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 bool virtio_queue_get_notification(VirtQueue *vq) 436 { 437 return vq->notification; 438 } 439 440 void virtio_queue_set_notification(VirtQueue *vq, int enable) 441 { 442 vq->notification = enable; 443 444 if (!vq->vring.desc) { 445 return; 446 } 447 448 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 449 virtio_queue_packed_set_notification(vq, enable); 450 } else { 451 virtio_queue_split_set_notification(vq, enable); 452 } 453 } 454 455 int virtio_queue_ready(VirtQueue *vq) 456 { 457 return vq->vring.avail != 0; 458 } 459 460 static void vring_packed_desc_read_flags(VirtIODevice *vdev, 461 uint16_t *flags, 462 MemoryRegionCache *cache, 463 int i) 464 { 465 address_space_read_cached(cache, 466 i * sizeof(VRingPackedDesc) + 467 offsetof(VRingPackedDesc, flags), 468 flags, sizeof(*flags)); 469 virtio_tswap16s(vdev, flags); 470 } 471 472 static void vring_packed_desc_read(VirtIODevice *vdev, 473 VRingPackedDesc *desc, 474 MemoryRegionCache *cache, 475 int i, bool strict_order) 476 { 477 hwaddr off = i * sizeof(VRingPackedDesc); 478 479 vring_packed_desc_read_flags(vdev, &desc->flags, cache, i); 480 481 if (strict_order) { 482 /* Make sure flags is read before the rest fields. */ 483 smp_rmb(); 484 } 485 486 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, addr), 487 &desc->addr, sizeof(desc->addr)); 488 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, id), 489 &desc->id, sizeof(desc->id)); 490 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, len), 491 &desc->len, sizeof(desc->len)); 492 virtio_tswap64s(vdev, &desc->addr); 493 virtio_tswap16s(vdev, &desc->id); 494 virtio_tswap32s(vdev, &desc->len); 495 } 496 497 static void vring_packed_desc_write_data(VirtIODevice *vdev, 498 VRingPackedDesc *desc, 499 MemoryRegionCache *cache, 500 int i) 501 { 502 hwaddr off_id = i * sizeof(VRingPackedDesc) + 503 offsetof(VRingPackedDesc, id); 504 hwaddr off_len = i * sizeof(VRingPackedDesc) + 505 offsetof(VRingPackedDesc, len); 506 507 virtio_tswap32s(vdev, &desc->len); 508 virtio_tswap16s(vdev, &desc->id); 509 address_space_write_cached(cache, off_id, &desc->id, sizeof(desc->id)); 510 address_space_cache_invalidate(cache, off_id, sizeof(desc->id)); 511 address_space_write_cached(cache, off_len, &desc->len, sizeof(desc->len)); 512 address_space_cache_invalidate(cache, off_len, sizeof(desc->len)); 513 } 514 515 static void vring_packed_desc_write_flags(VirtIODevice *vdev, 516 VRingPackedDesc *desc, 517 MemoryRegionCache *cache, 518 int i) 519 { 520 hwaddr off = i * sizeof(VRingPackedDesc) + offsetof(VRingPackedDesc, flags); 521 522 virtio_tswap16s(vdev, &desc->flags); 523 address_space_write_cached(cache, off, &desc->flags, sizeof(desc->flags)); 524 address_space_cache_invalidate(cache, off, sizeof(desc->flags)); 525 } 526 527 static void vring_packed_desc_write(VirtIODevice *vdev, 528 VRingPackedDesc *desc, 529 MemoryRegionCache *cache, 530 int i, bool strict_order) 531 { 532 vring_packed_desc_write_data(vdev, desc, cache, i); 533 if (strict_order) { 534 /* Make sure data is wrote before flags. */ 535 smp_wmb(); 536 } 537 vring_packed_desc_write_flags(vdev, desc, cache, i); 538 } 539 540 static inline bool is_desc_avail(uint16_t flags, bool wrap_counter) 541 { 542 bool avail, used; 543 544 avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL)); 545 used = !!(flags & (1 << VRING_PACKED_DESC_F_USED)); 546 return (avail != used) && (avail == wrap_counter); 547 } 548 549 /* Fetch avail_idx from VQ memory only when we really need to know if 550 * guest has added some buffers. 