vq->vring.num; 1207 wrap_counter ^= 1; 1208 } 1209 } 1210 1211 /* Record the index and wrap counter for a kick we want */ 1212 vq->shadow_avail_idx = idx; 1213 vq->shadow_avail_wrap_counter = wrap_counter; 1214 done: 1215 address_space_cache_destroy(&indirect_desc_cache); 1216 if (in_bytes) { 1217 *in_bytes = in_total; 1218 } 1219 if (out_bytes) { 1220 *out_bytes = out_total; 1221 } 1222 return; 1223 1224 err: 1225 in_total = out_total = 0; 1226 goto done; 1227 } 1228 1229 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 1230 unsigned int *out_bytes, 1231 unsigned max_in_bytes, unsigned max_out_bytes) 1232 { 1233 uint16_t desc_size; 1234 VRingMemoryRegionCaches *caches; 1235 1236 RCU_READ_LOCK_GUARD(); 1237 1238 if (unlikely(!vq->vring.desc)) { 1239 goto err; 1240 } 1241 1242 caches = vring_get_region_caches(vq); 1243 if (!caches) { 1244 goto err; 1245 } 1246 1247 desc_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ? 1248 sizeof(VRingPackedDesc) : sizeof(VRingDesc); 1249 if (caches->desc.len < vq->vring.num * desc_size) { 1250 virtio_error(vq->vdev, "Cannot map descriptor ring"); 1251 goto err; 1252 } 1253 1254 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1255 virtqueue_packed_get_avail_bytes(vq, in_bytes, out_bytes, 1256 max_in_bytes, max_out_bytes, 1257 caches); 1258 } else { 1259 virtqueue_split_get_avail_bytes(vq, in_bytes, out_bytes, 1260 max_in_bytes, max_out_bytes, 1261 caches); 1262 } 1263 1264 return; 1265 err: 1266 if (in_bytes) { 1267 *in_bytes = 0; 1268 } 1269 if (out_bytes) { 1270 *out_bytes = 0; 1271 } 1272 } 1273 1274 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 1275 unsigned int out_bytes) 1276 { 1277 unsigned int in_total, out_total; 1278 1279 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 1280 return in_bytes <= in_total && out_bytes <= out_total; 1281 } 1282 1283 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 1284 hwaddr *addr, struct iovec *iov, 1285 unsigned int max_num_sg, bool is_write, 1286 hwaddr pa, size_t sz) 1287 { 1288 bool ok = false; 1289 unsigned num_sg = *p_num_sg; 1290 assert(num_sg <= max_num_sg); 1291 1292 if (!sz) { 1293 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 1294 goto out; 1295 } 1296 1297 while (sz) { 1298 hwaddr len = sz; 1299 1300 if (num_sg == max_num_sg) { 1301 virtio_error(vdev, "virtio: too many write descriptors in " 1302 "indirect table"); 1303 goto out; 1304 } 1305 1306 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 1307 is_write ? 1308 DMA_DIRECTION_FROM_DEVICE : 1309 DMA_DIRECTION_TO_DEVICE, 1310 MEMTXATTRS_UNSPECIFIED); 1311 if (!iov[num_sg].iov_base) { 1312 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 1313 goto out; 1314 } 1315 1316 iov[num_sg].iov_len = len; 1317 addr[num_sg] = pa; 1318 1319 sz -= len; 1320 pa += len; 1321 num_sg++; 1322 } 1323 ok = true; 1324 1325 out: 1326 *p_num_sg = num_sg; 1327 return ok; 1328 } 1329 1330 /* Only used by error code paths before we have a VirtQueueElement (therefore 1331 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 1332 * yet. 1333 */ 1334 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 1335 struct iovec *iov) 1336 { 1337 unsigned int i; 1338 1339 for (i = 0; i < out_num + in_num; i++) { 1340 int is_write = i >= out_num; 1341 1342 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 1343 iov++; 1344 } 1345 } 1346 1347 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 1348 hwaddr *addr, unsigned int num_sg, 1349 bool is_write) 1350 { 1351 unsigned int i; 1352 hwaddr len; 1353 1354 for (i = 0; i < num_sg; i++) { 1355 len = sg[i].iov_len; 1356 sg[i].iov_base = dma_memory_map(vdev->dma_as, 1357 addr[i], &len, is_write ? 1358 DMA_DIRECTION_FROM_DEVICE : 1359 DMA_DIRECTION_TO_DEVICE, 1360 MEMTXATTRS_UNSPECIFIED); 1361 if (!sg[i].iov_base) { 1362 error_report("virtio: error trying to map MMIO memory"); 1363 exit(1); 1364 } 1365 if (len != sg[i].iov_len) { 1366 error_report("virtio: unexpected memory split"); 1367 exit(1); 1368 } 1369 } 1370 } 1371 1372 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 1373 { 1374 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, true); 1375 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 1376 false); 1377 } 1378 1379 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 1380 { 1381 VirtQueueElement *elem; 1382 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 1383 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 1384 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 1385 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 1386 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 1387 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 1388 1389 assert(sz >= sizeof(VirtQueueElement)); 1390 elem = g_malloc(out_sg_end); 1391 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 1392 elem->out_num = out_num; 1393 elem->in_num = in_num; 1394 elem->in_addr = (void *)elem + in_addr_ofs; 1395 elem->out_addr = (void *)elem + out_addr_ofs; 1396 elem->in_sg = (void *)elem + in_sg_ofs; 1397 elem->out_sg = (void *)elem + out_sg_ofs; 1398 return elem; 1399 } 1400 1401 static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) 1402 { 1403 unsigned int i, head, max; 1404 VRingMemoryRegionCaches *caches; 1405 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1406 MemoryRegionCache *desc_cache; 1407 int64_t len; 1408 VirtIODevice *vdev = vq->vdev; 1409 VirtQueueElement *elem = NULL; 1410 unsigned out_num, in_num, elem_entries; 1411 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1412 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1413 VRingDesc desc; 1414 int rc; 1415 1416 RCU_READ_LOCK_GUARD(); 1417 if (virtio_queue_empty_rcu(vq)) { 1418 goto done; 1419 } 1420 /* Needed after virtio_queue_empty(), see comment in 1421 * virtqueue_num_heads(). */ 1422 smp_rmb(); 1423 1424 /* When we start there are none of either input nor output. */ 1425 out_num = in_num = elem_entries = 0; 1426 1427 max = vq->vring.num; 1428 1429 if (vq->inuse >= vq->vring.num) { 1430 virtio_error(vdev, "Virtqueue size exceeded"); 1431 goto done; 1432 } 1433 1434 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 1435 goto done; 1436 } 1437 1438 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1439 vring_set_avail_event(vq, vq->last_avail_idx); 1440 } 1441 1442 i = head; 1443 1444 caches = vring_get_region_caches(vq); 1445 if (!caches) { 1446 virtio_error(vdev, "Region caches not initialized"); 1447 goto done; 1448 } 1449 1450 if (caches->desc.len < max * sizeof(VRingDesc)) { 1451 virtio_error(vdev, "Cannot map descriptor ring"); 1452 goto done; 1453 } 1454 1455 desc_cache = &caches->desc; 1456 vring_split_desc_read(vdev, &desc, desc_cache, i); 1457 if (desc.flags & VRING_DESC_F_INDIRECT) { 1458 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1459 virtio_error(vdev, "Invalid size for indirect buffer table"); 1460 goto done; 1461 } 1462 1463 /* loop over the indirect descriptor table */ 1464 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1465 desc.addr, desc.len, false); 1466 desc_cache = &indirect_desc_cache; 1467 if (len < desc.len) { 1468 virtio_error(vdev, "Cannot map indirect buffer"); 1469 goto done; 1470 } 1471 1472 max = desc.len / sizeof(VRingDesc); 1473 i = 0; 1474 vring_split_desc_read(vdev, &desc, desc_cache, i); 1475 } 1476 1477 /* Collect all the descriptors */ 1478 do { 1479 bool map_ok; 1480 1481 if (desc.flags & VRING_DESC_F_WRITE) { 1482 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1483 iov + out_num, 1484 VIRTQUEUE_MAX_SIZE - out_num, true, 1485 desc.addr, desc.len); 1486 } else { 1487 if (in_num) { 1488 virtio_error(vdev, "Incorrect order for descriptors"); 1489 goto err_undo_map; 1490 } 1491 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1492 VIRTQUEUE_MAX_SIZE, false, 1493 desc.addr, desc.len); 1494 } 1495 if (!map_ok) { 1496 goto err_undo_map; 1497 } 1498 1499 /* If we've got too many, that implies a descriptor loop. */ 1500 if (++elem_entries > max) { 1501 virtio_error(vdev, "Looped descriptor"); 1502 goto err_undo_map; 1503 } 1504 1505 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); 1506 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1507 1508 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1509 goto err_undo_map; 1510 } 1511 1512 /* Now copy what we have collected and mapped */ 1513 elem = virtqueue_alloc_element(sz, out_num, in_num); 1514 elem->index = head; 1515 elem->ndescs = 1; 1516 for (i = 0; i < out_num; i++) { 1517 elem->out_addr[i] = addr[i]; 1518 elem->out_sg[i] = iov[i]; 1519 } 1520 for (i = 0; i < in_num; i++) { 1521 elem->in_addr[i] = addr[out_num + i]; 1522 elem->in_sg[i] = iov[out_num + i]; 1523 } 1524 1525 vq->inuse++; 1526 1527 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1528 done: 1529 address_space_cache_destroy(&indirect_desc_cache); 1530 1531 return elem; 1532 1533 err_undo_map: 1534 virtqueue_undo_map_desc(out_num, in_num, iov); 1535 goto done; 1536 } 1537 1538 static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) 1539 { 1540 unsigned int i, max; 1541 VRingMemoryRegionCaches *caches; 1542 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1543 MemoryRegionCache *desc_cache; 1544 int64_t len; 1545 VirtIODevice *vdev = vq->vdev; 1546 VirtQueueElement *elem = NULL; 1547 unsigned out_num, in_num, elem_entries; 1548 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1549 