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 "qemu-common.h" 17 #include "cpu.h" 18 #include "trace.h" 19 #include "exec/address-spaces.h" 20 #include "qemu/error-report.h" 21 #include "hw/virtio/virtio.h" 22 #include "qemu/atomic.h" 23 #include "hw/virtio/virtio-bus.h" 24 #include "hw/virtio/virtio-access.h" 25 #include "sysemu/dma.h" 26 27 /* 28 * The alignment to use between consumer and producer parts of vring. 29 * x86 pagesize again. This is the default, used by transports like PCI 30 * which don't provide a means for the guest to tell the host the alignment. 31 */ 32 #define VIRTIO_PCI_VRING_ALIGN 4096 33 34 typedef struct VRingDesc 35 { 36 uint64_t addr; 37 uint32_t len; 38 uint16_t flags; 39 uint16_t next; 40 } VRingDesc; 41 42 typedef struct VRingAvail 43 { 44 uint16_t flags; 45 uint16_t idx; 46 uint16_t ring[0]; 47 } VRingAvail; 48 49 typedef struct VRingUsedElem 50 { 51 uint32_t id; 52 uint32_t len; 53 } VRingUsedElem; 54 55 typedef struct VRingUsed 56 { 57 uint16_t flags; 58 uint16_t idx; 59 VRingUsedElem ring[0]; 60 } VRingUsed; 61 62 typedef struct VRingMemoryRegionCaches { 63 struct rcu_head rcu; 64 MemoryRegionCache desc; 65 MemoryRegionCache avail; 66 MemoryRegionCache used; 67 } VRingMemoryRegionCaches; 68 69 typedef struct VRing 70 { 71 unsigned int num; 72 unsigned int num_default; 73 unsigned int align; 74 hwaddr desc; 75 hwaddr avail; 76 hwaddr used; 77 VRingMemoryRegionCaches *caches; 78 } VRing; 79 80 struct VirtQueue 81 { 82 VRing vring; 83 84 /* Next head to pop */ 85 uint16_t last_avail_idx; 86 87 /* Last avail_idx read from VQ. */ 88 uint16_t shadow_avail_idx; 89 90 uint16_t used_idx; 91 92 /* Last used index value we have signalled on */ 93 uint16_t signalled_used; 94 95 /* Last used index value we have signalled on */ 96 bool signalled_used_valid; 97 98 /* Notification enabled? */ 99 bool notification; 100 101 uint16_t queue_index; 102 103 unsigned int inuse; 104 105 uint16_t vector; 106 VirtIOHandleOutput handle_output; 107 VirtIOHandleAIOOutput handle_aio_output; 108 VirtIODevice *vdev; 109 EventNotifier guest_notifier; 110 EventNotifier host_notifier; 111 QLIST_ENTRY(VirtQueue) node; 112 }; 113 114 static void virtio_free_region_cache(VRingMemoryRegionCaches *caches) 115 { 116 if (!caches) { 117 return; 118 } 119 120 address_space_cache_destroy(&caches->desc); 121 address_space_cache_destroy(&caches->avail); 122 address_space_cache_destroy(&caches->used); 123 g_free(caches); 124 } 125 126 static void virtio_init_region_cache(VirtIODevice *vdev, int n) 127 { 128 VirtQueue *vq = &vdev->vq[n]; 129 VRingMemoryRegionCaches *old = vq->vring.caches; 130 VRingMemoryRegionCaches *new; 131 hwaddr addr, size; 132 int event_size; 133 int64_t len; 134 135 event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 136 137 addr = vq->vring.desc; 138 if (!addr) { 139 return; 140 } 141 new = g_new0(VRingMemoryRegionCaches, 1); 142 size = virtio_queue_get_desc_size(vdev, n); 143 len = address_space_cache_init(&new->desc, vdev->dma_as, 144 addr, size, false); 145 if (len < size) { 146 virtio_error(vdev, "Cannot map desc"); 147 goto err_desc; 148 } 149 150 size = virtio_queue_get_used_size(vdev, n) + event_size; 151 len = address_space_cache_init(&new->used, vdev->dma_as, 152 vq->vring.used, size, true); 153 if (len < size) { 154 virtio_error(vdev, "Cannot map used"); 155 goto err_used; 156 } 157 158 size = virtio_queue_get_avail_size(vdev, n) + event_size; 159 len = address_space_cache_init(&new->avail, vdev->dma_as, 160 vq->vring.avail, size, false); 161 if (len < size) { 162 virtio_error(vdev, "Cannot map avail"); 163 goto err_avail; 164 } 165 166 atomic_rcu_set(&vq->vring.caches, new); 167 if (old) { 168 call_rcu(old, virtio_free_region_cache, rcu); 169 } 170 return; 171 172 err_avail: 173 address_space_cache_destroy(&new->used); 174 err_used: 175 address_space_cache_destroy(&new->desc); 176 err_desc: 177 g_free(new); 178 } 179 180 /* virt queue functions */ 181 void virtio_queue_update_rings(VirtIODevice *vdev, int n) 182 { 183 VRing *vring = &vdev->vq[n].vring; 184 185 if (!vring->num || !vring->desc || !vring->align) { 186 /* not yet setup -> nothing to do */ 187 return; 188 } 189 vring->avail = vring->desc + vring->num * sizeof(VRingDesc); 190 vring->used = vring_align(vring->avail + 191 offsetof(VRingAvail, ring[vring->num]), 192 vring->align); 193 virtio_init_region_cache(vdev, n); 194 } 195 196 /* Called within rcu_read_lock(). */ 197 static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc, 198 MemoryRegionCache *cache, int i) 199 { 200 address_space_read_cached(cache, i * sizeof(VRingDesc), 201 desc, sizeof(VRingDesc)); 202 virtio_tswap64s(vdev, &desc->addr); 203 virtio_tswap32s(vdev, &desc->len); 204 virtio_tswap16s(vdev, &desc->flags); 205 virtio_tswap16s(vdev, &desc->next); 206 } 207 208 static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq) 209 { 210 VRingMemoryRegionCaches *caches = atomic_rcu_read(&vq->vring.caches); 211 assert(caches != NULL); 212 return caches; 213 } 214 /* Called within rcu_read_lock(). */ 215 static inline uint16_t vring_avail_flags(VirtQueue *vq) 216 { 217 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 218 hwaddr pa = offsetof(VRingAvail, flags); 219 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 220 } 221 222 /* Called within rcu_read_lock(). */ 223 static inline uint16_t vring_avail_idx(VirtQueue *vq) 224 { 225 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 226 hwaddr pa = offsetof(VRingAvail, idx); 227 vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 228 return vq->shadow_avail_idx; 229 } 230 231 /* Called within rcu_read_lock(). */ 232 static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) 233 { 234 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 235 hwaddr pa = offsetof(VRingAvail, ring[i]); 236 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 237 } 238 239 /* Called within rcu_read_lock(). */ 240 static inline uint16_t vring_get_used_event(VirtQueue *vq) 241 { 242 return vring_avail_ring(vq, vq->vring.num); 243 } 244 245 /* Called within rcu_read_lock(). */ 246 static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, 247 int i) 248 { 249 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 250 hwaddr pa = offsetof(VRingUsed, ring[i]); 251 virtio_tswap32s(vq->vdev, &uelem->id); 252 virtio_tswap32s(vq->vdev, &uelem->len); 253 address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem)); 254 address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem)); 255 } 256 257 /* Called within rcu_read_lock(). */ 258 static uint16_t vring_used_idx(VirtQueue *vq) 259 { 260 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 261 hwaddr pa = offsetof(VRingUsed, idx); 262 return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 263 } 264 265 /* Called within rcu_read_lock(). */ 266 static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val) 267 { 268 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 269 hwaddr pa = offsetof(VRingUsed, idx); 270 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 271 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 272 vq->used_idx = val; 273 } 274 275 /* Called within rcu_read_lock(). */ 276 static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) 277 { 278 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 279 VirtIODevice *vdev = vq->vdev; 280 hwaddr pa = offsetof(VRingUsed, flags); 281 uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 282 283 virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask); 284 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 285 } 286 287 /* Called within rcu_read_lock(). */ 288 static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) 289 { 290 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 291 VirtIODevice *vdev = vq->vdev; 292 hwaddr pa = offsetof(VRingUsed, flags); 293 uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 294 295 virtio_stw_phys_cached(vdev, &caches->used, pa, flags & ~mask); 296 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 297 } 298 299 /* Called within rcu_read_lock(). */ 300 static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) 301 { 302 VRingMemoryRegionCaches *caches; 303 hwaddr pa; 304 if (!vq->notification) { 305 return; 306 } 307 308 caches = vring_get_region_caches(vq); 309 pa = offsetof(VRingUsed, ring[vq->vring.num]); 310 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 311 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 312 } 313 314 void virtio_queue_set_notification(VirtQueue *vq, int enable) 315 { 316 vq->notification = enable; 317 318 if (!vq->vring.desc) { 319 return; 320 } 321 322 rcu_read_lock(); 323 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 324 vring_set_avail_event(vq, vring_avail_idx(vq)); 325 } else if (enable) { 326 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); 327 } else { 328 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); 329 } 330 if (enable) { 331 /* Expose avail event/used flags before caller checks the avail idx. */ 332 smp_mb(); 333 } 334 rcu_read_unlock(); 335 } 336 337 int virtio_queue_ready(VirtQueue *vq) 338 { 339 return vq->vring.avail != 0; 340 } 341 342 /* Fetch avail_idx from VQ memory only when we really need to know if 343 * guest has added some buffers. 