1 /* 2 * Virtio Support 3 * 4 * Copyright IBM, Corp. 2007 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 #include "qapi/error.h" 16 #include "cpu.h" 17 #include "trace.h" 18 #include "exec/address-spaces.h" 19 #include "qemu/error-report.h" 20 #include "qemu/module.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->vdev->broken)) { 362 return 1; 363 } 364 365 if (unlikely(!vq->vring.avail)) { 366 return 1; 367 } 368 369 if (vq->shadow_avail_idx != vq->last_avail_idx) { 370 return 0; 371 } 372 373 return vring_avail_idx(vq) == vq->last_avail_idx; 374 } 375 376 int virtio_queue_empty(VirtQueue *vq) 377 { 378 bool empty; 379 380 if (unlikely(vq->vdev->broken)) { 381 return 1; 382 } 383 384 if (unlikely(!vq->vring.avail)) { 385 return 1; 386 } 387 388 if (vq->shadow_avail_idx != vq->last_avail_idx) { 389 return 0; 390 } 391 392 rcu_read_lock(); 393 empty = vring_avail_idx(vq) == vq->last_avail_idx; 394 rcu_read_unlock(); 395 return empty; 396 } 397 398 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 399 unsigned int len) 400 { 401 AddressSpace *dma_as = vq->vdev->dma_as; 402 unsigned int offset; 403 int i; 404 405 offset = 0; 406 for (i = 0; i < elem->in_num; i++) { 407 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 408 409 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 410 elem->in_sg[i].iov_len, 411 DMA_DIRECTION_FROM_DEVICE, size); 412 413 offset += size; 414 } 415 416 for (i = 0; i < elem->out_num; i++) 417 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 418 elem->out_sg[i].iov_len, 419 DMA_DIRECTION_TO_DEVICE, 420 elem->out_sg[i].iov_len); 421 } 422 423 /* virtqueue_detach_element: 424 * @vq: The #VirtQueue 425 * @elem: The #VirtQueueElement 426 * @len: number of bytes written 427 * 428 * Detach the element from the virtqueue. This function is suitable for device 429 * reset or other situations where a #VirtQueueElement is simply freed and will 430 * not be pushed or discarded. 431 */ 432 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 433 unsigned int len) 434 { 435 vq->inuse--; 436 virtqueue_unmap_sg(vq, elem, len); 437 } 438 439 /* virtqueue_unpop: 440 * @vq: The #VirtQueue 441 * @elem: The #VirtQueueElement 442 * @len: number of bytes written 443 * 444 * Pretend the most recent element wasn't popped from the virtqueue. The next 445 * call to virtqueue_pop() will refetch the element. 446 */ 447 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 448 unsigned int len) 449 { 450 vq->last_avail_idx--; 451 virtqueue_detach_element(vq, elem, len); 452 } 453 454 /* virtqueue_rewind: 455 * @vq: The #VirtQueue 456 * @num: Number of elements to push back 457 * 458 * Pretend that elements weren't popped from the virtqueue. The next 459 * virtqueue_pop() will refetch the oldest element. 460 * 461 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 462 * 463 * Returns: true on success, false if @num is greater than the number of in use 464 * elements. 465 */ 466 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 467 { 468 if (num > vq->inuse) { 469 return false; 470 } 471 vq->last_avail_idx -= num; 472 vq->inuse -= num; 473 return true; 474 } 475 476 /* Called within rcu_read_lock(). */ 477 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 478 unsigned int len, unsigned int idx) 479 { 480 VRingUsedElem uelem; 481 482 trace_virtqueue_fill(vq, elem, len, idx); 483 484 virtqueue_unmap_sg(vq, elem, len); 485 486 if (unlikely(vq->vdev->broken)) { 487 return; 488 } 489 490 if (unlikely(!vq->vring.used)) { 491 return; 492 } 493 494 idx = (idx + vq->used_idx) % vq->vring.num; 495 496 uelem.id = elem->index; 497 uelem.len = len; 498 vring_used_write(vq, &uelem, idx); 499 } 500 501 /* Called within rcu_read_lock(). */ 502 void virtqueue_flush(VirtQueue *vq, unsigned int count) 503 { 504 uint16_t old, new; 505 506 if (unlikely(vq->vdev->broken)) { 507 vq->inuse -= count; 508 return; 509 } 510 511 if (unlikely(!vq->vring.used)) { 512 return; 513 } 514 515 /* Make sure buffer is written before we update index. */ 516 smp_wmb(); 517 trace_virtqueue_flush(vq, count); 518 old = vq->used_idx; 519 new = old + count; 520 vring_used_idx_set(vq, new); 521 vq->inuse -= count; 522 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 523 vq->signalled_used_valid = false; 524 } 525 526 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 527 unsigned int len) 528 { 529 rcu_read_lock(); 530 virtqueue_fill(vq, elem, len, 0); 531 virtqueue_flush(vq, 1); 532 rcu_read_unlock(); 533 } 534 535 /* Called within rcu_read_lock(). */ 536 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 537 { 538 uint16_t num_heads = vring_avail_idx(vq) - idx; 539 540 /* Check it isn't doing very strange things with descriptor numbers. */ 541 if (num_heads > vq->vring.num) { 542 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 543 idx, vq->shadow_avail_idx); 544 return -EINVAL; 545 } 546 /* On success, callers read a descriptor at vq->last_avail_idx. 547 * Make sure descriptor read does not bypass avail index read. */ 548 if (num_heads) { 549 smp_rmb(); 550 } 551 552 return num_heads; 553 } 554 555 /* Called within rcu_read_lock(). */ 556 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 557 unsigned int *head) 558 { 559 /* Grab the next descriptor number they're advertising, and increment 560 * the index we've seen. */ 561 *head = vring_avail_ring(vq, idx % vq->vring.num); 562 563 /* If their number is silly, that's a fatal mistake. */ 564 if (*head >= vq->vring.num) { 565 virtio_error(vq->vdev, "Guest says index %u is available", *head); 566 return false; 567 } 568 569 return true; 570 } 571 572 enum { 573 VIRTQUEUE_READ_DESC_ERROR = -1, 574 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 575 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 576 }; 577 578 static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 579 MemoryRegionCache *desc_cache, unsigned int max, 580 unsigned int *next) 581 { 582 /* If this descriptor says it doesn't chain, we're done. */ 583 if (!(desc->flags & VRING_DESC_F_NEXT)) { 584 return VIRTQUEUE_READ_DESC_DONE; 585 } 586 587 /* Check they're not leading us off end of descriptors. */ 588 *next = desc->next; 589 /* Make sure compiler knows to grab that: we don't want it changing! */ 590 smp_wmb(); 591 592 if (*next >= max) { 593 virtio_error(vdev, "Desc next is %u", *next); 594 return VIRTQUEUE_READ_DESC_ERROR; 595 } 596 597 vring_desc_read(vdev, desc, desc_cache, *next); 598 return VIRTQUEUE_READ_DESC_MORE; 599 } 600 601 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 602 unsigned int *out_bytes, 603 unsigned max_in_bytes, unsigned max_out_bytes) 604 { 605 VirtIODevice *vdev = vq->vdev; 606 unsigned int max, idx; 607 unsigned int total_bufs, in_total, out_total; 608 VRingMemoryRegionCaches *caches; 609 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 610 int64_t len = 0; 611 int rc; 612 613 if (unlikely(!vq->vring.desc)) { 614 if (in_bytes) { 615 *in_bytes = 0; 616 } 617 if (out_bytes) { 618 *out_bytes = 0; 619 } 620 return; 621 } 622 623 rcu_read_lock(); 624 idx = vq->last_avail_idx; 625 total_bufs = in_total = out_total = 0; 626 627 max = vq->vring.num; 628 caches = vring_get_region_caches(vq); 629 if (caches->desc.len < max * sizeof(VRingDesc)) { 630 virtio_error(vdev, "Cannot map descriptor ring"); 631 goto err; 632 } 633 634 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 635 MemoryRegionCache *desc_cache = &caches->desc; 636 unsigned int num_bufs; 637 VRingDesc desc; 638 unsigned int i; 639 640 num_bufs = total_bufs; 641 642 if (!virtqueue_get_head(vq, idx++, &i)) { 643 goto err; 644 } 645 646 vring_desc_read(vdev, &desc, desc_cache, i); 647 648 if (desc.flags & VRING_DESC_F_INDIRECT) { 649 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 650 virtio_error(vdev, "Invalid size for indirect buffer table"); 651 goto err; 652 } 653 654 /* 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 /* loop over the indirect descriptor table */ 661 len = address_space_cache_init(&indirect_desc_cache, 662 vdev->dma_as, 663 desc.addr, desc.len, false); 664 desc_cache = &indirect_desc_cache; 665 if (len < desc.len) { 666 virtio_error(vdev, "Cannot map indirect buffer"); 667 goto err; 668 } 669 670 max = desc.len / sizeof(VRingDesc); 671 num_bufs = i = 0; 672 vring_desc_read(vdev, &desc, desc_cache, i); 673 } 674 675 do { 676 /* If we've got too many, that implies a descriptor loop. */ 677 if (++num_bufs > max) { 678 virtio_error(vdev, "Looped descriptor"); 679 goto err; 680 } 681 682 if (desc.flags & VRING_DESC_F_WRITE) { 683 in_total += desc.len; 684 } else { 685 out_total += desc.len; 686 } 687 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 688 goto done; 689 } 690 691 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); 692 } while (rc == VIRTQUEUE_READ_DESC_MORE); 693 694 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 695 goto err; 696 } 697 698 if (desc_cache == &indirect_desc_cache) { 699 address_space_cache_destroy(&indirect_desc_cache); 700 total_bufs++; 701 } else { 702 total_bufs = num_bufs; 703 } 704 } 705 706 if (rc < 0) { 707 goto err; 708 } 709 710 done: 711 address_space_cache_destroy(&indirect_desc_cache); 712 if (in_bytes) { 713 *in_bytes = in_total; 714 } 715 if (out_bytes) { 716 *out_bytes = out_total; 717 } 718 rcu_read_unlock(); 719 return; 720 721 err: 722 in_total = out_total = 0; 723 goto done; 724 } 725 726 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 727 unsigned int out_bytes) 728 { 729 unsigned int in_total, out_total; 730 731 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 732 return in_bytes <= in_total && out_bytes <= out_total; 733 } 734 735 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 736 hwaddr *addr, struct iovec *iov, 737 unsigned int max_num_sg, bool is_write, 738 hwaddr pa, size_t sz) 739 { 740 bool ok = false; 741 unsigned num_sg = *p_num_sg; 742 assert(num_sg <= max_num_sg); 743 744 if (!sz) { 745 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 746 goto out; 747 } 748 749 while (sz) { 750 hwaddr len = sz; 751 752 if (num_sg == max_num_sg) { 753 virtio_error(vdev, "virtio: too many write descriptors in " 754 "indirect table"); 755 goto out; 756 } 757 758 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 759 is_write ? 760 DMA_DIRECTION_FROM_DEVICE : 761 DMA_DIRECTION_TO_DEVICE); 762 if (!iov[num_sg].iov_base) { 763 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 764 goto out; 765 } 766 767 iov[num_sg].iov_len = len; 768 addr[num_sg] = pa; 769 770 sz -= len; 771 pa += len; 772 num_sg++; 773 } 774 ok = true; 775 776 out: 777 *p_num_sg = num_sg; 778 return ok; 779 } 780 781 /* Only used by error code paths before we have a VirtQueueElement (therefore 782 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 783 * yet. 784 */ 785 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 786 struct iovec *iov) 787 { 788 unsigned int i; 789 790 for (i = 0; i < out_num + in_num; i++) { 791 int is_write = i >= out_num; 792 793 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 794 iov++; 795 } 796 } 797 798 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 799 hwaddr *addr, unsigned int num_sg, 800 int is_write) 801 { 802 unsigned int i; 803 hwaddr len; 804 805 for (i = 0; i < num_sg; i++) { 806 len = sg[i].iov_len; 807 sg[i].iov_base = dma_memory_map(vdev->dma_as, 808 addr[i], &len, is_write ? 809 DMA_DIRECTION_FROM_DEVICE : 810 DMA_DIRECTION_TO_DEVICE); 811 if (!sg[i].iov_base) { 812 error_report("virtio: error trying to map MMIO memory"); 813 exit(1); 814 } 815 if (len != sg[i].iov_len) { 816 error_report("virtio: unexpected memory split"); 817 exit(1); 818 } 819 } 820 } 821 822 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 823 { 824 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, 1); 825 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 0); 826 } 827 828 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 829 { 830 VirtQueueElement *elem; 831 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 832 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 833 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 834 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 835 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 836 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 837 838 assert(sz >= sizeof(VirtQueueElement)); 839 elem = g_malloc(out_sg_end); 840 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 841 elem->out_num = out_num; 842 elem->in_num = in_num; 843 elem->in_addr = (void *)elem + in_addr_ofs; 844 elem->out_addr = (void *)elem + out_addr_ofs; 845 elem->in_sg = (void *)elem + in_sg_ofs; 846 elem->out_sg = (void *)elem + out_sg_ofs; 847 return elem; 848 } 849 850 void *virtqueue_pop(VirtQueue *vq, size_t sz) 851 { 852 unsigned int i, head, max; 853 VRingMemoryRegionCaches *caches; 854 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 855 MemoryRegionCache *desc_cache; 856 int64_t len; 857 VirtIODevice *vdev = vq->vdev; 858 VirtQueueElement *elem = NULL; 859 unsigned out_num, in_num, elem_entries; 860 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 861 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 862 VRingDesc desc; 863 int rc; 864 865 if (unlikely(vdev->broken)) { 866 return NULL; 867 } 868 rcu_read_lock(); 869 if (virtio_queue_empty_rcu(vq)) { 870 goto done; 871 } 872 /* Needed after virtio_queue_empty(), see comment in 873 * virtqueue_num_heads(). */ 874 smp_rmb(); 875 876 /* When we start there are none of either input nor output. */ 877 out_num = in_num = elem_entries = 0; 878 879 max = vq->vring.num; 880 881 if (vq->inuse >= vq->vring.num) { 882 virtio_error(vdev, "Virtqueue size exceeded"); 883 goto done; 884 } 885 886 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 887 goto done; 888 } 889 890 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 891 vring_set_avail_event(vq, vq->last_avail_idx); 892 } 893 894 i = head; 895 896 caches = vring_get_region_caches(vq); 897 if (caches->desc.len < max * sizeof(VRingDesc)) { 898 virtio_error(vdev, "Cannot map descriptor ring"); 899 goto done; 900 } 901 902 desc_cache = &caches->desc; 903 vring_desc_read(vdev, &desc, desc_cache, i); 904 if (desc.flags & VRING_DESC_F_INDIRECT) { 905 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 906 virtio_error(vdev, "Invalid size for indirect buffer table"); 907 goto done; 908 } 909 910 /* loop over the indirect descriptor table */ 911 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 912 desc.addr, desc.len, false); 913 desc_cache = &indirect_desc_cache; 914 if (len < desc.len) { 915 virtio_error(vdev, "Cannot map indirect buffer"); 916 goto done; 917 } 918 919 max = desc.len / sizeof(VRingDesc); 920 i = 0; 921 vring_desc_read(vdev, &desc, desc_cache, i); 922 } 923 924 /* Collect all the descriptors */ 925 do { 926 bool map_ok; 927 928 if (desc.flags & VRING_DESC_F_WRITE) { 929 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 930 iov + out_num, 931 VIRTQUEUE_MAX_SIZE - out_num, true, 932 desc.addr, desc.len); 933 } else { 934 if (in_num) { 935 virtio_error(vdev, "Incorrect order for descriptors"); 936 goto err_undo_map; 937 } 938 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 939 VIRTQUEUE_MAX_SIZE, false, 940 desc.addr, desc.len); 941 } 942 if (!map_ok) { 943 goto err_undo_map; 944 } 945 946 /* If we've got too many, that implies a descriptor loop. */ 947 if (++elem_entries > max) { 948 virtio_error(vdev, "Looped descriptor"); 949 goto err_undo_map; 950 } 951 952 rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); 953 } while (rc == VIRTQUEUE_READ_DESC_MORE); 954 955 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 956 goto err_undo_map; 957 } 958 959 /* Now copy what we have collected and mapped */ 960 elem = virtqueue_alloc_element(sz, out_num, in_num); 961 elem->index = head; 962 for (i = 0; i < out_num; i++) { 963 elem->out_addr[i] = addr[i]; 964 elem->out_sg[i] = iov[i]; 965 } 966 for (i = 0; i < in_num; i++) { 967 elem->in_addr[i] = addr[out_num + i]; 968 elem->in_sg[i] = iov[out_num + i]; 969 } 970 971 vq->inuse++; 972 973 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 974 done: 975 address_space_cache_destroy(&indirect_desc_cache); 976 rcu_read_unlock(); 977 978 return elem; 979 980 err_undo_map: 981 virtqueue_undo_map_desc(out_num, in_num, iov); 982 goto done; 983 } 984 985 /* virtqueue_drop_all: 986 * @vq: The #VirtQueue 987 * Drops all queued buffers and indicates them to the guest 988 * as if they are done. Useful when buffers can not be 989 * processed but must be returned to the guest. 