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1550 VRingPackedDesc desc; 1551 uint16_t id; 1552 int rc; 1553 1554 RCU_READ_LOCK_GUARD(); 1555 if (virtio_queue_packed_empty_rcu(vq)) { 1556 goto done; 1557 } 1558 1559 /* When we start there are none of either input nor output. */ 1560 out_num = in_num = elem_entries = 0; 1561 1562 max = vq->vring.num; 1563 1564 if (vq->inuse >= vq->vring.num) { 1565 virtio_error(vdev, "Virtqueue size exceeded"); 1566 goto done; 1567 } 1568 1569 i = vq->last_avail_idx; 1570 1571 caches = vring_get_region_caches(vq); 1572 if (!caches) { 1573 virtio_error(vdev, "Region caches not initialized"); 1574 goto done; 1575 } 1576 1577 if (caches->desc.len < max * sizeof(VRingDesc)) { 1578 virtio_error(vdev, "Cannot map descriptor ring"); 1579 goto done; 1580 } 1581 1582 desc_cache = &caches->desc; 1583 vring_packed_desc_read(vdev, &desc, desc_cache, i, true); 1584 id = desc.id; 1585 if (desc.flags & VRING_DESC_F_INDIRECT) { 1586 if (desc.len % sizeof(VRingPackedDesc)) { 1587 virtio_error(vdev, "Invalid size for indirect buffer table"); 1588 goto done; 1589 } 1590 1591 /* loop over the indirect descriptor table */ 1592 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1593 desc.addr, desc.len, false); 1594 desc_cache = &indirect_desc_cache; 1595 if (len < desc.len) { 1596 virtio_error(vdev, "Cannot map indirect buffer"); 1597 goto done; 1598 } 1599 1600 max = desc.len / sizeof(VRingPackedDesc); 1601 i = 0; 1602 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1603 } 1604 1605 /* Collect all the descriptors */ 1606 do { 1607 bool map_ok; 1608 1609 if (desc.flags & VRING_DESC_F_WRITE) { 1610 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1611 iov + out_num, 1612 VIRTQUEUE_MAX_SIZE - out_num, true, 1613 desc.addr, desc.len); 1614 } else { 1615 if (in_num) { 1616 virtio_error(vdev, "Incorrect order for descriptors"); 1617 goto err_undo_map; 1618 } 1619 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1620 VIRTQUEUE_MAX_SIZE, false, 1621 desc.addr, desc.len); 1622 } 1623 if (!map_ok) { 1624 goto err_undo_map; 1625 } 1626 1627 /* If we've got too many, that implies a descriptor loop. */ 1628 if (++elem_entries > max) { 1629 virtio_error(vdev, "Looped descriptor"); 1630 goto err_undo_map; 1631 } 1632 1633 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, &i, 1634 desc_cache == 1635 &indirect_desc_cache); 1636 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1637 1638 /* Now copy what we have collected and mapped */ 1639 elem = virtqueue_alloc_element(sz, out_num, in_num); 1640 for (i = 0; i < out_num; i++) { 1641 elem->out_addr[i] = addr[i]; 1642 elem->out_sg[i] = iov[i]; 1643 } 1644 for (i = 0; i < in_num; i++) { 1645 elem->in_addr[i] = addr[out_num + i]; 1646 elem->in_sg[i] = iov[out_num + i]; 1647 } 1648 1649 elem->index = id; 1650 elem->ndescs = (desc_cache == &indirect_desc_cache) ? 1 : elem_entries; 1651 vq->last_avail_idx += elem->ndescs; 1652 vq->inuse += elem->ndescs; 1653 1654 if (vq->last_avail_idx >= vq->vring.num) { 1655 vq->last_avail_idx -= vq->vring.num; 1656 vq->last_avail_wrap_counter ^= 1; 1657 } 1658 1659 vq->shadow_avail_idx = vq->last_avail_idx; 1660 vq->shadow_avail_wrap_counter = vq->last_avail_wrap_counter; 1661 1662 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1663 done: 1664 address_space_cache_destroy(&indirect_desc_cache); 1665 1666 return elem; 1667 1668 err_undo_map: 1669 virtqueue_undo_map_desc(out_num, in_num, iov); 1670 goto done; 1671 } 1672 1673 void *virtqueue_pop(VirtQueue *vq, size_t sz) 1674 { 1675 if (virtio_device_disabled(vq->vdev)) { 1676 return NULL; 1677 } 1678 1679 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1680 return virtqueue_packed_pop(vq, sz); 1681 } else { 1682 return virtqueue_split_pop(vq, sz); 1683 } 1684 } 1685 1686 static unsigned int virtqueue_packed_drop_all(VirtQueue *vq) 1687 { 1688 VRingMemoryRegionCaches *caches; 1689 MemoryRegionCache *desc_cache; 1690 unsigned int dropped = 0; 1691 VirtQueueElement elem = {}; 1692 VirtIODevice *vdev = vq->vdev; 1693 VRingPackedDesc desc; 1694 1695 RCU_READ_LOCK_GUARD(); 1696 1697 caches = vring_get_region_caches(vq); 1698 if (!caches) { 1699 return 0; 1700 } 1701 1702 desc_cache = &caches->desc; 1703 1704 virtio_queue_set_notification(vq, 0); 1705 1706 while (vq->inuse < vq->vring.num) { 1707 unsigned int idx = vq->last_avail_idx; 1708 /* 1709 * works similar to virtqueue_pop but does not map buffers 1710 * and does not allocate any memory. 1711 */ 1712 vring_packed_desc_read(vdev, &desc, desc_cache, 1713 vq->last_avail_idx , true); 1714 if (!is_desc_avail(desc.flags, vq->last_avail_wrap_counter)) { 1715 break; 1716 } 1717 elem.index = desc.id; 1718 elem.ndescs = 1; 1719 while (virtqueue_packed_read_next_desc(vq, &desc, desc_cache, 1720 vq->vring.num, &idx, false)) { 1721 ++elem.ndescs; 1722 } 1723 /* 1724 * immediately push the element, nothing to unmap 1725 * as both in_num and out_num are set to 0. 1726 */ 1727 virtqueue_push(vq, &elem, 0); 1728 dropped++; 1729 vq->last_avail_idx += elem.ndescs; 1730 if (vq->last_avail_idx >= vq->vring.num) { 1731 vq->last_avail_idx -= vq->vring.num; 1732 vq->last_avail_wrap_counter ^= 1; 1733 } 1734 } 1735 1736 return dropped; 1737 } 1738 1739 static unsigned int virtqueue_split_drop_all(VirtQueue *vq) 1740 { 1741 unsigned int dropped = 0; 1742 VirtQueueElement elem = {}; 1743 VirtIODevice *vdev = vq->vdev; 1744 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 1745 1746 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 1747 /* works similar to virtqueue_pop but does not map buffers 1748 * and does not allocate any memory */ 1749 smp_rmb(); 1750 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 1751 break; 1752 } 1753 vq->inuse++; 1754 vq->last_avail_idx++; 1755 if (fEventIdx) { 1756 vring_set_avail_event(vq, vq->last_avail_idx); 1757 } 1758 /* immediately push the element, nothing to unmap 1759 * as both in_num and out_num are set to 0 */ 1760 virtqueue_push(vq, &elem, 0); 1761 dropped++; 1762 } 1763 1764 return dropped; 1765 } 1766 1767 /* virtqueue_drop_all: 1768 * @vq: The #VirtQueue 1769 * Drops all queued buffers and indicates them to the guest 1770 * as if they are done. Useful when buffers can not be 1771 * processed but must be returned to the guest. 1772 */ 1773 unsigned int virtqueue_drop_all(VirtQueue *vq) 1774 { 1775 struct VirtIODevice *vdev = vq->vdev; 1776 1777 if (virtio_device_disabled(vq->vdev)) { 1778 return 0; 1779 } 1780 1781 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1782 return virtqueue_packed_drop_all(vq); 1783 } else { 1784 return virtqueue_split_drop_all(vq); 1785 } 1786 } 1787 1788 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1789 * it is what QEMU has always done by mistake. We can change it sooner 1790 * or later by bumping the version number of the affected vm states. 1791 * In the meanwhile, since the in-memory layout of VirtQueueElement 1792 * has changed, we need to marshal to and from the layout that was 1793 * used before the change. 1794 */ 1795 typedef struct VirtQueueElementOld { 1796 unsigned int index; 1797 unsigned int out_num; 1798 unsigned int in_num; 1799 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1800 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1801 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1802 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1803 } VirtQueueElementOld; 1804 1805 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1806 { 1807 VirtQueueElement *elem; 1808 VirtQueueElementOld data; 1809 int i; 1810 1811 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1812 1813 /* TODO: teach all callers that this can fail, and return failure instead 1814 * of asserting here. 1815 * This is just one thing (there are probably more) that must be 1816 * fixed before we can allow NDEBUG compilation. 1817 */ 1818 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1819 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1820 1821 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1822 elem->index = data.index; 1823 1824 for (i = 0; i < elem->in_num; i++) { 1825 elem->in_addr[i] = data.in_addr[i]; 1826 } 1827 1828 for (i = 0; i < elem->out_num; i++) { 1829 elem->out_addr[i] = data.out_addr[i]; 1830 } 1831 1832 for (i = 0; i < elem->in_num; i++) { 1833 /* Base is overwritten by virtqueue_map. */ 1834 elem->in_sg[i].iov_base = 0; 1835 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1836 } 1837 1838 for (i = 0; i < elem->out_num; i++) { 1839 /* Base is overwritten by virtqueue_map. */ 1840 elem->out_sg[i].iov_base = 0; 1841 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1842 } 1843 1844 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1845 qemu_get_be32s(f, &elem->ndescs); 1846 } 1847 1848 virtqueue_map(vdev, elem); 1849 return elem; 1850 } 1851 1852 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 1853 VirtQueueElement *elem) 1854 { 1855 VirtQueueElementOld data; 1856 int i; 1857 1858 memset(&data, 0, sizeof(data)); 1859 data.index = elem->index; 1860 data.in_num = elem->in_num; 1861 data.out_num = elem->out_num; 1862 1863 for (i = 0; i < elem->in_num; i++) { 1864 data.in_addr[i] = elem->in_addr[i]; 1865 } 1866 1867 for (i = 0; i < elem->out_num; i++) { 1868 data.out_addr[i] = elem->out_addr[i]; 1869 } 1870 1871 for (i = 0; i < elem->in_num; i++) { 