551 * Called within rcu_read_lock(). */ 552 static int virtio_queue_empty_rcu(VirtQueue *vq) 553 { 554 if (virtio_device_disabled(vq->vdev)) { 555 return 1; 556 } 557 558 if (unlikely(!vq->vring.avail)) { 559 return 1; 560 } 561 562 if (vq->shadow_avail_idx != vq->last_avail_idx) { 563 return 0; 564 } 565 566 return vring_avail_idx(vq) == vq->last_avail_idx; 567 } 568 569 static int virtio_queue_split_empty(VirtQueue *vq) 570 { 571 bool empty; 572 573 if (virtio_device_disabled(vq->vdev)) { 574 return 1; 575 } 576 577 if (unlikely(!vq->vring.avail)) { 578 return 1; 579 } 580 581 if (vq->shadow_avail_idx != vq->last_avail_idx) { 582 return 0; 583 } 584 585 RCU_READ_LOCK_GUARD(); 586 empty = vring_avail_idx(vq) == vq->last_avail_idx; 587 return empty; 588 } 589 590 static int virtio_queue_packed_empty_rcu(VirtQueue *vq) 591 { 592 struct VRingPackedDesc desc; 593 VRingMemoryRegionCaches *cache; 594 595 if (unlikely(!vq->vring.desc)) { 596 return 1; 597 } 598 599 cache = vring_get_region_caches(vq); 600 vring_packed_desc_read_flags(vq->vdev, &desc.flags, &cache->desc, 601 vq->last_avail_idx); 602 603 return !is_desc_avail(desc.flags, vq->last_avail_wrap_counter); 604 } 605 606 static int virtio_queue_packed_empty(VirtQueue *vq) 607 { 608 RCU_READ_LOCK_GUARD(); 609 return virtio_queue_packed_empty_rcu(vq); 610 } 611 612 int virtio_queue_empty(VirtQueue *vq) 613 { 614 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 615 return virtio_queue_packed_empty(vq); 616 } else { 617 return virtio_queue_split_empty(vq); 618 } 619 } 620 621 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 622 unsigned int len) 623 { 624 AddressSpace *dma_as = vq->vdev->dma_as; 625 unsigned int offset; 626 int i; 627 628 offset = 0; 629 for (i = 0; i < elem->in_num; i++) { 630 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 631 632 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 633 elem->in_sg[i].iov_len, 634 DMA_DIRECTION_FROM_DEVICE, size); 635 636 offset += size; 637 } 638 639 for (i = 0; i < elem->out_num; i++) 640 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 641 elem->out_sg[i].iov_len, 642 DMA_DIRECTION_TO_DEVICE, 643 elem->out_sg[i].iov_len); 644 } 645 646 /* virtqueue_detach_element: 647 * @vq: The #VirtQueue 648 * @elem: The #VirtQueueElement 649 * @len: number of bytes written 650 * 651 * Detach the element from the virtqueue. This function is suitable for device 652 * reset or other situations where a #VirtQueueElement is simply freed and will 653 * not be pushed or discarded. 654 */ 655 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 656 unsigned int len) 657 { 658 vq->inuse -= elem->ndescs; 659 virtqueue_unmap_sg(vq, elem, len); 660 } 661 662 static void virtqueue_split_rewind(VirtQueue *vq, unsigned int num) 663 { 664 vq->last_avail_idx -= num; 665 } 666 667 static void virtqueue_packed_rewind(VirtQueue *vq, unsigned int num) 668 { 669 if (vq->last_avail_idx < num) { 670 vq->last_avail_idx = vq->vring.num + vq->last_avail_idx - num; 671 vq->last_avail_wrap_counter ^= 1; 672 } else { 673 vq->last_avail_idx -= num; 674 } 675 } 676 677 /* virtqueue_unpop: 678 * @vq: The #VirtQueue 679 * @elem: The #VirtQueueElement 680 * @len: number of bytes written 681 * 682 * Pretend the most recent element wasn't popped from the virtqueue. The next 683 * call to virtqueue_pop() will refetch the element. 684 */ 685 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 686 unsigned int len) 687 { 688 689 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 690 virtqueue_packed_rewind(vq, 1); 691 } else { 692 virtqueue_split_rewind(vq, 1); 693 } 694 695 virtqueue_detach_element(vq, elem, len); 696 } 697 698 /* virtqueue_rewind: 699 * @vq: The #VirtQueue 700 * @num: Number of elements to push back 701 * 702 * Pretend that elements weren't popped from the virtqueue. The next 703 * virtqueue_pop() will refetch the oldest element. 704 * 705 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 706 * 707 * Returns: true on success, false if @num is greater than the number of in use 708 * elements. 