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_virtqueue_reset_region_cache(struct VirtQueue *vq) 127 { 128 VRingMemoryRegionCaches *caches; 129 130 caches = atomic_read(&vq->vring.caches); 131 atomic_rcu_set(&vq->vring.caches, NULL); 132 if (caches) { 133 call_rcu(caches, virtio_free_region_cache, rcu); 134 } 135 } 136 137 static void virtio_init_region_cache(VirtIODevice *vdev, int n) 138 { 139 VirtQueue *vq = &vdev->vq[n]; 140 VRingMemoryRegionCaches *old = vq->vring.caches; 141 VRingMemoryRegionCaches *new = NULL; 142 hwaddr addr, size; 143 int event_size; 144 int64_t len; 145 146 event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 147 148 addr = vq->vring.desc; 149 if (!addr) { 150 goto out_no_cache; 151 } 152 new = g_new0(VRingMemoryRegionCaches, 1); 153 size = virtio_queue_get_desc_size(vdev, n); 154 len = address_space_cache_init(&new->desc, vdev->dma_as, 155 addr, size, false); 156 if (len < size) { 157 virtio_error(vdev, "Cannot map desc"); 158 goto err_desc; 159 } 160 161 size = virtio_queue_get_used_size(vdev, n) + event_size; 162 len = address_space_cache_init(&new->used, vdev->dma_as, 163 vq->vring.used, size, true); 164 if (len < size) { 165 virtio_error(vdev, "Cannot map used"); 166 goto err_used; 167 } 168 169 size = virtio_queue_get_avail_size(vdev, n) + event_size; 170 len = address_space_cache_init(&new->avail, vdev->dma_as, 171 vq->vring.avail, size, false); 172 if (len < size) { 173 virtio_error(vdev, "Cannot map avail"); 174 goto err_avail; 175 } 176 177 atomic_rcu_set(&vq->vring.caches, new); 178 if (old) { 179 call_rcu(old, virtio_free_region_cache, rcu); 180 } 181 return; 182 183 err_avail: 184 address_space_cache_destroy(&new->avail); 185 err_used: 186 address_space_cache_destroy(&new->used); 187 err_desc: 188 address_space_cache_destroy(&new->desc); 189 out_no_cache: 190 g_free(new); 191 virtio_virtqueue_reset_region_cache(vq); 192 } 193 194 /* virt queue functions */ 195 void virtio_queue_update_rings(VirtIODevice *vdev, int n) 196 { 197 VRing *vring = &vdev->vq[n].vring; 198 199 if (!vring->num || !vring->desc || !vring->align) { 200 /* not yet setup -> nothing to do */ 201 return; 202 } 203 vring->avail = vring->desc + vring->num * sizeof(VRingDesc); 204 vring->used = vring_align(vring->avail + 205 offsetof(VRingAvail, ring[vring->num]), 206 vring->align); 207 virtio_init_region_cache(vdev, n); 208 } 209 210 /* Called within rcu_read_lock(). */ 211 static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc, 212 MemoryRegionCache *cache, int i) 213 { 214 address_space_read_cached(cache, i * sizeof(VRingDesc), 215 desc, sizeof(VRingDesc)); 216 virtio_tswap64s(vdev, &desc->addr); 217 virtio_tswap32s(vdev, &desc->len); 218 virtio_tswap16s(vdev, &desc->flags); 219 virtio_tswap16s(vdev, &desc->next); 220 } 221 222 static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq) 223 { 224 VRingMemoryRegionCaches *caches = atomic_rcu_read(&vq->vring.caches); 225 assert(caches != NULL); 226 return caches; 227 } 228 /* Called within rcu_read_lock(). */ 229 static inline uint16_t vring_avail_flags(VirtQueue *vq) 230 { 231 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 232 hwaddr pa = offsetof(VRingAvail, flags); 233 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 234 } 235 236 /* Called within rcu_read_lock(). */ 237 static inline uint16_t vring_avail_idx(VirtQueue *vq) 238 { 239 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 240 hwaddr pa = offsetof(VRingAvail, idx); 241 vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 242 return vq->shadow_avail_idx; 243 } 244 245 /* Called within rcu_read_lock(). */ 246 static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) 247 { 248 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 249 hwaddr pa = offsetof(VRingAvail, ring[i]); 250 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 251 } 252 253 /* Called within rcu_read_lock(). */ 254 static inline uint16_t vring_get_used_event(VirtQueue *vq) 255 { 256 return vring_avail_ring(vq, vq->vring.num); 257 } 258 259 /* Called within rcu_read_lock(). */ 260 static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, 261 int i) 262 { 263 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 264 hwaddr pa = offsetof(VRingUsed, ring[i]); 265 virtio_tswap32s(vq->vdev, &uelem->id); 266 virtio_tswap32s(vq->vdev, &uelem->len); 267 address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem)); 268 address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem)); 269 } 270 271 /* Called within rcu_read_lock(). */ 272 static uint16_t vring_used_idx(VirtQueue *vq) 273 { 274 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 275 hwaddr pa = offsetof(VRingUsed, idx); 276 return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 277 } 278 279 /* Called within rcu_read_lock(). */ 280 static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val) 281 { 282 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 283 hwaddr pa = offsetof(VRingUsed, idx); 284 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 285 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 286 vq->used_idx = val; 287 } 288 289 /* Called within rcu_read_lock(). */ 290 static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) 291 { 292 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 293 VirtIODevice *vdev = vq->vdev; 294 hwaddr pa = offsetof(VRingUsed, flags); 295 uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 296 297 virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask); 298 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 299 } 300 301 /* Called within rcu_read_lock(). */ 302 static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) 303 { 304 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 305 VirtIODevice *vdev = vq->vdev; 306 hwaddr pa = offsetof(VRingUsed, flags); 307 uint16_t flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 308 309 virtio_stw_phys_cached(vdev, &caches->used, pa, flags & ~mask); 310 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 311 } 312 313 /* Called within rcu_read_lock(). */ 314 static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) 315 { 316 VRingMemoryRegionCaches *caches; 317 hwaddr pa; 318 if (!vq->notification) { 319 return; 320 } 321 322 caches = vring_get_region_caches(vq); 323 pa = offsetof(VRingUsed, ring[vq->vring.num]); 324 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 325 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 326 } 327 328 void virtio_queue_set_notification(VirtQueue *vq, int enable) 329 { 330 vq->notification = enable; 331 332 if (!vq->vring.desc) { 333 return; 334 } 335 336 rcu_read_lock(); 337 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 338 vring_set_avail_event(vq, vring_avail_idx(vq)); 339 } else if (enable) { 340 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); 341 } else { 342 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); 343 } 344 if (enable) { 345 /* Expose avail event/used flags before caller checks the avail idx. */ 346 smp_mb(); 347 } 348 rcu_read_unlock(); 349 } 350 351 int virtio_queue_ready(VirtQueue *vq) 352 { 353 return vq->vring.avail != 0; 354 } 355 356 /* Fetch avail_idx from VQ memory only when we really need to know if 357 * guest has added some buffers. 358 * Called within rcu_read_lock(). */ 359 static int virtio_queue_empty_rcu(VirtQueue *vq) 360 { 361 if (unlikely(!vq->vring.avail)) { 362 return 1; 363 } 364 365 if (vq->shadow_avail_idx != vq->last_avail_idx) { 366 return 0; 367 } 368 369 return vring_avail_idx(vq) == vq->last_avail_idx; 370 } 371 372 int virtio_queue_empty(VirtQueue *vq) 373 { 374 bool empty; 375 376 if (unlikely(!vq->vring.avail)) { 377 return 1; 378 } 379 380 if (vq->shadow_avail_idx != vq->last_avail_idx) { 381 return 0; 382 } 383 384 rcu_read_lock(); 385 empty = vring_avail_idx(vq) == vq->last_avail_idx; 386 rcu_read_unlock(); 387 return empty; 388 } 389 390 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 391 unsigned int len) 392 { 393 AddressSpace *dma_as = vq->vdev->dma_as; 394 unsigned int offset; 395 int i; 396 397 offset = 0; 398 for (i = 0; i < elem->in_num; i++) { 399 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 400 401 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 402 elem->in_sg[i].iov_len, 403 DMA_DIRECTION_FROM_DEVICE, size); 404 405 offset += size; 406 } 407 408 for (i = 0; i < elem->out_num; i++) 409 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 410 elem->out_sg[i].iov_len, 411 DMA_DIRECTION_TO_DEVICE, 412 elem->out_sg[i].iov_len); 413 } 414 415 /* virtqueue_detach_element: 416 * @vq: The #VirtQueue 417 * @elem: The #VirtQueueElement 418 * @len: number of bytes written 419 * 420 * Detach the element from the virtqueue. This function is suitable for device 421 * reset or other situations where a #VirtQueueElement is simply freed and will 422 * not be pushed or discarded. 