990 */ 991 unsigned int virtqueue_drop_all(VirtQueue *vq) 992 { 993 unsigned int dropped = 0; 994 VirtQueueElement elem = {}; 995 VirtIODevice *vdev = vq->vdev; 996 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 997 998 if (unlikely(vdev->broken)) { 999 return 0; 1000 } 1001 1002 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 1003 /* works similar to virtqueue_pop but does not map buffers 1004 * and does not allocate any memory */ 1005 smp_rmb(); 1006 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 1007 break; 1008 } 1009 vq->inuse++; 1010 vq->last_avail_idx++; 1011 if (fEventIdx) { 1012 vring_set_avail_event(vq, vq->last_avail_idx); 1013 } 1014 /* immediately push the element, nothing to unmap 1015 * as both in_num and out_num are set to 0 */ 1016 virtqueue_push(vq, &elem, 0); 1017 dropped++; 1018 } 1019 1020 return dropped; 1021 } 1022 1023 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1024 * it is what QEMU has always done by mistake. We can change it sooner 1025 * or later by bumping the version number of the affected vm states. 1026 * In the meanwhile, since the in-memory layout of VirtQueueElement 1027 * has changed, we need to marshal to and from the layout that was 1028 * used before the change. 1029 */ 1030 typedef struct VirtQueueElementOld { 1031 unsigned int index; 1032 unsigned int out_num; 1033 unsigned int in_num; 1034 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1035 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1036 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1037 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1038 } VirtQueueElementOld; 1039 1040 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1041 { 1042 VirtQueueElement *elem; 1043 VirtQueueElementOld data; 1044 int i; 1045 1046 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1047 1048 /* TODO: teach all callers that this can fail, and return failure instead 1049 * of asserting here. 1050 * This is just one thing (there are probably more) that must be 1051 * fixed before we can allow NDEBUG compilation. 1052 */ 1053 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1054 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1055 1056 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1057 elem->index = data.index; 1058 1059 for (i = 0; i < elem->in_num; i++) { 1060 elem->in_addr[i] = data.in_addr[i]; 1061 } 1062 1063 for (i = 0; i < elem->out_num; i++) { 1064 elem->out_addr[i] = data.out_addr[i]; 1065 } 1066 1067 for (i = 0; i < elem->in_num; i++) { 1068 /* Base is overwritten by virtqueue_map. */ 1069 elem->in_sg[i].iov_base = 0; 1070 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1071 } 1072 1073 for (i = 0; i < elem->out_num; i++) { 1074 /* Base is overwritten by virtqueue_map. */ 1075 elem->out_sg[i].iov_base = 0; 1076 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1077 } 1078 1079 virtqueue_map(vdev, elem); 1080 return elem; 1081 } 1082 1083 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem) 1084 { 1085 VirtQueueElementOld data; 1086 int i; 1087 1088 memset(&data, 0, sizeof(data)); 1089 data.index = elem->index; 1090 data.in_num = elem->in_num; 1091 data.out_num = elem->out_num; 1092 1093 for (i = 0; i < elem->in_num; i++) { 1094 data.in_addr[i] = elem->in_addr[i]; 1095 } 1096 1097 for (i = 0; i < elem->out_num; i++) { 1098 data.out_addr[i] = elem->out_addr[i]; 1099 } 1100 1101 for (i = 0; i < elem->in_num; i++) { 1102 /* Base is overwritten by virtqueue_map when loading. Do not 1103 * save it, as it would leak the QEMU address space layout. */ 1104 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1105 } 1106 1107 for (i = 0; i < elem->out_num; i++) { 1108 /* Do not save iov_base as above. */ 1109 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1110 } 1111 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1112 } 1113 1114 /* virtio device */ 1115 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1116 { 1117 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1118 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1119 1120 if (unlikely(vdev->broken)) { 1121 return; 1122 } 1123 1124 if (k->notify) { 1125 k->notify(qbus->parent, vector); 1126 } 1127 } 1128 1129 void virtio_update_irq(VirtIODevice *vdev) 1130 { 1131 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1132 } 1133 1134 static int virtio_validate_features(VirtIODevice *vdev) 1135 { 1136 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1137 1138 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 1139 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 1140 return -EFAULT; 1141 } 1142 1143 if (k->validate_features) { 1144 return k->validate_features(vdev); 1145 } else { 1146 return 0; 1147 } 1148 } 1149 1150 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 1151 { 1152 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1153 trace_virtio_set_status(vdev, val); 1154 1155 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1156 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 1157 val & VIRTIO_CONFIG_S_FEATURES_OK) { 1158 int ret = virtio_validate_features(vdev); 1159 1160 if (ret) { 1161 return ret; 1162 } 1163 } 1164 } 1165 1166 virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK); 1167 1168 if (k->set_status) { 1169 k->set_status(vdev, val); 1170 } 1171 vdev->status = val; 1172 1173 return 0; 1174 } 1175 1176 static enum virtio_device_endian virtio_default_endian(void) 1177 { 1178 if (target_words_bigendian()) { 1179 return VIRTIO_DEVICE_ENDIAN_BIG; 1180 } else { 1181 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1182 } 1183 } 1184 1185 static enum virtio_device_endian virtio_current_cpu_endian(void) 1186 { 1187 CPUClass *cc = CPU_GET_CLASS(current_cpu); 1188 1189 if (cc->virtio_is_big_endian(current_cpu)) { 1190 return VIRTIO_DEVICE_ENDIAN_BIG; 1191 } else { 1192 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1193 } 1194 } 1195 1196 void virtio_reset(void *opaque) 1197 { 1198 VirtIODevice *vdev = opaque; 1199 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1200 int i; 1201 1202 virtio_set_status(vdev, 0); 1203 if (current_cpu) { 1204 /* Guest initiated reset */ 1205 vdev->device_endian = virtio_current_cpu_endian(); 1206 } else { 1207 /* System reset */ 1208 vdev->device_endian = virtio_default_endian(); 1209 } 1210 1211 if (k->reset) { 1212 k->reset(vdev); 1213 } 1214 1215 vdev->start_on_kick = (virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) && 1216 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)); 1217 vdev->started = false; 1218 vdev->broken = false; 1219 vdev->guest_features = 0; 1220 vdev->queue_sel = 0; 1221 vdev->status = 0; 1222 atomic_set(&vdev->isr, 0); 1223 vdev->config_vector = VIRTIO_NO_VECTOR; 1224 virtio_notify_vector(vdev, vdev->config_vector); 1225 1226 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1227 vdev->vq[i].vring.desc = 0; 1228 vdev->vq[i].vring.avail = 0; 1229 vdev->vq[i].vring.used = 0; 1230 vdev->vq[i].last_avail_idx = 0; 1231 vdev->vq[i].shadow_avail_idx = 0; 1232 vdev->vq[i].used_idx = 0; 1233 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1234 vdev->vq[i].signalled_used = 0; 1235 vdev->vq[i].signalled_used_valid = false; 1236 vdev->vq[i].notification = true; 1237 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1238 vdev->vq[i].inuse = 0; 1239 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 1240 } 1241 } 1242 1243 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1244 { 1245 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1246 uint8_t val; 1247 1248 if (addr + sizeof(val) > vdev->config_len) { 1249 return (uint32_t)-1; 1250 } 1251 1252 k->get_config(vdev, vdev->config); 1253 1254 val = ldub_p(vdev->config + addr); 1255 return val; 1256 } 1257 1258 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1259 { 1260 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1261 uint16_t val; 1262 1263 if (addr + sizeof(val) > vdev->config_len) { 1264 return (uint32_t)-1; 1265 } 1266 1267 k->get_config(vdev, vdev->config); 1268 1269 val = lduw_p(vdev->config + addr); 1270 return val; 1271 } 1272 1273 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1274 { 1275 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1276 uint32_t val; 1277 1278 if (addr + sizeof(val) > vdev->config_len) { 1279 return (uint32_t)-1; 1280 } 1281 1282 k->get_config(vdev, vdev->config); 1283 1284 val = ldl_p(vdev->config + addr); 1285 return val; 1286 } 1287 1288 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1289 { 1290 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1291 uint8_t val = data; 1292 1293 if (addr + sizeof(val) > vdev->config_len) { 1294 return; 1295 } 1296 1297 stb_p(vdev->config + addr, val); 1298 1299 if (k->set_config) { 1300 k->set_config(vdev, vdev->config); 1301 } 1302 } 1303 1304 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1305 { 1306 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1307 uint16_t val = data; 1308 1309 if (addr + sizeof(val) > vdev->config_len) { 1310 return; 1311 } 1312 1313 stw_p(vdev->config + addr, val); 1314 1315 if (k->set_config) { 1316 k->set_config(vdev, vdev->config); 1317 } 1318 } 1319 1320 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1321 { 1322 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1323 uint32_t val = data; 1324 1325 if (addr + sizeof(val) > vdev->config_len) { 1326 return; 1327 } 1328 1329 stl_p(vdev->config + addr, val); 1330 1331 if (k->set_config) { 1332 k->set_config(vdev, vdev->config); 1333 } 1334 } 1335 1336 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 1337 { 1338 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1339 uint8_t val; 1340 1341 if (addr + sizeof(val) > vdev->config_len) { 1342 return (uint32_t)-1; 1343 } 1344 1345 k->get_config(vdev, vdev->config); 1346 1347 val = ldub_p(vdev->config + addr); 1348 return val; 1349 } 1350 1351 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 1352 { 1353 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1354 uint16_t val; 1355 1356 if (addr + sizeof(val) > vdev->config_len) { 1357 return (uint32_t)-1; 1358 } 1359 1360 k->get_config(vdev, vdev->config); 1361 1362 val = lduw_le_p(vdev->config + addr); 1363 return val; 1364 } 1365 1366 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 1367 { 1368 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1369 uint32_t val; 1370 1371 if (addr + sizeof(val) > vdev->config_len) { 1372 return (uint32_t)-1; 1373 } 1374 1375 k->get_config(vdev, vdev->config); 1376 1377 val = ldl_le_p(vdev->config + addr); 1378 return val; 1379 } 1380 1381 void virtio_config_modern_writeb(VirtIODevice *vdev, 1382 uint32_t addr, uint32_t data) 1383 { 1384 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1385 uint8_t val = data; 1386 1387 if (addr + sizeof(val) > vdev->config_len) { 1388 return; 1389 } 1390 1391 stb_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_writew(VirtIODevice *vdev, 1399 uint32_t addr, uint32_t data) 1400 { 1401 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1402 uint16_t val = data; 1403 1404 if (addr + sizeof(val) > vdev->config_len) { 1405 return; 1406 } 1407 1408 stw_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_config_modern_writel(VirtIODevice *vdev, 1416 uint32_t addr, uint32_t data) 1417 { 1418 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1419 uint32_t val = data; 1420 1421 if (addr + sizeof(val) > vdev->config_len) { 1422 return; 1423 } 1424 1425 stl_le_p(vdev->config + addr, val); 1426 1427 if (k->set_config) { 1428 k->set_config(vdev, vdev->config); 1429 } 1430 } 1431 1432 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 1433 { 1434 if (!vdev->vq[n].vring.num) { 1435 return; 1436 } 1437 vdev->vq[n].vring.desc = addr; 1438 virtio_queue_update_rings(vdev, n); 1439 } 1440 1441 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 1442 { 1443 return vdev->vq[n].vring.desc; 1444 } 1445 1446 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 1447 hwaddr avail, hwaddr used) 1448 { 1449 if (!vdev->vq[n].vring.num) { 1450 return; 1451 } 1452 vdev->vq[n].vring.desc = desc; 1453 vdev->vq[n].vring.avail = avail; 1454 vdev->vq[n].vring.used = used; 1455 virtio_init_region_cache(vdev, n); 1456 } 1457 1458 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 1459 { 1460 /* Don't allow guest to flip queue between existent and 1461 * nonexistent states, or to set it to an invalid size. 1462 */ 1463 if (!!num != !!vdev->vq[n].vring.num || 1464 num > VIRTQUEUE_MAX_SIZE || 1465 num < 0) { 1466 return; 1467 } 1468 vdev->vq[n].vring.num = num; 1469 } 1470 1471 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 1472 { 1473 return QLIST_FIRST(&vdev->vector_queues[vector]); 1474 } 1475 1476 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 1477 { 1478 return QLIST_NEXT(vq, node); 1479 } 1480 1481 int virtio_queue_get_num(VirtIODevice *vdev, int n) 1482 { 1483 return vdev->vq[n].vring.num; 1484 } 1485 1486 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 1487 { 1488 return vdev->vq[n].vring.num_default; 1489 } 1490 1491 int virtio_get_num_queues(VirtIODevice *vdev) 1492 { 1493 int i; 1494 1495 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1496 if (!virtio_queue_get_num(vdev, i)) { 1497 break; 1498 } 1499 } 1500 1501 return i; 1502 } 1503 1504 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 1505 { 1506 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1507 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1508 1509 /* virtio-1 compliant devices cannot change the alignment */ 1510 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1511 error_report("tried to modify queue alignment for virtio-1 device"); 1512 return; 1513 } 1514 /* Check that the transport told us it was going to do this 1515 * (so a buggy transport will immediately assert rather than 1516 * silently failing to migrate this state) 1517 */ 1518 assert(k->has_variable_vring_alignment); 1519 1520 if (align) { 1521 vdev->vq[n].vring.align = align; 1522 virtio_queue_update_rings(vdev, n); 1523 } 1524 } 1525 1526 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) 1527 { 1528 bool ret = false; 1529 1530 if (vq->vring.desc && vq->handle_aio_output) { 1531 VirtIODevice *vdev = vq->vdev; 1532 1533 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1534 ret = vq->handle_aio_output(vdev, vq); 1535 1536 if (unlikely(vdev->start_on_kick)) { 1537 virtio_set_started(vdev, true); 1538 } 1539 } 1540 1541 return ret; 1542 } 1543 1544 static void virtio_queue_notify_vq(VirtQueue *vq) 1545 { 1546 if (vq->vring.desc && vq->handle_output) { 1547 VirtIODevice *vdev = vq->vdev; 1548 1549 if (unlikely(vdev->broken)) { 1550 return; 1551 } 1552 1553 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1554 vq->handle_output(vdev, vq); 1555 1556 if (unlikely(vdev->start_on_kick)) { 1557 virtio_set_started(vdev, true); 1558 } 1559 } 1560 } 1561 1562 void virtio_queue_notify(VirtIODevice *vdev, int n) 1563 { 1564 VirtQueue *vq = &vdev->vq[n]; 1565 1566 if (unlikely(!vq->vring.desc || vdev->broken)) { 1567 return; 1568 } 1569 1570 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1571 if (vq->handle_aio_output) { 1572 event_notifier_set(&vq->host_notifier); 1573 } else if (vq->handle_output) { 1574 vq->handle_output(vdev, vq); 1575 } 1576 1577 if (unlikely(vdev->start_on_kick)) { 1578 virtio_set_started(vdev, true); 1579 } 1580 } 1581 1582 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 1583 { 1584 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 1585 VIRTIO_NO_VECTOR; 1586 } 1587 1588 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 1589 { 1590 VirtQueue *vq = &vdev->vq[n]; 1591 1592 if (n < VIRTIO_QUEUE_MAX) { 1593 if (vdev->vector_queues && 1594 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 1595 QLIST_REMOVE(vq, node); 1596 } 1597 vdev->vq[n].vector = vector; 1598 if (vdev->vector_queues && 1599 vector != VIRTIO_NO_VECTOR) { 1600 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 1601 } 1602 } 1603 } 1604 1605 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 1606 VirtIOHandleOutput handle_output) 1607 { 1608 int i; 1609 1610 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1611 if (vdev->vq[i].vring.num == 0) 1612 break; 1613 } 1614 1615 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 1616 abort(); 1617 1618 vdev->vq[i].vring.num = queue_size; 1619 vdev->vq[i].vring.num_default = queue_size; 1620 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 1621 vdev->vq[i].handle_output = handle_output; 1622 vdev->vq[i].handle_aio_output = NULL; 1623 1624 return &vdev->vq[i]; 1625 } 1626 1627 void virtio_del_queue(VirtIODevice *vdev, int n) 1628 { 1629 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 1630 abort(); 1631 } 1632 1633 vdev->vq[n].vring.num = 0; 1634 vdev->vq[n].vring.num_default = 0; 1635 vdev->vq[n].handle_output = NULL; 1636 vdev->vq[n].handle_aio_output = NULL; 1637 } 1638 1639 static void virtio_set_isr(VirtIODevice *vdev, int value) 1640 { 1641 uint8_t old = atomic_read(&vdev->isr); 1642 1643 /* Do not write ISR if it does not change, so that its cacheline remains 1644 * shared in the common case