709 */ 710 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 711 { 712 if (num > vq->inuse) { 713 return false; 714 } 715 716 vq->inuse -= num; 717 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 718 virtqueue_packed_rewind(vq, num); 719 } else { 720 virtqueue_split_rewind(vq, num); 721 } 722 return true; 723 } 724 725 static void virtqueue_split_fill(VirtQueue *vq, const VirtQueueElement *elem, 726 unsigned int len, unsigned int idx) 727 { 728 VRingUsedElem uelem; 729 730 if (unlikely(!vq->vring.used)) { 731 return; 732 } 733 734 idx = (idx + vq->used_idx) % vq->vring.num; 735 736 uelem.id = elem->index; 737 uelem.len = len; 738 vring_used_write(vq, &uelem, idx); 739 } 740 741 static void virtqueue_packed_fill(VirtQueue *vq, const VirtQueueElement *elem, 742 unsigned int len, unsigned int idx) 743 { 744 vq->used_elems[idx].index = elem->index; 745 vq->used_elems[idx].len = len; 746 vq->used_elems[idx].ndescs = elem->ndescs; 747 } 748 749 static void virtqueue_packed_fill_desc(VirtQueue *vq, 750 const VirtQueueElement *elem, 751 unsigned int idx, 752 bool strict_order) 753 { 754 uint16_t head; 755 VRingMemoryRegionCaches *caches; 756 VRingPackedDesc desc = { 757 .id = elem->index, 758 .len = elem->len, 759 }; 760 bool wrap_counter = vq->used_wrap_counter; 761 762 if (unlikely(!vq->vring.desc)) { 763 return; 764 } 765 766 head = vq->used_idx + idx; 767 if (head >= vq->vring.num) { 768 head -= vq->vring.num; 769 wrap_counter ^= 1; 770 } 771 if (wrap_counter) { 772 desc.flags |= (1 << VRING_PACKED_DESC_F_AVAIL); 773 desc.flags |= (1 << VRING_PACKED_DESC_F_USED); 774 } else { 775 desc.flags &= ~(1 << VRING_PACKED_DESC_F_AVAIL); 776 desc.flags &= ~(1 << VRING_PACKED_DESC_F_USED); 777 } 778 779 caches = vring_get_region_caches(vq); 780 vring_packed_desc_write(vq->vdev, &desc, &caches->desc, head, strict_order); 781 } 782 783 /* Called within rcu_read_lock(). */ 784 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 785 unsigned int len, unsigned int idx) 786 { 787 trace_virtqueue_fill(vq, elem, len, idx); 788 789 virtqueue_unmap_sg(vq, elem, len); 790 791 if (virtio_device_disabled(vq->vdev)) { 792 return; 793 } 794 795 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 796 virtqueue_packed_fill(vq, elem, len, idx); 797 } else { 798 virtqueue_split_fill(vq, elem, len, idx); 799 } 800 } 801 802 /* Called within rcu_read_lock(). */ 803 static void virtqueue_split_flush(VirtQueue *vq, unsigned int count) 804 { 805 uint16_t old, new; 806 807 if (unlikely(!vq->vring.used)) { 808 return; 809 } 810 811 /* Make sure buffer is written before we update index. */ 812 smp_wmb(); 813 trace_virtqueue_flush(vq, count); 814 old = vq->used_idx; 815 new = old + count; 816 vring_used_idx_set(vq, new); 817 vq->inuse -= count; 818 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 819 vq->signalled_used_valid = false; 820 } 821 822 static void virtqueue_packed_flush(VirtQueue *vq, unsigned int count) 823 { 824 unsigned int i, ndescs = 0; 825 826 if (unlikely(!vq->vring.desc)) { 827 return; 828 } 829 830 for (i = 1; i < count; i++) { 831 virtqueue_packed_fill_desc(vq, &vq->used_elems[i], i, false); 832 ndescs += vq->used_elems[i].ndescs; 833 } 834 virtqueue_packed_fill_desc(vq, &vq->used_elems[0], 0, true); 835 ndescs += vq->used_elems[0].ndescs; 836 837 vq->inuse -= ndescs; 838 vq->used_idx += ndescs; 839 if (vq->used_idx >= vq->vring.num) { 840 vq->used_idx -= vq->vring.num; 841 vq->used_wrap_counter ^= 1; 842 } 843 } 844 845 void virtqueue_flush(VirtQueue *vq, unsigned int count) 846 { 847 if (virtio_device_disabled(vq->vdev)) { 848 vq->inuse -= count; 849 return; 850 } 851 852 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 853 virtqueue_packed_flush(vq, count); 854 } else { 855 virtqueue_split_flush(vq, count); 856 } 857 } 858 859 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 860 unsigned int len) 861 { 862 RCU_READ_LOCK_GUARD(); 863 virtqueue_fill(vq, elem, len, 0); 864 virtqueue_flush(vq, 1); 865 } 866 867 /* Called within rcu_read_lock(). */ 868 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 