423 */ 424 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 425 unsigned int len) 426 { 427 vq->inuse--; 428 virtqueue_unmap_sg(vq, elem, len); 429 } 430 431 /* virtqueue_unpop: 432 * @vq: The #VirtQueue 433 * @elem: The #VirtQueueElement 434 * @len: number of bytes written 435 * 436 * Pretend the most recent element wasn't popped from the virtqueue. The next 437 * call to virtqueue_pop() will refetch the element. 438 */ 439 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 440 unsigned int len) 441 { 442 vq->last_avail_idx--; 443 virtqueue_detach_element(vq, elem, len); 444 } 445 446 /* virtqueue_rewind: 447 * @vq: The #VirtQueue 448 * @num: Number of elements to push back 449 * 450 * Pretend that elements weren't popped from the virtqueue. The next 451 * virtqueue_pop() will refetch the oldest element. 452 * 453 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 454 * 455 * Returns: true on success, false if @num is greater than the number of in use 456 * elements. 457 */ 458 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 459 { 460 if (num > vq->inuse) { 461 return false; 462 } 463 vq->last_avail_idx -= num; 464 vq->inuse -= num; 465 return true; 466 } 467 468 /* Called within rcu_read_lock(). */ 469 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 470 unsigned int len, unsigned int idx) 471 { 472 VRingUsedElem uelem; 473 474 trace_virtqueue_fill(vq, elem, len, idx); 475 476 virtqueue_unmap_sg(vq, elem, len); 477 478 if (unlikely(vq->vdev->broken)) { 479 return; 480 } 481 482 if (unlikely(!vq->vring.used)) { 483 return; 484 } 485 486 idx = (idx + vq->used_idx) % vq->vring.num; 487 488 uelem.id = elem->index; 489 uelem.len = len; 490 vring_used_write(vq, &uelem, idx); 491 } 492 493 /* Called within rcu_read_lock(). */ 494 void virtqueue_flush(VirtQueue *vq, unsigned int count) 495 { 496 uint16_t old, new; 497 498 if (unlikely(vq->vdev->broken)) { 499 vq->inuse -= count; 500 return; 501 } 502 503 if (unlikely(!vq->vring.used)) { 504 return; 505 } 506 507 /* Make sure buffer is written before we update index. */ 508 smp_wmb(); 509 trace_virtqueue_flush(vq, count); 510 old = vq->used_idx; 511 new = old + count; 512 vring_used_idx_set(vq, new); 513 vq->inuse -= count; 514 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 515 vq->signalled_used_valid = false; 516 } 517 518 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 519 unsigned int len) 520 { 521 rcu_read_lock(); 522 virtqueue_fill(vq, elem, len, 0); 523 virtqueue_flush(vq, 1); 524 rcu_read_unlock(); 525 } 526 527 /* Called within rcu_read_lock(). */ 528 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 529 { 530 uint16_t num_heads = vring_avail_idx(vq) - idx; 531 532 /* Check it isn't doing very strange things with descriptor numbers. */ 533 if (num_heads > vq->vring.num) { 534 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 535 idx, vq->shadow_avail_idx); 536 return -EINVAL; 537 } 538 /* On success, callers read a descriptor at vq->last_avail_idx. 539 * Make sure descriptor read does not bypass avail index read. */ 540 if (num_heads) { 541 smp_rmb(); 542 } 543 544 return num_heads; 545 } 546 547 /* Called within rcu_read_lock(). */ 548 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 549 unsigned int *head) 550 { 551 /* Grab the next descriptor number they're advertising, and increment 552 * the index we've seen. */ 553 *head = vring_avail_ring(vq, idx % vq->vring.num); 554 555 /* If their number is silly, that's a fatal mistake. */ 556 if (*head >= vq->vring.num) { 557 virtio_error(vq->vdev, "Guest says index %u is available", *head); 558 return false; 559 } 560 561 return true; 562 } 563 564 enum { 565 VIRTQUEUE_READ_DESC_ERROR = -1, 566 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 567 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 568 }; 569 570 static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 571 MemoryRegionCache *desc_cache, unsigned int max, 572 unsigned int *next) 573 { 574 /* If this descriptor says it doesn't chain, we're done. */ 575 if (!(desc->flags & VRING_DESC_F_NEXT)) { 576 return VIRTQUEUE_READ_DESC_DONE; 577 } 578 579 /* Check they're not leading us off end of descriptors. */ 580 *next = desc->next; 581 /* Make sure compiler knows to grab that: we don't want it changing! */ 582 smp_wmb(); 583 584 if (*next >= max) { 585 virtio_error(vdev, "Desc next is %u", *next); 586 return VIRTQUEUE_READ_DESC_ERROR; 587 } 588 589 vring_desc_read(vdev, desc, desc_cache, *next); 590 return VIRTQUEUE_READ_DESC_MORE; 591 } 592 593 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 594 unsigned int *out_bytes, 595 unsigned max_in_bytes, unsigned max_out_bytes) 596 { 597 VirtIODevice *vdev = vq->vdev; 598 unsigned int max, idx; 599 unsigned int total_bufs, in_total, out_total; 600 VRingMemoryRegionCaches *caches; 601 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 602 int64_t len = 0; 603 int rc; 604 605 if (unlikely(!vq->vring.desc)) { 606 if (in_bytes) { 607 *in_bytes = 0; 608 } 609 if (out_bytes) { 610 *out_bytes = 0; 611 } 612 return; 613 } 614 615 rcu_read_lock(); 616 idx = vq->last_avail_idx; 617 total_bufs = in_total = out_total = 0; 618 619 max = vq->vring.num; 620 caches = vring_get_region_caches(vq); 621 if (caches->desc.len < max * sizeof(VRingDesc)) { 622 virtio_error(vdev, "Cannot map descriptor ring"); 623 goto err; 624 } 625 626 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 627 MemoryRegionCache *desc_cache = &caches->desc; 628 unsigned int num_bufs; 629 VRingDesc desc; 630 unsigned int i; 631 632 num_bufs = total_bufs; 633 634 if (!virtqueue_get_head(vq, idx++, &i)) { 635 goto err; 636 } 637 638 vring_desc_read(vdev, &desc, desc_cache, i); 639 640 if (desc.flags & VRING_DESC_F_INDIRECT) { 641 if (desc.len % sizeof(VRingDesc)) { 642 virtio_error(vdev, "Invalid size for indirect buffer table"); 643 goto err; 644 } 645 646 /* If we've got too many, that implies a descriptor loop. */ 647 if (num_bufs >= max) { 648 virtio_error(vdev, "Looped descriptor"); 649 goto err; 650 } 651 652 /* loop over the indirect descriptor table */ 653 len = address_space_cache_init(&indirect_desc_cache, 654 vdev->dma_as, 655 desc.addr, desc.len, false); 656 desc_cache = &indirect_desc_cache; 657 if (len < desc.len) { 658 virtio_error(vdev, "Cannot map indirect buffer"); 659 goto err; 660 } 661 662 max = desc.len / sizeof(VRingDesc); 663 num_bufs = i = 0; 664 vring_desc_read(vdev, &desc, desc_cache, i); 665 } 666 667 do { 668 /* If we've got too many, that implies a descriptor loop. */ 669 if (++num_bufs > max) { 670 virtio_error(vdev, "Looped descriptor"); 671 goto err; 672 } 673 674 if (desc.flags & VRING_DESC_F_WRITE) { 675 in_total += desc.len; 676 } else { 677 out_total += desc.len; 678 } 679 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 680 goto done; 681 } 682 683 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); 684 } while (rc == VIRTQUEUE_READ_DESC_MORE); 685 686 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 687 goto err; 688 } 689 690 if (desc_cache == &indirect_desc_cache) { 691 address_space_cache_destroy(&indirect_desc_cache); 692 total_bufs++; 693 } else { 694 total_bufs = num_bufs; 695 } 696 } 697 698 if (rc < 0) { 699 goto err; 700 } 701 702 done: 703 address_space_cache_destroy(&indirect_desc_cache); 704 if (in_bytes) { 705 *in_bytes = in_total; 706 } 707 if (out_bytes) { 708 *out_bytes = out_total; 709 } 710 rcu_read_unlock(); 711 return; 712 713 err: 714 in_total = out_total = 0; 715 goto done; 716 } 717 718 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 719 unsigned int out_bytes) 720 { 721 unsigned int in_total, out_total; 722 723 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 724 return in_bytes <= in_total && out_bytes <= out_total; 725 } 726 727 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 728 hwaddr *addr, struct iovec *iov, 729 unsigned int max_num_sg, bool is_write, 730 hwaddr pa, size_t sz) 731 { 732 bool ok = false; 733 unsigned num_sg = *p_num_sg; 734 assert(num_sg <= max_num_sg); 735 736 if (!sz) { 737 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 738 goto out; 739 } 740 741 while (sz) { 742 hwaddr len = sz; 743 744 if (num_sg == max_num_sg) { 745 virtio_error(vdev, "virtio: too many write descriptors in " 746 "indirect table"); 747 goto out; 748 } 749 750 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 751 is_write ? 752 DMA_DIRECTION_FROM_DEVICE : 753 DMA_DIRECTION_TO_DEVICE); 754 if (!iov[num_sg].iov_base) { 755 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 756 goto out; 757 } 758 759 iov[num_sg].iov_len = len; 760 addr[num_sg] = pa; 761 762 sz -= len; 763 pa += len; 764 num_sg++; 765 } 766 ok = true; 767 768 out: 769 *p_num_sg = num_sg; 770 return ok; 771 } 772 773 /* Only used by error code paths before we have a VirtQueueElement (therefore 774 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 775 * yet. 776 */ 777 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 778 struct iovec *iov) 779 { 780 unsigned int i; 781 782 for (i = 0; i < out_num + in_num; i++) { 783 int is_write = i >= out_num; 784 785 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 786 iov++; 787 } 788 } 789 790 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 791 hwaddr *addr, unsigned int *num_sg, 792 int is_write) 793 { 794 unsigned int i; 795 hwaddr len; 796 797 for (i = 0; i < *num_sg; i++) { 798 len = sg[i].iov_len; 799 sg[i].iov_base = dma_memory_map(vdev->dma_as, 800 addr[i], &len, is_write ? 