344 * Called within rcu_read_lock(). */ 345 static int virtio_queue_empty_rcu(VirtQueue *vq) 346 { 347 if (unlikely(!vq->vring.avail)) { 348 return 1; 349 } 350 351 if (vq->shadow_avail_idx != vq->last_avail_idx) { 352 return 0; 353 } 354 355 return vring_avail_idx(vq) == vq->last_avail_idx; 356 } 357 358 int virtio_queue_empty(VirtQueue *vq) 359 { 360 bool empty; 361 362 if (unlikely(!vq->vring.avail)) { 363 return 1; 364 } 365 366 if (vq->shadow_avail_idx != vq->last_avail_idx) { 367 return 0; 368 } 369 370 rcu_read_lock(); 371 empty = vring_avail_idx(vq) == vq->last_avail_idx; 372 rcu_read_unlock(); 373 return empty; 374 } 375 376 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 377 unsigned int len) 378 { 379 AddressSpace *dma_as = vq->vdev->dma_as; 380 unsigned int offset; 381 int i; 382 383 offset = 0; 384 for (i = 0; i < elem->in_num; i++) { 385 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 386 387 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 388 elem->in_sg[i].iov_len, 389 DMA_DIRECTION_FROM_DEVICE, size); 390 391 offset += size; 392 } 393 394 for (i = 0; i < elem->out_num; i++) 395 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 396 elem->out_sg[i].iov_len, 397 DMA_DIRECTION_TO_DEVICE, 398 elem->out_sg[i].iov_len); 399 } 400 401 /* virtqueue_detach_element: 402 * @vq: The #VirtQueue 403 * @elem: The #VirtQueueElement 404 * @len: number of bytes written 405 * 406 * Detach the element from the virtqueue. This function is suitable for device 407 * reset or other situations where a #VirtQueueElement is simply freed and will 408 * not be pushed or discarded. 409 */ 410 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 411 unsigned int len) 412 { 413 vq->inuse--; 414 virtqueue_unmap_sg(vq, elem, len); 415 } 416 417 /* virtqueue_unpop: 418 * @vq: The #VirtQueue 419 * @elem: The #VirtQueueElement 420 * @len: number of bytes written 421 * 422 * Pretend the most recent element wasn't popped from the virtqueue. The next 423 * call to virtqueue_pop() will refetch the element. 424 */ 425 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 426 unsigned int len) 427 { 428 vq->last_avail_idx--; 429 virtqueue_detach_element(vq, elem, len); 430 } 431 432 /* virtqueue_rewind: 433 * @vq: The #VirtQueue 434 * @num: Number of elements to push back 435 * 436 * Pretend that elements weren't popped from the virtqueue. The next 437 * virtqueue_pop() will refetch the oldest element. 438 * 439 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 440 * 441 * Returns: true on success, false if @num is greater than the number of in use 442 * elements. 443 */ 444 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 445 { 446 if (num > vq->inuse) { 447 return false; 448 } 449 vq->last_avail_idx -= num; 450 vq->inuse -= num; 451 return true; 452 } 453 454 /* Called within rcu_read_lock(). */ 455 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 456 unsigned int len, unsigned int idx) 457 { 458 VRingUsedElem uelem; 459 460 trace_virtqueue_fill(vq, elem, len, idx); 461 462 virtqueue_unmap_sg(vq, elem, len); 463 464 if (unlikely(vq->vdev->broken)) { 465 return; 466 } 467 468 if (unlikely(!vq->vring.used)) { 469 return; 470 } 471 472 idx = (idx + vq->used_idx) % vq->vring.num; 473 474 uelem.id = elem->index; 475 uelem.len = len; 476 vring_used_write(vq, &uelem, idx); 477 } 478 479 /* Called within rcu_read_lock(). */ 480 void virtqueue_flush(VirtQueue *vq, unsigned int count) 481 { 482 uint16_t old, new; 483 484 if (unlikely(vq->vdev->broken)) { 485 vq->inuse -= count; 486 return; 487 } 488 489 if (unlikely(!vq->vring.used)) { 490 return; 491 } 492 493 /* Make sure buffer is written before we update index. */ 494 smp_wmb(); 495 trace_virtqueue_flush(vq, count); 496 old = vq->used_idx; 497 new = old + count; 498 vring_used_idx_set(vq, new); 499 vq->inuse -= count; 500 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 501 vq->signalled_used_valid = false; 502 } 503 504 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 505 unsigned int len) 506 { 507 rcu_read_lock(); 508 virtqueue_fill(vq, elem, len, 0); 509 virtqueue_flush(vq, 1); 510 rcu_read_unlock(); 511 } 512 513 /* Called within rcu_read_lock(). */ 514 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 515 { 516 uint16_t num_heads = vring_avail_idx(vq) - idx; 517 518 /* Check it isn't doing very strange things with descriptor numbers. */ 519 if (num_heads > vq->vring.num) { 520 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 521 idx, vq->shadow_avail_idx); 522 return -EINVAL; 523 } 524 /* On success, callers read a descriptor at vq->last_avail_idx. 525 * Make sure descriptor read does not bypass avail index read. */ 526 if (num_heads) { 527 smp_rmb(); 528 } 529 530 return num_heads; 531 } 532 533 /* Called within rcu_read_lock(). */ 534 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 535 unsigned int *head) 536 { 537 /* Grab the next descriptor number they're advertising, and increment 538 * the index we've seen. */ 539 *head = vring_avail_ring(vq, idx % vq->vring.num); 540 541 /* If their number is silly, that's a fatal mistake. */ 542 if (*head >= vq->vring.num) { 543 virtio_error(vq->vdev, "Guest says index %u is available", *head); 544 return false; 545 } 546 547 return true; 548 } 549 550 enum { 551 VIRTQUEUE_READ_DESC_ERROR = -1, 552 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 553 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 554 }; 555 556 static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 557 MemoryRegionCache *desc_cache, unsigned int max, 558 unsigned int *next) 559 { 560 /* If this descriptor says it doesn't chain, we're done. */ 561 if (!(desc->flags & VRING_DESC_F_NEXT)) { 562 return VIRTQUEUE_READ_DESC_DONE; 563 } 564 565 /* Check they're not leading us off end of descriptors. */ 566 *next = desc->next; 567 /* Make sure compiler knows to grab that: we don't want it changing! */ 568 smp_wmb(); 569 570 if (*next >= max) { 571 virtio_error(vdev, "Desc next is %u", *next); 572 return VIRTQUEUE_READ_DESC_ERROR; 573 } 574 575 vring_desc_read(vdev, desc, desc_cache, *next); 576 return VIRTQUEUE_READ_DESC_MORE; 577 } 578 579 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 580 unsigned int *out_bytes, 581 unsigned max_in_bytes, unsigned max_out_bytes) 582 { 583 VirtIODevice *vdev = vq->vdev; 584 unsigned int max, idx; 585 unsigned int total_bufs, in_total, out_total; 586 VRingMemoryRegionCaches *caches; 587 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 588 int64_t len = 0; 589 int rc; 590 591 if (unlikely(!vq->vring.desc)) { 592 if (in_bytes) { 593 *in_bytes = 0; 594 } 595 if (out_bytes) { 596 *out_bytes = 0; 597 } 598 return; 599 } 600 601 rcu_read_lock(); 602 idx = vq->last_avail_idx; 603 total_bufs = in_total = out_total = 0; 604 605 max = vq->vring.num; 606 caches = vring_get_region_caches(vq); 607 if (caches->desc.len < max * sizeof(VRingDesc)) { 608 virtio_error(vdev, "Cannot map descriptor ring"); 609 goto err; 610 } 611 612 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 613 MemoryRegionCache *desc_cache = &caches->desc; 614 unsigned int num_bufs; 615 VRingDesc desc; 616 unsigned int i; 617 618 num_bufs = total_bufs; 619 620 if (!virtqueue_get_head(vq, idx++, &i)) { 621 goto err; 622 } 623 624 vring_desc_read(vdev, &desc, desc_cache, i); 625 626 if (desc.flags & VRING_DESC_F_INDIRECT) { 627 if (desc.len % sizeof(VRingDesc)) { 628 virtio_error(vdev, "Invalid size for indirect buffer table"); 629 goto err; 630 } 631 632 /* If we've got too many, that implies a descriptor loop. */ 633 if (num_bufs >= max) { 634 virtio_error(vdev, "Looped descriptor"); 635 goto err; 636 } 637 638 /* loop over the indirect descriptor table */ 639 len = address_space_cache_init(&indirect_desc_cache, 640 vdev->dma_as, 641 desc.addr, desc.len, false); 642 desc_cache = &indirect_desc_cache; 643 if (len < desc.len) { 644 virtio_error(vdev, "Cannot map indirect buffer"); 645 goto err; 646 } 647 648 max = desc.len / sizeof(VRingDesc); 649 num_bufs = i = 0; 650 vring_desc_read(vdev, &desc, desc_cache, i); 651 } 652 653 do { 654 /* If we've got too many, that implies a descriptor loop. */ 655 if (++num_bufs > max) { 656 virtio_error(vdev, "Looped descriptor"); 657 goto err; 658 } 659 660 if (desc.flags & VRING_DESC_F_WRITE) { 661 in_total += desc.len; 662 } else { 663 out_total += desc.len; 664 } 665 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 666 goto done; 667 } 668 669 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); 670 } while (rc == VIRTQUEUE_READ_DESC_MORE); 671 672 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 673 goto err; 674 } 675 676 if (desc_cache == &indirect_desc_cache) { 677 address_space_cache_destroy(&indirect_desc_cache); 678 total_bufs++; 679 } else { 680 total_bufs = num_bufs; 681 } 682 } 683 684 if (rc < 0) { 685 goto err; 686 } 687 688 done: 689 address_space_cache_destroy(&indirect_desc_cache); 690 if (in_bytes) { 691 *in_bytes = in_total; 692 } 693 if (out_bytes) { 694 *out_bytes = out_total; 695 } 696 rcu_read_unlock(); 697 return; 698 699 err: 700 in_total = out_total = 0; 701 goto done; 702 } 703 704 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 705 unsigned int out_bytes) 706 { 707 unsigned int in_total, out_total; 708 709 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 710 return in_bytes <= in_total && out_bytes <= out_total; 711 } 712 713 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 714 hwaddr *addr, struct iovec *iov, 715 unsigned int max_num_sg, bool is_write, 716 hwaddr pa, size_t sz) 717 { 718 bool ok = false; 719 unsigned num_sg = *p_num_sg; 720 assert(num_sg <= max_num_sg); 721 722 if (!sz) { 723 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 724 goto out; 725 } 726 727 while (sz) { 728 hwaddr len = sz; 729 730 if (num_sg == max_num_sg) { 731 virtio_error(vdev, "virtio: too many write descriptors in " 732 "indirect table"); 733 goto out; 734 } 735 736 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 737 is_write ? 