869 { 870 uint16_t num_heads = vring_avail_idx(vq) - idx; 871 872 /* Check it isn't doing very strange things with descriptor numbers. */ 873 if (num_heads > vq->vring.num) { 874 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 875 idx, vq->shadow_avail_idx); 876 return -EINVAL; 877 } 878 /* On success, callers read a descriptor at vq->last_avail_idx. 879 * Make sure descriptor read does not bypass avail index read. */ 880 if (num_heads) { 881 smp_rmb(); 882 } 883 884 return num_heads; 885 } 886 887 /* Called within rcu_read_lock(). */ 888 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 889 unsigned int *head) 890 { 891 /* Grab the next descriptor number they're advertising, and increment 892 * the index we've seen. */ 893 *head = vring_avail_ring(vq, idx % vq->vring.num); 894 895 /* If their number is silly, that's a fatal mistake. */ 896 if (*head >= vq->vring.num) { 897 virtio_error(vq->vdev, "Guest says index %u is available", *head); 898 return false; 899 } 900 901 return true; 902 } 903 904 enum { 905 VIRTQUEUE_READ_DESC_ERROR = -1, 906 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 907 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 908 }; 909 910 static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 911 MemoryRegionCache *desc_cache, 912 unsigned int max, unsigned int *next) 913 { 914 /* If this descriptor says it doesn't chain, we're done. */ 915 if (!(desc->flags & VRING_DESC_F_NEXT)) { 916 return VIRTQUEUE_READ_DESC_DONE; 917 } 918 919 /* Check they're not leading us off end of descriptors. */ 920 *next = desc->next; 921 /* Make sure compiler knows to grab that: we don't want it changing! */ 922 smp_wmb(); 923 924 if (*next >= max) { 925 virtio_error(vdev, "Desc next is %u", *next); 926 return VIRTQUEUE_READ_DESC_ERROR; 927 } 928 929 vring_split_desc_read(vdev, desc, desc_cache, *next); 930 return VIRTQUEUE_READ_DESC_MORE; 931 } 932 933 static void virtqueue_split_get_avail_bytes(VirtQueue *vq, 934 unsigned int *in_bytes, unsigned int *out_bytes, 935 unsigned max_in_bytes, unsigned max_out_bytes) 936 { 937 VirtIODevice *vdev = vq->vdev; 938 unsigned int max, idx; 939 unsigned int total_bufs, in_total, out_total; 940 VRingMemoryRegionCaches *caches; 941 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 942 int64_t len = 0; 943 int rc; 944 945 RCU_READ_LOCK_GUARD(); 946 947 idx = vq->last_avail_idx; 948 total_bufs = in_total = out_total = 0; 949 950 max = vq->vring.num; 951 caches = vring_get_region_caches(vq); 952 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 953 MemoryRegionCache *desc_cache = &caches->desc; 954 unsigned int num_bufs; 955 VRingDesc desc; 956 unsigned int i; 957 958 num_bufs = total_bufs; 959 960 if (!virtqueue_get_head(vq, idx++, &i)) { 961 goto err; 962 } 963 964 vring_split_desc_read(vdev, &desc, desc_cache, i); 965 966 if (desc.flags & VRING_DESC_F_INDIRECT) { 967 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 968 virtio_error(vdev, "Invalid size for indirect buffer table"); 969 goto err; 970 } 971 972 /* If we've got too many, that implies a descriptor loop. */ 973 if (num_bufs >= max) { 974 virtio_error(vdev, "Looped descriptor"); 975 goto err; 976 } 977 978 /* loop over the indirect descriptor table */ 979 len = address_space_cache_init(&indirect_desc_cache, 980 vdev->dma_as, 981 desc.addr, desc.len, false); 982 desc_cache = &indirect_desc_cache; 983 if (len < desc.len) { 984 virtio_error(vdev, "Cannot map indirect buffer"); 985 goto err; 986 } 987 988 max = desc.len / sizeof(VRingDesc); 989 num_bufs = i = 0; 990 vring_split_desc_read(vdev, &desc, desc_cache, i); 991 } 992 993 do { 994 /* If we've got too many, that implies a descriptor loop. */ 995 if (++num_bufs > max) { 996 virtio_error(vdev, "Looped descriptor"); 997 goto err; 998 } 999 1000 if (desc.flags & VRING_DESC_F_WRITE) { 1001 in_total += desc.len; 1002 } else { 1003 out_total += desc.len; 1004 } 