801 DMA_DIRECTION_FROM_DEVICE : 802 DMA_DIRECTION_TO_DEVICE); 803 if (!sg[i].iov_base) { 804 error_report("virtio: error trying to map MMIO memory"); 805 exit(1); 806 } 807 if (len != sg[i].iov_len) { 808 error_report("virtio: unexpected memory split"); 809 exit(1); 810 } 811 } 812 } 813 814 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 815 { 816 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num, 1); 817 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num, 0); 818 } 819 820 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 821 { 822 VirtQueueElement *elem; 823 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 824 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 825 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 826 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 827 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 828 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 829 830 assert(sz >= sizeof(VirtQueueElement)); 831 elem = g_malloc(out_sg_end); 832 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 833 elem->out_num = out_num; 834 elem->in_num = in_num; 835 elem->in_addr = (void *)elem + in_addr_ofs; 836 elem->out_addr = (void *)elem + out_addr_ofs; 837 elem->in_sg = (void *)elem + in_sg_ofs; 838 elem->out_sg = (void *)elem + out_sg_ofs; 839 return elem; 840 } 841 842 void *virtqueue_pop(VirtQueue *vq, size_t sz) 843 { 844 unsigned int i, head, max; 845 VRingMemoryRegionCaches *caches; 846 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 847 MemoryRegionCache *desc_cache; 848 int64_t len; 849 VirtIODevice *vdev = vq->vdev; 850 VirtQueueElement *elem = NULL; 851 unsigned out_num, in_num, elem_entries; 852 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 853 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 854 VRingDesc desc; 855 int rc; 856 857 if (unlikely(vdev->broken)) { 858 return NULL; 859 } 860 rcu_read_lock(); 861 if (virtio_queue_empty_rcu(vq)) { 862 goto done; 863 } 864 /* Needed after virtio_queue_empty(), see comment in 865 * virtqueue_num_heads(). */ 866 smp_rmb(); 867 868 /* When we start there are none of either input nor output. */ 869 out_num = in_num = elem_entries = 0; 870 871 max = vq->vring.num; 872 873 if (vq->inuse >= vq->vring.num) { 874 virtio_error(vdev, "Virtqueue size exceeded"); 875 goto done; 876 } 877 878 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 879 goto done; 880 } 881 882 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 883 vring_set_avail_event(vq, vq->last_avail_idx); 884 } 885 886 i = head; 887 888 caches = vring_get_region_caches(vq); 889 if (caches->desc.len < max * sizeof(VRingDesc)) { 890 virtio_error(vdev, "Cannot map descriptor ring"); 891 goto done; 892 } 893 894 desc_cache = &caches->desc; 895 vring_desc_read(vdev, &desc, desc_cache, i); 896 if (desc.flags & VRING_DESC_F_INDIRECT) { 897 if (desc.len % sizeof(VRingDesc)) { 898 virtio_error(vdev, "Invalid size for indirect buffer table"); 899 goto done; 900 } 901 902 /* loop over the indirect descriptor table */ 903 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 904 desc.addr, desc.len, false); 905 desc_cache = &indirect_desc_cache; 906 if (len < desc.len) { 907 virtio_error(vdev, "Cannot map indirect buffer"); 908 goto done; 909 } 910 911 max = desc.len / sizeof(VRingDesc); 912 i = 0; 913 vring_desc_read(vdev, &desc, desc_cache, i); 914 } 915 916 /* Collect all the descriptors */ 917 do { 918 bool map_ok; 919 920 if (desc.flags & VRING_DESC_F_WRITE) { 921 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 922 iov + out_num, 923 VIRTQUEUE_MAX_SIZE - out_num, true, 924 desc.addr, desc.len); 925 } else { 926 if (in_num) { 927 virtio_error(vdev, "Incorrect order for descriptors"); 928 goto err_undo_map; 929 } 930 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 931 VIRTQUEUE_MAX_SIZE, false, 932 desc.addr, desc.len); 933 } 934 if (!map_ok) { 935 goto err_undo_map; 936 } 937 938 /* If we've got too many, that implies a descriptor loop. */ 939 if (++elem_entries > max) { 940 virtio_error(vdev, "Looped descriptor"); 941 goto err_undo_map; 942 } 943 944 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); 945 } while (rc == VIRTQUEUE_READ_DESC_MORE); 946 947 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 948 goto err_undo_map; 949 } 950 951 /* Now copy what we have collected and mapped */ 952 elem = virtqueue_alloc_element(sz, out_num, in_num); 953 elem->index = head; 954 for (i = 0; i < out_num; i++) { 955 elem->out_addr[i] = addr[i]; 956 elem->out_sg[i] = iov[i]; 957 } 958 for (i = 0; i < in_num; i++) { 959 elem->in_addr[i] = addr[out_num + i]; 960 elem->in_sg[i] = iov[out_num + i]; 961 } 962 963 vq->inuse++; 964 965 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 966 done: 967 address_space_cache_destroy(&indirect_desc_cache); 968 rcu_read_unlock(); 969 970 return elem; 971 972 err_undo_map: 973 virtqueue_undo_map_desc(out_num, in_num, iov); 974 goto done; 975 } 976 977 /* virtqueue_drop_all: 978 * @vq: The #VirtQueue 979 * Drops all queued buffers and indicates them to the guest 980 * as if they are done. Useful when buffers can not be 981 * processed but must be returned to the guest. 982 */ 983 unsigned int virtqueue_drop_all(VirtQueue *vq) 984 { 985 unsigned int dropped = 0; 986 VirtQueueElement elem = {}; 987 VirtIODevice *vdev = vq->vdev; 988 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 989 990 if (unlikely(vdev->broken)) { 991 return 0; 992 } 993 994 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 995 /* works similar to virtqueue_pop but does not map buffers 996 * and does not allocate any memory */ 997 smp_rmb(); 998 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 999 break; 1000 } 1001 vq->inuse++; 1002 vq->last_avail_idx++; 1003 if (fEventIdx) { 1004 vring_set_avail_event(vq, vq->last_avail_idx); 1005 } 1006 /* immediately push the element, nothing to unmap 1007 * as both in_num and out_num are set to 0 */ 1008 virtqueue_push(vq, &elem, 0); 1009 dropped++; 1010 } 1011 1012 return dropped; 1013 } 1014 1015 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1016 * it is what QEMU has always done by mistake. We can change it sooner 1017 * or later by bumping the version number of the affected vm states. 1018 * In the meanwhile, since the in-memory layout of VirtQueueElement 1019 * has changed, we need to marshal to and from the layout that was 1020 * used before the change. 1021 */ 1022 typedef struct VirtQueueElementOld { 1023 unsigned int index; 1024 unsigned int out_num; 1025 unsigned int in_num; 1026 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1027 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1028 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1029 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1030 } VirtQueueElementOld; 1031 1032 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1033 { 1034 VirtQueueElement *elem; 1035 VirtQueueElementOld data; 1036 int i; 1037 1038 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1039 1040 /* TODO: teach all callers that this can fail, and return failure instead 1041 * of asserting here. 1042 * This is just one thing (there are probably more) that must be 1043 * fixed before we can allow NDEBUG compilation. 1044 */ 1045 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1046 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1047 1048 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1049 elem->index = data.index; 1050 1051 for (i = 0; i < elem->in_num; i++) { 1052 elem->in_addr[i] = data.in_addr[i]; 1053 } 1054 1055 for (i = 0; i < elem->out_num; i++) { 1056 elem->out_addr[i] = data.out_addr[i]; 1057 } 1058 1059 for (i = 0; i < elem->in_num; i++) { 1060 /* Base is overwritten by virtqueue_map. */ 1061 elem->in_sg[i].iov_base = 0; 1062 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1063 } 1064 1065 for (i = 0; i < elem->out_num; i++) { 1066 /* Base is overwritten by virtqueue_map. */ 1067 elem->out_sg[i].iov_base = 0; 1068 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1069 } 1070 1071 virtqueue_map(vdev, elem); 1072 return elem; 1073 } 1074 1075 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem) 1076 { 1077 VirtQueueElementOld data; 1078 int i; 1079 1080 memset(&data, 0, sizeof(data)); 1081 data.index = elem->index; 1082 data.in_num = elem->in_num; 1083 data.out_num = elem->out_num; 1084 1085 for (i = 0; i < elem->in_num; i++) { 1086 data.in_addr[i] = elem->in_addr[i]; 1087 } 1088 1089 for (i = 0; i < elem->out_num; i++) { 1090 data.out_addr[i] = elem->out_addr[i]; 1091 } 1092 1093 for (i = 0; i < elem->in_num; i++) { 1094 /* Base is overwritten by virtqueue_map when loading. Do not 1095 * save it, as it would leak the QEMU address space layout. */ 1096 