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 vdev->started = val & VIRTIO_CONFIG_S_DRIVER_OK; 1166 if (unlikely(vdev->start_on_kick && vdev->started)) { 1167 vdev->start_on_kick = false; 1168 } 1169 1170 if (k->set_status) { 1171 k->set_status(vdev, val); 1172 } 1173 vdev->status = val; 1174 1175 return 0; 1176 } 1177 1178 static enum virtio_device_endian virtio_default_endian(void) 1179 { 1180 if (target_words_bigendian()) { 1181 return VIRTIO_DEVICE_ENDIAN_BIG; 1182 } else { 1183 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1184 } 1185 } 1186 1187 static enum virtio_device_endian virtio_current_cpu_endian(void) 1188 { 1189 CPUClass *cc = CPU_GET_CLASS(current_cpu); 1190 1191 if (cc->virtio_is_big_endian(current_cpu)) { 1192 return VIRTIO_DEVICE_ENDIAN_BIG; 1193 } else { 1194 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1195 } 1196 } 1197 1198 void virtio_reset(void *opaque) 1199 { 1200 VirtIODevice *vdev = opaque; 1201 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1202 int i; 1203 1204 virtio_set_status(vdev, 0); 1205 if (current_cpu) { 1206 /* Guest initiated reset */ 1207 vdev->device_endian = virtio_current_cpu_endian(); 1208 } else { 1209 /* System reset */ 1210 vdev->device_endian = virtio_default_endian(); 1211 } 1212 1213 if (k->reset) { 1214 k->reset(vdev); 1215 } 1216 1217 vdev->start_on_kick = (virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) && 1218 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)); 1219 vdev->started = false; 1220 vdev->broken = false; 1221 vdev->guest_features = 0; 1222 vdev->queue_sel = 0; 1223 vdev->status = 0; 1224 atomic_set(&vdev->isr, 0); 1225 vdev->config_vector = VIRTIO_NO_VECTOR; 1226 virtio_notify_vector(vdev, vdev->config_vector); 1227 1228 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1229 vdev->vq[i].vring.desc = 0; 1230 vdev->vq[i].vring.avail = 0; 1231 vdev->vq[i].vring.used = 0; 1232 vdev->vq[i].last_avail_idx = 0; 1233 vdev->vq[i].shadow_avail_idx = 0; 1234 vdev->vq[i].used_idx = 0; 1235 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1236 vdev->vq[i].signalled_used = 0; 1237 vdev->vq[i].signalled_used_valid = false; 1238 vdev->vq[i].notification = true; 1239 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1240 vdev->vq[i].inuse = 0; 1241 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 1242 } 1243 } 1244 1245 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1246 { 1247 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1248 uint8_t val; 1249 1250 if (addr + sizeof(val) > vdev->config_len) { 1251 return (uint32_t)-1; 1252 } 1253 1254 k->get_config(vdev, vdev->config); 1255 1256 val = ldub_p(vdev->config + addr); 1257 return val; 1258 } 1259 1260 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1261 { 1262 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1263 uint16_t val; 1264 1265 if (addr + sizeof(val) > vdev->config_len) { 1266 return (uint32_t)-1; 1267 } 1268 1269 k->get_config(vdev, vdev->config); 1270 1271 val = lduw_p(vdev->config + addr); 1272 return val; 1273 } 1274 1275 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1276 { 1277 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1278 uint32_t val; 1279 1280 if (addr + sizeof(val) > vdev->config_len) { 1281 return (uint32_t)-1; 1282 } 1283 1284 k->get_config(vdev, vdev->config); 1285 1286 val = ldl_p(vdev->config + addr); 1287 return val; 1288 } 1289 1290 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1291 { 1292 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1293 uint8_t val = data; 1294 1295 if (addr + sizeof(val) > vdev->config_len) { 1296 return; 1297 } 1298 1299 stb_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_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1307 { 1308 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1309 uint16_t val = data; 1310 1311 if (addr + sizeof(val) > vdev->config_len) { 1312 return; 1313 } 1314 1315 stw_p(vdev->config + addr, val); 1316 1317 if (k->set_config) { 1318 k->set_config(vdev, vdev->config); 1319 } 1320 } 1321 1322 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1323 { 1324 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1325 uint32_t val = data; 1326 1327 if (addr + sizeof(val) > vdev->config_len) { 1328 return; 1329 } 1330 1331 stl_p(vdev->config + addr, val); 1332 1333 if (k->set_config) { 1334 k->set_config(vdev, vdev->config); 1335 } 1336 } 1337 1338 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 1339 { 1340 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1341 uint8_t val; 1342 1343 if (addr + sizeof(val) > vdev->config_len) { 1344 return (uint32_t)-1; 1345 } 1346 1347 k->get_config(vdev, vdev->config); 1348 1349 val = ldub_p(vdev->config + addr); 1350 return val; 1351 } 1352 1353 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 1354 { 1355 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1356 uint16_t val; 1357 1358 if (addr + sizeof(val) > vdev->config_len) { 1359 return (uint32_t)-1; 1360 } 1361 1362 k->get_config(vdev, vdev->config); 1363 1364 val = lduw_le_p(vdev->config + addr); 1365 return val; 1366 } 1367 1368 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 1369 { 1370 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1371 uint32_t val; 1372 1373 if (addr + sizeof(val) > vdev->config_len) { 1374 return (uint32_t)-1; 1375 } 1376 1377 k->get_config(vdev, vdev->config); 1378 1379 val = ldl_le_p(vdev->config + addr); 1380 return val; 1381 } 1382 1383 void virtio_config_modern_writeb(VirtIODevice *vdev, 1384 uint32_t addr, uint32_t data) 1385 { 1386 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1387 uint8_t val = data; 1388 1389 if (addr + sizeof(val) > vdev->config_len) { 1390 return; 1391 } 1392 1393 