1005 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1006 goto done; 1007 } 1008 1009 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); 1010 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1011 1012 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1013 goto err; 1014 } 1015 1016 if (desc_cache == &indirect_desc_cache) { 1017 address_space_cache_destroy(&indirect_desc_cache); 1018 total_bufs++; 1019 } else { 1020 total_bufs = num_bufs; 1021 } 1022 } 1023 1024 if (rc < 0) { 1025 goto err; 1026 } 1027 1028 done: 1029 address_space_cache_destroy(&indirect_desc_cache); 1030 if (in_bytes) { 1031 *in_bytes = in_total; 1032 } 1033 if (out_bytes) { 1034 *out_bytes = out_total; 1035 } 1036 return; 1037 1038 err: 1039 in_total = out_total = 0; 1040 goto done; 1041 } 1042 1043 static int virtqueue_packed_read_next_desc(VirtQueue *vq, 1044 VRingPackedDesc *desc, 1045 MemoryRegionCache 1046 *desc_cache, 1047 unsigned int max, 1048 unsigned int *next, 1049 bool indirect) 1050 { 1051 /* If this descriptor says it doesn't chain, we're done. */ 1052 if (!indirect && !(desc->flags & VRING_DESC_F_NEXT)) { 1053 return VIRTQUEUE_READ_DESC_DONE; 1054 } 1055 1056 ++*next; 1057 if (*next == max) { 1058 if (indirect) { 1059 return VIRTQUEUE_READ_DESC_DONE; 1060 } else { 1061 (*next) -= vq->vring.num; 1062 } 1063 } 1064 1065 vring_packed_desc_read(vq->vdev, desc, desc_cache, *next, false); 1066 return VIRTQUEUE_READ_DESC_MORE; 1067 } 1068 1069 static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, 1070 unsigned int *in_bytes, 1071 unsigned int *out_bytes, 1072 unsigned max_in_bytes, 1073 unsigned max_out_bytes) 1074 { 1075 VirtIODevice *vdev = vq->vdev; 1076 unsigned int max, idx; 1077 unsigned int total_bufs, in_total, out_total; 1078 MemoryRegionCache *desc_cache; 1079 VRingMemoryRegionCaches *caches; 1080 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1081 int64_t len = 0; 1082 VRingPackedDesc desc; 1083 bool wrap_counter; 1084 1085 RCU_READ_LOCK_GUARD(); 1086 idx = vq->last_avail_idx; 1087 wrap_counter = vq->last_avail_wrap_counter; 1088 total_bufs = in_total = out_total = 0; 1089 1090 max = vq->vring.num; 1091 caches = vring_get_region_caches(vq); 1092 1093 for (;;) { 1094 unsigned int num_bufs = total_bufs; 1095 unsigned int i = idx; 1096 int rc; 1097 1098 desc_cache = &caches->desc; 1099 vring_packed_desc_read(vdev, &desc, desc_cache, idx, true); 1100 if (!is_desc_avail(desc.flags, wrap_counter)) { 1101 break; 1102 } 1103 1104 if (desc.flags & VRING_DESC_F_INDIRECT) { 1105 if (desc.len % sizeof(VRingPackedDesc)) { 1106 virtio_error(vdev, "Invalid size for indirect buffer table"); 1107 goto err; 1108 } 1109 1110 /* If we've got too many, that implies a descriptor loop. */ 1111 if (num_bufs >= max) { 1112 virtio_error(vdev, "Looped descriptor"); 1113 goto err; 1114 } 1115 1116 /* loop over the indirect descriptor table */ 1117 len = address_space_cache_init(&indirect_desc_cache, 1118 vdev->dma_as, 1119 desc.addr, desc.len, false); 1120 desc_cache = &indirect_desc_cache; 1121 if (len < desc.len) { 1122 virtio_error(vdev, "Cannot map indirect buffer"); 1123 goto err; 1124 } 1125 1126 max = desc.len / sizeof(VRingPackedDesc); 1127 num_bufs = i = 0; 1128 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1129 } 1130 1131 do { 1132 /* If we've got too many, that implies a descriptor loop. */ 1133 if (++num_bufs > max) { 1134 virtio_error(vdev, "Looped descriptor"); 1135 goto err; 1136 } 1137 1138 if (desc.flags & VRING_DESC_F_WRITE) { 1139 in_total += desc.len; 1140 } else { 1141 out_total += desc.len; 1142 } 1143 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1144 goto done; 1145 } 1146 1147 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, 1148 &i, desc_cache == 1149 &indirect_desc_cache); 1150 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1151 1152 if (desc_cache == &indirect_desc_cache) { 1153 