1872 /* Base is overwritten by virtqueue_map when loading. Do not 1873 * save it, as it would leak the QEMU address space layout. */ 1874 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1875 } 1876 1877 for (i = 0; i < elem->out_num; i++) { 1878 /* Do not save iov_base as above. */ 1879 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1880 } 1881 1882 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1883 qemu_put_be32s(f, &elem->ndescs); 1884 } 1885 1886 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1887 } 1888 1889 /* virtio device */ 1890 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1891 { 1892 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1893 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1894 1895 if (virtio_device_disabled(vdev)) { 1896 return; 1897 } 1898 1899 if (k->notify) { 1900 k->notify(qbus->parent, vector); 1901 } 1902 } 1903 1904 void virtio_update_irq(VirtIODevice *vdev) 1905 { 1906 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1907 } 1908 1909 static int virtio_validate_features(VirtIODevice *vdev) 1910 { 1911 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1912 1913 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 1914 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 1915 return -EFAULT; 1916 } 1917 1918 if (k->validate_features) { 1919 return k->validate_features(vdev); 1920 } else { 1921 return 0; 1922 } 1923 } 1924 1925 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 1926 { 1927 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1928 trace_virtio_set_status(vdev, val); 1929 1930 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1931 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 1932 val & VIRTIO_CONFIG_S_FEATURES_OK) { 1933 int ret = virtio_validate_features(vdev); 1934 1935 if (ret) { 1936 return ret; 1937 } 1938 } 1939 } 1940 1941 if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) != 1942 (val & VIRTIO_CONFIG_S_DRIVER_OK)) { 1943 virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK); 1944 } 1945 1946 if (k->set_status) { 1947 k->set_status(vdev, val); 1948 } 1949 vdev->status = val; 1950 1951 return 0; 1952 } 1953 1954 static enum virtio_device_endian virtio_default_endian(void) 1955 { 1956 if (target_words_bigendian()) { 1957 return VIRTIO_DEVICE_ENDIAN_BIG; 1958 } else { 1959 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1960 } 1961 } 1962 1963 static enum virtio_device_endian virtio_current_cpu_endian(void) 1964 { 1965 if (cpu_virtio_is_big_endian(current_cpu)) { 1966 return VIRTIO_DEVICE_ENDIAN_BIG; 1967 } else { 1968 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1969 } 1970 } 1971 1972 void virtio_reset(void *opaque) 1973 { 1974 VirtIODevice *vdev = opaque; 1975 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1976 int i; 1977 1978 virtio_set_status(vdev, 0); 1979 if (current_cpu) { 1980 /* Guest initiated reset */ 1981 vdev->device_endian = virtio_current_cpu_endian(); 1982 } else { 1983 /* System reset */ 1984 vdev->device_endian = virtio_default_endian(); 1985 } 1986 1987 if (k->reset) { 1988 k->reset(vdev); 1989 } 1990 1991 vdev->start_on_kick = false; 1992 vdev->started = false; 1993 vdev->broken = false; 1994 vdev->guest_features = 0; 1995 vdev->queue_sel = 0; 1996 vdev->status = 0; 1997 vdev->disabled = false; 1998 qatomic_set(&vdev->isr, 0); 1999 vdev->config_vector = VIRTIO_NO_VECTOR; 2000 virtio_notify_vector(vdev, vdev->config_vector); 2001 2002 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2003 vdev->vq[i].vring.desc = 0; 2004 vdev->vq[i].vring.avail = 0; 2005 vdev->vq[i].vring.used = 0; 2006 vdev->vq[i].last_avail_idx = 0; 2007 vdev->vq[i].shadow_avail_idx = 0; 2008 vdev->vq[i].used_idx = 0; 2009 vdev->vq[i].last_avail_wrap_counter = true; 2010 vdev->vq[i].shadow_avail_wrap_counter = true; 2011 vdev->vq[i].used_wrap_counter = true; 2012 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 2013 vdev->vq[i].signalled_used = 0; 2014 vdev->vq[i].signalled_used_valid = false; 2015 vdev->vq[i].notification = true; 2016 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 2017 vdev->vq[i].inuse = 0; 2018 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2019 } 2020 } 2021 2022 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 2023 { 2024 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2025 uint8_t val; 2026 2027 if (addr + sizeof(val) > vdev->config_len) { 2028 return (uint32_t)-1; 2029 } 2030 2031 k->get_config(vdev, vdev->config); 2032 2033 val = ldub_p(vdev->config + addr); 2034 return val; 2035 } 2036 2037 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 2038 { 2039 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2040 uint16_t val; 2041 2042 if (addr + sizeof(val) > vdev->config_len) { 2043 return (uint32_t)-1; 2044 } 2045 2046 k->get_config(vdev, vdev->config); 2047 2048 val = lduw_p(vdev->config + addr); 2049 return val; 2050 } 2051 2052 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 2053 { 2054 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2055 uint32_t val; 2056 2057 if (addr + sizeof(val) > vdev->config_len) { 2058 return (uint32_t)-1; 2059 } 2060 2061 k->get_config(vdev, vdev->config); 2062 2063 val = ldl_p(vdev->config + addr); 2064 return val; 2065 } 2066 2067 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 2068 { 2069 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2070 uint8_t val = data; 2071 2072 if (addr + sizeof(val) > vdev->config_len) { 2073 return; 2074 } 2075 2076 stb_p(vdev->config + addr, val); 2077 2078 if (k->set_config) { 2079 k->set_config(vdev, vdev->config); 2080 } 2081 } 2082 2083 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 2084 { 2085 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2086 uint16_t val = data; 2087 2088 if (addr + sizeof(val) > vdev->config_len) { 2089 return; 2090 } 2091 2092 stw_p(vdev->config + addr, val); 2093 2094 if (k->set_config) { 2095 k->set_config(vdev, vdev->config); 2096 } 2097 } 2098 2099 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 2100 { 2101 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2102 uint32_t val = data; 2103 2104 if (addr + sizeof(val) > vdev->config_len) { 2105 return; 2106 } 2107 2108 stl_p(vdev->config + addr, val); 2109 2110 if (k->set_config) { 2111 k->set_config(vdev, vdev->config); 2112 } 2113 } 2114 2115 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 2116 { 2117 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2118 uint8_t val; 2119 2120 if (addr + sizeof(val) > vdev->config_len) { 2121 return (uint32_t)-1; 2122 } 2123 2124 k->get_config(vdev, vdev->config); 2125 2126 val = ldub_p(vdev->config + addr); 2127 return val; 2128 } 2129 2130 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 2131 { 2132 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2133 uint16_t val; 2134 2135 if (addr + sizeof(val) > vdev->config_len) { 2136 return (uint32_t)-1; 2137 } 2138 2139 k->get_config(vdev, vdev->config); 2140 2141 val = lduw_le_p(vdev->config + addr); 2142 return val; 2143 } 2144 2145 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 2146 { 2147 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2148 uint32_t val; 2149 2150 if (addr + sizeof(val) > vdev->config_len) { 2151 return (uint32_t)-1; 2152 } 2153 2154 k->get_config(vdev, vdev->config); 2155 2156 val = ldl_le_p(vdev->config + addr); 2157 return val; 2158 } 2159 2160 void virtio_config_modern_writeb(VirtIODevice *vdev, 2161 uint32_t addr, uint32_t data) 2162 { 2163 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2164 uint8_t val = data; 2165 2166 if (addr + sizeof(val) > vdev->config_len) { 2167 return; 2168 } 2169 2170 stb_p(vdev->config + addr, val); 2171 2172 if (k->set_config) { 2173 k->set_config(vdev, vdev->config); 2174 } 2175 } 2176 2177 void virtio_config_modern_writew(VirtIODevice *vdev, 2178 uint32_t addr, uint32_t data) 2179 { 2180 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2181 uint16_t val = data; 2182 2183 if (addr + sizeof(val) > vdev->config_len) { 2184 return; 2185 } 2186 2187 stw_le_p(vdev->config + addr, val); 2188 2189 if (k->set_config) { 2190 k->set_config(vdev, vdev->config); 2191 } 2192 } 2193 2194 void virtio_config_modern_writel(VirtIODevice *vdev, 2195 uint32_t addr, uint32_t data) 2196 { 2197 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2198 uint32_t val = data; 2199 2200 if (addr + sizeof(val) > vdev->config_len) { 2201 return; 2202 } 2203 2204 stl_le_p(vdev->config + addr, val); 2205 2206 if (k->set_config) { 2207 k->set_config(vdev, vdev->config); 2208 } 2209 } 2210 2211 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 2212 { 2213 if (!vdev->vq[n].vring.num) { 2214 return; 2215 } 2216 vdev->vq[n].vring.desc = addr; 2217 virtio_queue_update_rings(vdev, n); 2218 } 2219 2220 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 2221 { 2222 return vdev->vq[n].vring.desc; 2223 } 2224 2225 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 2226 hwaddr avail, hwaddr used) 2227 { 2228 if (!vdev->vq[n].vring.num) { 2229 return; 2230 } 2231 vdev->vq[n].vring.desc = desc; 2232 vdev->vq[n].vring.avail = avail; 2233 vdev->vq[n].vring.used = used; 2234 virtio_init_region_cache(vdev, n); 2235 } 2236 2237 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 2238 { 2239 /* Don't allow guest to flip queue between existent and 2240 * nonexistent states, or