738 DMA_DIRECTION_FROM_DEVICE : 739 DMA_DIRECTION_TO_DEVICE); 740 if (!iov[num_sg].iov_base) { 741 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 742 goto out; 743 } 744 745 iov[num_sg].iov_len = len; 746 addr[num_sg] = pa; 747 748 sz -= len; 749 pa += len; 750 num_sg++; 751 } 752 ok = true; 753 754 out: 755 *p_num_sg = num_sg; 756 return ok; 757 } 758 759 /* Only used by error code paths before we have a VirtQueueElement (therefore 760 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 761 * yet. 762 */ 763 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 764 struct iovec *iov) 765 { 766 unsigned int i; 767 768 for (i = 0; i < out_num + in_num; i++) { 769 int is_write = i >= out_num; 770 771 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 772 iov++; 773 } 774 } 775 776 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 777 hwaddr *addr, unsigned int *num_sg, 778 int is_write) 779 { 780 unsigned int i; 781 hwaddr len; 782 783 for (i = 0; i < *num_sg; i++) { 784 len = sg[i].iov_len; 785 sg[i].iov_base = dma_memory_map(vdev->dma_as, 786 addr[i], &len, is_write ? 787 DMA_DIRECTION_FROM_DEVICE : 788 DMA_DIRECTION_TO_DEVICE); 789 if (!sg[i].iov_base) { 790 error_report("virtio: error trying to map MMIO memory"); 791 exit(1); 792 } 793 if (len != sg[i].iov_len) { 794 error_report("virtio: unexpected memory split"); 795 exit(1); 796 } 797 } 798 } 799 800 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 801 { 802 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num, 1); 803 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num, 0); 804 } 805 806 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 807 { 808 VirtQueueElement *elem; 809 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 810 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 811 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 812 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 813 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 814 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 815 816 assert(sz >= sizeof(VirtQueueElement)); 817 elem = g_malloc(out_sg_end); 818 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 819 elem->out_num = out_num; 820 elem->in_num = in_num; 821 elem->in_addr = (void *)elem + in_addr_ofs; 822 elem->out_addr = (void *)elem + out_addr_ofs; 823 elem->in_sg = (void *)elem + in_sg_ofs; 824 elem->out_sg = (void *)elem + out_sg_ofs; 825 return elem; 826 } 827 828 void *virtqueue_pop(VirtQueue *vq, size_t sz) 829 { 830 unsigned int i, head, max; 831 VRingMemoryRegionCaches *caches; 832 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 833 MemoryRegionCache *desc_cache; 834 int64_t len; 835 VirtIODevice *vdev = vq->vdev; 836 VirtQueueElement *elem = NULL; 837 unsigned out_num, in_num, elem_entries; 838 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 839 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 840 VRingDesc desc; 841 int rc; 842 843 if (unlikely(vdev->broken)) { 844 return NULL; 845 } 846 rcu_read_lock(); 847 if (virtio_queue_empty_rcu(vq)) { 848 goto done; 849 } 850 /* Needed after virtio_queue_empty(), see comment in 851 * virtqueue_num_heads(). */ 852 smp_rmb(); 853 854 /* When we start there are none of either input nor output. */ 855 out_num = in_num = elem_entries = 0; 856 857 max = vq->vring.num; 858 859 if (vq->inuse >= vq->vring.num) { 860 virtio_error(vdev, "Virtqueue size exceeded"); 861 goto done; 862 } 863 864 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 865 goto done; 866 } 867 868 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 869 vring_set_avail_event(vq, vq->last_avail_idx); 870 } 871 872 i = head; 873 874 caches = vring_get_region_caches(vq); 875 if (caches->desc.len < max * sizeof(VRingDesc)) { 876 virtio_error(vdev, "Cannot map descriptor ring"); 877 goto done; 878 } 879 880 desc_cache = &caches->desc; 881 vring_desc_read(vdev, &desc, desc_cache, i); 882 if (desc.flags & VRING_DESC_F_INDIRECT) { 883 if (desc.len % sizeof(VRingDesc)) { 884 virtio_error(vdev, "Invalid size for indirect buffer table"); 885 goto done; 886 } 887 888 /* loop over the indirect descriptor table */ 889 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 890 desc.addr, desc.len, false); 891 desc_cache = &indirect_desc_cache; 892 if (len < desc.len) { 893 virtio_error(vdev, "Cannot map indirect buffer"); 894 goto done; 895 } 896 897 max = desc.len / sizeof(VRingDesc); 898 i = 0; 899 vring_desc_read(vdev, &desc, desc_cache, i); 900 } 901 902 /* Collect all the descriptors */ 903 do { 904 bool map_ok; 905 906 if (desc.flags & VRING_DESC_F_WRITE) { 907 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 908 iov + out_num, 909 VIRTQUEUE_MAX_SIZE - out_num, true, 910 desc.addr, desc.len); 911 } else { 912 if (in_num) { 913 virtio_error(vdev, "Incorrect order for descriptors"); 914 goto err_undo_map; 915 } 916 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 917 VIRTQUEUE_MAX_SIZE, false, 918 desc.addr, desc.len); 919 } 920 if (!map_ok) { 921 goto err_undo_map; 922 } 923 924 /* If we've got too many, that implies a descriptor loop. */ 925 if (++elem_entries > max) { 926 virtio_error(vdev, "Looped descriptor"); 927 goto err_undo_map; 928 } 929 930 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); 931 } while (rc == VIRTQUEUE_READ_DESC_MORE); 932 933 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 934 goto err_undo_map; 935 } 936 937 /* Now copy what we have collected and mapped */ 938 elem = virtqueue_alloc_element(sz, out_num, in_num); 939 elem->index = head; 940 for (i = 0; i < out_num; i++) { 941 elem->out_addr[i] = addr[i]; 942 elem->out_sg[i] = iov[i]; 943 } 944 for (i = 0; i < in_num; i++) { 945 elem->in_addr[i] = addr[out_num + i]; 946 elem->in_sg[i] = iov[out_num + i]; 947 } 948 949 vq->inuse++; 950 951 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 952 done: 953 address_space_cache_destroy(&indirect_desc_cache); 954 rcu_read_unlock(); 955 956 return elem; 957 958 err_undo_map: 959 virtqueue_undo_map_desc(out_num, in_num, iov); 960 goto done; 961 } 962 963 /* virtqueue_drop_all: 964 * @vq: The #VirtQueue 965 * Drops all queued buffers and indicates them to the guest 966 * as if they are done. Useful when buffers can not be 967 * processed but must be returned to the guest. 968 */ 969 unsigned int virtqueue_drop_all(VirtQueue *vq) 970 { 971 unsigned int dropped = 0; 972 VirtQueueElement elem = {}; 973 VirtIODevice *vdev = vq->vdev; 974 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 975 976 if (unlikely(vdev->broken)) { 977 return 0; 978 } 979 980 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 981 /* works similar to virtqueue_pop but does not map buffers 982 * and does not allocate any memory */ 983 smp_rmb(); 984 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 985 break; 986 } 987 vq->inuse++; 988 vq->last_avail_idx++; 989 if (fEventIdx) { 990 vring_set_avail_event(vq, vq->last_avail_idx); 991 } 992 /* immediately push the element, nothing to unmap 993 * as both in_num and out_num are set to 0 */ 994 virtqueue_push(vq, &elem, 0); 995 dropped++; 996 } 997 998 return dropped; 999 } 1000 1001 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1002 * it is what QEMU has always done by mistake. We can change it sooner 1003 * or later by bumping the version number of the affected vm states. 1004 * In the meanwhile, since the in-memory layout of VirtQueueElement 1005 * has changed, we need to marshal to and from the layout that was 1006 * used before the change. 1007 */ 1008 typedef struct VirtQueueElementOld { 1009 unsigned int index; 1010 unsigned int out_num; 1011 unsigned int in_num; 1012 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1013 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1014 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1015 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1016 } VirtQueueElementOld; 1017 1018 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1019 { 1020 VirtQueueElement *elem; 1021 VirtQueueElementOld data; 1022 int i; 1023 1024 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1025 1026 /* TODO: teach all callers that this can fail, and return failure instead 1027 * of asserting here. 1028 * This is just one thing (there are probably more) that must be 1029 * fixed before we can allow NDEBUG compilation. 