where the guest does not read it. 1645 */ 1646 if ((old & value) != value) { 1647 atomic_or(&vdev->isr, value); 1648 } 1649 } 1650 1651 /* Called within rcu_read_lock(). */ 1652 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 1653 { 1654 uint16_t old, new; 1655 bool v; 1656 /* We need to expose used array entries before checking used event. */ 1657 smp_mb(); 1658 /* Always notify when queue is empty (when feature acknowledge) */ 1659 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 1660 !vq->inuse && virtio_queue_empty(vq)) { 1661 return true; 1662 } 1663 1664 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1665 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 1666 } 1667 1668 v = vq->signalled_used_valid; 1669 vq->signalled_used_valid = true; 1670 old = vq->signalled_used; 1671 new = vq->signalled_used = vq->used_idx; 1672 return !v || vring_need_event(vring_get_used_event(vq), new, old); 1673 } 1674 1675 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 1676 { 1677 bool should_notify; 1678 rcu_read_lock(); 1679 should_notify = virtio_should_notify(vdev, vq); 1680 rcu_read_unlock(); 1681 1682 if (!should_notify) { 1683 return; 1684 } 1685 1686 trace_virtio_notify_irqfd(vdev, vq); 1687 1688 /* 1689 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 1690 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 1691 * incorrectly polling this bit during crashdump and hibernation 1692 * in MSI mode, causing a hang if this bit is never updated. 1693 * Recent releases of Windows do not really shut down, but rather 1694 * log out and hibernate to make the next startup faster. Hence, 1695 * this manifested as a more serious hang during shutdown with 1696 * 1697 * Next driver release from 2016 fixed this problem, so working around it 1698 * is not a must, but it's easy to do so let's do it here. 1699 * 1700 * Note: it's safe to update ISR from any thread as it was switched 1701 * to an atomic operation. 1702 */ 1703 virtio_set_isr(vq->vdev, 0x1); 1704 event_notifier_set(&vq->guest_notifier); 1705 } 1706 1707 static void virtio_irq(VirtQueue *vq) 1708 { 1709 virtio_set_isr(vq->vdev, 0x1); 1710 virtio_notify_vector(vq->vdev, vq->vector); 1711 } 1712 1713 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 1714 { 1715 bool should_notify; 1716 rcu_read_lock(); 1717 should_notify = virtio_should_notify(vdev, vq); 1718 rcu_read_unlock(); 1719 1720 if (!should_notify) { 1721 return; 1722 } 1723 1724 trace_virtio_notify(vdev, vq); 1725 virtio_irq(vq); 1726 } 1727 1728 void virtio_notify_config(VirtIODevice *vdev) 1729 { 1730 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 1731 return; 1732 1733 virtio_set_isr(vdev, 0x3); 1734 vdev->generation++; 1735 virtio_notify_vector(vdev, vdev->config_vector); 1736 } 1737 1738 static bool virtio_device_endian_needed(void *opaque) 1739 { 1740 VirtIODevice *vdev = opaque; 1741 1742 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 1743 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1744 return vdev->device_endian != virtio_default_endian(); 1745 } 1746 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 1747 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 1748 } 1749 1750 static bool virtio_64bit_features_needed(void *opaque) 1751 { 1752 VirtIODevice *vdev = opaque; 1753 1754 return (vdev->host_features >> 32) != 0; 1755 } 1756 1757 static bool virtio_virtqueue_needed(void *opaque) 1758 { 1759 VirtIODevice *vdev = opaque; 1760 1761 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 1762 } 1763 1764 static bool virtio_ringsize_needed(void *opaque) 1765 { 1766 VirtIODevice *vdev = opaque; 1767 int i; 1768 1769 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1770 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 1771 return true; 1772 } 1773 } 1774 return false; 1775 } 1776 1777 static bool virtio_extra_state_needed(void *opaque) 1778 { 1779 VirtIODevice *vdev = opaque; 1780 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1781 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1782 1783 return k->has_extra_state && 1784 k->has_extra_state(qbus->parent); 1785 } 1786 1787 static bool virtio_broken_needed(void *opaque) 1788 { 1789 VirtIODevice *vdev = opaque; 1790 1791 return vdev->broken; 1792 } 1793 1794 static bool virtio_started_needed(void *opaque) 1795 { 1796 VirtIODevice *vdev = opaque; 1797 1798 return vdev->started; 1799 } 1800 1801 static const VMStateDescription vmstate_virtqueue = { 1802 .name = "virtqueue_state", 1803 .version_id = 1, 1804 .minimum_version_id = 1, 1805 .fields = (VMStateField[]) { 1806 VMSTATE_UINT64(vring.avail, struct VirtQueue), 1807 VMSTATE_UINT64(vring.used, struct VirtQueue), 1808 VMSTATE_END_OF_LIST() 1809 } 1810 }; 1811 1812 static const VMStateDescription vmstate_virtio_virtqueues = { 1813 .name = "virtio/virtqueues", 1814 .version_id = 1, 1815 .minimum_version_id = 1, 1816 .needed = &virtio_virtqueue_needed, 1817 .fields = (VMStateField[]) { 1818 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1819 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 1820 VMSTATE_END_OF_LIST() 1821 } 1822 }; 1823 1824 static const VMStateDescription vmstate_ringsize = { 1825 .name = "ringsize_state", 1826 .version_id = 1, 1827 .minimum_version_id = 1, 1828 .fields = (VMStateField[]) { 1829 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 1830 VMSTATE_END_OF_LIST() 1831 } 1832 }; 1833 1834 static const VMStateDescription vmstate_virtio_ringsize = { 1835 .name = "virtio/ringsize", 1836 .version_id = 1, 1837 .minimum_version_id = 1, 1838 .needed = &virtio_ringsize_needed, 1839 .fields = (VMStateField[]) { 1840 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1841 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 1842 VMSTATE_END_OF_LIST() 1843 } 1844 }; 1845 1846 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 1847 const VMStateField *field) 1848 { 1849 VirtIODevice *vdev = pv; 1850 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1851 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1852 1853 if (!k->load_extra_state) { 1854 return -1; 1855 } else { 1856 return k->load_extra_state(qbus->parent, f); 1857 } 1858 } 1859 1860 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 1861 const VMStateField *field, QJSON *vmdesc) 1862 { 1863 VirtIODevice *vdev = pv; 1864 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1865 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1866 1867 k->save_extra_state(qbus->parent, f); 1868 return 0; 1869 } 1870 1871 static const VMStateInfo vmstate_info_extra_state = { 1872 .name = "virtqueue_extra_state", 1873 .get = get_extra_state, 1874 .put = put_extra_state, 1875 }; 1876 1877 static const VMStateDescription vmstate_virtio_extra_state = { 1878 .name = "virtio/extra_state", 1879 .version_id = 1, 1880 .minimum_version_id = 1, 1881 .needed = &virtio_extra_state_needed, 1882 .fields = (VMStateField[]) { 1883 { 1884 .name = "extra_state", 1885 .version_id = 0, 1886 .field_exists = NULL, 1887 .size = 0, 1888 .info = &vmstate_info_extra_state, 1889 .flags = VMS_SINGLE, 1890 .offset = 0, 1891 }, 1892 VMSTATE_END_OF_LIST() 1893 } 1894 }; 1895 1896 static const VMStateDescription vmstate_virtio_device_endian = { 1897 .name = "virtio/device_endian", 1898 .version_id = 1, 1899 .minimum_version_id = 1, 1900 .needed = &virtio_device_endian_needed, 1901 .fields = (VMStateField[]) { 1902 VMSTATE_UINT8(device_endian, VirtIODevice), 1903 VMSTATE_END_OF_LIST() 1904 } 1905 }; 1906 1907 static const VMStateDescription vmstate_virtio_64bit_features = { 1908 .name = "virtio/64bit_features", 1909 .version_id = 1, 1910 .minimum_version_id = 1, 1911 .needed = &virtio_64bit_features_needed, 1912 .fields = (VMStateField[]) { 1913 VMSTATE_UINT64(guest_features, VirtIODevice), 1914 VMSTATE_END_OF_LIST() 1915 } 1916 }; 1917 1918 static const VMStateDescription vmstate_virtio_broken = { 1919 .name = "virtio/broken", 1920 .version_id = 1, 1921 .minimum_version_id = 1, 1922 .needed = &virtio_broken_needed, 1923 .fields = (VMStateField[]) { 1924 VMSTATE_BOOL(broken, VirtIODevice), 1925 VMSTATE_END_OF_LIST() 1926 } 1927 }; 1928 1929 static const VMStateDescription vmstate_virtio_started = { 1930 .name = "virtio/started", 1931 .version_id = 1, 1932 .minimum_version_id = 1, 1933 .needed = &virtio_started_needed, 1934 .fields = (VMStateField[]) { 1935 VMSTATE_BOOL(started, VirtIODevice), 1936 VMSTATE_END_OF_LIST() 1937 } 1938 }; 