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1097 } 1098 1099 for (i = 0; i < elem->out_num; i++) { 1100 /* Do not save iov_base as above. */ 1101 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1102 } 1103 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1104 } 1105 1106 /* virtio device */ 1107 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1108 { 1109 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1110 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1111 1112 if (unlikely(vdev->broken)) { 1113 return; 1114 } 1115 1116 if (k->notify) { 1117 k->notify(qbus->parent, vector); 1118 } 1119 } 1120 1121 void virtio_update_irq(VirtIODevice *vdev) 1122 { 1123 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1124 } 1125 1126 static int virtio_validate_features(VirtIODevice *vdev) 1127 { 1128 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1129 1130 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 1131 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 1132 return -EFAULT; 1133 } 1134 1135 if (k->validate_features) { 1136 return k->validate_features(vdev); 1137 } else { 1138 return 0; 1139 } 1140 } 1141 1142 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 1143 { 1144 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1145 trace_virtio_set_status(vdev, val); 1146 1147 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1148 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 1149 val & VIRTIO_CONFIG_S_FEATURES_OK) { 1150 int ret = virtio_validate_features(vdev); 1151 1152 if (ret) { 1153 return ret; 1154 } 1155 } 1156 } 1157 if (k->set_status) { 1158 k->set_status(vdev, val); 1159 } 1160 vdev->status = val; 1161 return 0; 1162 } 1163 1164 bool target_words_bigendian(void); 1165 static enum virtio_device_endian virtio_default_endian(void) 1166 { 1167 if (target_words_bigendian()) { 1168 return VIRTIO_DEVICE_ENDIAN_BIG; 1169 } else { 1170 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1171 } 1172 } 1173 1174 static enum virtio_device_endian virtio_current_cpu_endian(void) 1175 { 1176 CPUClass *cc = CPU_GET_CLASS(current_cpu); 1177 1178 if (cc->virtio_is_big_endian(current_cpu)) { 1179 return VIRTIO_DEVICE_ENDIAN_BIG; 1180 } else { 1181 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1182 } 1183 } 1184 1185 void virtio_reset(void *opaque) 1186 { 1187 VirtIODevice *vdev = opaque; 1188 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1189 int i; 1190 1191 virtio_set_status(vdev, 0); 1192 if (current_cpu) { 1193 /* Guest initiated reset */ 1194 vdev->device_endian = virtio_current_cpu_endian(); 1195 } else { 1196 /* System reset */ 1197 vdev->device_endian = virtio_default_endian(); 1198 } 1199 1200 if (k->reset) { 1201 k->reset(vdev); 1202 } 1203 1204 vdev->broken = false; 1205 vdev->guest_features = 0; 1206 vdev->queue_sel = 0; 1207 vdev->status = 0; 1208 atomic_set(&vdev->isr, 0); 1209 vdev->config_vector = VIRTIO_NO_VECTOR; 1210 virtio_notify_vector(vdev, vdev->config_vector); 1211 1212 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1213 vdev->vq[i].vring.desc = 0; 1214 vdev->vq[i].vring.avail = 0; 1215 vdev->vq[i].vring.used = 0; 1216 vdev->vq[i].last_avail_idx = 0; 1217 vdev->vq[i].shadow_avail_idx = 0; 1218 vdev->vq[i].used_idx = 0; 1219 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1220 vdev->vq[i].signalled_used = 0; 1221 vdev->vq[i].signalled_used_valid = false; 1222 vdev->vq[i].notification = true; 1223 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1224 vdev->vq[i].inuse = 0; 1225 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 1226 } 1227 } 1228 1229 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1230 { 1231 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1232 uint8_t val; 1233 1234 if (addr + sizeof(val) > vdev->config_len) { 1235 return (uint32_t)-1; 1236 } 1237 1238 k->get_config(vdev, vdev->config); 1239 1240 val = ldub_p(vdev->config + addr); 1241 return val; 1242 } 1243 1244 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1245 { 1246 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1247 uint16_t val; 1248 1249 if (addr + sizeof(val) > vdev->config_len) { 1250 return (uint32_t)-1; 1251 } 1252 1253 k->get_config(vdev, vdev->config); 1254 1255 val = lduw_p(vdev->config + addr); 1256 return val; 1257 } 1258 1259 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1260 { 1261 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1262 uint32_t val; 1263 1264 if (addr + sizeof(val) > vdev->config_len) { 1265 return (uint32_t)-1; 1266 } 1267 1268 k->get_config(vdev, vdev->config); 1269 1270 val = ldl_p(vdev->config + addr); 1271 return val; 1272 } 1273 1274 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1275 { 1276 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1277 uint8_t val = data; 1278 1279 if (addr + sizeof(val) > vdev->config_len) { 1280 return; 1281 } 1282 1283 stb_p(vdev->config + addr, val); 1284 1285 if (k->set_config) { 1286 k->set_config(vdev, vdev->config); 1287 } 1288 } 1289 1290 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1291 { 1292 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1293 uint16_t val = data; 1294 1295 if (addr + sizeof(val) > vdev->config_len) { 1296 return; 1297 } 1298 1299 stw_p(vdev->config + addr, val); 1300 1301 if (k->set_config) { 1302 k->set_config(vdev, vdev->config); 1303 } 1304 } 1305 1306 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1307 { 1308 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1309 uint32_t val = data; 1310 1311 if (addr + sizeof(val) > vdev->config_len) { 1312 return; 1313 } 1314 1315 stl_p(vdev->config + addr, val); 1316 1317 if (k->set_config) { 1318 k->set_config(vdev, vdev->config); 1319 } 1320 } 1321 1322 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 1323 { 1324 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1325 uint8_t val; 1326 1327 if (addr + sizeof(val) > vdev->config_len) { 1328 return (uint32_t)-1; 1329 } 1330 1331 k->get_config(vdev, vdev->config); 1332 1333 val = ldub_p(vdev->config + addr); 1334 return val; 1335 } 1336 1337 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 1338 { 1339 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1340 uint16_t val; 1341 1342 if (addr + sizeof(val) > vdev->config_len) { 1343 return (uint32_t)-1; 1344 } 1345 1346 k->get_config(vdev, vdev->config); 1347 1348 val = lduw_le_p(vdev->config + addr); 1349 return val; 1350 } 1351 1352 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 1353 { 1354 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1355 uint32_t val; 1356 1357 if (addr + sizeof(val) > vdev->config_len) { 1358 return (uint32_t)-1; 1359 } 1360 1361 k->get_config(vdev, vdev->config); 1362 1363 val = ldl_le_p(vdev->config + addr); 1364 return val; 1365 } 1366 1367 void virtio_config_modern_writeb(VirtIODevice *vdev, 1368 uint32_t addr, uint32_t data) 1369 { 1370 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1371 uint8_t val = data; 1372 1373 if (addr + sizeof(val) > vdev->config_len) { 1374 return; 1375 } 1376 1377 stb_p(vdev->config + addr, val); 1378 1379 if (k->set_config) { 1380 k->set_config(vdev, vdev->config); 1381 } 1382 } 1383 1384 void virtio_config_modern_writew(VirtIODevice *vdev, 1385 uint32_t addr, uint32_t data) 1386 { 1387 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1388 uint16_t val = data; 1389 1390 if (addr + sizeof(val) > vdev->config_len) { 1391 return; 1392 } 1393 1394 stw_le_p(vdev->config + addr, val); 1395 1396 if (k->set_config) { 1397 k->set_config(vdev, vdev->config); 1398 } 1399 } 1400 1401 void virtio_config_modern_writel(VirtIODevice *vdev, 1402 uint32_t addr, uint32_t data) 1403 { 1404 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1405 uint32_t val = data; 1406 1407 if (addr + sizeof(val) > vdev->config_len) { 1408 return; 1409 } 1410 1411 stl_le_p(vdev->config + addr, val); 1412 1413 if (k->set_config) { 1414 k->set_config(vdev, vdev->config); 1415 } 1416 } 1417 1418 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 1419 { 1420 if (!vdev->vq[n].vring.num) { 1421 return; 1422 } 1423 vdev->vq[n].vring.desc = addr; 1424 virtio_queue_update_rings(vdev, n); 1425 } 1426 1427 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 1428 { 1429 return vdev->vq[n].vring.desc; 1430 } 1431 1432 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 1433 hwaddr avail, hwaddr used) 1434 { 1435 if (!vdev->vq[n].vring.num) { 1436 return; 1437 } 1438 vdev->vq[n].vring.desc = desc; 1439 vdev->vq[n].vring.avail = avail; 1440 vdev->vq[n].vring.used = used; 1441 virtio_init_region_cache(vdev, n); 1442 } 1443 1444 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 1445 { 1446 /* Don't allow guest to flip queue between existent and 1447 * nonexistent states, or to set it to an invalid size. 1448 */ 1449 if (!!num != !!vdev->vq[n].vring.num || 1450 num > VIRTQUEUE_MAX_SIZE || 1451 num < 0) { 1452 return; 1453 } 1454 vdev->vq[n].vring.num = num; 1455 } 1456 1457 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 1458 { 1459 return QLIST_FIRST(&vdev->vector_queues[vector]); 