1030 */ 1031 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1032 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1033 1034 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1035 elem->index = data.index; 1036 1037 for (i = 0; i < elem->in_num; i++) { 1038 elem->in_addr[i] = data.in_addr[i]; 1039 } 1040 1041 for (i = 0; i < elem->out_num; i++) { 1042 elem->out_addr[i] = data.out_addr[i]; 1043 } 1044 1045 for (i = 0; i < elem->in_num; i++) { 1046 /* Base is overwritten by virtqueue_map. */ 1047 elem->in_sg[i].iov_base = 0; 1048 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1049 } 1050 1051 for (i = 0; i < elem->out_num; i++) { 1052 /* Base is overwritten by virtqueue_map. */ 1053 elem->out_sg[i].iov_base = 0; 1054 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1055 } 1056 1057 virtqueue_map(vdev, elem); 1058 return elem; 1059 } 1060 1061 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem) 1062 { 1063 VirtQueueElementOld data; 1064 int i; 1065 1066 memset(&data, 0, sizeof(data)); 1067 data.index = elem->index; 1068 data.in_num = elem->in_num; 1069 data.out_num = elem->out_num; 1070 1071 for (i = 0; i < elem->in_num; i++) { 1072 data.in_addr[i] = elem->in_addr[i]; 1073 } 1074 1075 for (i = 0; i < elem->out_num; i++) { 1076 data.out_addr[i] = elem->out_addr[i]; 1077 } 1078 1079 for (i = 0; i < elem->in_num; i++) { 1080 /* Base is overwritten by virtqueue_map when loading. Do not 1081 * save it, as it would leak the QEMU address space layout. */ 1082 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1083 } 1084 1085 for (i = 0; i < elem->out_num; i++) { 1086 /* Do not save iov_base as above. */ 1087 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1088 } 1089 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1090 } 1091 1092 /* virtio device */ 1093 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1094 { 1095 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1096 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1097 1098 if (unlikely(vdev->broken)) { 1099 return; 1100 } 1101 1102 if (k->notify) { 1103 k->notify(qbus->parent, vector); 1104 } 1105 } 1106 1107 void virtio_update_irq(VirtIODevice *vdev) 1108 { 1109 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1110 } 1111 1112 static int virtio_validate_features(VirtIODevice *vdev) 1113 { 1114 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1115 1116 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 1117 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 1118 return -EFAULT; 1119 } 1120 1121 if (k->validate_features) { 1122 return k->validate_features(vdev); 1123 } else { 1124 return 0; 1125 } 1126 } 1127 1128 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 1129 { 1130 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1131 trace_virtio_set_status(vdev, val); 1132 1133 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1134 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 1135 val & VIRTIO_CONFIG_S_FEATURES_OK) { 1136 int ret = virtio_validate_features(vdev); 1137 1138 if (ret) { 1139 return ret; 1140 } 1141 } 1142 } 1143 if (k->set_status) { 1144 k->set_status(vdev, val); 1145 } 1146 vdev->status = val; 1147 return 0; 1148 } 1149 1150 bool target_words_bigendian(void); 1151 static enum virtio_device_endian virtio_default_endian(void) 1152 { 1153 if (target_words_bigendian()) { 1154 return VIRTIO_DEVICE_ENDIAN_BIG; 1155 } else { 1156 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1157 } 1158 } 1159 1160 static enum virtio_device_endian virtio_current_cpu_endian(void) 1161 { 1162 CPUClass *cc = CPU_GET_CLASS(current_cpu); 1163 1164 if (cc->virtio_is_big_endian(current_cpu)) { 1165 return VIRTIO_DEVICE_ENDIAN_BIG; 1166 } else { 1167 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1168 } 1169 } 1170 1171 static void virtio_virtqueue_reset_region_cache(struct VirtQueue *vq) 1172 { 1173 VRingMemoryRegionCaches *caches; 1174 1175 caches = atomic_read(&vq->vring.caches); 1176 atomic_rcu_set(&vq->vring.caches, NULL); 1177 if (caches) { 1178 call_rcu(caches, virtio_free_region_cache, rcu); 1179 } 1180 } 1181 1182 void virtio_reset(void *opaque) 1183 { 1184 VirtIODevice *vdev = opaque; 1185 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1186 int i; 1187 1188 virtio_set_status(vdev, 0); 1189 if (current_cpu) { 1190 /* Guest initiated reset */ 1191 vdev->device_endian = virtio_current_cpu_endian(); 1192 } else { 1193 /* System reset */ 1194 vdev->device_endian = virtio_default_endian(); 1195 } 1196 1197 if (k->reset) { 1198 k->reset(vdev); 1199 } 1200 1201 vdev->broken = false; 1202 vdev->guest_features = 0; 1203 vdev->queue_sel = 0; 1204 vdev->status = 0; 1205 atomic_set(&vdev->isr, 0); 1206 vdev->config_vector = VIRTIO_NO_VECTOR; 1207 virtio_notify_vector(vdev, vdev->config_vector); 1208 1209 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1210 vdev->vq[i].vring.desc = 0; 1211 vdev->vq[i].vring.avail = 0; 1212 vdev->vq[i].vring.used = 0; 1213 vdev->vq[i].last_avail_idx = 0; 1214 vdev->vq[i].shadow_avail_idx = 0; 1215 vdev->vq[i].used_idx = 0; 1216 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1217 vdev->vq[i].signalled_used = 0; 1218 vdev->vq[i].signalled_used_valid = false; 1219 vdev->vq[i].notification = true; 1220 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1221 vdev->vq[i].inuse = 0; 1222 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 1223 } 1224 } 1225 1226 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1227 { 1228 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1229 uint8_t val; 1230 1231 if (addr + sizeof(val) > vdev->config_len) { 1232 return (uint32_t)-1; 1233 } 1234 1235 k->get_config(vdev, vdev->config); 1236 1237 val = ldub_p(vdev->config + addr); 1238 return val; 1239 } 1240 1241 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1242 { 1243 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1244 uint16_t val; 1245 1246 if (addr + sizeof(val) > vdev->config_len) { 1247 return (uint32_t)-1; 1248 } 1249 1250 k->get_config(vdev, vdev->config); 1251 1252 val = lduw_p(vdev->config + addr); 1253 return val; 1254 } 1255 1256 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1257 { 1258 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1259 uint32_t val; 1260 1261 if (addr + sizeof(val) > vdev->config_len) { 1262 return (uint32_t)-1; 1263 } 1264 1265 k->get_config(vdev, vdev->config); 1266 1267 val = ldl_p(vdev->config + addr); 1268 return val; 1269 } 1270 1271 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1272 { 1273 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1274 uint8_t val = data; 1275 1276 if (addr + sizeof(val) > vdev->config_len) { 1277 return; 1278 } 1279 1280 stb_p(vdev->config + addr, val); 1281 1282 if (k->set_config) { 1283 k->set_config(vdev, vdev->config); 1284 } 1285 } 1286 1287 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1288 { 1289 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1290 uint16_t val = data; 1291 1292 if (addr + sizeof(val) > vdev->config_len) { 1293 return; 1294 } 1295 1296 stw_p(vdev->config + addr, val); 1297 1298 if (k->set_config) { 1299 k->set_config(vdev, vdev->config); 1300 } 1301 } 1302 1303 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1304 { 1305 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1306 uint32_t val = data; 1307 1308 if (addr + sizeof(val) > vdev->config_len) { 1309 return; 1310 } 1311 1312 stl_p(vdev->config + addr, val); 1313 1314 if (k->set_config) { 1315 k->set_config(vdev, vdev->config); 1316 } 1317 } 1318 1319 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 1320 { 1321 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1322 uint8_t val; 1323 1324 if (addr + sizeof(val) > vdev->config_len) { 1325 return (uint32_t)-1; 1326 } 1327 1328 k->get_config(vdev, vdev->config); 1329 1330 val = ldub_p(vdev->config + addr); 1331 return val; 1332 } 1333 1334 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 1335 { 1336 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1337 uint16_t val; 1338 1339 if (addr + sizeof(val) > vdev->config_len) { 1340 return (uint32_t)-1; 1341 } 1342 1343 k->get_config(vdev, vdev->config); 1344 1345 val = lduw_le_p(vdev->config + addr); 1346 return val; 1347 } 1348 1349 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 1350 { 1351 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1352 uint32_t val; 1353 1354 if (addr + sizeof(val) > vdev->config_len) { 1355 return (uint32_t)-1; 1356 } 1357 1358 k->get_config(vdev, vdev->config); 1359 1360 val = ldl_le_p(vdev->config + addr); 1361 return val; 1362 } 1363 1364 void virtio_config_modern_writeb(VirtIODevice *vdev, 1365 uint32_t addr, uint32_t data) 1366 { 1367 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1368 uint8_t val = data; 1369 1370 if (addr + sizeof(val) > vdev->config_len) { 1371 return; 1372 } 1373 1374 stb_p(vdev->config + addr, val); 1375 1376 if (k->set_config) { 1377 k->set_config(vdev, vdev->config); 1378 } 1379 } 1380 1381 void virtio_config_modern_writew(VirtIODevice *vdev, 1382 uint32_t addr, uint32_t data) 1383 { 1384 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1385 uint16_t val = data; 1386 1387 if (addr + sizeof(val) > vdev->config_len) { 1388 return; 1389 } 1390 1391 