stb_p(vdev->config + addr, val); 1394 1395 if (k->set_config) { 1396 k->set_config(vdev, vdev->config); 1397 } 1398 } 1399 1400 void virtio_config_modern_writew(VirtIODevice *vdev, 1401 uint32_t addr, uint32_t data) 1402 { 1403 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1404 uint16_t val = data; 1405 1406 if (addr + sizeof(val) > vdev->config_len) { 1407 return; 1408 } 1409 1410 stw_le_p(vdev->config + addr, val); 1411 1412 if (k->set_config) { 1413 k->set_config(vdev, vdev->config); 1414 } 1415 } 1416 1417 void virtio_config_modern_writel(VirtIODevice *vdev, 1418 uint32_t addr, uint32_t data) 1419 { 1420 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1421 uint32_t val = data; 1422 1423 if (addr + sizeof(val) > vdev->config_len) { 1424 return; 1425 } 1426 1427 stl_le_p(vdev->config + addr, val); 1428 1429 if (k->set_config) { 1430 k->set_config(vdev, vdev->config); 1431 } 1432 } 1433 1434 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 1435 { 1436 if (!vdev->vq[n].vring.num) { 1437 return; 1438 } 1439 vdev->vq[n].vring.desc = addr; 1440 virtio_queue_update_rings(vdev, n); 1441 } 1442 1443 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 1444 { 1445 return vdev->vq[n].vring.desc; 1446 } 1447 1448 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 1449 hwaddr avail, hwaddr used) 1450 { 1451 if (!vdev->vq[n].vring.num) { 1452 return; 1453 } 1454 vdev->vq[n].vring.desc = desc; 1455 vdev->vq[n].vring.avail = avail; 1456 vdev->vq[n].vring.used = used; 1457 virtio_init_region_cache(vdev, n); 1458 } 1459 1460 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 1461 { 1462 /* Don't allow guest to flip queue between existent and 1463 * nonexistent states, or to set it to an invalid size. 1464 */ 1465 if (!!num != !!vdev->vq[n].vring.num || 1466 num > VIRTQUEUE_MAX_SIZE || 1467 num < 0) { 1468 return; 1469 } 1470 vdev->vq[n].vring.num = num; 1471 } 1472 1473 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 1474 { 1475 return QLIST_FIRST(&vdev->vector_queues[vector]); 1476 } 1477 1478 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 1479 { 1480 return QLIST_NEXT(vq, node); 1481 } 1482 1483 int virtio_queue_get_num(VirtIODevice *vdev, int n) 1484 { 1485 return vdev->vq[n].vring.num; 1486 } 1487 1488 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 1489 { 1490 return vdev->vq[n].vring.num_default; 1491 } 1492 1493 int virtio_get_num_queues(VirtIODevice *vdev) 1494 { 1495 int i; 1496 1497 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1498 if (!virtio_queue_get_num(vdev, i)) { 1499 break; 1500 } 1501 } 1502 1503 return i; 1504 } 1505 1506 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 1507 { 1508 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1509 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1510 1511 /* virtio-1 compliant devices cannot change the alignment */ 1512 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1513 error_report("tried to modify queue alignment for virtio-1 device"); 1514 return; 1515 } 1516 /* Check that the transport told us it was going to do this 1517 * (so a buggy transport will immediately assert rather than 1518 * silently failing to migrate this state) 1519 */ 1520 assert(k->has_variable_vring_alignment); 1521 1522 if (align) { 1523 vdev->vq[n].vring.align = align; 1524 virtio_queue_update_rings(vdev, n); 1525 } 1526 } 1527 1528 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) 1529 { 1530 bool ret = false; 1531 1532 if (vq->vring.desc && vq->handle_aio_output) { 1533 VirtIODevice *vdev = vq->vdev; 1534 1535 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1536 ret = vq->handle_aio_output(vdev, vq); 1537 1538 if (unlikely(vdev->start_on_kick)) { 1539 vdev->started = true; 1540 vdev->start_on_kick = false; 1541 } 1542 } 1543 1544 return ret; 1545 } 1546 1547 static void virtio_queue_notify_vq(VirtQueue *vq) 1548 { 1549 if (vq->vring.desc && vq->handle_output) { 1550 VirtIODevice *vdev = vq->vdev; 1551 1552 if (unlikely(vdev->broken)) { 1553 return; 1554 } 1555 1556 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1557 vq->handle_output(vdev, vq); 1558 1559 if (unlikely(vdev->start_on_kick)) { 1560 vdev->started = true; 1561 vdev->start_on_kick = false; 1562 } 1563 } 1564 } 1565 1566 void virtio_queue_notify(VirtIODevice *vdev, int n) 1567 { 1568 VirtQueue *vq = &vdev->vq[n]; 1569 1570 if (unlikely(!vq->vring.desc || vdev->broken)) { 1571 return; 1572 } 1573 1574 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1575 if (vq->handle_aio_output) { 1576 event_notifier_set(&vq->host_notifier); 1577 } else if (vq->handle_output) { 1578 vq->handle_output(vdev, vq); 1579 } 1580 1581 if (unlikely(vdev->start_on_kick)) { 1582 vdev->started = true; 1583 vdev->start_on_kick = false; 1584 } 1585 } 1586 1587 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 1588 { 1589 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 1590 VIRTIO_NO_VECTOR; 1591 } 1592 1593 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 1594 { 1595 VirtQueue *vq = &vdev->vq[n]; 1596 1597 if (n < VIRTIO_QUEUE_MAX) { 1598 if (vdev->vector_queues && 1599 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 1600 QLIST_REMOVE(vq, node); 1601 } 1602 vdev->vq[n].vector = vector; 1603 if (vdev->vector_queues && 1604 vector != VIRTIO_NO_VECTOR) { 1605 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 1606 } 1607 } 1608 } 1609 1610 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 1611 VirtIOHandleOutput handle_output) 1612 { 1613 int i; 1614 1615 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1616 if (vdev->vq[i].vring.num == 0) 1617 break; 1618 } 1619 1620 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 1621 abort(); 1622 1623 vdev->vq[i].vring.num = queue_size; 1624 vdev->vq[i].vring.num_default = queue_size; 1625 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 1626 vdev->vq[i].handle_output = handle_output; 1627 vdev->vq[i].handle_aio_output = NULL; 1628 1629 return &vdev->vq[i]; 1630 } 1631 1632 void virtio_del_queue(VirtIODevice *vdev, int n) 1633 { 1634 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 1635 abort(); 1636 } 1637 1638 vdev->vq[n].vring.num = 0; 1639 vdev->vq[n].vring.num_default = 0; 1640 vdev->vq[n].handle_output = NULL; 1641 vdev->vq[n].handle_aio_output = NULL; 1642 } 1643 1644 static void virtio_set_isr(VirtIODevice *vdev, int value) 1645 { 1646 uint8_t old = atomic_read(&vdev->isr); 1647 1648 /* Do not write ISR if it does not change, so that its cacheline remains 1649 * shared in the common case where the guest does not read it. 1650 */ 1651 if ((old & value) != value) { 1652 atomic_or(&vdev->isr, value); 1653 } 1654 } 1655 1656 /* Called within rcu_read_lock(). */ 1657 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 1658 { 1659 uint16_t old, new; 1660 bool v; 1661 /* We need to expose used array entries before checking used event. */ 1662 smp_mb(); 1663 /* Always notify when queue is empty (when feature acknowledge) */ 1664 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 1665 !vq->inuse && virtio_queue_empty(vq)) { 1666 return true; 1667 } 1668 1669 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1670 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 1671 } 1672 1673 v = vq->signalled_used_valid; 1674 vq->signalled_used_valid = true; 1675 old = vq->signalled_used; 1676 new = vq->signalled_used = vq->used_idx; 1677 return !v || vring_need_event(vring_get_used_event(vq), new, old); 1678 } 1679 1680 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 1681 { 1682 bool should_notify; 1683 rcu_read_lock(); 1684 should_notify = virtio_should_notify(vdev, vq); 1685 rcu_read_unlock(); 1686 1687 if (!should_notify) { 1688 return; 1689 } 1690 1691 trace_virtio_notify_irqfd(vdev, vq); 1692 1693 /* 1694 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 1695 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 1696 * incorrectly polling this bit during crashdump and hibernation 1697 * in MSI mode, causing a hang if this bit is never updated. 1698 * Recent releases of Windows do not really shut down, but rather 1699 * log out and hibernate to make the next startup faster. Hence, 1700 * this manifested as a more serious hang during shutdown with 1701 * 1702 * Next driver release from 2016 fixed this problem, so working around it 1703 * is not a must, but it's easy to do so let's do it here. 1704 * 1705 * Note: it's safe to update ISR from any thread as it was switched 1706 * to an atomic operation. 1707 */ 1708 virtio_set_isr(vq->vdev, 0x1); 1709 event_notifier_set(&vq->guest_notifier); 1710 } 1711 1712 static void virtio_irq(VirtQueue *vq) 1713 { 1714 virtio_set_isr(vq->vdev, 0x1); 1715 virtio_notify_vector(vq->vdev, vq->vector); 1716 } 1717 1718 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 1719 { 1720 bool should_notify; 1721 rcu_read_lock(); 1722 should_notify = virtio_should_notify(vdev, vq); 1723 rcu_read_unlock(); 1724 1725 if (!should_notify) { 1726 return; 1727 } 1728 1729 trace_virtio_notify(vdev, vq); 1730 virtio_irq(vq); 1731 } 1732 1733 void virtio_notify_config(VirtIODevice *vdev) 1734 { 1735 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 1736 return; 1737 1738 virtio_set_isr(vdev, 0x3); 1739 vdev->generation++; 1740 virtio_notify_vector(vdev, vdev->config_vector); 1741 } 1742 1743 static bool virtio_device_endian_needed(void *opaque) 1744 { 1745 VirtIODevice *vdev = opaque; 1746 1747 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 1748 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1749 return vdev->device_endian != virtio_default_endian(); 1750 } 1751 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 1752 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 1753 } 1754 1755 static bool virtio_64bit_features_needed(void *opaque) 1756 { 1757 VirtIODevice *vdev = opaque; 1758 1759 return (vdev->host_features >> 32) != 0; 1760 } 1761 1762 static bool virtio_virtqueue_needed(void *opaque) 1763 { 1764 VirtIODevice *vdev = opaque; 1765 1766 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 1767 } 1768 1769 static bool virtio_ringsize_needed(void *opaque) 1770 { 1771 VirtIODevice *vdev = opaque; 1772 int i; 1773 1774 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1775 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 1776 return true; 1777 } 1778 } 1779 return false; 1780 } 1781 1782 static bool virtio_extra_state_needed(void *opaque) 1783 { 1784 VirtIODevice *vdev = opaque; 1785 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1786 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1787 1788 return k->has_extra_state && 1789 k->has_extra_state(qbus->parent); 1790 } 1791 1792 static bool virtio_broken_needed(void *opaque) 1793 { 1794 VirtIODevice *vdev = opaque; 1795 1796 return vdev->broken; 1797 } 1798 1799 static bool virtio_started_needed(void *opaque) 1800 { 1801 VirtIODevice *vdev = opaque; 1802 1803 return vdev->started; 1804 } 1805 1806 static const VMStateDescription vmstate_virtqueue = { 1807 .name = "virtqueue_state", 1808 .version_id = 1, 1809 .minimum_version_id = 1, 1810 .fields = (VMStateField[]) { 1811 VMSTATE_UINT64(vring.avail, struct VirtQueue), 1812 VMSTATE_UINT64(vring.used, struct VirtQueue), 1813 VMSTATE_END_OF_LIST() 1814 } 1815 }; 1816 1817 static const VMStateDescription vmstate_virtio_virtqueues = { 1818 .name = "virtio/virtqueues", 1819 .version_id = 1, 1820 .minimum_version_id = 1, 1821 .needed = &virtio_virtqueue_needed, 1822 .fields = (VMStateField[]) { 1823 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1824 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 1825 VMSTATE_END_OF_LIST() 1826 } 1827 }; 1828 1829 static const VMStateDescription vmstate_ringsize = { 1830 .name = "ringsize_state", 1831 .version_id = 1, 1832 .minimum_version_id = 1, 1833 .fields = (VMStateField[]) { 1834 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 1835 VMSTATE_END_OF_LIST() 1836 } 1837 }; 1838 1839 static const VMStateDescription vmstate_virtio_ringsize = { 1840 .name = "virtio/ringsize", 1841 .version_id = 1, 1842 .minimum_version_id = 1, 1843 .needed = &virtio_ringsize_needed, 1844 .fields = (VMStateField[]) { 1845 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1846 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 1847 VMSTATE_END_OF_LIST() 1848 } 1849 }; 1850 1851 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 1852 const VMStateField *field) 1853 { 1854 VirtIODevice *vdev = pv; 1855 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1856 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1857 1858 if (!k->load_extra_state) { 1859 return -1; 1860 } else { 1861 return k->load_extra_state(qbus->parent, f); 1862 } 1863 } 1864 1865 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 1866 const VMStateField *field, QJSON *vmdesc) 1867 { 1868 VirtIODevice *vdev = pv; 1869 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1870 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1871 1872 k->save_extra_state(qbus->parent, f); 1873 return 0; 1874 } 1875 1876 static const VMStateInfo vmstate_info_extra_state = { 1877 .name = "virtqueue_extra_state", 1878 .get = get_extra_state, 1879 .put = put_extra_state, 1880 }; 1881 1882 static const VMStateDescription vmstate_virtio_extra_state = { 1883 .name = "virtio/extra_state", 1884 .version_id = 1, 1885 .minimum_version_id = 1, 1886 .needed = &virtio_extra_state_needed, 1887 .fields = (VMStateField[]) { 1888 { 1889 .name = "extra_state", 1890 .version_id = 0, 1891 .field_exists = NULL, 1892 .size = 0, 1893 .info = &vmstate_info_extra_state, 1894 .flags = VMS_SINGLE, 1895 .offset = 0, 1896 }, 1897 VMSTATE_END_OF_LIST() 1898 } 1899 }; 1900 1901 static const VMStateDescription vmstate_virtio_device_endian = { 1902 .name = "virtio/device_endian", 1903 .version_id = 1, 1904 .minimum_version_id = 1, 1905 .needed = &virtio_device_endian_needed, 1906 .fields = (VMStateField[]) { 1907 VMSTATE_UINT8(device_endian, VirtIODevice), 1908 VMSTATE_END_OF_LIST() 1909 } 1910 }; 1911 1912 static const VMStateDescription vmstate_virtio_64bit_features = { 1913 .name = "virtio/64bit_features", 1914 .version_id = 1, 1915 .minimum_version_id = 1, 1916 .needed = &virtio_64bit_features_needed, 1917 .fields = (VMStateField[]) { 1918 VMSTATE_UINT64(guest_features, VirtIODevice), 1919 VMSTATE_END_OF_LIST() 1920 } 1921 }; 1922 1923 static const VMStateDescription vmstate_virtio_broken = { 1924 .name = "virtio/broken", 1925 .version_id = 1, 1926 .minimum_version_id = 1, 1927 .needed = &virtio_broken_needed, 1928 .fields = (VMStateField[]) { 1929 VMSTATE_BOOL(broken, VirtIODevice), 1930 VMSTATE_END_OF_LIST() 1931 } 1932 }; 1933 1934 static const VMStateDescription vmstate_virtio_started = { 1935 .name = "virtio/started", 1936 .version_id = 1, 1937 .minimum_version_id = 1, 1938 .needed = &virtio_started_needed, 1939 .fields = (VMStateField[]) { 1940 VMSTATE_BOOL(started, VirtIODevice), 1941 VMSTATE_END_OF_LIST() 1942 } 1943 }; 1944 1945 static const VMStateDescription vmstate_virtio = { 1946 .name = "virtio", 1947 .version_id = 1, 1948 .minimum_version_id = 1, 1949 .minimum_version_id_old = 1, 1950 .fields = (VMStateField[]) { 1951 VMSTATE_END_OF_LIST() 1952 }, 1953 .subsections = (const VMStateDescription*[]) { 1954 &vmstate_virtio_device_endian, 1955 &vmstate_virtio_64bit_features, 1956 &vmstate_virtio_virtqueues, 1957 &vmstate_virtio_ringsize, 1958 &vmstate_virtio_broken, 1959 &vmstate_virtio_extra_state, 1960 &vmstate_virtio_started, 1961 NULL 1962 } 1963 }; 1964 1965 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 1966 { 1967 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1968 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1969 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1970 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 1971 int i; 1972 1973 if (k->save_config) { 1974 k->save_config(qbus->parent, f); 1975 } 1976 1977 qemu_put_8s(f, &vdev->status); 1978 qemu_put_8s(f, &vdev->isr); 1979 qemu_put_be16s(f, &vdev->queue_sel); 1980 qemu_put_be32s(f, &guest_features_lo); 1981 qemu_put_be32(f, vdev->config_len); 1982 qemu_put_buffer(f, vdev->config, vdev->config_len); 1983 1984 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1985 if (vdev->vq[i].vring.num == 0) 1986 break; 1987 } 1988 1989 qemu_put_be32(f, i); 1990 1991 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1992 if (vdev->vq[i].vring.num == 0) 1993 break; 1994 1995 qemu_put_be32(f, vdev->vq[i].vring.num); 1996 if (k->has_variable_vring_alignment) { 1997 qemu_put_be32(f, vdev->vq[i].vring.align); 1998 } 1999 /* 2000 * Save desc now, the rest of the ring addresses are saved in 2001 * subsections for VIRTIO-1 devices. 