1460 } 1461 1462 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 1463 { 1464 return QLIST_NEXT(vq, node); 1465 } 1466 1467 int virtio_queue_get_num(VirtIODevice *vdev, int n) 1468 { 1469 return vdev->vq[n].vring.num; 1470 } 1471 1472 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 1473 { 1474 return vdev->vq[n].vring.num_default; 1475 } 1476 1477 int virtio_get_num_queues(VirtIODevice *vdev) 1478 { 1479 int i; 1480 1481 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1482 if (!virtio_queue_get_num(vdev, i)) { 1483 break; 1484 } 1485 } 1486 1487 return i; 1488 } 1489 1490 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 1491 { 1492 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1493 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1494 1495 /* virtio-1 compliant devices cannot change the alignment */ 1496 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1497 error_report("tried to modify queue alignment for virtio-1 device"); 1498 return; 1499 } 1500 /* Check that the transport told us it was going to do this 1501 * (so a buggy transport will immediately assert rather than 1502 * silently failing to migrate this state) 1503 */ 1504 assert(k->has_variable_vring_alignment); 1505 1506 if (align) { 1507 vdev->vq[n].vring.align = align; 1508 virtio_queue_update_rings(vdev, n); 1509 } 1510 } 1511 1512 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) 1513 { 1514 if (vq->vring.desc && vq->handle_aio_output) { 1515 VirtIODevice *vdev = vq->vdev; 1516 1517 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1518 return vq->handle_aio_output(vdev, vq); 1519 } 1520 1521 return false; 1522 } 1523 1524 static void virtio_queue_notify_vq(VirtQueue *vq) 1525 { 1526 if (vq->vring.desc && vq->handle_output) { 1527 VirtIODevice *vdev = vq->vdev; 1528 1529 if (unlikely(vdev->broken)) { 1530 return; 1531 } 1532 1533 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1534 vq->handle_output(vdev, vq); 1535 } 1536 } 1537 1538 void virtio_queue_notify(VirtIODevice *vdev, int n) 1539 { 1540 VirtQueue *vq = &vdev->vq[n]; 1541 1542 if (unlikely(!vq->vring.desc || vdev->broken)) { 1543 return; 1544 } 1545 1546 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1547 if (vq->handle_aio_output) { 1548 event_notifier_set(&vq->host_notifier); 1549 } else if (vq->handle_output) { 1550 vq->handle_output(vdev, vq); 1551 } 1552 } 1553 1554 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 1555 { 1556 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 1557 VIRTIO_NO_VECTOR; 1558 } 1559 1560 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 1561 { 1562 VirtQueue *vq = &vdev->vq[n]; 1563 1564 if (n < VIRTIO_QUEUE_MAX) { 1565 if (vdev->vector_queues && 1566 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 1567 QLIST_REMOVE(vq, node); 1568 } 1569 vdev->vq[n].vector = vector; 1570 if (vdev->vector_queues && 1571 vector != VIRTIO_NO_VECTOR) { 1572 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 1573 } 1574 } 1575 } 1576 1577 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 1578 VirtIOHandleOutput handle_output) 1579 { 1580 int i; 1581 1582 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1583 if (vdev->vq[i].vring.num == 0) 1584 break; 1585 } 1586 1587 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 1588 abort(); 1589 1590 vdev->vq[i].vring.num = queue_size; 1591 vdev->vq[i].vring.num_default = queue_size; 1592 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 1593 vdev->vq[i].handle_output = handle_output; 1594 vdev->vq[i].handle_aio_output = NULL; 1595 1596 return &vdev->vq[i]; 1597 } 1598 1599 void virtio_del_queue(VirtIODevice *vdev, int n) 1600 { 1601 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 1602 abort(); 1603 } 1604 1605 vdev->vq[n].vring.num = 0; 1606 vdev->vq[n].vring.num_default = 0; 1607 } 1608 1609 static void virtio_set_isr(VirtIODevice *vdev, int value) 1610 { 1611 uint8_t old = atomic_read(&vdev->isr); 1612 1613 /* Do not write ISR if it does not change, so that its cacheline remains 1614 * shared in the common case where the guest does not read it. 1615 */ 1616 if ((old & value) != value) { 1617 atomic_or(&vdev->isr, value); 1618 } 1619 } 1620 1621 /* Called within rcu_read_lock(). */ 1622 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 1623 { 1624 uint16_t old, new; 1625 bool v; 1626 /* We need to expose used array entries before checking used event. */ 1627 smp_mb(); 1628 /* Always notify when queue is empty (when feature acknowledge) */ 1629 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 1630 !vq->inuse && virtio_queue_empty(vq)) { 1631 return true; 1632 } 1633 1634 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1635 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 1636 } 1637 1638 v = vq->signalled_used_valid; 1639 vq->signalled_used_valid = true; 1640 old = vq->signalled_used; 1641 new = vq->signalled_used = vq->used_idx; 1642 return !v || vring_need_event(vring_get_used_event(vq), new, old); 1643 } 1644 1645 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 1646 { 1647 bool should_notify; 1648 rcu_read_lock(); 1649 should_notify = virtio_should_notify(vdev, vq); 1650 rcu_read_unlock(); 1651 1652 if (!should_notify) { 1653 return; 1654 } 1655 1656 trace_virtio_notify_irqfd(vdev, vq); 1657 1658 /* 1659 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 1660 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 1661 * incorrectly polling this bit during crashdump and hibernation 1662 * in MSI mode, causing a hang if this bit is never updated. 1663 * Recent releases of Windows do not really shut down, but rather 1664 * log out and hibernate to make the next startup faster. Hence, 1665 * this manifested as a more serious hang during shutdown with 1666 * 1667 * Next driver release from 2016 fixed this problem, so working around it 1668 * is not a must, but it's easy to do so let's do it here. 1669 * 1670 * Note: it's safe to update ISR from any thread as it was switched 1671 * to an atomic operation. 1672 */ 1673 virtio_set_isr(vq->vdev, 0x1); 1674 event_notifier_set(&vq->guest_notifier); 1675 } 1676 1677 static void virtio_irq(VirtQueue *vq) 1678 { 1679 virtio_set_isr(vq->vdev, 0x1); 1680 virtio_notify_vector(vq->vdev, vq->vector); 1681 } 1682 1683 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 1684 { 1685 bool should_notify; 1686 rcu_read_lock(); 1687 should_notify = virtio_should_notify(vdev, vq); 1688 rcu_read_unlock(); 1689 1690 if (!should_notify) { 1691 return; 1692 } 1693 1694 trace_virtio_notify(vdev, vq); 1695 virtio_irq(vq); 1696 } 1697 1698 void virtio_notify_config(VirtIODevice *vdev) 1699 { 1700 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 1701 return; 1702 1703 virtio_set_isr(vdev, 0x3); 1704 vdev->generation++; 1705 virtio_notify_vector(vdev, vdev->config_vector); 1706 } 1707 1708 static bool virtio_device_endian_needed(void *opaque) 1709 { 1710 VirtIODevice *vdev = opaque; 1711 1712 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 1713 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1714 return vdev->device_endian != virtio_default_endian(); 1715 } 1716 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 1717 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 1718 } 1719 1720 static bool virtio_64bit_features_needed(void *opaque) 1721 { 1722 VirtIODevice *vdev = opaque; 1723 1724 return (vdev->host_features >> 32) != 0; 1725 } 1726 1727 static bool virtio_virtqueue_needed(void *opaque) 1728 { 1729 VirtIODevice *vdev = opaque; 1730 1731 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 1732 } 1733 1734 static bool virtio_ringsize_needed(void *opaque) 1735 { 1736 VirtIODevice *vdev = opaque; 1737 int i; 1738 1739 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1740 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 1741 return true; 1742 } 1743 } 1744 return false; 1745 } 1746 1747 static bool virtio_extra_state_needed(void *opaque) 1748 { 1749 VirtIODevice *vdev = opaque; 1750 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1751 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1752 1753 return k->has_extra_state && 1754 k->has_extra_state(qbus->parent); 1755 } 1756 1757 static bool virtio_broken_needed(void *opaque) 1758 { 1759 VirtIODevice *vdev = opaque; 1760 1761 return vdev->broken; 1762 } 1763 1764 static const VMStateDescription vmstate_virtqueue = { 1765 .name = "virtqueue_state", 1766 .version_id = 1, 1767 .minimum_version_id = 1, 1768 .fields = (VMStateField[]) { 1769 VMSTATE_UINT64(vring.avail, struct VirtQueue), 1770 VMSTATE_UINT64(vring.used, struct VirtQueue), 1771 VMSTATE_END_OF_LIST() 1772 } 1773 }; 1774 1775 static const VMStateDescription vmstate_virtio_virtqueues = { 1776 .name = "virtio/virtqueues", 1777 .version_id = 1, 1778 .minimum_version_id = 1, 1779 .needed = &virtio_virtqueue_needed, 1780 .fields = (VMStateField[]) { 1781 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1782 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 1783 VMSTATE_END_OF_LIST() 1784 } 1785 }; 1786 1787 