stw_le_p(vdev->config + addr, val); 1392 1393 if (k->set_config) { 1394 k->set_config(vdev, vdev->config); 1395 } 1396 } 1397 1398 void virtio_config_modern_writel(VirtIODevice *vdev, 1399 uint32_t addr, uint32_t data) 1400 { 1401 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1402 uint32_t val = data; 1403 1404 if (addr + sizeof(val) > vdev->config_len) { 1405 return; 1406 } 1407 1408 stl_le_p(vdev->config + addr, val); 1409 1410 if (k->set_config) { 1411 k->set_config(vdev, vdev->config); 1412 } 1413 } 1414 1415 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 1416 { 1417 if (!vdev->vq[n].vring.num) { 1418 return; 1419 } 1420 vdev->vq[n].vring.desc = addr; 1421 virtio_queue_update_rings(vdev, n); 1422 } 1423 1424 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 1425 { 1426 return vdev->vq[n].vring.desc; 1427 } 1428 1429 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 1430 hwaddr avail, hwaddr used) 1431 { 1432 if (!vdev->vq[n].vring.num) { 1433 return; 1434 } 1435 vdev->vq[n].vring.desc = desc; 1436 vdev->vq[n].vring.avail = avail; 1437 vdev->vq[n].vring.used = used; 1438 virtio_init_region_cache(vdev, n); 1439 } 1440 1441 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 1442 { 1443 /* Don't allow guest to flip queue between existent and 1444 * nonexistent states, or to set it to an invalid size. 1445 */ 1446 if (!!num != !!vdev->vq[n].vring.num || 1447 num > VIRTQUEUE_MAX_SIZE || 1448 num < 0) { 1449 return; 1450 } 1451 vdev->vq[n].vring.num = num; 1452 } 1453 1454 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 1455 { 1456 return QLIST_FIRST(&vdev->vector_queues[vector]); 1457 } 1458 1459 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 1460 { 1461 return QLIST_NEXT(vq, node); 1462 } 1463 1464 int virtio_queue_get_num(VirtIODevice *vdev, int n) 1465 { 1466 return vdev->vq[n].vring.num; 1467 } 1468 1469 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 1470 { 1471 return vdev->vq[n].vring.num_default; 1472 } 1473 1474 int virtio_get_num_queues(VirtIODevice *vdev) 1475 { 1476 int i; 1477 1478 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1479 if (!virtio_queue_get_num(vdev, i)) { 1480 break; 1481 } 1482 } 1483 1484 return i; 1485 } 1486 1487 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 1488 { 1489 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1490 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1491 1492 /* virtio-1 compliant devices cannot change the alignment */ 1493 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1494 error_report("tried to modify queue alignment for virtio-1 device"); 1495 return; 1496 } 1497 /* Check that the transport told us it was going to do this 1498 * (so a buggy transport will immediately assert rather than 1499 * silently failing to migrate this state) 1500 */ 1501 assert(k->has_variable_vring_alignment); 1502 1503 if (align) { 1504 vdev->vq[n].vring.align = align; 1505 virtio_queue_update_rings(vdev, n); 1506 } 1507 } 1508 1509 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) 1510 { 1511 if (vq->vring.desc && vq->handle_aio_output) { 1512 VirtIODevice *vdev = vq->vdev; 1513 1514 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1515 return vq->handle_aio_output(vdev, vq); 1516 } 1517 1518 return false; 1519 } 1520 1521 static void virtio_queue_notify_vq(VirtQueue *vq) 1522 { 1523 if (vq->vring.desc && vq->handle_output) { 1524 VirtIODevice *vdev = vq->vdev; 1525 1526 if (unlikely(vdev->broken)) { 1527 return; 1528 } 1529 1530 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1531 vq->handle_output(vdev, vq); 1532 } 1533 } 1534 1535 void virtio_queue_notify(VirtIODevice *vdev, int n) 1536 { 1537 VirtQueue *vq = &vdev->vq[n]; 1538 1539 if (unlikely(!vq->vring.desc || vdev->broken)) { 1540 return; 1541 } 1542 1543 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1544 if (vq->handle_aio_output) { 1545 event_notifier_set(&vq->host_notifier); 1546 } else if (vq->handle_output) { 1547 vq->handle_output(vdev, vq); 1548 } 1549 } 1550 1551 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 1552 { 1553 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 1554 VIRTIO_NO_VECTOR; 1555 } 1556 1557 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 1558 { 1559 VirtQueue *vq = &vdev->vq[n]; 1560 1561 if (n < VIRTIO_QUEUE_MAX) { 1562 if (vdev->vector_queues && 1563 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 1564 QLIST_REMOVE(vq, node); 1565 } 1566 vdev->vq[n].vector = vector; 1567 if (vdev->vector_queues && 1568 vector != VIRTIO_NO_VECTOR) { 1569 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 1570 } 1571 } 1572 } 1573 1574 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 1575 VirtIOHandleOutput handle_output) 1576 { 1577 int i; 1578 1579 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1580 if (vdev->vq[i].vring.num == 0) 1581 break; 1582 } 1583 1584 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 1585 abort(); 1586 1587 vdev->vq[i].vring.num = queue_size; 1588 vdev->vq[i].vring.num_default = queue_size; 1589 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 1590 vdev->vq[i].handle_output = handle_output; 1591 vdev->vq[i].handle_aio_output = NULL; 1592 1593 return &vdev->vq[i]; 1594 } 1595 1596 void virtio_del_queue(VirtIODevice *vdev, int n) 1597 { 1598 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 1599 abort(); 1600 } 1601 1602 vdev->vq[n].vring.num = 0; 1603 vdev->vq[n].vring.num_default = 0; 1604 } 1605 1606 static void virtio_set_isr(VirtIODevice *vdev, int value) 1607 { 1608 uint8_t old = atomic_read(&vdev->isr); 1609 1610 /* Do not write ISR if it does not change, so that its cacheline remains 1611 * shared in the common case where the guest does not read it. 1612 */ 1613 if ((old & value) != value) { 1614 atomic_or(&vdev->isr, value); 1615 } 1616 } 1617 1618 /* Called within rcu_read_lock(). */ 1619 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 1620 { 1621 uint16_t old, new; 1622 bool v; 1623 /* We need to expose used array entries before checking used event. */ 1624 smp_mb(); 1625 /* Always notify when queue is empty (when feature acknowledge) */ 1626 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 1627 !vq->inuse && virtio_queue_empty(vq)) { 1628 return true; 1629 } 1630 1631 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1632 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 1633 } 1634 1635 v = vq->signalled_used_valid; 1636 vq->signalled_used_valid = true; 1637 old = vq->signalled_used; 1638 new = vq->signalled_used = vq->used_idx; 1639 return !v || vring_need_event(vring_get_used_event(vq), new, old); 1640 } 1641 1642 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 1643 { 1644 bool should_notify; 1645 rcu_read_lock(); 1646 should_notify = virtio_should_notify(vdev, vq); 1647 rcu_read_unlock(); 1648 1649 if (!should_notify) { 1650 return; 1651 } 1652 1653 trace_virtio_notify_irqfd(vdev, vq); 1654 1655 /* 1656 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 1657 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 1658 * incorrectly polling this bit during crashdump and hibernation 1659 * in MSI mode, causing a hang if this bit is never updated. 1660 * Recent releases of Windows do not really shut down, but rather 1661 * log out and hibernate to make the next startup faster. Hence, 1662 * this manifested as a more serious hang during shutdown with 1663 * 1664 * Next driver release from 2016 fixed this problem, so working around it 1665 * is not a must, but it's easy to do so let's do it here. 1666 * 1667 * Note: it's safe to update ISR from any thread as it was switched 1668 * to an atomic operation. 1669 */ 1670 virtio_set_isr(vq->vdev, 0x1); 1671 event_notifier_set(&vq->guest_notifier); 1672 } 1673 1674 static void virtio_irq(VirtQueue *vq) 1675 { 1676 virtio_set_isr(vq->vdev, 0x1); 1677 virtio_notify_vector(vq->vdev, vq->vector); 1678 } 1679 1680 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 1681 { 1682 bool should_notify; 1683 rcu_read_lock(); 1684 should_notify = virtio_should_notify(vdev, vq); 1685 rcu_read_unlock(); 1686 1687 if (!should_notify) { 1688 return; 1689 } 1690 1691 trace_virtio_notify(vdev, vq); 1692 virtio_irq(vq); 1693 } 1694 1695 void virtio_notify_config(VirtIODevice *vdev) 1696 { 1697 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 1698 return; 1699 1700 virtio_set_isr(vdev, 0x3); 1701 vdev->generation++; 1702 virtio_notify_vector(vdev, vdev->config_vector); 1703 } 1704 1705 static bool virtio_device_endian_needed(void *opaque) 1706 { 1707 VirtIODevice *vdev = opaque; 1708 1709 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 1710 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1711 return vdev->device_endian != virtio_default_endian(); 1712 } 1713 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 1714 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 1715 } 1716 1717 static bool virtio_64bit_features_needed(void *opaque) 1718 { 1719 VirtIODevice *vdev = opaque; 1720 1721 return (vdev->host_features >> 32) != 0; 1722 } 1723 1724 static bool virtio_virtqueue_needed(void *opaque) 1725 { 1726 VirtIODevice *vdev = opaque; 1727 1728 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 1729 } 1730 