address_space_cache_destroy(&indirect_desc_cache); 1154 total_bufs++; 1155 idx++; 1156 } else { 1157 idx += num_bufs - total_bufs; 1158 total_bufs = num_bufs; 1159 } 1160 1161 if (idx >= vq->vring.num) { 1162 idx -= vq->vring.num; 1163 wrap_counter ^= 1; 1164 } 1165 } 1166 1167 /* Record the index and wrap counter for a kick we want */ 1168 vq->shadow_avail_idx = idx; 1169 vq->shadow_avail_wrap_counter = wrap_counter; 1170 done: 1171 address_space_cache_destroy(&indirect_desc_cache); 1172 if (in_bytes) { 1173 *in_bytes = in_total; 1174 } 1175 if (out_bytes) { 1176 *out_bytes = out_total; 1177 } 1178 return; 1179 1180 err: 1181 in_total = out_total = 0; 1182 goto done; 1183 } 1184 1185 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 1186 unsigned int *out_bytes, 1187 unsigned max_in_bytes, unsigned max_out_bytes) 1188 { 1189 uint16_t desc_size; 1190 VRingMemoryRegionCaches *caches; 1191 1192 if (unlikely(!vq->vring.desc)) { 1193 goto err; 1194 } 1195 1196 caches = vring_get_region_caches(vq); 1197 desc_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ? 1198 sizeof(VRingPackedDesc) : sizeof(VRingDesc); 1199 if (caches->desc.len < vq->vring.num * desc_size) { 1200 virtio_error(vq->vdev, "Cannot map descriptor ring"); 1201 goto err; 1202 } 1203 1204 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1205 virtqueue_packed_get_avail_bytes(vq, in_bytes, out_bytes, 1206 max_in_bytes, max_out_bytes); 1207 } else { 1208 virtqueue_split_get_avail_bytes(vq, in_bytes, out_bytes, 1209 max_in_bytes, max_out_bytes); 1210 } 1211 1212 return; 1213 err: 1214 if (in_bytes) { 1215 *in_bytes = 0; 1216 } 1217 if (out_bytes) { 1218 *out_bytes = 0; 1219 } 1220 } 1221 1222 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 1223 unsigned int out_bytes) 1224 { 1225 unsigned int in_total, out_total; 1226 1227 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 1228 return in_bytes <= in_total && out_bytes <= out_total; 1229 } 1230 1231 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 1232 hwaddr *addr, struct iovec *iov, 1233 unsigned int max_num_sg, bool is_write, 1234 hwaddr pa, size_t sz) 1235 { 1236 bool ok = false; 1237 unsigned num_sg = *p_num_sg; 1238 assert(num_sg <= max_num_sg); 1239 1240 if (!sz) { 1241 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 1242 goto out; 1243 } 1244 1245 while (sz) { 1246 hwaddr len = sz; 1247 1248 if (num_sg == max_num_sg) { 1249 virtio_error(vdev, "virtio: too many write descriptors in " 1250 "indirect table"); 1251 goto out; 1252 } 1253 1254 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 1255 is_write ? 1256 DMA_DIRECTION_FROM_DEVICE : 1257 DMA_DIRECTION_TO_DEVICE); 1258 if (!iov[num_sg].iov_base) { 1259 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 1260 goto out; 1261 } 1262 1263 iov[num_sg].iov_len = len; 1264 addr[num_sg] = pa; 1265 1266 sz -= len; 1267 pa += len; 1268 num_sg++; 1269 } 1270 ok = true; 1271 1272 out: 1273 *p_num_sg = num_sg; 1274 return ok; 1275 } 1276 1277 /* Only used by error code paths before we have a VirtQueueElement (therefore 1278 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 1279 * yet. 1280 */ 1281 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 1282 struct iovec *iov) 1283 { 1284 unsigned int i; 1285 1286 for (i = 0; i < out_num + in_num; i++) { 1287 int is_write = i >= out_num; 1288 1289 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 1290 iov++; 1291 } 1292 } 1293 1294 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 1295 hwaddr *addr, unsigned int num_sg, 1296 int is_write) 1297 { 1298 unsigned int i; 1299 hwaddr len; 1300 1301 for (i = 0; i < num_sg; i++) { 1302 len = sg[i].iov_len; 1303 sg[i].iov_base = dma_memory_map(vdev->dma_as, 1304 addr[i], &len, is_write ? 