static const VMStateDescription vmstate_ringsize = { 1788 .name = "ringsize_state", 1789 .version_id = 1, 1790 .minimum_version_id = 1, 1791 .fields = (VMStateField[]) { 1792 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 1793 VMSTATE_END_OF_LIST() 1794 } 1795 }; 1796 1797 static const VMStateDescription vmstate_virtio_ringsize = { 1798 .name = "virtio/ringsize", 1799 .version_id = 1, 1800 .minimum_version_id = 1, 1801 .needed = &virtio_ringsize_needed, 1802 .fields = (VMStateField[]) { 1803 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1804 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 1805 VMSTATE_END_OF_LIST() 1806 } 1807 }; 1808 1809 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 1810 VMStateField *field) 1811 { 1812 VirtIODevice *vdev = pv; 1813 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1814 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1815 1816 if (!k->load_extra_state) { 1817 return -1; 1818 } else { 1819 return k->load_extra_state(qbus->parent, f); 1820 } 1821 } 1822 1823 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 1824 VMStateField *field, QJSON *vmdesc) 1825 { 1826 VirtIODevice *vdev = pv; 1827 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1828 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1829 1830 k->save_extra_state(qbus->parent, f); 1831 return 0; 1832 } 1833 1834 static const VMStateInfo vmstate_info_extra_state = { 1835 .name = "virtqueue_extra_state", 1836 .get = get_extra_state, 1837 .put = put_extra_state, 1838 }; 1839 1840 static const VMStateDescription vmstate_virtio_extra_state = { 1841 .name = "virtio/extra_state", 1842 .version_id = 1, 1843 .minimum_version_id = 1, 1844 .needed = &virtio_extra_state_needed, 1845 .fields = (VMStateField[]) { 1846 { 1847 .name = "extra_state", 1848 .version_id = 0, 1849 .field_exists = NULL, 1850 .size = 0, 1851 .info = &vmstate_info_extra_state, 1852 .flags = VMS_SINGLE, 1853 .offset = 0, 1854 }, 1855 VMSTATE_END_OF_LIST() 1856 } 1857 }; 1858 1859 static const VMStateDescription vmstate_virtio_device_endian = { 1860 .name = "virtio/device_endian", 1861 .version_id = 1, 1862 .minimum_version_id = 1, 1863 .needed = &virtio_device_endian_needed, 1864 .fields = (VMStateField[]) { 1865 VMSTATE_UINT8(device_endian, VirtIODevice), 1866 VMSTATE_END_OF_LIST() 1867 } 1868 }; 1869 1870 static const VMStateDescription vmstate_virtio_64bit_features = { 1871 .name = "virtio/64bit_features", 1872 .version_id = 1, 1873 .minimum_version_id = 1, 1874 .needed = &virtio_64bit_features_needed, 1875 .fields = (VMStateField[]) { 1876 VMSTATE_UINT64(guest_features, VirtIODevice), 1877 VMSTATE_END_OF_LIST() 1878 } 1879 }; 1880 1881 static const VMStateDescription vmstate_virtio_broken = { 1882 .name = "virtio/broken", 1883 .version_id = 1, 1884 .minimum_version_id = 1, 1885 .needed = &virtio_broken_needed, 1886 .fields = (VMStateField[]) { 1887 VMSTATE_BOOL(broken, VirtIODevice), 1888 VMSTATE_END_OF_LIST() 1889 } 1890 }; 1891 1892 static const VMStateDescription vmstate_virtio = { 1893 .name = "virtio", 1894 .version_id = 1, 1895 .minimum_version_id = 1, 1896 .minimum_version_id_old = 1, 1897 .fields = (VMStateField[]) { 1898 VMSTATE_END_OF_LIST() 1899 }, 1900 .subsections = (const VMStateDescription*[]) { 1901 &vmstate_virtio_device_endian, 1902 &vmstate_virtio_64bit_features, 1903 &vmstate_virtio_virtqueues, 1904 &vmstate_virtio_ringsize, 1905 &vmstate_virtio_broken, 1906 &vmstate_virtio_extra_state, 1907 NULL 1908 } 1909 }; 1910 1911 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 1912 { 1913 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1914 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1915 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1916 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 1917 int i; 1918 1919 if (k->save_config) { 1920 k->save_config(qbus->parent, f); 1921 } 1922 1923 qemu_put_8s(f, &vdev->status); 1924 qemu_put_8s(f, &vdev->isr); 1925 qemu_put_be16s(f, &vdev->queue_sel); 1926 qemu_put_be32s(f, &guest_features_lo); 1927 qemu_put_be32(f, vdev->config_len); 1928 qemu_put_buffer(f, vdev->config, vdev->config_len); 1929 1930 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1931 if (vdev->vq[i].vring.num == 0) 1932 break; 1933 } 1934 1935 qemu_put_be32(f, i); 1936 1937 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1938 if (vdev->vq[i].vring.num == 0) 1939 break; 1940 1941 qemu_put_be32(f, vdev->vq[i].vring.num); 1942 if (k->has_variable_vring_alignment) { 1943 qemu_put_be32(f, vdev->vq[i].vring.align); 1944 } 1945 /* 1946 * Save desc now, the rest of the ring addresses are saved in 1947 * subsections for VIRTIO-1 devices. 1948 */ 1949 qemu_put_be64(f, vdev->vq[i].vring.desc); 1950 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 1951 if (k->save_queue) { 1952 k->save_queue(qbus->parent, i, f); 1953 } 1954 } 1955 1956 if (vdc->save != NULL) { 1957 vdc->save(vdev, f); 1958 } 1959 1960 if (vdc->vmsd) { 1961 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 1962 if (ret) { 1963 return ret; 1964 } 1965 } 1966 1967 /* Subsections */ 1968 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 1969 } 1970 1971 /* A wrapper for use as a VMState .put function */ 1972 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 1973 VMStateField *field, QJSON *vmdesc) 1974 { 1975 return virtio_save(VIRTIO_DEVICE(opaque), f); 1976 } 1977 1978 /* A wrapper for use as a VMState .get function */ 1979 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 1980 VMStateField *field) 1981 { 1982 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1983 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 1984 1985 return virtio_load(vdev, f, dc->vmsd->version_id); 1986 } 1987 1988 const VMStateInfo virtio_vmstate_info = { 1989 .name = "virtio", 1990 .get = virtio_device_get, 1991 .put = virtio_device_put, 1992 }; 1993 1994 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 1995 { 1996 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1997 bool bad = (val & ~(vdev->host_features)) != 0; 1998 1999 val &= vdev->host_features; 2000 if (k->set_features) { 2001 k->set_features(vdev, val); 2002 } 2003 vdev->guest_features = val; 2004 return bad ? -1 : 0; 2005 } 2006 2007 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2008 { 2009 /* 2010 * The driver must not attempt to set features after feature negotiation 2011 * has finished. 2012 */ 2013 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2014 return -EINVAL; 2015 } 2016 return virtio_set_features_nocheck(vdev, val); 2017 } 2018 2019 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2020 { 2021 int i, ret; 2022 int32_t config_len; 2023 uint32_t num; 2024 uint32_t features; 2025 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2026 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2027 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2028 2029 /* 2030 * We poison the endianness to ensure it does not get used before 2031 * subsections have been loaded. 2032 */ 2033 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2034 2035 if (k->load_config) { 2036 ret = k->load_config(qbus->parent, f); 2037 if (ret) 2038 return ret; 2039 } 2040 2041 qemu_get_8s(f, &vdev->status); 2042 qemu_get_8s(f, &vdev->isr); 2043 qemu_get_be16s(f, &vdev->queue_sel); 2044 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2045 return -1; 2046 } 2047 qemu_get_be32s(f, &features); 2048 2049 /* 2050 * Temporarily set guest_features low bits - needed by 2051 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2052 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2053 * 2054 * Note: devices should always test host features in future - don't create 2055 * new dependencies like this. 2056 */ 2057 vdev->guest_features = features; 2058 2059 config_len = qemu_get_be32(f); 2060 2061 /* 2062 * There are cases where the incoming config can be bigger or smaller 2063 * than what we have; so load what we have space for, and skip 2064 * any excess that's in the stream. 2065 */ 2066 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 2067 2068 while (config_len > vdev->config_len) { 2069 qemu_get_byte(f); 2070 config_len--; 2071 } 2072 2073 num = qemu_get_be32(f); 2074 2075 if (num > VIRTIO_QUEUE_MAX) { 2076 error_report("Invalid number of virtqueues: 0x%x", num); 2077 return -1; 2078 } 2079 2080 for (i = 0; i < num; i++) { 2081 vdev->vq[i].vring.num = qemu_get_be32(f); 2082 if (k->has_variable_vring_alignment) { 2083 vdev->vq[i].vring.align = qemu_get_be32(f); 2084 } 2085 vdev->vq[i].vring.desc = qemu_get_be64(f); 2086 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 2087 vdev->vq[i].signalled_used_valid = false; 2088 vdev->vq[i].notification = true; 2089 2090 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 2091 error_report("VQ %d address 0x0 " 2092 "inconsistent with Host index 0x%x", 2093 i, vdev->vq[i].last_avail_idx); 2094 return -1; 2095 } 2096 if (k->load_queue) { 2097 ret = k->load_queue(qbus->parent, i, f); 2098 if (ret) 2099 return ret; 2100 } 2101 } 2102 2103 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 2104 2105 if (vdc->load != NULL) { 2106 ret = vdc->load(vdev, f, version_id); 2107 if (ret) { 2108 return ret; 2109 } 2110 } 2111 2112 if (vdc->vmsd) { 2113 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 2114 if (ret) { 2115 return ret; 2116 } 2117 } 2118 2119 /* Subsections */ 2120 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 2121 if (ret) { 2122 return ret; 2123 } 2124 2125 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 2126 vdev->device_endian = virtio_default_endian(); 2127 } 2128 2129 if (virtio_64bit_features_needed(vdev)) { 2130 /* 2131 * Subsection load filled vdev->guest_features. Run them 2132 * through virtio_set_features to sanity-check them against 2133 * host_features. 