1939 1940 static const VMStateDescription vmstate_virtio = { 1941 .name = "virtio", 1942 .version_id = 1, 1943 .minimum_version_id = 1, 1944 .minimum_version_id_old = 1, 1945 .fields = (VMStateField[]) { 1946 VMSTATE_END_OF_LIST() 1947 }, 1948 .subsections = (const VMStateDescription*[]) { 1949 &vmstate_virtio_device_endian, 1950 &vmstate_virtio_64bit_features, 1951 &vmstate_virtio_virtqueues, 1952 &vmstate_virtio_ringsize, 1953 &vmstate_virtio_broken, 1954 &vmstate_virtio_extra_state, 1955 &vmstate_virtio_started, 1956 NULL 1957 } 1958 }; 1959 1960 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 1961 { 1962 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1963 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1964 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1965 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 1966 int i; 1967 1968 if (k->save_config) { 1969 k->save_config(qbus->parent, f); 1970 } 1971 1972 qemu_put_8s(f, &vdev->status); 1973 qemu_put_8s(f, &vdev->isr); 1974 qemu_put_be16s(f, &vdev->queue_sel); 1975 qemu_put_be32s(f, &guest_features_lo); 1976 qemu_put_be32(f, vdev->config_len); 1977 qemu_put_buffer(f, vdev->config, vdev->config_len); 1978 1979 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1980 if (vdev->vq[i].vring.num == 0) 1981 break; 1982 } 1983 1984 qemu_put_be32(f, i); 1985 1986 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1987 if (vdev->vq[i].vring.num == 0) 1988 break; 1989 1990 qemu_put_be32(f, vdev->vq[i].vring.num); 1991 if (k->has_variable_vring_alignment) { 1992 qemu_put_be32(f, vdev->vq[i].vring.align); 1993 } 1994 /* 1995 * Save desc now, the rest of the ring addresses are saved in 1996 * subsections for VIRTIO-1 devices. 1997 */ 1998 qemu_put_be64(f, vdev->vq[i].vring.desc); 1999 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 2000 if (k->save_queue) { 2001 k->save_queue(qbus->parent, i, f); 2002 } 2003 } 2004 2005 if (vdc->save != NULL) { 2006 vdc->save(vdev, f); 2007 } 2008 2009 if (vdc->vmsd) { 2010 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 2011 if (ret) { 2012 return ret; 2013 } 2014 } 2015 2016 /* Subsections */ 2017 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 2018 } 2019 2020 /* A wrapper for use as a VMState .put function */ 2021 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 2022 const VMStateField *field, QJSON *vmdesc) 2023 { 2024 return virtio_save(VIRTIO_DEVICE(opaque), f); 2025 } 2026 2027 /* A wrapper for use as a VMState .get function */ 2028 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 2029 const VMStateField *field) 2030 { 2031 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 2032 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 2033 2034 return virtio_load(vdev, f, dc->vmsd->version_id); 2035 } 2036 2037 const VMStateInfo virtio_vmstate_info = { 2038 .name = "virtio", 2039 .get = virtio_device_get, 2040 .put = virtio_device_put, 2041 }; 2042 2043 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 2044 { 2045 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2046 bool bad = (val & ~(vdev->host_features)) != 0; 2047 2048 val &= vdev->host_features; 2049 if (k->set_features) { 2050 k->set_features(vdev, val); 2051 } 2052 vdev->guest_features = val; 2053 return bad ? -1 : 0; 2054 } 2055 2056 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2057 { 2058 int ret; 2059 /* 2060 * The driver must not attempt to set features after feature negotiation 2061 * has finished. 2062 */ 2063 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2064 return -EINVAL; 2065 } 2066 ret = virtio_set_features_nocheck(vdev, val); 2067 if (!ret && virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2068 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ 2069 int i; 2070 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2071 if (vdev->vq[i].vring.num != 0) { 2072 virtio_init_region_cache(vdev, i); 2073 } 2074 } 2075 } 2076 return ret; 2077 } 2078 2079 size_t virtio_feature_get_config_size(VirtIOFeature *feature_sizes, 2080 uint64_t host_features) 2081 { 2082 size_t config_size = 0; 2083 int i; 2084 2085 for (i = 0; feature_sizes[i].flags != 0; i++) { 2086 if (host_features & feature_sizes[i].flags) { 2087 config_size = MAX(feature_sizes[i].end, config_size); 2088 } 2089 } 2090 2091 return config_size; 2092 } 2093 2094 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2095 { 2096 int i, ret; 2097 int32_t config_len; 2098 uint32_t num; 2099 uint32_t features; 2100 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2101 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2102 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2103 2104 /* 2105 * We poison the endianness to ensure it does not get used before 2106 * subsections have been loaded. 2107 */ 2108 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2109 2110 if (k->load_config) { 2111 ret = k->load_config(qbus->parent, f); 2112 if (ret) 2113 return ret; 2114 } 2115 2116 qemu_get_8s(f, &vdev->status); 2117 qemu_get_8s(f, &vdev->isr); 2118 qemu_get_be16s(f, &vdev->queue_sel); 2119 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2120 return -1; 2121 } 2122 qemu_get_be32s(f, &features); 2123 2124 /* 2125 * Temporarily set guest_features low bits - needed by 2126 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2127 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2128 * 2129 * Note: devices should always test host features in future - don't create 2130 * new dependencies like this. 2131 */ 2132 vdev->guest_features = features; 2133 2134 config_len = qemu_get_be32(f); 2135 2136 /* 2137 * There are cases where the incoming config can be bigger or smaller 2138 * than what we have; so load what we have space for, and skip 2139 * any excess that's in the stream. 2140 */ 2141 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 2142 2143 while (config_len > vdev->config_len) { 2144 qemu_get_byte(f); 2145 config_len--; 2146 } 2147 2148 num = qemu_get_be32(f); 2149 2150 if (num > VIRTIO_QUEUE_MAX) { 2151 error_report("Invalid number of virtqueues: 0x%x", num); 2152 return -1; 2153 } 2154 2155 for (i = 0; i < num; i++) { 2156 vdev->vq[i].vring.num = qemu_get_be32(f); 2157 if (k->has_variable_vring_alignment) { 2158 vdev->vq[i].vring.align = qemu_get_be32(f); 2159 } 2160 vdev->vq[i].vring.desc = qemu_get_be64(f); 2161 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 2162 vdev->vq[i].signalled_used_valid = false; 2163 vdev->vq[i].notification = true; 2164 2165 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 2166 error_report("VQ %d address 0x0 " 2167 "inconsistent with Host index 0x%x", 2168 i, vdev->vq[i].last_avail_idx); 2169 return -1; 2170 } 2171 if (k->load_queue) { 2172 ret = k->load_queue(qbus->parent, i, f); 2173 if (ret) 2174 return ret; 2175 } 2176 } 2177 2178 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 2179 2180 if (vdc->load != NULL) { 2181 ret = vdc->load(vdev, f, version_id); 2182 if (ret) { 2183 return ret; 2184 } 2185 } 2186 2187 if (vdc->vmsd) { 2188 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 2189 if (ret) { 2190 return ret; 2191 } 2192 } 2193 2194 /* Subsections */ 2195 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 2196 if (ret) { 2197 return ret; 2198 } 2199 2200 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 2201 vdev->device_endian = virtio_default_endian(); 2202 } 2203 2204 if (virtio_64bit_features_needed(vdev)) { 2205 /* 2206 * Subsection load filled vdev->guest_features. Run them 2207 * through virtio_set_features to sanity-check them against 2208 * host_features. 2209 */ 2210 uint64_t features64 = vdev->guest_features; 2211 if (virtio_set_features_nocheck(vdev, features64) < 0) { 2212 error_report("Features 0x%" PRIx64 " unsupported. " 2213 "Allowed features: 0x%" PRIx64, 2214 features64, vdev->host_features); 2215 return -1; 2216 } 2217 } else { 2218 if (virtio_set_features_nocheck(vdev, features) < 0) { 2219 error_report("Features 0x%x unsupported. " 2220 "Allowed features: 0x%" PRIx64, 2221 features, vdev->host_features); 2222 return -1; 2223 } 2224 } 2225 2226 rcu_read_lock(); 2227 for (i = 0; i < num; i++) { 2228 if (vdev->vq[i].vring.desc) { 2229 uint16_t nheads; 2230 2231 /* 2232 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 2233 * only the region cache needs to be set up. Legacy devices need 2234 * to calculate used and avail ring addresses based on the desc 2235 * address. 