2002 */ 2003 qemu_put_be64(f, vdev->vq[i].vring.desc); 2004 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 2005 if (k->save_queue) { 2006 k->save_queue(qbus->parent, i, f); 2007 } 2008 } 2009 2010 if (vdc->save != NULL) { 2011 vdc->save(vdev, f); 2012 } 2013 2014 if (vdc->vmsd) { 2015 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 2016 if (ret) { 2017 return ret; 2018 } 2019 } 2020 2021 /* Subsections */ 2022 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 2023 } 2024 2025 /* A wrapper for use as a VMState .put function */ 2026 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 2027 const VMStateField *field, QJSON *vmdesc) 2028 { 2029 return virtio_save(VIRTIO_DEVICE(opaque), f); 2030 } 2031 2032 /* A wrapper for use as a VMState .get function */ 2033 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 2034 const VMStateField *field) 2035 { 2036 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 2037 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 2038 2039 return virtio_load(vdev, f, dc->vmsd->version_id); 2040 } 2041 2042 const VMStateInfo virtio_vmstate_info = { 2043 .name = "virtio", 2044 .get = virtio_device_get, 2045 .put = virtio_device_put, 2046 }; 2047 2048 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 2049 { 2050 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2051 bool bad = (val & ~(vdev->host_features)) != 0; 2052 2053 val &= vdev->host_features; 2054 if (k->set_features) { 2055 k->set_features(vdev, val); 2056 } 2057 vdev->guest_features = val; 2058 return bad ? -1 : 0; 2059 } 2060 2061 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2062 { 2063 int ret; 2064 /* 2065 * The driver must not attempt to set features after feature negotiation 2066 * has finished. 2067 */ 2068 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2069 return -EINVAL; 2070 } 2071 ret = virtio_set_features_nocheck(vdev, val); 2072 if (!ret && virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2073 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ 2074 int i; 2075 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2076 if (vdev->vq[i].vring.num != 0) { 2077 virtio_init_region_cache(vdev, i); 2078 } 2079 } 2080 } 2081 return ret; 2082 } 2083 2084 size_t virtio_feature_get_config_size(VirtIOFeature *feature_sizes, 2085 uint64_t host_features) 2086 { 2087 size_t config_size = 0; 2088 int i; 2089 2090 for (i = 0; feature_sizes[i].flags != 0; i++) { 2091 if (host_features & feature_sizes[i].flags) { 2092 config_size = MAX(feature_sizes[i].end, config_size); 2093 } 2094 } 2095 2096 return config_size; 2097 } 2098 2099 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2100 { 2101 int i, ret; 2102 int32_t config_len; 2103 uint32_t num; 2104 uint32_t features; 2105 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2106 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2107 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2108 2109 /* 2110 * We poison the endianness to ensure it does not get used before 2111 * subsections have been loaded. 2112 */ 2113 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2114 2115 if (k->load_config) { 2116 ret = k->load_config(qbus->parent, f); 2117 if (ret) 2118 return ret; 2119 } 2120 2121 qemu_get_8s(f, &vdev->status); 2122 qemu_get_8s(f, &vdev->isr); 2123 qemu_get_be16s(f, &vdev->queue_sel); 2124 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2125 return -1; 2126 } 2127 qemu_get_be32s(f, &features); 2128 2129 /* 2130 * Temporarily set guest_features low bits - needed by 2131 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2132 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2133 * 2134 * Note: devices should always test host features in future - don't create 2135 * new dependencies like this. 2136 */ 2137 vdev->guest_features = features; 2138 2139 config_len = qemu_get_be32(f); 2140 2141 /* 2142 * There are cases where the incoming config can be bigger or smaller 2143 * than what we have; so load what we have space for, and skip 2144 * any excess that's in the stream. 2145 */ 2146 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 2147 2148 while (config_len > vdev->config_len) { 2149 qemu_get_byte(f); 2150 config_len--; 2151 } 2152 2153 num = qemu_get_be32(f); 2154 2155 if (num > VIRTIO_QUEUE_MAX) { 2156 error_report("Invalid number of virtqueues: 0x%x", num); 2157 return -1; 2158 } 2159 2160 for (i = 0; i < num; i++) { 2161 vdev->vq[i].vring.num = qemu_get_be32(f); 2162 if (k->has_variable_vring_alignment) { 2163 vdev->vq[i].vring.align = qemu_get_be32(f); 2164 } 2165 vdev->vq[i].vring.desc = qemu_get_be64(f); 2166 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 2167 vdev->vq[i].signalled_used_valid = false; 2168 vdev->vq[i].notification = true; 2169 2170 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 2171 error_report("VQ %d address 0x0 " 2172 "inconsistent with Host index 0x%x", 2173 i, vdev->vq[i].last_avail_idx); 2174 return -1; 2175 } 2176 if (k->load_queue) { 2177 ret = k->load_queue(qbus->parent, i, f); 2178 if (ret) 2179 return ret; 2180 } 2181 } 2182 2183 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 2184 2185 if (vdc->load != NULL) { 2186 ret = vdc->load(vdev, f, version_id); 2187 if (ret) { 2188 return ret; 2189 } 2190 } 2191 2192 if (vdc->vmsd) { 2193 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 2194 if (ret) { 2195 return ret; 2196 } 2197 } 2198 2199 /* Subsections */ 2200 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 2201 if (ret) { 2202 return ret; 2203 } 2204 2205 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 2206 vdev->device_endian = virtio_default_endian(); 2207 } 2208 2209 if (virtio_64bit_features_needed(vdev)) { 2210 /* 2211 * Subsection load filled vdev->guest_features. Run them 2212 * through virtio_set_features to sanity-check them against 2213 * host_features. 