2134 */ 2135 uint64_t features64 = vdev->guest_features; 2136 if (virtio_set_features_nocheck(vdev, features64) < 0) { 2137 error_report("Features 0x%" PRIx64 " unsupported. " 2138 "Allowed features: 0x%" PRIx64, 2139 features64, vdev->host_features); 2140 return -1; 2141 } 2142 } else { 2143 if (virtio_set_features_nocheck(vdev, features) < 0) { 2144 error_report("Features 0x%x unsupported. " 2145 "Allowed features: 0x%" PRIx64, 2146 features, vdev->host_features); 2147 return -1; 2148 } 2149 } 2150 2151 rcu_read_lock(); 2152 for (i = 0; i < num; i++) { 2153 if (vdev->vq[i].vring.desc) { 2154 uint16_t nheads; 2155 2156 /* 2157 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 2158 * only the region cache needs to be set up. Legacy devices need 2159 * to calculate used and avail ring addresses based on the desc 2160 * address. 2161 */ 2162 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2163 virtio_init_region_cache(vdev, i); 2164 } else { 2165 virtio_queue_update_rings(vdev, i); 2166 } 2167 2168 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 2169 /* Check it isn't doing strange things with descriptor numbers. */ 2170 if (nheads > vdev->vq[i].vring.num) { 2171 error_report("VQ %d size 0x%x Guest index 0x%x " 2172 "inconsistent with Host index 0x%x: delta 0x%x", 2173 i, vdev->vq[i].vring.num, 2174 vring_avail_idx(&vdev->vq[i]), 2175 vdev->vq[i].last_avail_idx, nheads); 2176 return -1; 2177 } 2178 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 2179 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 2180 2181 /* 2182 * Some devices migrate VirtQueueElements that have been popped 2183 * from the avail ring but not yet returned to the used ring. 2184 * Since max ring size < UINT16_MAX it's safe to use modulo 2185 * UINT16_MAX + 1 subtraction. 2186 */ 2187 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 2188 vdev->vq[i].used_idx); 2189 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 2190 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 2191 "used_idx 0x%x", 2192 i, vdev->vq[i].vring.num, 2193 vdev->vq[i].last_avail_idx, 2194 vdev->vq[i].used_idx); 2195 return -1; 2196 } 2197 } 2198 } 2199 rcu_read_unlock(); 2200 2201 return 0; 2202 } 2203 2204 void virtio_cleanup(VirtIODevice *vdev) 2205 { 2206 qemu_del_vm_change_state_handler(vdev->vmstate); 2207 } 2208 2209 static void virtio_vmstate_change(void *opaque, int running, RunState state) 2210 { 2211 VirtIODevice *vdev = opaque; 2212 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2213 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2214 bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK); 2215 vdev->vm_running = running; 2216 2217 if (backend_run) { 2218 virtio_set_status(vdev, vdev->status); 2219 } 2220 2221 if (k->vmstate_change) { 2222 k->vmstate_change(qbus->parent, backend_run); 2223 } 2224 2225 if (!backend_run) { 2226 virtio_set_status(vdev, vdev->status); 2227 } 2228 } 2229 2230 void virtio_instance_init_common(Object *proxy_obj, void *data, 2231 size_t vdev_size, const char *vdev_name) 2232 { 2233 DeviceState *vdev = data; 2234 2235 object_initialize(vdev, vdev_size, vdev_name); 2236 object_property_add_child(proxy_obj, "virtio-backend", OBJECT(vdev), NULL); 2237 object_unref(OBJECT(vdev)); 2238 qdev_alias_all_properties(vdev, proxy_obj); 2239 } 2240 2241 void virtio_init(VirtIODevice *vdev, const char *name, 2242 uint16_t device_id, size_t config_size) 2243 { 2244 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2245 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2246 int i; 2247 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 2248 2249 if (nvectors) { 2250 vdev->vector_queues = 2251 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 2252 } 2253 2254 vdev->device_id = device_id; 2255 vdev->status = 0; 2256 atomic_set(&vdev->isr, 0); 2257 vdev->queue_sel = 0; 2258 vdev->config_vector = VIRTIO_NO_VECTOR; 2259 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 2260 vdev->vm_running = runstate_is_running(); 2261 vdev->broken = false; 2262 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2263 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 2264 vdev->vq[i].vdev = vdev; 2265 vdev->vq[i].queue_index = i; 2266 } 2267 2268 vdev->name = name; 2269 vdev->config_len = config_size; 2270 if (vdev->config_len) { 2271 vdev->config = g_malloc0(config_size); 2272 } else { 2273 vdev->config = NULL; 2274 } 2275 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, 2276 vdev); 2277 vdev->device_endian = virtio_default_endian(); 2278 vdev->use_guest_notifier_mask = true; 2279 } 2280 2281 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 2282 { 2283 return vdev->vq[n].vring.desc; 2284 } 2285 2286 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 2287 { 2288 return vdev->vq[n].vring.avail; 2289 } 2290 2291 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 2292 { 2293 return vdev->vq[n].vring.used; 2294 } 2295 2296 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 2297 { 2298 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 2299 } 2300 2301 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 2302 { 2303 return offsetof(VRingAvail, ring) + 2304 sizeof(uint16_t) * vdev->vq[n].vring.num; 2305 } 2306 2307 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 2308 { 2309 return offsetof(VRingUsed, ring) + 2310 sizeof(VRingUsedElem) * vdev->vq[n].vring.num; 2311 } 2312 2313 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 2314 { 2315 return vdev->vq[n].last_avail_idx; 2316 } 2317 2318 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) 2319 { 2320 vdev->vq[n].last_avail_idx = idx; 2321 vdev->vq[n].shadow_avail_idx = idx; 2322 } 2323 2324 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 2325 { 2326 rcu_read_lock(); 2327 if (vdev->vq[n].vring.desc) { 2328 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 2329 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 2330 } 2331 rcu_read_unlock(); 2332 } 2333 2334 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 2335 { 2336 rcu_read_lock(); 2337 if (vdev->vq[n].vring.desc) { 2338 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 2339 } 2340 rcu_read_unlock(); 2341 } 2342 2343 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 2344 { 2345 vdev->vq[n].signalled_used_valid = false; 2346 } 2347 2348 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 2349 { 2350 return vdev->vq + n; 2351 } 2352 2353 uint16_t virtio_get_queue_index(VirtQueue *vq) 2354 { 2355 return vq->queue_index; 2356 } 2357 2358 static void virtio_queue_guest_notifier_read(EventNotifier *n) 2359 { 2360 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 2361 if (event_notifier_test_and_clear(n)) { 2362 virtio_irq(vq); 2363 } 2364 } 2365 2366 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 2367 bool with_irqfd) 2368 { 2369 if (assign && !with_irqfd) { 2370 event_notifier_set_handler(&vq->guest_notifier, 2371 virtio_queue_guest_notifier_read); 2372 } else { 2373 event_notifier_set_handler(&vq->guest_notifier, NULL); 2374 } 2375 if (!assign) { 2376 /* Test and clear notifier before closing it, 2377 * in case poll callback didn't have time to run. */ 2378 virtio_queue_guest_notifier_read(&vq->guest_notifier); 2379 } 2380 } 2381 2382 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 2383 { 2384 return &vq->guest_notifier; 2385 } 2386 2387 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 2388 { 2389 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2390 if (event_notifier_test_and_clear(n)) { 2391 virtio_queue_notify_aio_vq(vq); 2392 } 2393 } 2394 2395 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 2396 { 2397 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2398 2399 virtio_queue_set_notification(vq, 0); 2400 } 2401 2402 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 2403 { 2404 EventNotifier *n = opaque; 2405 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2406 bool progress; 2407 2408 if (!vq->vring.desc || virtio_queue_empty(vq)) { 2409 return false; 2410 } 2411 2412 progress = virtio_queue_notify_aio_vq(vq); 2413 2414 /* In case the handler function re-enabled notifications */ 2415 virtio_queue_set_notification(vq, 0); 2416 return progress; 2417 } 2418 2419 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 2420 { 2421 