to set it to an invalid size. 2241 */ 2242 if (!!num != !!vdev->vq[n].vring.num || 2243 num > VIRTQUEUE_MAX_SIZE || 2244 num < 0) { 2245 return; 2246 } 2247 vdev->vq[n].vring.num = num; 2248 } 2249 2250 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 2251 { 2252 return QLIST_FIRST(&vdev->vector_queues[vector]); 2253 } 2254 2255 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 2256 { 2257 return QLIST_NEXT(vq, node); 2258 } 2259 2260 int virtio_queue_get_num(VirtIODevice *vdev, int n) 2261 { 2262 return vdev->vq[n].vring.num; 2263 } 2264 2265 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 2266 { 2267 return vdev->vq[n].vring.num_default; 2268 } 2269 2270 int virtio_get_num_queues(VirtIODevice *vdev) 2271 { 2272 int i; 2273 2274 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2275 if (!virtio_queue_get_num(vdev, i)) { 2276 break; 2277 } 2278 } 2279 2280 return i; 2281 } 2282 2283 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 2284 { 2285 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2286 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2287 2288 /* virtio-1 compliant devices cannot change the alignment */ 2289 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2290 error_report("tried to modify queue alignment for virtio-1 device"); 2291 return; 2292 } 2293 /* Check that the transport told us it was going to do this 2294 * (so a buggy transport will immediately assert rather than 2295 * silently failing to migrate this state) 2296 */ 2297 assert(k->has_variable_vring_alignment); 2298 2299 if (align) { 2300 vdev->vq[n].vring.align = align; 2301 virtio_queue_update_rings(vdev, n); 2302 } 2303 } 2304 2305 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) 2306 { 2307 bool ret = false; 2308 2309 if (vq->vring.desc && vq->handle_aio_output) { 2310 VirtIODevice *vdev = vq->vdev; 2311 2312 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2313 ret = vq->handle_aio_output(vdev, vq); 2314 2315 if (unlikely(vdev->start_on_kick)) { 2316 virtio_set_started(vdev, true); 2317 } 2318 } 2319 2320 return ret; 2321 } 2322 2323 static void virtio_queue_notify_vq(VirtQueue *vq) 2324 { 2325 if (vq->vring.desc && vq->handle_output) { 2326 VirtIODevice *vdev = vq->vdev; 2327 2328 if (unlikely(vdev->broken)) { 2329 return; 2330 } 2331 2332 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2333 vq->handle_output(vdev, vq); 2334 2335 if (unlikely(vdev->start_on_kick)) { 2336 virtio_set_started(vdev, true); 2337 } 2338 } 2339 } 2340 2341 void virtio_queue_notify(VirtIODevice *vdev, int n) 2342 { 2343 VirtQueue *vq = &vdev->vq[n]; 2344 2345 if (unlikely(!vq->vring.desc || vdev->broken)) { 2346 return; 2347 } 2348 2349 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2350 if (vq->host_notifier_enabled) { 2351 event_notifier_set(&vq->host_notifier); 2352 } else if (vq->handle_output) { 2353 vq->handle_output(vdev, vq); 2354 2355 if (unlikely(vdev->start_on_kick)) { 2356 virtio_set_started(vdev, true); 2357 } 2358 } 2359 } 2360 2361 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 2362 { 2363 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 2364 VIRTIO_NO_VECTOR; 2365 } 2366 2367 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 2368 { 2369 VirtQueue *vq = &vdev->vq[n]; 2370 2371 if (n < VIRTIO_QUEUE_MAX) { 2372 if (vdev->vector_queues && 2373 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 2374 QLIST_REMOVE(vq, node); 2375 } 2376 vdev->vq[n].vector = vector; 2377 if (vdev->vector_queues && 2378 vector != VIRTIO_NO_VECTOR) { 2379 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 2380 } 2381 } 2382 } 2383 2384 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 2385 VirtIOHandleOutput handle_output) 2386 { 2387 int i; 2388 2389 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2390 if (vdev->vq[i].vring.num == 0) 2391 break; 2392 } 2393 2394 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 2395 abort(); 2396 2397 vdev->vq[i].vring.num = queue_size; 2398 vdev->vq[i].vring.num_default = queue_size; 2399 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 2400 vdev->vq[i].handle_output = handle_output; 2401 vdev->vq[i].handle_aio_output = NULL; 2402 vdev->vq[i].used_elems = g_malloc0(sizeof(VirtQueueElement) * 2403 queue_size); 2404 2405 return &vdev->vq[i]; 2406 } 2407 2408 void virtio_delete_queue(VirtQueue *vq) 2409 { 2410 vq->vring.num = 0; 2411 vq->vring.num_default = 0; 2412 vq->handle_output = NULL; 2413 vq->handle_aio_output = NULL; 2414 g_free(vq->used_elems); 2415 vq->used_elems = NULL; 2416 virtio_virtqueue_reset_region_cache(vq); 2417 } 2418 2419 void virtio_del_queue(VirtIODevice *vdev, int n) 2420 { 2421 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 2422 abort(); 2423 } 2424 2425 virtio_delete_queue(&vdev->vq[n]); 2426 } 2427 2428 static void virtio_set_isr(VirtIODevice *vdev, int value) 2429 { 2430 uint8_t old = qatomic_read(&vdev->isr); 2431 2432 /* Do not write ISR if it does not change, so that its cacheline remains 2433 * shared in the common case where the guest does not read it. 2434 */ 2435 if ((old & value) != value) { 2436 qatomic_or(&vdev->isr, value); 2437 } 2438 } 2439 2440 /* Called within rcu_read_lock(). */ 2441 static bool virtio_split_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2442 { 2443 uint16_t old, new; 2444 bool v; 2445 /* We need to expose used array entries before checking used event. */ 2446 smp_mb(); 2447 /* Always notify when queue is empty (when feature acknowledge) */ 2448 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 2449 !vq->inuse && virtio_queue_empty(vq)) { 2450 return true; 2451 } 2452 2453 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2454 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 2455 } 2456 2457 v = vq->signalled_used_valid; 2458 vq->signalled_used_valid = true; 2459 old = vq->signalled_used; 2460 new = vq->signalled_used = vq->used_idx; 2461 return !v || vring_need_event(vring_get_used_event(vq), new, old); 2462 } 2463 2464 static bool vring_packed_need_event(VirtQueue *vq, bool wrap, 2465 uint16_t off_wrap, uint16_t new, 2466 uint16_t old) 2467 { 2468 int off = off_wrap & ~(1 << 15); 2469 2470 if (wrap != off_wrap >> 15) { 2471 off -= vq->vring.num; 2472 } 2473 2474 return vring_need_event(off, new, old); 2475 } 2476 2477 /* Called within rcu_read_lock(). */ 2478 static bool virtio_packed_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2479 { 2480 VRingPackedDescEvent e; 2481 uint16_t old, new; 2482 bool v; 2483 VRingMemoryRegionCaches *caches; 2484 2485 caches = vring_get_region_caches(vq); 2486 if (!caches) { 2487 return false; 2488 } 2489 2490 vring_packed_event_read(vdev, &caches->avail, &e); 2491 2492 old = vq->signalled_used; 2493 new = vq->signalled_used = vq->used_idx; 2494 v = vq->signalled_used_valid; 2495 vq->signalled_used_valid = true; 2496 2497 if (e.flags == VRING_PACKED_EVENT_FLAG_DISABLE) { 2498 return false; 2499 } else if (e.flags == VRING_PACKED_EVENT_FLAG_ENABLE) { 2500 return true; 2501 } 2502 2503 return !v || vring_packed_need_event(vq, vq->used_wrap_counter, 2504 e.off_wrap, new, old); 2505 } 2506 2507 /* Called within rcu_read_lock(). */ 2508 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2509 { 2510 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 2511 return virtio_packed_should_notify(vdev, vq); 2512 } else { 2513 return virtio_split_should_notify(vdev, vq); 2514 } 2515 } 2516 2517 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 2518 { 2519 WITH_RCU_READ_LOCK_GUARD() { 2520 if (!virtio_should_notify(vdev, vq)) { 2521 return; 2522 } 2523 } 2524 2525 trace_virtio_notify_irqfd(vdev, vq); 2526 2527 /* 2528 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 2529 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 2530 * incorrectly polling this bit during crashdump and hibernation 2531 * in MSI mode, causing a hang if this bit is never updated. 2532 * Recent releases of Windows do not really shut down, but rather 2533 * log out and hibernate to make the next startup faster. Hence, 2534 * this manifested as a more serious hang during shutdown with 2535 * 2536 * Next driver release from 2016 fixed this problem, so working around it 2537 * is not a must, but it's easy to do so let's do it here. 2538 * 2539 * Note: it's safe to update ISR from any thread as it was switched 2540 * to an atomic operation. 