2214 */ 2215 uint64_t features64 = vdev->guest_features; 2216 if (virtio_set_features_nocheck(vdev, features64) < 0) { 2217 error_report("Features 0x%" PRIx64 " unsupported. " 2218 "Allowed features: 0x%" PRIx64, 2219 features64, vdev->host_features); 2220 return -1; 2221 } 2222 } else { 2223 if (virtio_set_features_nocheck(vdev, features) < 0) { 2224 error_report("Features 0x%x unsupported. " 2225 "Allowed features: 0x%" PRIx64, 2226 features, vdev->host_features); 2227 return -1; 2228 } 2229 } 2230 2231 rcu_read_lock(); 2232 for (i = 0; i < num; i++) { 2233 if (vdev->vq[i].vring.desc) { 2234 uint16_t nheads; 2235 2236 /* 2237 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 2238 * only the region cache needs to be set up. Legacy devices need 2239 * to calculate used and avail ring addresses based on the desc 2240 * address. 2241 */ 2242 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2243 virtio_init_region_cache(vdev, i); 2244 } else { 2245 virtio_queue_update_rings(vdev, i); 2246 } 2247 2248 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 2249 /* Check it isn't doing strange things with descriptor numbers. */ 2250 if (nheads > vdev->vq[i].vring.num) { 2251 error_report("VQ %d size 0x%x Guest index 0x%x " 2252 "inconsistent with Host index 0x%x: delta 0x%x", 2253 i, vdev->vq[i].vring.num, 2254 vring_avail_idx(&vdev->vq[i]), 2255 vdev->vq[i].last_avail_idx, nheads); 2256 return -1; 2257 } 2258 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 2259 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 2260 2261 /* 2262 * Some devices migrate VirtQueueElements that have been popped 2263 * from the avail ring but not yet returned to the used ring. 2264 * Since max ring size < UINT16_MAX it's safe to use modulo 2265 * UINT16_MAX + 1 subtraction. 2266 */ 2267 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 2268 vdev->vq[i].used_idx); 2269 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 2270 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 2271 "used_idx 0x%x", 2272 i, vdev->vq[i].vring.num, 2273 vdev->vq[i].last_avail_idx, 2274 vdev->vq[i].used_idx); 2275 return -1; 2276 } 2277 } 2278 } 2279 rcu_read_unlock(); 2280 2281 return 0; 2282 } 2283 2284 void virtio_cleanup(VirtIODevice *vdev) 2285 { 2286 qemu_del_vm_change_state_handler(vdev->vmstate); 2287 } 2288 2289 static void virtio_vmstate_change(void *opaque, int running, RunState state) 2290 { 2291 VirtIODevice *vdev = opaque; 2292 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2293 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2294 bool backend_run = running && vdev->started; 2295 vdev->vm_running = running; 2296 2297 if (backend_run) { 2298 virtio_set_status(vdev, vdev->status); 2299 } 2300 2301 if (k->vmstate_change) { 2302 k->vmstate_change(qbus->parent, backend_run); 2303 } 2304 2305 if (!backend_run) { 2306 virtio_set_status(vdev, vdev->status); 2307 } 2308 } 2309 2310 void virtio_instance_init_common(Object *proxy_obj, void *data, 2311 size_t vdev_size, const char *vdev_name) 2312 { 2313 DeviceState *vdev = data; 2314 2315 object_initialize_child(proxy_obj, "virtio-backend", vdev, vdev_size, 2316 vdev_name, &error_abort, NULL); 2317 qdev_alias_all_properties(vdev, proxy_obj); 2318 } 2319 2320 void virtio_init(VirtIODevice *vdev, const char *name, 2321 uint16_t device_id, size_t config_size) 2322 { 2323 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2324 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2325 int i; 2326 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 2327 2328 if (nvectors) { 2329 vdev->vector_queues = 2330 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 2331 } 2332 2333 vdev->start_on_kick = (virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) && 2334 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)); 2335 vdev->started = false; 2336 vdev->device_id = device_id; 2337 vdev->status = 0; 2338 atomic_set(&vdev->isr, 0); 2339 vdev->queue_sel = 0; 2340 vdev->config_vector = VIRTIO_NO_VECTOR; 2341 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 2342 vdev->vm_running = runstate_is_running(); 2343 vdev->broken = false; 2344 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2345 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 2346 vdev->vq[i].vdev = vdev; 2347 vdev->vq[i].queue_index = i; 2348 } 2349 2350 vdev->name = name; 2351 vdev->config_len = config_size; 2352 if (vdev->config_len) { 2353 vdev->config = g_malloc0(config_size); 2354 } else { 2355 vdev->config = NULL; 2356 } 2357 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, 2358 vdev); 2359 vdev->device_endian = virtio_default_endian(); 2360 vdev->use_guest_notifier_mask = true; 2361 } 2362 2363 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 2364 { 2365 return vdev->vq[n].vring.desc; 2366 } 2367 2368 bool virtio_queue_enabled(VirtIODevice *vdev, int n) 2369 { 2370 return virtio_queue_get_desc_addr(vdev, n) != 0; 2371 } 2372 2373 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 2374 { 2375 return vdev->vq[n].vring.avail; 2376 } 2377 2378 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 2379 { 2380 return vdev->vq[n].vring.used; 2381 } 2382 2383 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 2384 { 2385 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 2386 } 2387 2388 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 2389 { 2390 return offsetof(VRingAvail, ring) + 2391 sizeof(uint16_t) * vdev->vq[n].vring.num; 2392 } 2393 2394 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 2395 { 2396 return offsetof(VRingUsed, ring) + 2397 sizeof(VRingUsedElem) * vdev->vq[n].vring.num; 2398 } 2399 2400 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 2401 { 2402 return vdev->vq[n].last_avail_idx; 2403 } 2404 2405 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) 2406 { 2407 vdev->vq[n].last_avail_idx = idx; 2408 vdev->vq[n].shadow_avail_idx = idx; 2409 } 2410 2411 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 2412 { 2413 rcu_read_lock(); 2414 if (vdev->vq[n].vring.desc) { 2415 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 2416 