1731 static bool virtio_ringsize_needed(void *opaque) 1732 { 1733 VirtIODevice *vdev = opaque; 1734 int i; 1735 1736 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1737 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 1738 return true; 1739 } 1740 } 1741 return false; 1742 } 1743 1744 static bool virtio_extra_state_needed(void *opaque) 1745 { 1746 VirtIODevice *vdev = opaque; 1747 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1748 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1749 1750 return k->has_extra_state && 1751 k->has_extra_state(qbus->parent); 1752 } 1753 1754 static bool virtio_broken_needed(void *opaque) 1755 { 1756 VirtIODevice *vdev = opaque; 1757 1758 return vdev->broken; 1759 } 1760 1761 static const VMStateDescription vmstate_virtqueue = { 1762 .name = "virtqueue_state", 1763 .version_id = 1, 1764 .minimum_version_id = 1, 1765 .fields = (VMStateField[]) { 1766 VMSTATE_UINT64(vring.avail, struct VirtQueue), 1767 VMSTATE_UINT64(vring.used, struct VirtQueue), 1768 VMSTATE_END_OF_LIST() 1769 } 1770 }; 1771 1772 static const VMStateDescription vmstate_virtio_virtqueues = { 1773 .name = "virtio/virtqueues", 1774 .version_id = 1, 1775 .minimum_version_id = 1, 1776 .needed = &virtio_virtqueue_needed, 1777 .fields = (VMStateField[]) { 1778 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1779 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 1780 VMSTATE_END_OF_LIST() 1781 } 1782 }; 1783 1784 static const VMStateDescription vmstate_ringsize = { 1785 .name = "ringsize_state", 1786 .version_id = 1, 1787 .minimum_version_id = 1, 1788 .fields = (VMStateField[]) { 1789 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 1790 VMSTATE_END_OF_LIST() 1791 } 1792 }; 1793 1794 static const VMStateDescription vmstate_virtio_ringsize = { 1795 .name = "virtio/ringsize", 1796 .version_id = 1, 1797 .minimum_version_id = 1, 1798 .needed = &virtio_ringsize_needed, 1799 .fields = (VMStateField[]) { 1800 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1801 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 1802 VMSTATE_END_OF_LIST() 1803 } 1804 }; 1805 1806 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 1807 VMStateField *field) 1808 { 1809 VirtIODevice *vdev = pv; 1810 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1811 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1812 1813 if (!k->load_extra_state) { 1814 return -1; 1815 } else { 1816 return k->load_extra_state(qbus->parent, f); 1817 } 1818 } 1819 1820 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 1821 VMStateField *field, QJSON *vmdesc) 1822 { 1823 VirtIODevice *vdev = pv; 1824 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1825 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1826 1827 k->save_extra_state(qbus->parent, f); 1828 return 0; 1829 } 1830 1831 static const VMStateInfo vmstate_info_extra_state = { 1832 .name = "virtqueue_extra_state", 1833 .get = get_extra_state, 1834 .put = put_extra_state, 1835 }; 1836 1837 static const VMStateDescription vmstate_virtio_extra_state = { 1838 .name = "virtio/extra_state", 1839 .version_id = 1, 1840 .minimum_version_id = 1, 1841 .needed = &virtio_extra_state_needed, 1842 .fields = (VMStateField[]) { 1843 { 1844 .name = "extra_state", 1845 .version_id = 0, 1846 .field_exists = NULL, 1847 .size = 0, 1848 .info = &vmstate_info_extra_state, 1849 .flags = VMS_SINGLE, 1850 .offset = 0, 1851 }, 1852 VMSTATE_END_OF_LIST() 1853 } 1854 }; 1855 1856 static const VMStateDescription vmstate_virtio_device_endian = { 1857 .name = "virtio/device_endian", 1858 .version_id = 1, 1859 .minimum_version_id = 1, 1860 .needed = &virtio_device_endian_needed, 1861 .fields = (VMStateField[]) { 1862 VMSTATE_UINT8(device_endian, VirtIODevice), 1863 VMSTATE_END_OF_LIST() 1864 } 1865 }; 1866 1867 static const VMStateDescription vmstate_virtio_64bit_features = { 1868 .name = "virtio/64bit_features", 1869 .version_id = 1, 1870 .minimum_version_id = 1, 1871 .needed = &virtio_64bit_features_needed, 1872 .fields = (VMStateField[]) { 1873 VMSTATE_UINT64(guest_features, VirtIODevice), 1874 VMSTATE_END_OF_LIST() 1875 } 1876 }; 1877 1878 static const VMStateDescription vmstate_virtio_broken = { 1879 .name = "virtio/broken", 1880 .version_id = 1, 1881 .minimum_version_id = 1, 1882 .needed = &virtio_broken_needed, 1883 .fields = (VMStateField[]) { 1884 VMSTATE_BOOL(broken, VirtIODevice), 1885 VMSTATE_END_OF_LIST() 1886 } 1887 }; 1888 1889 static const VMStateDescription vmstate_virtio = { 1890 .name = "virtio", 1891 .version_id = 1, 1892 .minimum_version_id = 1, 1893 .minimum_version_id_old = 1, 1894 .fields = (VMStateField[]) { 1895 VMSTATE_END_OF_LIST() 1896 }, 1897 .subsections = (const VMStateDescription*[]) { 1898 &vmstate_virtio_device_endian, 1899 &vmstate_virtio_64bit_features, 1900 &vmstate_virtio_virtqueues, 1901 &vmstate_virtio_ringsize, 1902 &vmstate_virtio_broken, 1903 &vmstate_virtio_extra_state, 1904 NULL 1905 } 1906 }; 1907 1908 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 1909 { 1910 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1911 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1912 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1913 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 1914 int i; 1915 1916 if (k->save_config) { 1917 k->save_config(qbus->parent, f); 1918 } 1919 1920 qemu_put_8s(f, &vdev->status); 1921 qemu_put_8s(f, &vdev->isr); 1922 qemu_put_be16s(f, &vdev->queue_sel); 1923 qemu_put_be32s(f, &guest_features_lo); 1924 qemu_put_be32(f, vdev->config_len); 1925 qemu_put_buffer(f, vdev->config, vdev->config_len); 1926 1927 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1928 if (vdev->vq[i].vring.num == 0) 1929 break; 1930 } 1931 1932 qemu_put_be32(f, i); 1933 1934 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1935 if (vdev->vq[i].vring.num == 0) 1936 break; 1937 1938 qemu_put_be32(f, vdev->vq[i].vring.num); 1939 if (k->has_variable_vring_alignment) { 1940 qemu_put_be32(f, vdev->vq[i].vring.align); 1941 } 1942 /* 1943 * Save desc now, the rest of the ring addresses are saved in 1944 * subsections for VIRTIO-1 devices. 1945 */ 1946 qemu_put_be64(f, vdev->vq[i].vring.desc); 1947 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 1948 if (k->save_queue) { 1949 k->save_queue(qbus->parent, i, f); 1950 } 1951 } 1952 1953 if (vdc->save != NULL) { 1954 vdc->save(vdev, f); 1955 } 1956 1957 if (vdc->vmsd) { 1958 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 1959 if (ret) { 1960 return ret; 1961 } 1962 } 1963 1964 /* Subsections */ 1965 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 1966 } 1967 1968 /* A wrapper for use as a VMState .put function */ 1969 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 1970 VMStateField *field, QJSON *vmdesc) 1971 { 1972 return virtio_save(VIRTIO_DEVICE(opaque), f); 1973 } 1974 1975 /* A wrapper for use as a VMState .get function */ 1976 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 1977 VMStateField *field) 1978 { 1979 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1980 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 1981 1982 return virtio_load(vdev, f, dc->vmsd->version_id); 1983 } 1984 1985 const VMStateInfo virtio_vmstate_info = { 1986 .name = "virtio", 1987 .get = virtio_device_get, 1988 .put = virtio_device_put, 1989 }; 1990 1991 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 1992 { 1993 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1994 bool bad = (val & ~(vdev->host_features)) != 0; 1995 1996 val &= vdev->host_features; 1997 if (k->set_features) { 1998 k->set_features(vdev, val); 1999 } 2000 vdev->guest_features = val; 2001 return bad ? -1 : 0; 2002 } 2003 2004 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2005 { 2006 /* 2007 * The driver must not attempt to set features after feature negotiation 2008 * has finished. 2009 */ 2010 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2011 return -EINVAL; 2012 } 2013 return virtio_set_features_nocheck(vdev, val); 2014 } 2015 2016 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2017 { 2018 int i, ret; 2019 int32_t config_len; 2020 uint32_t num; 2021 uint32_t features; 2022 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2023 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2024 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2025 2026 /* 2027 * We poison the endianness to ensure it does not get used before 2028 * subsections have been loaded. 2029 */ 2030 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2031 2032 if (k->load_config) { 2033 ret = k->load_config(qbus->parent, f); 2034 if (ret) 2035 return ret; 2036 } 2037 2038 qemu_get_8s(f, &vdev->status); 2039 qemu_get_8s(f, &vdev->isr); 2040 qemu_get_be16s(f, &vdev->queue_sel); 2041 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2042 return -1; 2043 } 2044 qemu_get_be32s(f, &features); 2045 2046 /* 2047 * Temporarily set guest_features low bits - needed by 2048 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2049 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2050 * 2051 * Note: devices should always test host features in future - don't create 2052 * new dependencies like this. 2053 */ 2054 vdev->guest_features = features; 2055 2056 config_len = qemu_get_be32(f); 2057 2058 /* 2059 * There are cases where the incoming config can be bigger or smaller 2060 * than what we have; so load what we have space for, and skip 2061 * any excess that's in the stream. 