2236 */ 2237 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2238 virtio_init_region_cache(vdev, i); 2239 } else { 2240 virtio_queue_update_rings(vdev, i); 2241 } 2242 2243 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 2244 /* Check it isn't doing strange things with descriptor numbers. */ 2245 if (nheads > vdev->vq[i].vring.num) { 2246 error_report("VQ %d size 0x%x Guest index 0x%x " 2247 "inconsistent with Host index 0x%x: delta 0x%x", 2248 i, vdev->vq[i].vring.num, 2249 vring_avail_idx(&vdev->vq[i]), 2250 vdev->vq[i].last_avail_idx, nheads); 2251 return -1; 2252 } 2253 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 2254 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 2255 2256 /* 2257 * Some devices migrate VirtQueueElements that have been popped 2258 * from the avail ring but not yet returned to the used ring. 2259 * Since max ring size < UINT16_MAX it's safe to use modulo 2260 * UINT16_MAX + 1 subtraction. 2261 */ 2262 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 2263 vdev->vq[i].used_idx); 2264 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 2265 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 2266 "used_idx 0x%x", 2267 i, vdev->vq[i].vring.num, 2268 vdev->vq[i].last_avail_idx, 2269 vdev->vq[i].used_idx); 2270 return -1; 2271 } 2272 } 2273 } 2274 rcu_read_unlock(); 2275 2276 return 0; 2277 } 2278 2279 void virtio_cleanup(VirtIODevice *vdev) 2280 { 2281 qemu_del_vm_change_state_handler(vdev->vmstate); 2282 } 2283 2284 static void virtio_vmstate_change(void *opaque, int running, RunState state) 2285 { 2286 VirtIODevice *vdev = opaque; 2287 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2288 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2289 bool backend_run = running && virtio_device_started(vdev, vdev->status); 2290 vdev->vm_running = running; 2291 2292 if (backend_run) { 2293 virtio_set_status(vdev, vdev->status); 2294 } 2295 2296 if (k->vmstate_change) { 2297 k->vmstate_change(qbus->parent, backend_run); 2298 } 2299 2300 if (!backend_run) { 2301 virtio_set_status(vdev, vdev->status); 2302 } 2303 } 2304 2305 void virtio_instance_init_common(Object *proxy_obj, void *data, 2306 size_t vdev_size, const char *vdev_name) 2307 { 2308 DeviceState *vdev = data; 2309 2310 object_initialize_child(proxy_obj, "virtio-backend", vdev, vdev_size, 2311 vdev_name, &error_abort, NULL); 2312 qdev_alias_all_properties(vdev, proxy_obj); 2313 } 2314 2315 void virtio_init(VirtIODevice *vdev, const char *name, 2316 uint16_t device_id, size_t config_size) 2317 { 2318 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2319 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2320 int i; 2321 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 2322 2323 if (nvectors) { 2324 vdev->vector_queues = 2325 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 2326 } 2327 2328 vdev->start_on_kick = (virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) && 2329 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)); 2330 vdev->started = false; 2331 vdev->device_id = device_id; 2332 vdev->status = 0; 2333 atomic_set(&vdev->isr, 0); 2334 vdev->queue_sel = 0; 2335 vdev->config_vector = VIRTIO_NO_VECTOR; 2336 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 2337 vdev->vm_running = runstate_is_running(); 2338 vdev->broken = false; 2339 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2340 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 2341 vdev->vq[i].vdev = vdev; 2342 vdev->vq[i].queue_index = i; 2343 } 2344 2345 vdev->name = name; 2346 vdev->config_len = config_size; 2347 if (vdev->config_len) { 2348 vdev->config = g_malloc0(config_size); 2349 } else { 2350 vdev->config = NULL; 2351 } 2352 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, 2353 vdev); 2354 vdev->device_endian = virtio_default_endian(); 2355 vdev->use_guest_notifier_mask = true; 2356 } 2357 2358 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 2359 { 2360 return vdev->vq[n].vring.desc; 2361 } 2362 2363 bool virtio_queue_enabled(VirtIODevice *vdev, int n) 2364 { 2365 return virtio_queue_get_desc_addr(vdev, n) != 0; 2366 } 2367 2368 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 2369 { 2370 return vdev->vq[n].vring.avail; 2371 } 2372 2373 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 2374 { 2375 return vdev->vq[n].vring.used; 2376 } 2377 2378 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 2379 { 2380 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 2381 } 2382 2383 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 2384 { 2385 return offsetof(VRingAvail, ring) + 2386 sizeof(uint16_t) * vdev->vq[n].vring.num; 2387 } 2388 2389 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 2390 { 2391 return offsetof(VRingUsed, ring) + 2392 sizeof(VRingUsedElem) * vdev->vq[n].vring.num; 2393 } 2394 2395 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 2396 { 2397 return vdev->vq[n].last_avail_idx; 2398 } 2399 2400 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) 2401 { 2402 vdev->vq[n].last_avail_idx = idx; 2403 vdev->vq[n].shadow_avail_idx = idx; 2404 } 2405 2406 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 2407 { 2408 rcu_read_lock(); 2409 if (vdev->vq[n].vring.desc) { 2410 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 2411 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 2412 } 2413 rcu_read_unlock(); 2414 } 2415 2416 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 2417 { 2418 rcu_read_lock(); 2419 if (vdev->vq[n].vring.desc) { 2420 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 2421 } 2422 rcu_read_unlock(); 2423 } 2424 2425 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 2426 { 2427 vdev->vq[n].signalled_used_valid = false; 2428 } 2429 2430 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 2431 { 2432 return vdev->vq + n; 2433 } 2434 2435 uint16_t virtio_get_queue_index(VirtQueue *vq) 2436 { 2437 return vq->queue_index; 2438 } 2439 2440 static void virtio_queue_guest_notifier_read(EventNotifier *n) 2441 { 2442 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 2443 if (event_notifier_test_and_clear(n)) { 2444 virtio_irq(vq); 2445 } 2446 } 2447 2448 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 2449 bool with_irqfd) 2450 { 2451 if (assign && !with_irqfd) { 2452 event_notifier_set_handler(&vq->guest_notifier, 2453 virtio_queue_guest_notifier_read); 2454 } else { 2455 event_notifier_set_handler(&vq->guest_notifier, NULL); 2456 } 2457 if (!assign) { 2458 /* Test and clear notifier before closing it, 2459 * in case poll callback didn't have time to run. */ 2460 virtio_queue_guest_notifier_read(&vq->guest_notifier); 2461 } 2462 } 2463 2464 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 2465 { 2466 return &vq->guest_notifier; 2467 } 2468 2469 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 2470 { 2471 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2472 if (event_notifier_test_and_clear(n)) { 2473 virtio_queue_notify_aio_vq(vq); 2474 } 2475 } 2476 2477 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 2478 { 2479 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2480 2481 virtio_queue_set_notification(vq, 0); 2482 } 2483 2484 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 2485 { 2486 EventNotifier *n = opaque; 2487 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2488 bool progress; 2489 2490 if (!vq->vring.desc || virtio_queue_empty(vq)) { 2491 return false; 2492 } 2493 2494 progress = virtio_queue_notify_aio_vq(vq); 2495 2496 /* In case the handler function re-enabled notifications */ 2497 virtio_queue_set_notification(vq, 0); 2498 return progress; 2499 } 2500 2501 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 2502 { 2503 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2504 2505 /* Caller polls once more after this to catch requests that race with us */ 2506 virtio_queue_set_notification(vq, 1); 2507 } 2508 2509 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 2510 VirtIOHandleAIOOutput handle_output) 2511 { 2512 if (handle_output) { 2513 vq->handle_aio_output = handle_output; 2514 aio_set_event_notifier(ctx, &vq->host_notifier, true, 2515 virtio_queue_host_notifier_aio_read, 2516 virtio_queue_host_notifier_aio_poll); 2517 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 2518 virtio_queue_host_notifier_aio_poll_begin, 2519 virtio_queue_host_notifier_aio_poll_end); 2520 } else { 2521 