2541 */ 2542 virtio_set_isr(vq->vdev, 0x1); 2543 event_notifier_set(&vq->guest_notifier); 2544 } 2545 2546 static void virtio_irq(VirtQueue *vq) 2547 { 2548 virtio_set_isr(vq->vdev, 0x1); 2549 virtio_notify_vector(vq->vdev, vq->vector); 2550 } 2551 2552 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 2553 { 2554 WITH_RCU_READ_LOCK_GUARD() { 2555 if (!virtio_should_notify(vdev, vq)) { 2556 return; 2557 } 2558 } 2559 2560 trace_virtio_notify(vdev, vq); 2561 virtio_irq(vq); 2562 } 2563 2564 void virtio_notify_config(VirtIODevice *vdev) 2565 { 2566 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 2567 return; 2568 2569 virtio_set_isr(vdev, 0x3); 2570 vdev->generation++; 2571 virtio_notify_vector(vdev, vdev->config_vector); 2572 } 2573 2574 static bool virtio_device_endian_needed(void *opaque) 2575 { 2576 VirtIODevice *vdev = opaque; 2577 2578 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 2579 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2580 return vdev->device_endian != virtio_default_endian(); 2581 } 2582 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 2583 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 2584 } 2585 2586 static bool virtio_64bit_features_needed(void *opaque) 2587 { 2588 VirtIODevice *vdev = opaque; 2589 2590 return (vdev->host_features >> 32) != 0; 2591 } 2592 2593 static bool virtio_virtqueue_needed(void *opaque) 2594 { 2595 VirtIODevice *vdev = opaque; 2596 2597 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 2598 } 2599 2600 static bool virtio_packed_virtqueue_needed(void *opaque) 2601 { 2602 VirtIODevice *vdev = opaque; 2603 2604 return virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED); 2605 } 2606 2607 static bool virtio_ringsize_needed(void *opaque) 2608 { 2609 VirtIODevice *vdev = opaque; 2610 int i; 2611 2612 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2613 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 2614 return true; 2615 } 2616 } 2617 return false; 2618 } 2619 2620 static bool virtio_extra_state_needed(void *opaque) 2621 { 2622 VirtIODevice *vdev = opaque; 2623 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2624 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2625 2626 return k->has_extra_state && 2627 k->has_extra_state(qbus->parent); 2628 } 2629 2630 static bool virtio_broken_needed(void *opaque) 2631 { 2632 VirtIODevice *vdev = opaque; 2633 2634 return vdev->broken; 2635 } 2636 2637 static bool virtio_started_needed(void *opaque) 2638 { 2639 VirtIODevice *vdev = opaque; 2640 2641 return vdev->started; 2642 } 2643 2644 static bool virtio_disabled_needed(void *opaque) 2645 { 2646 VirtIODevice *vdev = opaque; 2647 2648 return vdev->disabled; 2649 } 2650 2651 static const VMStateDescription vmstate_virtqueue = { 2652 .name = "virtqueue_state", 2653 .version_id = 1, 2654 .minimum_version_id = 1, 2655 .fields = (VMStateField[]) { 2656 VMSTATE_UINT64(vring.avail, struct VirtQueue), 2657 VMSTATE_UINT64(vring.used, struct VirtQueue), 2658 VMSTATE_END_OF_LIST() 2659 } 2660 }; 2661 2662 static const VMStateDescription vmstate_packed_virtqueue = { 2663 .name = "packed_virtqueue_state", 2664 .version_id = 1, 2665 .minimum_version_id = 1, 2666 .fields = (VMStateField[]) { 2667 VMSTATE_UINT16(last_avail_idx, struct VirtQueue), 2668 VMSTATE_BOOL(last_avail_wrap_counter, struct VirtQueue), 2669 VMSTATE_UINT16(used_idx, struct VirtQueue), 2670 VMSTATE_BOOL(used_wrap_counter, struct VirtQueue), 2671 VMSTATE_UINT32(inuse, struct VirtQueue), 2672 VMSTATE_END_OF_LIST() 2673 } 2674 }; 2675 2676 static const VMStateDescription vmstate_virtio_virtqueues = { 2677 .name = "virtio/virtqueues", 2678 .version_id = 1, 2679 .minimum_version_id = 1, 2680 .needed = &virtio_virtqueue_needed, 2681 .fields = (VMStateField[]) { 2682 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2683 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 2684 VMSTATE_END_OF_LIST() 2685 } 2686 }; 2687 2688 static const VMStateDescription vmstate_virtio_packed_virtqueues = { 2689 .name = "virtio/packed_virtqueues", 2690 .version_id = 1, 2691 .minimum_version_id = 1, 2692 .needed = &virtio_packed_virtqueue_needed, 2693 .fields = (VMStateField[]) { 2694 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2695 VIRTIO_QUEUE_MAX, 0, vmstate_packed_virtqueue, VirtQueue), 2696 VMSTATE_END_OF_LIST() 2697 } 2698 }; 2699 2700 static const VMStateDescription vmstate_ringsize = { 2701 .name = "ringsize_state", 2702 .version_id = 1, 2703 .minimum_version_id = 1, 2704 .fields = (VMStateField[]) { 2705 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 2706 VMSTATE_END_OF_LIST() 2707 } 2708 }; 2709 2710 static const VMStateDescription vmstate_virtio_ringsize = { 2711 .name = "virtio/ringsize", 2712 .version_id = 1, 2713 .minimum_version_id = 1, 2714 .needed = &virtio_ringsize_needed, 2715 .fields = (VMStateField[]) { 2716 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2717 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 2718 VMSTATE_END_OF_LIST() 2719 } 2720 }; 2721 2722 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 2723 const VMStateField *field) 2724 { 2725 VirtIODevice *vdev = pv; 2726 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2727 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2728 2729 if (!k->load_extra_state) { 2730 return -1; 2731 } else { 2732 return k->load_extra_state(qbus->parent, f); 2733 } 2734 } 2735 2736 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 2737 const VMStateField *field, JSONWriter *vmdesc) 2738 { 2739 VirtIODevice *vdev = pv; 2740 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2741 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2742 2743 k->save_extra_state(qbus->parent, f); 2744 return 0; 2745 } 2746 2747 static const VMStateInfo vmstate_info_extra_state = { 2748 .name = "virtqueue_extra_state", 2749 .get = get_extra_state, 2750 .put = put_extra_state, 2751 }; 2752 2753 static const VMStateDescription vmstate_virtio_extra_state = { 2754 .name = "virtio/extra_state", 2755 .version_id = 1, 2756 .minimum_version_id = 1, 2757 .needed = &virtio_extra_state_needed, 2758 .fields = (VMStateField[]) { 2759 { 2760 .name = "extra_state", 2761 .version_id = 0, 2762 .field_exists = NULL, 2763 .size = 0, 2764 .info = &vmstate_info_extra_state, 2765 .flags = VMS_SINGLE, 2766 .offset = 0, 2767 }, 2768 VMSTATE_END_OF_LIST() 2769 } 2770 }; 2771 2772 static const VMStateDescription vmstate_virtio_device_endian = { 2773 .name = "virtio/device_endian", 2774 .version_id = 1, 2775 .minimum_version_id = 1, 2776 .needed = &virtio_device_endian_needed, 2777 .fields = (VMStateField[]) { 2778 VMSTATE_UINT8(device_endian, VirtIODevice), 2779 VMSTATE_END_OF_LIST() 2780 } 2781 }; 2782 2783 static const VMStateDescription vmstate_virtio_64bit_features = { 2784 .name = "virtio/64bit_features", 2785 .version_id = 1, 2786 .minimum_version_id = 1, 2787 .needed = &virtio_64bit_features_needed, 2788 .fields = (VMStateField[]) { 2789 VMSTATE_UINT64(guest_features, VirtIODevice), 2790 VMSTATE_END_OF_LIST() 2791 } 2792 }; 2793 2794 static const VMStateDescription vmstate_virtio_broken = { 2795 .name = "virtio/broken", 2796 .version_id = 1, 2797 .minimum_version_id = 1, 2798 .needed = &virtio_broken_needed, 2799 .fields = (VMStateField[]) { 2800 VMSTATE_BOOL(broken, VirtIODevice), 2801 VMSTATE_END_OF_LIST() 2802 } 2803 }; 2804 2805 static const VMStateDescription vmstate_virtio_started = { 2806 .name = "virtio/started", 2807 .version_id = 1, 2808 .minimum_version_id = 1, 2809 .needed = &virtio_started_needed, 2810 .fields = (VMStateField[]) { 2811 VMSTATE_BOOL(started, VirtIODevice), 2812 VMSTATE_END_OF_LIST() 2813 } 2814 }; 2815 2816 static const VMStateDescription vmstate_virtio_disabled = { 2817 .name = "virtio/disabled", 2818 .version_id = 1, 2819 .minimum_version_id = 1, 2820 .needed = &virtio_disabled_needed, 2821 .fields = (VMStateField[]) { 2822 VMSTATE_BOOL(disabled, VirtIODevice), 2823 VMSTATE_END_OF_LIST() 2824 } 2825 }; 2826 2827 static const VMStateDescription vmstate_virtio = { 2828 .name = "virtio", 2829 .version_id = 1, 2830 .minimum_version_id = 1, 2831 .minimum_version_id_old = 1, 2832 .fields = (VMStateField[]) { 2833 VMSTATE_END_OF_LIST() 2834 }, 2835 .subsections = (const VMStateDescription*[]) { 2836 &vmstate_virtio_device_endian, 2837 &vmstate_virtio_64bit_features, 2838 &vmstate_virtio_virtqueues, 2839 &vmstate_virtio_ringsize, 2840 &vmstate_virtio_broken, 2841 &vmstate_virtio_extra_state, 2842 &vmstate_virtio_started, 2843 &vmstate_virtio_packed_virtqueues, 2844 &vmstate_virtio_disabled, 2845 NULL 2846 } 2847 }; 2848 2849 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 2850 { 2851 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2852 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2853 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2854 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 2855 int i; 2856 2857 if (k->save_config) { 2858 k->save_config(qbus->parent, f); 2859 } 2860 2861 qemu_put_8s(f, &vdev->status); 2862 qemu_put_8s(f, &vdev->isr); 2863 qemu_put_be16s(f, &vdev->queue_sel); 2864 qemu_put_be32s(f, &guest_features_lo); 2865 qemu_put_be32(f, vdev->config_len); 2866 qemu_put_buffer(f, vdev->config, vdev->config_len); 2867 2868 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2869 if (vdev->vq[i].vring.num == 0) 2870 break; 2871 } 2872 2873 qemu_put_be32(f, i); 2874 2875 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2876 if (vdev->vq[i].vring.num == 0) 2877 break; 2878 2879 qemu_put_be32(f, vdev->vq[i].vring.num); 2880 if (k->has_variable_vring_alignment) { 2881 qemu_put_be32(f, vdev->vq[i].vring.align); 2882 } 2883 /* 2884 * Save desc now, the rest of the ring addresses are saved in 2885 * subsections for VIRTIO-1 devices. 