2062 */ 2063 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 2064 2065 while (config_len > vdev->config_len) { 2066 qemu_get_byte(f); 2067 config_len--; 2068 } 2069 2070 num = qemu_get_be32(f); 2071 2072 if (num > VIRTIO_QUEUE_MAX) { 2073 error_report("Invalid number of virtqueues: 0x%x", num); 2074 return -1; 2075 } 2076 2077 for (i = 0; i < num; i++) { 2078 vdev->vq[i].vring.num = qemu_get_be32(f); 2079 if (k->has_variable_vring_alignment) { 2080 vdev->vq[i].vring.align = qemu_get_be32(f); 2081 } 2082 vdev->vq[i].vring.desc = qemu_get_be64(f); 2083 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 2084 vdev->vq[i].signalled_used_valid = false; 2085 vdev->vq[i].notification = true; 2086 2087 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 2088 error_report("VQ %d address 0x0 " 2089 "inconsistent with Host index 0x%x", 2090 i, vdev->vq[i].last_avail_idx); 2091 return -1; 2092 } 2093 if (k->load_queue) { 2094 ret = k->load_queue(qbus->parent, i, f); 2095 if (ret) 2096 return ret; 2097 } 2098 } 2099 2100 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 2101 2102 if (vdc->load != NULL) { 2103 ret = vdc->load(vdev, f, version_id); 2104 if (ret) { 2105 return ret; 2106 } 2107 } 2108 2109 if (vdc->vmsd) { 2110 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 2111 if (ret) { 2112 return ret; 2113 } 2114 } 2115 2116 /* Subsections */ 2117 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 2118 if (ret) { 2119 return ret; 2120 } 2121 2122 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 2123 vdev->device_endian = virtio_default_endian(); 2124 } 2125 2126 if (virtio_64bit_features_needed(vdev)) { 2127 /* 2128 * Subsection load filled vdev->guest_features. Run them 2129 * through virtio_set_features to sanity-check them against 2130 * host_features. 2131 */ 2132 uint64_t features64 = vdev->guest_features; 2133 if (virtio_set_features_nocheck(vdev, features64) < 0) { 2134 error_report("Features 0x%" PRIx64 " unsupported. " 2135 "Allowed features: 0x%" PRIx64, 2136 features64, vdev->host_features); 2137 return -1; 2138 } 2139 } else { 2140 if (virtio_set_features_nocheck(vdev, features) < 0) { 2141 error_report("Features 0x%x unsupported. " 2142 "Allowed features: 0x%" PRIx64, 2143 features, vdev->host_features); 2144 return -1; 2145 } 2146 } 2147 2148 rcu_read_lock(); 2149 for (i = 0; i < num; i++) { 2150 if (vdev->vq[i].vring.desc) { 2151 uint16_t nheads; 2152 2153 /* 2154 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 2155 * only the region cache needs to be set up. Legacy devices need 2156 * to calculate used and avail ring addresses based on the desc 2157 * address. 2158 */ 2159 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2160 virtio_init_region_cache(vdev, i); 2161 } else { 2162 virtio_queue_update_rings(vdev, i); 2163 } 2164 2165 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 2166 /* Check it isn't doing strange things with descriptor numbers. */ 2167 if (nheads > vdev->vq[i].vring.num) { 2168 error_report("VQ %d size 0x%x Guest index 0x%x " 2169 "inconsistent with Host index 0x%x: delta 0x%x", 2170 i, vdev->vq[i].vring.num, 2171 vring_avail_idx(&vdev->vq[i]), 2172 vdev->vq[i].last_avail_idx, nheads); 2173 return -1; 2174 } 2175 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 2176 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 2177 2178 /* 2179 * Some devices migrate VirtQueueElements that have been popped 2180 * from the avail ring but not yet returned to the used ring. 2181 * Since max ring size < UINT16_MAX it's safe to use modulo 2182 * UINT16_MAX + 1 subtraction. 2183 */ 2184 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 2185 vdev->vq[i].used_idx); 2186 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 2187 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 2188 "used_idx 0x%x", 2189 i, vdev->vq[i].vring.num, 2190 vdev->vq[i].last_avail_idx, 2191 vdev->vq[i].used_idx); 2192 return -1; 2193 } 2194 } 2195 } 2196 rcu_read_unlock(); 2197 2198 return 0; 2199 } 2200 2201 void virtio_cleanup(VirtIODevice *vdev) 2202 { 2203 qemu_del_vm_change_state_handler(vdev->vmstate); 2204 } 2205 2206 static void virtio_vmstate_change(void *opaque, int running, RunState state) 2207 { 2208 VirtIODevice *vdev = opaque; 2209 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2210 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2211 bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK); 2212 vdev->vm_running = running; 2213 2214 if (backend_run) { 2215 virtio_set_status(vdev, vdev->status); 2216 } 2217 2218 if (k->vmstate_change) { 2219 k->vmstate_change(qbus->parent, backend_run); 2220 } 2221 2222 if (!backend_run) { 2223 virtio_set_status(vdev, vdev->status); 2224 } 2225 } 2226 2227 void virtio_instance_init_common(Object *proxy_obj, void *data, 2228 size_t vdev_size, const char *vdev_name) 2229 { 2230 DeviceState *vdev = data; 2231 2232 object_initialize(vdev, vdev_size, vdev_name); 2233 object_property_add_child(proxy_obj, "virtio-backend", OBJECT(vdev), NULL); 2234 object_unref(OBJECT(vdev)); 2235 qdev_alias_all_properties(vdev, proxy_obj); 2236 } 2237 2238 void virtio_init(VirtIODevice *vdev, const char *name, 2239 uint16_t device_id, size_t config_size) 2240 { 2241 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2242 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2243 int i; 2244 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 2245 2246 if (nvectors) { 2247 vdev->vector_queues = 2248 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 2249 } 2250 2251 vdev->device_id = device_id; 2252 vdev->status = 0; 2253 atomic_set(&vdev->isr, 0); 2254 vdev->queue_sel = 0; 2255 vdev->config_vector = VIRTIO_NO_VECTOR; 2256 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 2257 vdev->vm_running = runstate_is_running(); 2258 vdev->broken = false; 2259 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2260 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 2261 vdev->vq[i].vdev = vdev; 2262 vdev->vq[i].queue_index = i; 2263 } 2264 2265 vdev->name = name; 2266 vdev->config_len = config_size; 2267 if (vdev->config_len) { 2268 vdev->config = g_malloc0(config_size); 2269 } else { 2270 vdev->config = NULL; 2271 } 2272 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, 2273 vdev); 2274 vdev->device_endian = virtio_default_endian(); 2275 vdev->use_guest_notifier_mask = true; 2276 } 2277 2278 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 2279 { 2280 return vdev->vq[n].vring.desc; 2281 } 2282 2283 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 2284 { 2285 return vdev->vq[n].vring.avail; 2286 } 2287 2288 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 2289 { 2290 return vdev->vq[n].vring.used; 2291 } 2292 2293 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 2294 { 2295 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 2296 } 2297 2298 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 2299 { 2300 return offsetof(VRingAvail, ring) + 2301 sizeof(uint16_t) * vdev->vq[n].vring.num; 2302 } 2303 2304 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 2305 { 2306 return offsetof(VRingUsed, ring) + 2307 sizeof(VRingUsedElem) * vdev->vq[n].vring.num; 2308 } 2309 2310 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 2311 { 2312 return vdev->vq[n].last_avail_idx; 2313 } 2314 2315 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) 2316 { 2317 vdev->vq[n].last_avail_idx = idx; 2318 vdev->vq[n].shadow_avail_idx = idx; 2319 } 2320 2321 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 2322 { 2323 rcu_read_lock(); 2324 if (vdev->vq[n].vring.desc) { 2325 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 2326 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 2327 } 2328 rcu_read_unlock(); 2329 } 2330 2331 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 2332 { 2333 rcu_read_lock(); 2334 if (vdev->vq[n].vring.desc) { 2335 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 2336 } 2337 rcu_read_unlock(); 2338 } 2339 2340 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 2341 { 2342 vdev->vq[n].signalled_used_valid = false; 2343 } 2344 2345 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 2346 { 2347 return vdev->vq + n; 2348 } 2349 2350 uint16_t virtio_get_queue_index(VirtQueue *vq) 2351 { 2352 return vq->queue_index; 2353 } 2354 2355 static void virtio_queue_guest_notifier_read(EventNotifier *n) 2356 { 2357 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 2358 if (event_notifier_test_and_clear(n)) { 2359 virtio_irq(vq); 2360 } 2361 } 2362 2363 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 2364 bool with_irqfd) 2365 { 2366 if (assign && !with_irqfd) { 2367 event_notifier_set_handler(&vq->guest_notifier, 2368 virtio_queue_guest_notifier_read); 2369 } else { 2370 event_notifier_set_handler(&vq->guest_notifier, NULL); 2371 } 2372 if (!assign) { 2373 /* Test and clear notifier before closing it, 2374 * in case poll callback didn't have time to run. */ 2375 