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 2417 } 2418 rcu_read_unlock(); 2419 } 2420 2421 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 2422 { 2423 rcu_read_lock(); 2424 if (vdev->vq[n].vring.desc) { 2425 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 2426 } 2427 rcu_read_unlock(); 2428 } 2429 2430 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 2431 { 2432 vdev->vq[n].signalled_used_valid = false; 2433 } 2434 2435 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 2436 { 2437 return vdev->vq + n; 2438 } 2439 2440 uint16_t virtio_get_queue_index(VirtQueue *vq) 2441 { 2442 return vq->queue_index; 2443 } 2444 2445 static void virtio_queue_guest_notifier_read(EventNotifier *n) 2446 { 2447 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 2448 if (event_notifier_test_and_clear(n)) { 2449 virtio_irq(vq); 2450 } 2451 } 2452 2453 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 2454 bool with_irqfd) 2455 { 2456 if (assign && !with_irqfd) { 2457 event_notifier_set_handler(&vq->guest_notifier, 2458 virtio_queue_guest_notifier_read); 2459 } else { 2460 event_notifier_set_handler(&vq->guest_notifier, NULL); 2461 } 2462 if (!assign) { 2463 /* Test and clear notifier before closing it, 2464 * in case poll callback didn't have time to run. */ 2465 virtio_queue_guest_notifier_read(&vq->guest_notifier); 2466 } 2467 } 2468 2469 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 2470 { 2471 return &vq->guest_notifier; 2472 } 2473 2474 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 2475 { 2476 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2477 if (event_notifier_test_and_clear(n)) { 2478 virtio_queue_notify_aio_vq(vq); 2479 } 2480 } 2481 2482 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 2483 { 2484 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2485 2486 virtio_queue_set_notification(vq, 0); 2487 } 2488 2489 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 2490 { 2491 EventNotifier *n = opaque; 2492 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2493 bool progress; 2494 2495 if (!vq->vring.desc || virtio_queue_empty(vq)) { 2496 return false; 2497 } 2498 2499 progress = virtio_queue_notify_aio_vq(vq); 2500 2501 /* In case the handler function re-enabled notifications */ 2502 virtio_queue_set_notification(vq, 0); 2503 return progress; 2504 } 2505 2506 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 2507 { 2508 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2509 2510 /* Caller polls once more after this to catch requests that race with us */ 2511 virtio_queue_set_notification(vq, 1); 2512 } 2513 2514 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 2515 VirtIOHandleAIOOutput handle_output) 2516 { 2517 if (handle_output) { 2518 vq->handle_aio_output = handle_output; 2519 aio_set_event_notifier(ctx, &vq->host_notifier, true, 2520 virtio_queue_host_notifier_aio_read, 2521 virtio_queue_host_notifier_aio_poll); 2522 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 2523 virtio_queue_host_notifier_aio_poll_begin, 2524 virtio_queue_host_notifier_aio_poll_end); 2525 } else { 2526 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 2527 /* Test and clear notifier before after disabling event, 2528 * in case poll callback didn't have time to run. */ 2529 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 2530 vq->handle_aio_output = NULL; 2531 } 2532 } 2533 2534 void virtio_queue_host_notifier_read(EventNotifier *n) 2535 { 2536 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2537 if (event_notifier_test_and_clear(n)) { 2538 virtio_queue_notify_vq(vq); 2539 } 2540 } 2541 2542 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 2543 { 2544 return &vq->host_notifier; 2545 } 2546 2547 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 2548 MemoryRegion *mr, bool assign) 2549 { 2550 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2551 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2552 2553 if (k->set_host_notifier_mr) { 2554 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 2555 } 2556 2557 return -1; 2558 } 2559 2560 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 2561 { 2562 g_free(vdev->bus_name); 2563 vdev->bus_name = g_strdup(bus_name); 2564 } 2565 2566 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 2567 { 2568 va_list ap; 2569 2570 va_start(ap, fmt); 2571 error_vreport(fmt, ap); 2572 va_end(ap); 2573 2574 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2575 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 2576 virtio_notify_config(vdev); 2577 } 2578 2579 vdev->broken = true; 2580 } 2581 2582 static void virtio_memory_listener_commit(MemoryListener *listener) 2583 { 2584 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 2585 int i; 2586 2587 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2588 if (vdev->vq[i].vring.num == 0) { 2589 break; 2590 } 2591 virtio_init_region_cache(vdev, i); 2592 } 2593 } 2594 2595 static void virtio_device_realize(DeviceState *dev, Error **errp) 2596 { 2597 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2598 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2599 Error *err = NULL; 2600 2601 /* Devices should either use vmsd or the load/save methods */ 2602 assert(!vdc->vmsd || !vdc->load); 2603 2604 if (vdc->realize != NULL) { 2605 vdc->realize(dev, &err); 2606 if (err != NULL) { 2607 error_propagate(errp, err); 2608 return; 2609 } 2610 } 2611 2612 virtio_bus_device_plugged(vdev, &err); 2613 if (err != NULL) { 2614 error_propagate(errp, err); 2615 vdc->unrealize(dev, NULL); 2616 return; 2617 } 2618 2619 vdev->listener.commit = virtio_memory_listener_commit; 2620 memory_listener_register(&vdev->listener, vdev->dma_as); 2621 } 2622 2623 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 