1305 DMA_DIRECTION_FROM_DEVICE : 1306 DMA_DIRECTION_TO_DEVICE); 1307 if (!sg[i].iov_base) { 1308 error_report("virtio: error trying to map MMIO memory"); 1309 exit(1); 1310 } 1311 if (len != sg[i].iov_len) { 1312 error_report("virtio: unexpected memory split"); 1313 exit(1); 1314 } 1315 } 1316 } 1317 1318 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 1319 { 1320 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, 1); 1321 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 0); 1322 } 1323 1324 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 1325 { 1326 VirtQueueElement *elem; 1327 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 1328 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 1329 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 1330 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 1331 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 1332 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 1333 1334 assert(sz >= sizeof(VirtQueueElement)); 1335 elem = g_malloc(out_sg_end); 1336 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 1337 elem->out_num = out_num; 1338 elem->in_num = in_num; 1339 elem->in_addr = (void *)elem + in_addr_ofs; 1340 elem->out_addr = (void *)elem + out_addr_ofs; 1341 elem->in_sg = (void *)elem + in_sg_ofs; 1342 elem->out_sg = (void *)elem + out_sg_ofs; 1343 return elem; 1344 } 1345 1346 static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) 1347 { 1348 unsigned int i, head, max; 1349 VRingMemoryRegionCaches *caches; 1350 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1351 MemoryRegionCache *desc_cache; 1352 int64_t len; 1353 VirtIODevice *vdev = vq->vdev; 1354 VirtQueueElement *elem = NULL; 1355 unsigned out_num, in_num, elem_entries; 1356 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1357 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1358 VRingDesc desc; 1359 int rc; 1360 1361 RCU_READ_LOCK_GUARD(); 1362 if (virtio_queue_empty_rcu(vq)) { 1363 goto done; 1364 } 1365 /* Needed after virtio_queue_empty(), see comment in 1366 * virtqueue_num_heads(). */ 1367 smp_rmb(); 1368 1369 /* When we start there are none of either input nor output. */ 1370 out_num = in_num = elem_entries = 0; 1371 1372 max = vq->vring.num; 1373 1374 if (vq->inuse >= vq->vring.num) { 1375 virtio_error(vdev, "Virtqueue size exceeded"); 1376 goto done; 1377 } 1378 1379 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 1380 goto done; 1381 } 1382 1383 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1384 vring_set_avail_event(vq, vq->last_avail_idx); 1385 } 1386 1387 i = head; 1388 1389 caches = vring_get_region_caches(vq); 1390 if (caches->desc.len < max * sizeof(VRingDesc)) { 1391 virtio_error(vdev, "Cannot map descriptor ring"); 1392 goto done; 1393 } 1394 1395 desc_cache = &caches->desc; 1396 vring_split_desc_read(vdev, &desc, desc_cache, i); 1397 if (desc.flags & VRING_DESC_F_INDIRECT) { 1398 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1399 virtio_error(vdev, "Invalid size for indirect buffer table"); 1400 goto done; 1401 } 1402 1403 /* loop over the indirect descriptor table */ 1404 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1405 desc.addr, desc.len, false); 1406 desc_cache = &indirect_desc_cache; 1407 if (len < desc.len) { 1408 virtio_error(vdev, "Cannot map indirect buffer"); 1409 goto done; 1410 } 1411 1412 max = desc.len / sizeof(VRingDesc); 1413 i = 0; 1414 vring_split_desc_read(vdev, &desc, desc_cache, i); 1415 } 1416 1417 /* Collect all the descriptors */ 1418 do { 1419 bool map_ok; 1420 1421 if (desc.flags & VRING_DESC_F_WRITE) { 1422 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1423 iov + out_num, 1424 VIRTQUEUE_MAX_SIZE - out_num, true, 1425 desc.addr, desc.len); 1426 } else { 1427 if (in_num) { 1428 virtio_error(vdev, "Incorrect order for descriptors"); 1429 goto err_undo_map; 1430 } 1431 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1432 VIRTQUEUE_MAX_SIZE, false, 1433 desc.addr, desc.len); 1434 } 1435 if (!map_ok) { 1436 goto err_undo_map; 1437 } 1438 1439 /* If we've got too many, that implies a descriptor loop. */ 