virtio_queue_guest_notifier_read(&vq->guest_notifier); 2376 } 2377 } 2378 2379 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 2380 { 2381 return &vq->guest_notifier; 2382 } 2383 2384 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 2385 { 2386 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2387 if (event_notifier_test_and_clear(n)) { 2388 virtio_queue_notify_aio_vq(vq); 2389 } 2390 } 2391 2392 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 2393 { 2394 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2395 2396 virtio_queue_set_notification(vq, 0); 2397 } 2398 2399 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 2400 { 2401 EventNotifier *n = opaque; 2402 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2403 bool progress; 2404 2405 if (!vq->vring.desc || virtio_queue_empty(vq)) { 2406 return false; 2407 } 2408 2409 progress = virtio_queue_notify_aio_vq(vq); 2410 2411 /* In case the handler function re-enabled notifications */ 2412 virtio_queue_set_notification(vq, 0); 2413 return progress; 2414 } 2415 2416 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 2417 { 2418 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2419 2420 /* Caller polls once more after this to catch requests that race with us */ 2421 virtio_queue_set_notification(vq, 1); 2422 } 2423 2424 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 2425 VirtIOHandleAIOOutput handle_output) 2426 { 2427 if (handle_output) { 2428 vq->handle_aio_output = handle_output; 2429 aio_set_event_notifier(ctx, &vq->host_notifier, true, 2430 virtio_queue_host_notifier_aio_read, 2431 virtio_queue_host_notifier_aio_poll); 2432 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 2433 virtio_queue_host_notifier_aio_poll_begin, 2434 virtio_queue_host_notifier_aio_poll_end); 2435 } else { 2436 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 2437 /* Test and clear notifier before after disabling event, 2438 * in case poll callback didn't have time to run. */ 2439 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 2440 vq->handle_aio_output = NULL; 2441 } 2442 } 2443 2444 void virtio_queue_host_notifier_read(EventNotifier *n) 2445 { 2446 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2447 if (event_notifier_test_and_clear(n)) { 2448 virtio_queue_notify_vq(vq); 2449 } 2450 } 2451 2452 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 2453 { 2454 return &vq->host_notifier; 2455 } 2456 2457 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 2458 { 2459 g_free(vdev->bus_name); 2460 vdev->bus_name = g_strdup(bus_name); 2461 } 2462 2463 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 2464 { 2465 va_list ap; 2466 2467 va_start(ap, fmt); 2468 error_vreport(fmt, ap); 2469 va_end(ap); 2470 2471 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2472 virtio_set_status(vdev, vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET); 2473 virtio_notify_config(vdev); 2474 } 2475 2476 vdev->broken = true; 2477 } 2478 2479 static void virtio_memory_listener_commit(MemoryListener *listener) 2480 { 2481 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 2482 int i; 2483 2484 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2485 if (vdev->vq[i].vring.num == 0) { 2486 break; 2487 } 2488 virtio_init_region_cache(vdev, i); 2489 } 2490 } 2491 2492 static void virtio_device_realize(DeviceState *dev, Error **errp) 2493 { 2494 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2495 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2496 Error *err = NULL; 2497 2498 /* Devices should either use vmsd or the load/save methods */ 2499 assert(!vdc->vmsd || !vdc->load); 2500 2501 if (vdc->realize != NULL) { 2502 vdc->realize(dev, &err); 2503 if (err != NULL) { 2504 error_propagate(errp, err); 2505 return; 2506 } 2507 } 2508 2509 virtio_bus_device_plugged(vdev, &err); 2510 if (err != NULL) { 2511 error_propagate(errp, err); 2512 vdc->unrealize(dev, NULL); 2513 return; 2514 } 2515 2516 vdev->listener.commit = virtio_memory_listener_commit; 2517 memory_listener_register(&vdev->listener, vdev->dma_as); 2518 } 2519 2520 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 2521 { 2522 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2523 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2524 Error *err = NULL; 2525 2526 virtio_bus_device_unplugged(vdev); 2527 2528 if (vdc->unrealize != NULL) { 2529 vdc->unrealize(dev, &err); 2530 if (err != NULL) { 2531 error_propagate(errp, err); 2532 return; 2533 } 2534 } 2535 2536 g_free(vdev->bus_name); 2537 vdev->bus_name = NULL; 2538 } 2539 2540 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 2541 { 2542 int i; 2543 if (!vdev->vq) { 2544 return; 2545 } 2546 2547 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2548 if (vdev->vq[i].vring.num == 0) { 2549 break; 2550 } 2551 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2552 } 2553 g_free(vdev->vq); 2554 } 2555 2556 static void virtio_device_instance_finalize(Object *obj) 2557 { 2558 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 2559 2560 memory_listener_unregister(&vdev->listener); 2561 virtio_device_free_virtqueues(vdev); 2562 2563 g_free(vdev->config); 2564 g_free(vdev->vector_queues); 2565 } 2566 2567 static Property virtio_properties[] = { 2568 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 2569 DEFINE_PROP_END_OF_LIST(), 2570 }; 2571 2572 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 2573 { 2574 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2575 int n, r, err; 2576 2577 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2578 VirtQueue *vq = &vdev->vq[n]; 2579 if (!virtio_queue_get_num(vdev, n)) { 2580 continue; 2581 } 2582 r = virtio_bus_set_host_notifier(qbus, n, true); 2583 if (r < 0) { 2584 err = r; 2585 goto assign_error; 2586 } 2587 event_notifier_set_handler(&vq->host_notifier, 2588 virtio_queue_host_notifier_read); 2589 } 2590 2591 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2592 /* Kick right away to begin processing requests already in vring */ 2593 VirtQueue *vq = &vdev->vq[n]; 2594 if (!vq->vring.num) { 2595 continue; 2596 } 2597 event_notifier_set(&vq->host_notifier); 2598 } 2599 return 0; 2600 2601 assign_error: 2602 while (--n >= 0) { 2603 VirtQueue *vq = &vdev->vq[n]; 2604 if (!virtio_queue_get_num(vdev, n)) { 2605 continue; 2606 } 2607 2608 event_notifier_set_handler(&vq->host_notifier, NULL); 2609 r = virtio_bus_set_host_notifier(qbus, n, false); 2610 assert(r >= 0); 2611 } 2612 return err; 2613 } 2614 2615 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 2616 { 2617 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2618 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2619 2620 return virtio_bus_start_ioeventfd(vbus); 2621 } 2622 2623 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 2624 { 2625 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2626 int n, r; 2627 2628 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2629 VirtQueue *vq = &vdev->vq[n]; 2630 2631 if (!virtio_queue_get_num(vdev, n)) { 2632 continue; 2633 } 2634 event_notifier_set_handler(&vq->host_notifier, NULL); 2635 r = virtio_bus_set_host_notifier(qbus, n, false); 2636 assert(r >= 0); 2637 } 2638 } 2639 2640 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) 2641 { 2642 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2643 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2644 2645 virtio_bus_stop_ioeventfd(vbus); 2646 } 2647 2648 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 2649 { 2650 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2651 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2652 2653 return virtio_bus_grab_ioeventfd(vbus); 2654 } 2655 2656 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 2657 { 2658 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2659 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2660 2661 virtio_bus_release_ioeventfd(vbus); 2662 } 2663 2664 static void virtio_device_class_init(ObjectClass *klass, void *data) 2665 { 2666 /* Set the default value here. */ 2667 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 2668 DeviceClass *dc = DEVICE_CLASS(klass); 2669 2670 dc->realize = virtio_device_realize; 2671 dc->unrealize = virtio_device_unrealize; 2672 dc->bus_type = TYPE_VIRTIO_BUS; 2673 dc->props = virtio_properties; 2674 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 2675 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 2676 2677 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 2678 } 2679 2680 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 2681 { 2682 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2683 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2684 2685 return virtio_bus_ioeventfd_enabled(vbus); 2686 } 2687 2688 static const TypeInfo virtio_device_info = { 2689 .name = TYPE_VIRTIO_DEVICE, 2690 .parent = TYPE_DEVICE, 2691 .instance_size = sizeof(VirtIODevice), 2692 .class_init = virtio_device_class_init, 2693 .instance_finalize = virtio_device_instance_finalize, 2694 .abstract = true, 2695 .class_size = sizeof(VirtioDeviceClass), 2696 }; 2697 2698 static void virtio_register_types(void) 2699 { 2700 type_register_static(&virtio_device_info); 2701 } 2702 2703 type_init(virtio_register_types) 2704