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