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 2522 /* Test and clear notifier before after disabling event, 2523 * in case poll callback didn't have time to run. */ 2524 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 2525 vq->handle_aio_output = NULL; 2526 } 2527 } 2528 2529 void virtio_queue_host_notifier_read(EventNotifier *n) 2530 { 2531 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2532 if (event_notifier_test_and_clear(n)) { 2533 virtio_queue_notify_vq(vq); 2534 } 2535 } 2536 2537 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 2538 { 2539 return &vq->host_notifier; 2540 } 2541 2542 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 2543 MemoryRegion *mr, bool assign) 2544 { 2545 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2546 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2547 2548 if (k->set_host_notifier_mr) { 2549 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 2550 } 2551 2552 return -1; 2553 } 2554 2555 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 2556 { 2557 g_free(vdev->bus_name); 2558 vdev->bus_name = g_strdup(bus_name); 2559 } 2560 2561 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 2562 { 2563 va_list ap; 2564 2565 va_start(ap, fmt); 2566 error_vreport(fmt, ap); 2567 va_end(ap); 2568 2569 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2570 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 2571 virtio_notify_config(vdev); 2572 } 2573 2574 vdev->broken = true; 2575 } 2576 2577 static void virtio_memory_listener_commit(MemoryListener *listener) 2578 { 2579 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 2580 int i; 2581 2582 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2583 if (vdev->vq[i].vring.num == 0) { 2584 break; 2585 } 2586 virtio_init_region_cache(vdev, i); 2587 } 2588 } 2589 2590 static void virtio_device_realize(DeviceState *dev, Error **errp) 2591 { 2592 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2593 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2594 Error *err = NULL; 2595 2596 /* Devices should either use vmsd or the load/save methods */ 2597 assert(!vdc->vmsd || !vdc->load); 2598 2599 if (vdc->realize != NULL) { 2600 vdc->realize(dev, &err); 2601 if (err != NULL) { 2602 error_propagate(errp, err); 2603 return; 2604 } 2605 } 2606 2607 virtio_bus_device_plugged(vdev, &err); 2608 if (err != NULL) { 2609 error_propagate(errp, err); 2610 vdc->unrealize(dev, NULL); 2611 return; 2612 } 2613 2614 vdev->listener.commit = virtio_memory_listener_commit; 2615 memory_listener_register(&vdev->listener, vdev->dma_as); 2616 } 2617 2618 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 2619 { 2620 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2621 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2622 Error *err = NULL; 2623 2624 virtio_bus_device_unplugged(vdev); 2625 2626 if (vdc->unrealize != NULL) { 2627 vdc->unrealize(dev, &err); 2628 if (err != NULL) { 2629 error_propagate(errp, err); 2630 return; 2631 } 2632 } 2633 2634 g_free(vdev->bus_name); 2635 vdev->bus_name = NULL; 2636 } 2637 2638 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 2639 { 2640 int i; 2641 if (!vdev->vq) { 2642 return; 2643 } 2644 2645 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2646 if (vdev->vq[i].vring.num == 0) { 2647 break; 2648 } 2649 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2650 } 2651 g_free(vdev->vq); 2652 } 2653 2654 static void virtio_device_instance_finalize(Object *obj) 2655 { 2656 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 2657 2658 memory_listener_unregister(&vdev->listener); 2659 virtio_device_free_virtqueues(vdev); 2660 2661 g_free(vdev->config); 2662 g_free(vdev->vector_queues); 2663 } 2664 2665 static Property virtio_properties[] = { 2666 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 2667 DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true), 2668 DEFINE_PROP_END_OF_LIST(), 2669 }; 2670 2671 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 2672 { 2673 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2674 int i, n, r, err; 2675 2676 memory_region_transaction_begin(); 2677 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2678 VirtQueue *vq = &vdev->vq[n]; 2679 if (!virtio_queue_get_num(vdev, n)) { 2680 continue; 2681 } 2682 r = virtio_bus_set_host_notifier(qbus, n, true); 2683 if (r < 0) { 2684 err = r; 2685 goto assign_error; 2686 } 2687 event_notifier_set_handler(&vq->host_notifier, 2688 virtio_queue_host_notifier_read); 2689 } 2690 2691 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2692 /* Kick right away to begin processing requests already in vring */ 2693 VirtQueue *vq = &vdev->vq[n]; 2694 if (!vq->vring.num) { 2695 continue; 2696 } 2697 event_notifier_set(&vq->host_notifier); 2698 } 2699 memory_region_transaction_commit(); 2700 return 0; 2701 2702 assign_error: 2703 i = n; /* save n for a second iteration after transaction is committed. */ 2704 while (--n >= 0) { 2705 VirtQueue *vq = &vdev->vq[n]; 2706 if (!virtio_queue_get_num(vdev, n)) { 2707 continue; 2708 } 2709 2710 event_notifier_set_handler(&vq->host_notifier, NULL); 2711 r = virtio_bus_set_host_notifier(qbus, n, false); 2712 assert(r >= 0); 2713 } 2714 memory_region_transaction_commit(); 2715 2716 while (--i >= 0) { 2717 if (!virtio_queue_get_num(vdev, i)) { 2718 continue; 2719 } 2720 virtio_bus_cleanup_host_notifier(qbus, i); 2721 } 2722 return err; 2723 } 2724 2725 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 2726 { 2727 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2728 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2729 2730 return virtio_bus_start_ioeventfd(vbus); 2731 } 2732 2733 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 2734 { 2735 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2736 int n, r; 2737 2738 memory_region_transaction_begin(); 2739 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2740 VirtQueue *vq = &vdev->vq[n]; 2741 2742 if (!virtio_queue_get_num(vdev, n)) { 2743 continue; 2744 } 2745 event_notifier_set_handler(&vq->host_notifier, NULL); 2746 r = virtio_bus_set_host_notifier(qbus, n, false); 2747 assert(r >= 0); 2748 } 2749 memory_region_transaction_commit(); 2750 2751 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2752 if (!virtio_queue_get_num(vdev, n)) { 2753 continue; 2754 } 2755 virtio_bus_cleanup_host_notifier(qbus, n); 2756 } 2757 } 2758 2759 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) 2760 { 2761 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2762 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2763 2764 virtio_bus_stop_ioeventfd(vbus); 2765 } 2766 2767 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 2768 { 2769 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2770 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2771 2772 return virtio_bus_grab_ioeventfd(vbus); 2773 } 2774 2775 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 2776 { 2777 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2778 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2779 2780 virtio_bus_release_ioeventfd(vbus); 2781 } 2782 2783 static void virtio_device_class_init(ObjectClass *klass, void *data) 2784 { 2785 /* Set the default value here. */ 2786 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 2787 DeviceClass *dc = DEVICE_CLASS(klass); 2788 2789 dc->realize = virtio_device_realize; 2790 dc->unrealize = virtio_device_unrealize; 2791 dc->bus_type = TYPE_VIRTIO_BUS; 2792 dc->props = virtio_properties; 2793 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 2794 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 2795 2796 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 2797 } 2798 2799 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 2800 { 2801 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2802 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2803 2804 return virtio_bus_ioeventfd_enabled(vbus); 2805 } 2806 2807 static const TypeInfo virtio_device_info = { 2808 .name = TYPE_VIRTIO_DEVICE, 2809 .parent = TYPE_DEVICE, 2810 .instance_size = sizeof(VirtIODevice), 2811 .class_init = virtio_device_class_init, 2812 .instance_finalize = virtio_device_instance_finalize, 2813 .abstract = true, 2814 .class_size = sizeof(VirtioDeviceClass), 2815 }; 2816 2817 static void virtio_register_types(void) 2818 { 2819 type_register_static(&virtio_device_info); 2820 } 2821 2822 type_init(virtio_register_types) 2823