2624 { 2625 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2626 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2627 Error *err = NULL; 2628 2629 virtio_bus_device_unplugged(vdev); 2630 2631 if (vdc->unrealize != NULL) { 2632 vdc->unrealize(dev, &err); 2633 if (err != NULL) { 2634 error_propagate(errp, err); 2635 return; 2636 } 2637 } 2638 2639 g_free(vdev->bus_name); 2640 vdev->bus_name = NULL; 2641 } 2642 2643 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 2644 { 2645 int i; 2646 if (!vdev->vq) { 2647 return; 2648 } 2649 2650 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2651 if (vdev->vq[i].vring.num == 0) { 2652 break; 2653 } 2654 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2655 } 2656 g_free(vdev->vq); 2657 } 2658 2659 static void virtio_device_instance_finalize(Object *obj) 2660 { 2661 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 2662 2663 memory_listener_unregister(&vdev->listener); 2664 virtio_device_free_virtqueues(vdev); 2665 2666 g_free(vdev->config); 2667 g_free(vdev->vector_queues); 2668 } 2669 2670 static Property virtio_properties[] = { 2671 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 2672 DEFINE_PROP_END_OF_LIST(), 2673 }; 2674 2675 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 2676 { 2677 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2678 int i, n, r, err; 2679 2680 memory_region_transaction_begin(); 2681 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2682 VirtQueue *vq = &vdev->vq[n]; 2683 if (!virtio_queue_get_num(vdev, n)) { 2684 continue; 2685 } 2686 r = virtio_bus_set_host_notifier(qbus, n, true); 2687 if (r < 0) { 2688 err = r; 2689 goto assign_error; 2690 } 2691 event_notifier_set_handler(&vq->host_notifier, 2692 virtio_queue_host_notifier_read); 2693 } 2694 2695 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2696 /* Kick right away to begin processing requests already in vring */ 2697 VirtQueue *vq = &vdev->vq[n]; 2698 if (!vq->vring.num) { 2699 continue; 2700 } 2701 event_notifier_set(&vq->host_notifier); 2702 } 2703 memory_region_transaction_commit(); 2704 return 0; 2705 2706 assign_error: 2707 i = n; /* save n for a second iteration after transaction is committed. */ 2708 while (--n >= 0) { 2709 VirtQueue *vq = &vdev->vq[n]; 2710 if (!virtio_queue_get_num(vdev, n)) { 2711 continue; 2712 } 2713 2714 event_notifier_set_handler(&vq->host_notifier, NULL); 2715 r = virtio_bus_set_host_notifier(qbus, n, false); 2716 assert(r >= 0); 2717 } 2718 memory_region_transaction_commit(); 2719 2720 while (--i >= 0) { 2721 if (!virtio_queue_get_num(vdev, i)) { 2722 continue; 2723 } 2724 virtio_bus_cleanup_host_notifier(qbus, i); 2725 } 2726 return err; 2727 } 2728 2729 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 2730 { 2731 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2732 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2733 2734 return virtio_bus_start_ioeventfd(vbus); 2735 } 2736 2737 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 2738 { 2739 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2740 int n, r; 2741 2742 memory_region_transaction_begin(); 2743 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2744 VirtQueue *vq = &vdev->vq[n]; 2745 2746 if (!virtio_queue_get_num(vdev, n)) { 2747 continue; 2748 } 2749 event_notifier_set_handler(&vq->host_notifier, NULL); 2750 r = virtio_bus_set_host_notifier(qbus, n, false); 2751 assert(r >= 0); 2752 } 2753 memory_region_transaction_commit(); 2754 2755 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2756 if (!virtio_queue_get_num(vdev, n)) { 2757 continue; 2758 } 2759 virtio_bus_cleanup_host_notifier(qbus, n); 2760 } 2761 } 2762 2763 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) 2764 { 2765 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2766 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2767 2768 virtio_bus_stop_ioeventfd(vbus); 2769 } 2770 2771 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 2772 { 2773 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2774 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2775 2776 return virtio_bus_grab_ioeventfd(vbus); 2777 } 2778 2779 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 2780 { 2781 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2782 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2783 2784 virtio_bus_release_ioeventfd(vbus); 2785 } 2786 2787 static void virtio_device_class_init(ObjectClass *klass, void *data) 2788 { 2789 /* Set the default value here. */ 2790 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 2791 DeviceClass *dc = DEVICE_CLASS(klass); 2792 2793 dc->realize = virtio_device_realize; 2794 dc->unrealize = virtio_device_unrealize; 2795 dc->bus_type = TYPE_VIRTIO_BUS; 2796 dc->props = virtio_properties; 2797 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 2798 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 2799 2800 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 2801 } 2802 2803 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 2804 { 2805 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2806 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2807 2808 return virtio_bus_ioeventfd_enabled(vbus); 2809 } 2810 2811 static const TypeInfo virtio_device_info = { 2812 .name = TYPE_VIRTIO_DEVICE, 2813 .parent = TYPE_DEVICE, 2814 .instance_size = sizeof(VirtIODevice), 2815 .class_init = virtio_device_class_init, 2816 .instance_finalize = virtio_device_instance_finalize, 2817 .abstract = true, 2818 .class_size = sizeof(VirtioDeviceClass), 2819 }; 2820 2821 static void virtio_register_types(void) 2822 { 2823 type_register_static(&virtio_device_info); 2824 } 2825 2826 type_init(virtio_register_types) 2827