2886 */ 2887 qemu_put_be64(f, vdev->vq[i].vring.desc); 2888 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 2889 if (k->save_queue) { 2890 k->save_queue(qbus->parent, i, f); 2891 } 2892 } 2893 2894 if (vdc->save != NULL) { 2895 vdc->save(vdev, f); 2896 } 2897 2898 if (vdc->vmsd) { 2899 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 2900 if (ret) { 2901 return ret; 2902 } 2903 } 2904 2905 /* Subsections */ 2906 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 2907 } 2908 2909 /* A wrapper for use as a VMState .put function */ 2910 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 2911 const VMStateField *field, JSONWriter *vmdesc) 2912 { 2913 return virtio_save(VIRTIO_DEVICE(opaque), f); 2914 } 2915 2916 /* A wrapper for use as a VMState .get function */ 2917 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 2918 const VMStateField *field) 2919 { 2920 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 2921 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 2922 2923 return virtio_load(vdev, f, dc->vmsd->version_id); 2924 } 2925 2926 const VMStateInfo virtio_vmstate_info = { 2927 .name = "virtio", 2928 .get = virtio_device_get, 2929 .put = virtio_device_put, 2930 }; 2931 2932 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 2933 { 2934 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2935 bool bad = (val & ~(vdev->host_features)) != 0; 2936 2937 val &= vdev->host_features; 2938 if (k->set_features) { 2939 k->set_features(vdev, val); 2940 } 2941 vdev->guest_features = val; 2942 return bad ? -1 : 0; 2943 } 2944 2945 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2946 { 2947 int ret; 2948 /* 2949 * The driver must not attempt to set features after feature negotiation 2950 * has finished. 2951 */ 2952 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2953 return -EINVAL; 2954 } 2955 ret = virtio_set_features_nocheck(vdev, val); 2956 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2957 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ 2958 int i; 2959 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2960 if (vdev->vq[i].vring.num != 0) { 2961 virtio_init_region_cache(vdev, i); 2962 } 2963 } 2964 } 2965 if (!ret) { 2966 if (!virtio_device_started(vdev, vdev->status) && 2967 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2968 vdev->start_on_kick = true; 2969 } 2970 } 2971 return ret; 2972 } 2973 2974 size_t virtio_feature_get_config_size(const VirtIOFeature *feature_sizes, 2975 uint64_t host_features) 2976 { 2977 size_t config_size = 0; 2978 int i; 2979 2980 for (i = 0; feature_sizes[i].flags != 0; i++) { 2981 if (host_features & feature_sizes[i].flags) { 2982 config_size = MAX(feature_sizes[i].end, config_size); 2983 } 2984 } 2985 2986 return config_size; 2987 } 2988 2989 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2990 { 2991 int i, ret; 2992 int32_t config_len; 2993 uint32_t num; 2994 uint32_t features; 2995 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2996 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2997 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2998 2999 /* 3000 * We poison the endianness to ensure it does not get used before 3001 * subsections have been loaded. 3002 */ 3003 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 3004 3005 if (k->load_config) { 3006 ret = k->load_config(qbus->parent, f); 3007 if (ret) 3008 return ret; 3009 } 3010 3011 qemu_get_8s(f, &vdev->status); 3012 qemu_get_8s(f, &vdev->isr); 3013 qemu_get_be16s(f, &vdev->queue_sel); 3014 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 3015 return -1; 3016 } 3017 qemu_get_be32s(f, &features); 3018 3019 /* 3020 * Temporarily set guest_features low bits - needed by 3021 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 3022 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 3023 * 3024 * Note: devices should always test host features in future - don't create 3025 * new dependencies like this. 3026 */ 3027 vdev->guest_features = features; 3028 3029 config_len = qemu_get_be32(f); 3030 3031 /* 3032 * There are cases where the incoming config can be bigger or smaller 3033 * than what we have; so load what we have space for, and skip 3034 * any excess that's in the stream. 3035 */ 3036 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 3037 3038 while (config_len > vdev->config_len) { 3039 qemu_get_byte(f); 3040 config_len--; 3041 } 3042 3043 num = qemu_get_be32(f); 3044 3045 if (num > VIRTIO_QUEUE_MAX) { 3046 error_report("Invalid number of virtqueues: 0x%x", num); 3047 return -1; 3048 } 3049 3050 for (i = 0; i < num; i++) { 3051 vdev->vq[i].vring.num = qemu_get_be32(f); 3052 if (k->has_variable_vring_alignment) { 3053 vdev->vq[i].vring.align = qemu_get_be32(f); 3054 } 3055 vdev->vq[i].vring.desc = qemu_get_be64(f); 3056 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 3057 vdev->vq[i].signalled_used_valid = false; 3058 vdev->vq[i].notification = true; 3059 3060 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 3061 error_report("VQ %d address 0x0 " 3062 "inconsistent with Host index 0x%x", 3063 i, vdev->vq[i].last_avail_idx); 3064 return -1; 3065 } 3066 if (k->load_queue) { 3067 ret = k->load_queue(qbus->parent, i, f); 3068 if (ret) 3069 return ret; 3070 } 3071 } 3072 3073 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 3074 3075 if (vdc->load != NULL) { 3076 ret = vdc->load(vdev, f, version_id); 3077 if (ret) { 3078 return ret; 3079 } 3080 } 3081 3082 if (vdc->vmsd) { 3083 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 3084 if (ret) { 3085 return ret; 3086 } 3087 } 3088 3089 /* Subsections */ 3090 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 3091 if (ret) { 3092 return ret; 3093 } 3094 3095 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 3096 vdev->device_endian = virtio_default_endian(); 3097 } 3098 3099 if (virtio_64bit_features_needed(vdev)) { 3100 /* 3101 * Subsection load filled vdev->guest_features. Run them 3102 * through virtio_set_features to sanity-check them against 3103 * host_features. 3104 */ 3105 uint64_t features64 = vdev->guest_features; 3106 if (virtio_set_features_nocheck(vdev, features64) < 0) { 3107 error_report("Features 0x%" PRIx64 " unsupported. " 3108 "Allowed features: 0x%" PRIx64, 3109 features64, vdev->host_features); 3110 return -1; 3111 } 3112 } else { 3113 if (virtio_set_features_nocheck(vdev, features) < 0) { 3114 error_report("Features 0x%x unsupported. " 3115 "Allowed features: 0x%" PRIx64, 3116 features, vdev->host_features); 3117 return -1; 3118 } 3119 } 3120 3121 if (!virtio_device_started(vdev, vdev->status) && 3122 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3123 vdev->start_on_kick = true; 3124 } 3125 3126 RCU_READ_LOCK_GUARD(); 3127 for (i = 0; i < num; i++) { 3128 if (vdev->vq[i].vring.desc) { 3129 uint16_t nheads; 3130 3131 /* 3132 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 3133 * only the region cache needs to be set up. Legacy devices need 3134 * to calculate used and avail ring addresses based on the desc 3135 * address. 3136 */ 3137 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3138 virtio_init_region_cache(vdev, i); 3139 } else { 3140 virtio_queue_update_rings(vdev, i); 3141 } 3142 3143 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3144 vdev->vq[i].shadow_avail_idx = vdev->vq[i].last_avail_idx; 3145 vdev->vq[i].shadow_avail_wrap_counter = 3146 vdev->vq[i].last_avail_wrap_counter; 3147 continue; 3148 } 3149 3150 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 3151 /* Check it isn't doing strange things with descriptor numbers. */ 3152 if (nheads > vdev->vq[i].vring.num) { 3153 virtio_error(vdev, "VQ %d size 0x%x Guest index 0x%x " 3154 "inconsistent with Host index 0x%x: delta 0x%x", 3155 i, vdev->vq[i].vring.num, 3156 vring_avail_idx(&vdev->vq[i]), 3157 vdev->vq[i].last_avail_idx, nheads); 3158 vdev->vq[i].used_idx = 0; 3159 vdev->vq[i].shadow_avail_idx = 0; 3160 vdev->vq[i].inuse = 0; 3161 continue; 3162 } 3163 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 3164 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 3165 3166 /* 3167 * Some devices migrate VirtQueueElements that have been popped 3168 * from the avail ring but not yet returned to the used ring. 3169 * Since max ring size < UINT16_MAX it's safe to use modulo 3170 * UINT16_MAX + 1 subtraction. 3171 */ 3172 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 3173 vdev->vq[i].used_idx); 3174 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 3175 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 3176 "used_idx 0x%x", 3177 i, vdev->vq[i].vring.num, 3178 vdev->vq[i].last_avail_idx, 3179 vdev->vq[i].used_idx); 3180 return -1; 3181 } 3182 } 3183 } 3184 3185 if (vdc->post_load) { 3186 ret = vdc->post_load(vdev); 3187 if (ret) { 3188 return ret; 3189 } 3190 } 3191 3192 return 0; 3193 } 3194 3195 void virtio_cleanup(VirtIODevice *vdev) 3196 { 3197 qemu_del_vm_change_state_handler(vdev->vmstate); 3198 } 3199 3200 static void virtio_vmstate_change(void *opaque, bool running, RunState state) 3201 { 3202 VirtIODevice *vdev = opaque; 3203 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3204 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3205 bool backend_run = running && virtio_device_started(vdev, vdev->status); 3206 vdev->vm_running = running; 3207 3208 if (backend_run) { 3209 virtio_set_status(vdev, vdev->status); 3210 } 3211 3212 if (k->vmstate_change) { 3213 k->vmstate_change(qbus->parent, backend_run); 3214 } 3215 3216 if (!backend_run) { 3217 virtio_set_status(vdev, vdev->status); 3218 } 3219 } 3220 3221 void virtio_instance_init_common(Object *proxy_obj, void *data, 3222 size_t vdev_size, const char *vdev_name) 3223 { 3224 DeviceState *vdev = data; 3225 3226 object_initialize_child_with_props(proxy_obj, "virtio-backend", vdev, 3227 vdev_size, vdev_name, &error_abort, 3228 NULL); 3229 qdev_alias_all_properties(vdev, proxy_obj); 3230 } 3231 3232 void