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2422 2423 /* Caller polls once more after this to catch requests that race with us */ 2424 virtio_queue_set_notification(vq, 1); 2425 } 2426 2427 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 2428 VirtIOHandleAIOOutput handle_output) 2429 { 2430 if (handle_output) { 2431 vq->handle_aio_output = handle_output; 2432 aio_set_event_notifier(ctx, &vq->host_notifier, true, 2433 virtio_queue_host_notifier_aio_read, 2434 virtio_queue_host_notifier_aio_poll); 2435 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 2436 virtio_queue_host_notifier_aio_poll_begin, 2437 virtio_queue_host_notifier_aio_poll_end); 2438 } else { 2439 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 2440 /* Test and clear notifier before after disabling event, 2441 * in case poll callback didn't have time to run. */ 2442 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 2443 vq->handle_aio_output = NULL; 2444 } 2445 } 2446 2447 void virtio_queue_host_notifier_read(EventNotifier *n) 2448 { 2449 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2450 if (event_notifier_test_and_clear(n)) { 2451 virtio_queue_notify_vq(vq); 2452 } 2453 } 2454 2455 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 2456 { 2457 return &vq->host_notifier; 2458 } 2459 2460 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 2461 MemoryRegion *mr, bool assign) 2462 { 2463 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2464 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2465 2466 if (k->set_host_notifier_mr) { 2467 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 2468 } 2469 2470 return -1; 2471 } 2472 2473 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 2474 { 2475 g_free(vdev->bus_name); 2476 vdev->bus_name = g_strdup(bus_name); 2477 } 2478 2479 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 2480 { 2481 va_list ap; 2482 2483 va_start(ap, fmt); 2484 error_vreport(fmt, ap); 2485 va_end(ap); 2486 2487 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2488 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 2489 virtio_notify_config(vdev); 2490 } 2491 2492 vdev->broken = true; 2493 } 2494 2495 static void virtio_memory_listener_commit(MemoryListener *listener) 2496 { 2497 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 2498 int i; 2499 2500 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2501 if (vdev->vq[i].vring.num == 0) { 2502 break; 2503 } 2504 virtio_init_region_cache(vdev, i); 2505 } 2506 } 2507 2508 static void virtio_device_realize(DeviceState *dev, Error **errp) 2509 { 2510 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2511 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2512 Error *err = NULL; 2513 2514 /* Devices should either use vmsd or the load/save methods */ 2515 assert(!vdc->vmsd || !vdc->load); 2516 2517 if (vdc->realize != NULL) { 2518 vdc->realize(dev, &err); 2519 if (err != NULL) { 2520 error_propagate(errp, err); 2521 return; 2522 } 2523 } 2524 2525 virtio_bus_device_plugged(vdev, &err); 2526 if (err != NULL) { 2527 error_propagate(errp, err); 2528 vdc->unrealize(dev, NULL); 2529 return; 2530 } 2531 2532 vdev->listener.commit = virtio_memory_listener_commit; 2533 memory_listener_register(&vdev->listener, vdev->dma_as); 2534 } 2535 2536 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 2537 { 2538 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2539 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2540 Error *err = NULL; 2541 2542 virtio_bus_device_unplugged(vdev); 2543 2544 if (vdc->unrealize != NULL) { 2545 vdc->unrealize(dev, &err); 2546 if (err != NULL) { 2547 error_propagate(errp, err); 2548 return; 2549 } 2550 } 2551 2552 g_free(vdev->bus_name); 2553 vdev->bus_name = NULL; 2554 } 2555 2556 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 2557 { 2558 int i; 2559 if (!vdev->vq) { 2560 return; 2561 } 2562 2563 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2564 if (vdev->vq[i].vring.num == 0) { 2565 break; 2566 } 2567 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2568 } 2569 g_free(vdev->vq); 2570 } 2571 2572 static void virtio_device_instance_finalize(Object *obj) 2573 { 2574 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 2575 2576 memory_listener_unregister(&vdev->listener); 2577 virtio_device_free_virtqueues(vdev); 2578 2579 g_free(vdev->config); 2580 g_free(vdev->vector_queues); 2581 } 2582 2583 static Property virtio_properties[] = { 2584 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 2585 DEFINE_PROP_END_OF_LIST(), 2586 }; 2587 2588 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 2589 { 2590 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2591 int i, n, r, err; 2592 2593 memory_region_transaction_begin(); 2594 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2595 VirtQueue *vq = &vdev->vq[n]; 2596 if (!virtio_queue_get_num(vdev, n)) { 2597 continue; 2598 } 2599 r = virtio_bus_set_host_notifier(qbus, n, true); 2600 if (r < 0) { 2601 err = r; 2602 goto assign_error; 2603 } 2604 event_notifier_set_handler(&vq->host_notifier, 2605 virtio_queue_host_notifier_read); 2606 } 2607 2608 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2609 /* Kick right away to begin processing requests already in vring */ 2610 VirtQueue *vq = &vdev->vq[n]; 2611 if (!vq->vring.num) { 2612 continue; 2613 } 2614 event_notifier_set(&vq->host_notifier); 2615 } 2616 memory_region_transaction_commit(); 2617 return 0; 2618 2619 assign_error: 2620 i = n; /* save n for a second iteration after transaction is committed. */ 2621 while (--n >= 0) { 2622 VirtQueue *vq = &vdev->vq[n]; 2623 if (!virtio_queue_get_num(vdev, n)) { 2624 continue; 2625 } 2626 2627 event_notifier_set_handler(&vq->host_notifier, NULL); 2628 r = virtio_bus_set_host_notifier(qbus, n, false); 2629 assert(r >= 0); 2630 } 2631 memory_region_transaction_commit(); 2632 2633 while (--i >= 0) { 2634 if (!virtio_queue_get_num(vdev, i)) { 2635 continue; 2636 } 2637 virtio_bus_cleanup_host_notifier(qbus, i); 2638 } 2639 return err; 2640 } 2641 2642 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 2643 { 2644 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2645 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2646 2647 return virtio_bus_start_ioeventfd(vbus); 2648 } 2649 2650 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 2651 { 2652 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2653 int n, r; 2654 2655 memory_region_transaction_begin(); 2656 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2657 VirtQueue *vq = &vdev->vq[n]; 2658 2659 if (!virtio_queue_get_num(vdev, n)) { 2660 continue; 2661 } 2662 event_notifier_set_handler(&vq->host_notifier, NULL); 2663 r = virtio_bus_set_host_notifier(qbus, n, false); 2664 assert(r >= 0); 2665 } 2666 memory_region_transaction_commit(); 2667 2668 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2669 if (!virtio_queue_get_num(vdev, n)) { 2670 continue; 2671 } 2672 virtio_bus_cleanup_host_notifier(qbus, n); 2673 } 2674 } 2675 2676 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) 2677 { 2678 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2679 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2680 2681 virtio_bus_stop_ioeventfd(vbus); 2682 } 2683 2684 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 2685 { 2686 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2687 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2688 2689 return virtio_bus_grab_ioeventfd(vbus); 2690 } 2691 2692 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 2693 { 2694 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2695 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2696 2697 virtio_bus_release_ioeventfd(vbus); 2698 } 2699 2700 static void virtio_device_class_init(ObjectClass *klass, void *data) 2701 { 2702 /* Set the default value here. */ 2703 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 2704 DeviceClass *dc = DEVICE_CLASS(klass); 2705 2706 dc->realize = virtio_device_realize; 2707 dc->unrealize = virtio_device_unrealize; 2708 dc->bus_type = TYPE_VIRTIO_BUS; 2709 dc->props = virtio_properties; 2710 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 2711 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 2712 2713 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 2714 } 2715 2716 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 2717 { 2718 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2719 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2720 2721 return virtio_bus_ioeventfd_enabled(vbus); 2722 } 2723 2724 static const TypeInfo virtio_device_info = { 2725 .name = TYPE_VIRTIO_DEVICE, 2726 .parent = TYPE_DEVICE, 2727 .instance_size = sizeof(VirtIODevice), 2728 .class_init = virtio_device_class_init, 2729 .instance_finalize = virtio_device_instance_finalize, 2730 .abstract = true, 2731 .class_size = sizeof(VirtioDeviceClass), 2732 }; 2733 2734 static void virtio_register_types(void) 2735 { 2736 type_register_static(&virtio_device_info); 2737 } 2738 2739 type_init(virtio_register_types) 2740