virtio_init(VirtIODevice *vdev, const char *name, 3233 uint16_t device_id, size_t config_size) 3234 { 3235 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3236 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3237 int i; 3238 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 3239 3240 if (nvectors) { 3241 vdev->vector_queues = 3242 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 3243 } 3244 3245 vdev->start_on_kick = false; 3246 vdev->started = false; 3247 vdev->device_id = device_id; 3248 vdev->status = 0; 3249 qatomic_set(&vdev->isr, 0); 3250 vdev->queue_sel = 0; 3251 vdev->config_vector = VIRTIO_NO_VECTOR; 3252 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 3253 vdev->vm_running = runstate_is_running(); 3254 vdev->broken = false; 3255 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3256 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 3257 vdev->vq[i].vdev = vdev; 3258 vdev->vq[i].queue_index = i; 3259 vdev->vq[i].host_notifier_enabled = false; 3260 } 3261 3262 vdev->name = name; 3263 vdev->config_len = config_size; 3264 if (vdev->config_len) { 3265 vdev->config = g_malloc0(config_size); 3266 } else { 3267 vdev->config = NULL; 3268 } 3269 vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev), 3270 virtio_vmstate_change, vdev); 3271 vdev->device_endian = virtio_default_endian(); 3272 vdev->use_guest_notifier_mask = true; 3273 } 3274 3275 /* 3276 * Only devices that have already been around prior to defining the virtio 3277 * standard support legacy mode; this includes devices not specified in the 3278 * standard. All newer devices conform to the virtio standard only. 3279 */ 3280 bool virtio_legacy_allowed(VirtIODevice *vdev) 3281 { 3282 switch (vdev->device_id) { 3283 case VIRTIO_ID_NET: 3284 case VIRTIO_ID_BLOCK: 3285 case VIRTIO_ID_CONSOLE: 3286 case VIRTIO_ID_RNG: 3287 case VIRTIO_ID_BALLOON: 3288 case VIRTIO_ID_RPMSG: 3289 case VIRTIO_ID_SCSI: 3290 case VIRTIO_ID_9P: 3291 case VIRTIO_ID_RPROC_SERIAL: 3292 case VIRTIO_ID_CAIF: 3293 return true; 3294 default: 3295 return false; 3296 } 3297 } 3298 3299 bool virtio_legacy_check_disabled(VirtIODevice *vdev) 3300 { 3301 return vdev->disable_legacy_check; 3302 } 3303 3304 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 3305 { 3306 return vdev->vq[n].vring.desc; 3307 } 3308 3309 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n) 3310 { 3311 return virtio_queue_get_desc_addr(vdev, n) != 0; 3312 } 3313 3314 bool virtio_queue_enabled(VirtIODevice *vdev, int n) 3315 { 3316 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3317 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3318 3319 if (k->queue_enabled) { 3320 return k->queue_enabled(qbus->parent, n); 3321 } 3322 return virtio_queue_enabled_legacy(vdev, n); 3323 } 3324 3325 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 3326 { 3327 return vdev->vq[n].vring.avail; 3328 } 3329 3330 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 3331 { 3332 return vdev->vq[n].vring.used; 3333 } 3334 3335 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 3336 { 3337 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 3338 } 3339 3340 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 3341 { 3342 int s; 3343 3344 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3345 return sizeof(struct VRingPackedDescEvent); 3346 } 3347 3348 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3349 return offsetof(VRingAvail, ring) + 3350 sizeof(uint16_t) * vdev->vq[n].vring.num + s; 3351 } 3352 3353 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 3354 { 3355 int s; 3356 3357 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3358 return sizeof(struct VRingPackedDescEvent); 3359 } 3360 3361 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3362 return offsetof(VRingUsed, ring) + 3363 sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s; 3364 } 3365 3366 static unsigned int virtio_queue_packed_get_last_avail_idx(VirtIODevice *vdev, 3367 int n) 3368 { 3369 unsigned int avail, used; 3370 3371 avail = vdev->vq[n].last_avail_idx; 3372 avail |= ((uint16_t)vdev->vq[n].last_avail_wrap_counter) << 15; 3373 3374 used = vdev->vq[n].used_idx; 3375 used |= ((uint16_t)vdev->vq[n].used_wrap_counter) << 15; 3376 3377 return avail | used << 16; 3378 } 3379 3380 static uint16_t virtio_queue_split_get_last_avail_idx(VirtIODevice *vdev, 3381 int n) 3382 { 3383 return vdev->vq[n].last_avail_idx; 3384 } 3385 3386 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 3387 { 3388 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3389 return virtio_queue_packed_get_last_avail_idx(vdev, n); 3390 } else { 3391 return virtio_queue_split_get_last_avail_idx(vdev, n); 3392 } 3393 } 3394 3395 static void virtio_queue_packed_set_last_avail_idx(VirtIODevice *vdev, 3396 int n, unsigned int idx) 3397 { 3398 struct VirtQueue *vq = &vdev->vq[n]; 3399 3400 vq->last_avail_idx = vq->shadow_avail_idx = idx & 0x7fff; 3401 vq->last_avail_wrap_counter = 3402 vq->shadow_avail_wrap_counter = !!(idx & 0x8000); 3403 idx >>= 16; 3404 vq->used_idx = idx & 0x7ffff; 3405 vq->used_wrap_counter = !!(idx & 0x8000); 3406 } 3407 3408 static void virtio_queue_split_set_last_avail_idx(VirtIODevice *vdev, 3409 int n, unsigned int idx) 3410 { 3411 vdev->vq[n].last_avail_idx = idx; 3412 vdev->vq[n].shadow_avail_idx = idx; 3413 } 3414 3415 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 3416 unsigned int idx) 3417 { 3418 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3419 virtio_queue_packed_set_last_avail_idx(vdev, n, idx); 3420 } else { 3421 virtio_queue_split_set_last_avail_idx(vdev, n, idx); 3422 } 3423 } 3424 3425 static void virtio_queue_packed_restore_last_avail_idx(VirtIODevice *vdev, 3426 int n) 3427 { 3428 /* We don't have a reference like avail idx in shared memory */ 3429 return; 3430 } 3431 3432 static void virtio_queue_split_restore_last_avail_idx(VirtIODevice *vdev, 3433 int n) 3434 { 3435 RCU_READ_LOCK_GUARD(); 3436 if (vdev->vq[n].vring.desc) { 3437 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 3438 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 3439 } 3440 } 3441 3442 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 3443 { 3444 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3445 virtio_queue_packed_restore_last_avail_idx(vdev, n); 3446 } else { 3447 virtio_queue_split_restore_last_avail_idx(vdev, n); 3448 } 3449 } 3450 3451 static void virtio_queue_packed_update_used_idx(VirtIODevice *vdev, int n) 3452 { 3453 /* used idx was updated through set_last_avail_idx() */ 3454 return; 3455 } 3456 3457 static void virtio_split_packed_update_used_idx(VirtIODevice *vdev, int n) 3458 { 3459 RCU_READ_LOCK_GUARD(); 3460 if (vdev->vq[n].vring.desc) { 3461 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 3462 } 3463 } 3464 3465 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 3466 { 3467 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3468 return virtio_queue_packed_update_used_idx(vdev, n); 3469 } else { 3470 return virtio_split_packed_update_used_idx(vdev, n); 3471 } 3472 } 3473 3474 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 3475 { 3476 vdev->vq[n].signalled_used_valid = false; 3477 } 3478 3479 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 3480 { 3481 return vdev->vq + n; 3482 } 3483 3484 uint16_t virtio_get_queue_index(VirtQueue *vq) 3485 { 3486 return vq->queue_index; 3487 } 3488 3489 static void virtio_queue_guest_notifier_read(EventNotifier *n) 3490 { 3491 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 3492 if (event_notifier_test_and_clear(n)) { 3493 virtio_irq(vq); 3494 } 3495 } 3496 3497 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 3498 bool with_irqfd) 3499 { 3500 if (assign && !with_irqfd) { 3501 event_notifier_set_handler(&vq->guest_notifier, 3502 virtio_queue_guest_notifier_read); 3503 } else { 3504 event_notifier_set_handler(&vq->guest_notifier, NULL); 3505 } 3506 if (!assign) { 3507 /* Test and clear notifier before closing it, 3508 * in case poll callback didn't have time to run. */ 3509 virtio_queue_guest_notifier_read(&vq->guest_notifier); 3510 } 3511 } 3512 3513 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 3514 { 3515 return &vq->guest_notifier; 3516 } 3517 3518 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 3519 { 3520 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3521 if (event_notifier_test_and_clear(n)) { 3522 virtio_queue_notify_aio_vq(vq); 3523 } 3524 } 3525 3526 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 3527 { 3528 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3529 3530 virtio_queue_set_notification(vq, 0); 3531 } 3532 3533 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 3534 { 3535 EventNotifier *n = opaque; 3536 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3537 3538 if (!vq->vring.desc || virtio_queue_empty(vq)) { 3539 return false; 3540 } 3541 3542 return virtio_queue_notify_aio_vq(vq); 3543 } 3544 3545 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 3546 { 3547 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3548 3549 /* Caller polls once more after this to catch requests that race with us */ 3550 virtio_queue_set_notification(vq, 1); 3551 } 3552 3553 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 3554 VirtIOHandleAIOOutput handle_output) 3555 { 3556 if (handle_output) { 3557 vq->handle_aio_output = handle_output; 3558 aio_set_event_notifier(ctx, &vq->host_notifier, true, 3559 virtio_queue_host_notifier_aio_read, 3560 virtio_queue_host_notifier_aio_poll); 3561 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 3562 virtio_queue_host_notifier_aio_poll_begin, 3563 virtio_queue_host_notifier_aio_poll_end); 3564 } else { 3565 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 3566 /* Test and clear notifier before after disabling event, 3567 * in case poll callback didn't have time to run. */ 3568 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 3569 vq->handle_aio_output = NULL; 3570 } 3571 } 3572 3573 void virtio_queue_host_notifier_read(EventNotifier *n) 3574 { 3575 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3576 if (event_notifier_test_and_clear(n)) { 3577 virtio_queue_notify_vq(vq); 3578 } 3579 } 3580 3581 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 3582 { 3583 return &vq->host_notifier; 3584 } 3585 3586 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled) 3587 { 3588 vq->host_notifier_enabled = enabled; 3589 } 3590 3591 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 3592 MemoryRegion *mr, bool assign) 3593 { 3594 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3595 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3596 3597 if (k->set_host_notifier_mr) { 3598 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 3599 } 3600 3601 return -1; 3602 } 3603 3604 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 3605 { 3606 g_free(vdev->bus_name); 3607 vdev->bus_name = g_strdup(bus_name); 3608 } 3609 3610 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 3611 { 3612 va_list ap; 3613 3614 va_start(ap, fmt); 3615 error_vreport(fmt, ap); 3616 va_end(ap); 3617 3618 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3619 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 3620 virtio_notify_config(vdev); 3621 } 3622 3623 vdev->broken = true; 3624 } 3625 3626 static void virtio_memory_listener_commit(MemoryListener *listener) 3627 { 3628 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 3629 int i; 3630 3631 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3632 if (vdev->vq[i].vring.num == 0) { 3633 break; 3634 } 3635 virtio_init_region_cache(vdev, i); 3636 } 3637 } 3638 3639 static void virtio_device_realize(DeviceState *dev, Error **errp) 3640 { 3641 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3642 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3643 Error *err = NULL; 3644 3645 /* Devices should either use vmsd or the load/save methods */ 3646 assert(!vdc->vmsd || !vdc->load); 3647 3648 if (vdc->realize != NULL) { 3649 vdc->realize(dev, &err); 3650 if (err != NULL) { 3651 error_propagate(errp, err); 3652 return; 3653 } 3654 } 3655 3656 virtio_bus_device_plugged(vdev, &err); 3657 if (err != NULL) { 3658 error_propagate(errp, err); 3659 vdc->unrealize(dev); 3660 return; 3661 } 3662 3663 vdev->listener.commit = virtio_memory_listener_commit; 3664 vdev->listener.name = "virtio"; 3665 memory_listener_register(&vdev->listener, vdev->dma_as); 3666 } 3667 3668 static void virtio_device_unrealize(DeviceState *dev) 3669 { 3670 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3671 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3672 3673 memory_listener_unregister(&vdev->listener); 3674 virtio_bus_device_unplugged(vdev); 3675 3676 if (vdc->unrealize != NULL) { 3677 vdc->unrealize(dev); 3678 } 3679 3680 g_free(vdev->bus_name); 3681 vdev->bus_name = NULL; 3682 } 3683 3684 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 3685 { 3686 int i; 3687 if (!vdev->vq) { 3688 return; 3689 } 3690 3691 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3692 if (vdev->vq[i].vring.num == 0) { 3693 break; 3694 } 3695 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 3696 } 3697 g_free(vdev->vq); 3698 } 3699 3700 static void virtio_device_instance_finalize(Object *obj) 3701 { 3702 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 3703 3704 virtio_device_free_virtqueues(vdev); 3705 3706 g_free(vdev->config); 3707 g_free(vdev->vector_queues); 3708 } 3709 3710 static Property virtio_properties[] = { 3711 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 3712 DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true), 3713 DEFINE_PROP_BOOL("use-disabled-flag", VirtIODevice, use_disabled_flag, true), 3714 DEFINE_PROP_BOOL("x-disable-legacy-check", VirtIODevice, 3715 disable_legacy_check, false), 3716 DEFINE_PROP_END_OF_LIST(), 3717 }; 3718 3719 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 3720 { 3721 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3722 int i, n, r, err; 3723 3724 /* 3725 * Batch all the host notifiers in a single transaction to avoid 3726 * quadratic time complexity in address_space_update_ioeventfds(). 3727 */ 3728 memory_region_transaction_begin(); 3729 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3730 VirtQueue *vq = &vdev->vq[n]; 3731 if (!virtio_queue_get_num(vdev, n)) { 3732 continue; 3733 } 3734 r = virtio_bus_set_host_notifier(qbus, n, true); 3735 if (r < 0) { 3736 err = r; 3737 goto assign_error; 3738 } 3739 event_notifier_set_handler(&vq->host_notifier, 3740 virtio_queue_host_notifier_read); 3741 } 3742 3743 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3744 /* Kick right away to begin processing requests already in vring */ 3745 VirtQueue *vq = &vdev->vq[n]; 3746 if (!vq->vring.num) { 3747 continue; 3748 } 3749 event_notifier_set(&vq->host_notifier); 3750 } 3751 memory_region_transaction_commit(); 3752 return 0; 3753 3754 assign_error: 3755 i = n; /* save n for a second iteration after transaction is committed. */ 3756 while (--n >= 0) { 3757 VirtQueue *vq = &vdev->vq[n]; 3758 if (!virtio_queue_get_num(vdev, n)) { 3759 continue; 3760 } 3761 3762 event_notifier_set_handler(&vq->host_notifier, NULL); 3763 r = virtio_bus_set_host_notifier(qbus, n, false); 3764 assert(r >= 0); 3765 } 3766 /* 3767 * The transaction expects the ioeventfds to be open when it 3768 * commits. Do it now, before the cleanup loop. 3769 */ 3770 memory_region_transaction_commit(); 3771 3772 while (--i >= 0) { 3773 if (!virtio_queue_get_num(vdev, i)) { 3774 continue; 3775 } 3776 virtio_bus_cleanup_host_notifier(qbus, i); 3777 } 3778 return err; 3779 } 3780 3781 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 3782 { 3783 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3784 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3785 3786 return virtio_bus_start_ioeventfd(vbus); 3787 } 3788 3789 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 3790 { 3791 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3792 int n, r; 3793 3794 /* 3795 * Batch all the host notifiers in a single transaction to avoid 3796 * quadratic time complexity in address_space_update_ioeventfds(). 3797 */ 3798 memory_region_transaction_begin(); 3799 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3800 VirtQueue *vq = &vdev->vq[n]; 3801 3802 if (!virtio_queue_get_num(vdev, n)) { 3803 continue; 3804 } 3805 event_notifier_set_handler(&vq->host_notifier, NULL); 3806 r = virtio_bus_set_host_notifier(qbus, n, false); 3807 assert(r >= 0); 3808 } 3809 /* 3810 * The transaction expects the ioeventfds to be open when it 3811 * commits. Do it now, before the cleanup loop. 3812 */ 3813 memory_region_transaction_commit(); 3814 3815 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3816 if (!virtio_queue_get_num(vdev, n)) { 3817 continue; 3818 } 3819 virtio_bus_cleanup_host_notifier(qbus, n); 3820 } 3821 } 3822 3823 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 3824 { 3825 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3826 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3827 3828 return virtio_bus_grab_ioeventfd(vbus); 3829 } 3830 3831 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 3832 { 3833 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3834 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3835 3836 virtio_bus_release_ioeventfd(vbus); 3837 } 3838 3839 static void virtio_device_class_init(ObjectClass *klass, void *data) 3840 { 3841 /* Set the default value here. */ 3842 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 3843 DeviceClass *dc = DEVICE_CLASS(klass); 3844 3845 dc->realize = virtio_device_realize; 3846 dc->unrealize = virtio_device_unrealize; 3847 dc->bus_type = TYPE_VIRTIO_BUS; 3848 device_class_set_props(dc, virtio_properties); 3849 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 3850 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 3851 3852 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 3853 } 3854 3855 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 3856 { 3857 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3858 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3859 3860 return virtio_bus_ioeventfd_enabled(vbus); 3861 } 3862 3863 static const TypeInfo virtio_device_info = { 3864 .name = TYPE_VIRTIO_DEVICE, 3865 .parent = TYPE_DEVICE, 3866 .instance_size = sizeof(VirtIODevice), 3867 .class_init = virtio_device_class_init, 3868 .instance_finalize = virtio_device_instance_finalize, 3869 .abstract = true, 3870 .class_size = sizeof(VirtioDeviceClass), 3871 }; 3872 3873 static void virtio_register_types(void) 3874 { 3875 type_register_static(&virtio_device_info); 3876 } 3877 3878 type_init(virtio_register_types) 3879