1440 if (++elem_entries > max) { 1441 virtio_error(vdev, "Looped descriptor"); 1442 goto err_undo_map; 1443 } 1444 1445 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); 1446 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1447 1448 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1449 goto err_undo_map; 1450 } 1451 1452 /* Now copy what we have collected and mapped */ 1453 elem = virtqueue_alloc_element(sz, out_num, in_num); 1454 elem->index = head; 1455 elem->ndescs = 1; 1456 for (i = 0; i < out_num; i++) { 1457 elem->out_addr[i] = addr[i]; 1458 elem->out_sg[i] = iov[i]; 1459 } 1460 for (i = 0; i < in_num; i++) { 1461 elem->in_addr[i] = addr[out_num + i]; 1462 elem->in_sg[i] = iov[out_num + i]; 1463 } 1464 1465 vq->inuse++; 1466 1467 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1468 done: 1469 address_space_cache_destroy(&indirect_desc_cache); 1470 1471 return elem; 1472 1473 err_undo_map: 1474 virtqueue_undo_map_desc(out_num, in_num, iov); 1475 goto done; 1476 } 1477 1478 static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) 1479 { 1480 unsigned int i, max; 1481 VRingMemoryRegionCaches *caches; 1482 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1483 MemoryRegionCache *desc_cache; 1484 int64_t len; 1485 VirtIODevice *vdev = vq->vdev; 1486 VirtQueueElement *elem = NULL; 1487 unsigned out_num, in_num, elem_entries; 1488 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1489 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1490 VRingPackedDesc desc; 1491 uint16_t id; 1492 int rc; 1493 1494 RCU_READ_LOCK_GUARD(); 1495 if (virtio_queue_packed_empty_rcu(vq)) { 1496 goto done; 1497 } 1498 1499 /* When we start there are none of either input nor output. */ 1500 out_num = in_num = elem_entries = 0; 1501 1502 max = vq->vring.num; 1503 1504 if (vq->inuse >= vq->vring.num) { 1505 virtio_error(vdev, "Virtqueue size exceeded"); 1506 goto done; 1507 } 1508 1509 i = vq->last_avail_idx; 1510 1511 caches = vring_get_region_caches(vq); 1512 if (caches->desc.len < max * sizeof(VRingDesc)) { 1513 virtio_error(vdev, "Cannot map descriptor ring"); 1514 goto done; 1515 } 1516 1517 desc_cache = &caches->desc; 1518 vring_packed_desc_read(vdev, &desc, desc_cache, i, true); 1519 id = desc.id; 1520 if (desc.flags & VRING_DESC_F_INDIRECT) { 1521 if (desc.len % sizeof(VRingPackedDesc)) { 1522 virtio_error(vdev, "Invalid size for indirect buffer table"); 1523 goto done; 1524 } 1525 1526 /* loop over the indirect descriptor table */ 1527 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1528 desc.addr, desc.len, false); 1529 desc_cache = &indirect_desc_cache; 1530 if (len < desc.len) { 1531 virtio_error(vdev, "Cannot map indirect buffer"); 1532 goto done; 1533 } 1534 1535 max = desc.len / sizeof(VRingPackedDesc); 1536 i = 0; 1537 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1538 } 1539 1540 /* Collect all the descriptors */ 1541 do { 1542 bool map_ok; 1543 1544 if (desc.flags & VRING_DESC_F_WRITE) { 1545 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1546 iov + out_num, 1547 VIRTQUEUE_MAX_SIZE - out_num, true, 1548 desc.addr, desc.len); 1549 } else { 1550 if (in_num) { 1551 virtio_error(vdev, "Incorrect order for descriptors"); 1552 goto err_undo_map; 1553 } 1554 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1555 VIRTQUEUE_MAX_SIZE, false, 1556 desc.addr, desc.len); 1557 } 1558 if (!map_ok) { 1559 goto err_undo_map; 1560 } 1561 1562 /* If we've got too many, that implies a descriptor loop. */ 1563 if (++elem_entries > max) { 1564 virtio_error(vdev, "Looped descriptor"); 1565 goto err_undo_map; 1566 } 1567 1568 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, &i, 1569 desc_cache == 1570 &indirect_desc_cache); 1571 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1572 1573 /* Now copy what we have collected and mapped */ 1574 elem = virtqueue_alloc_element(sz, out_num, in_num); 1575 for (i = 0; i < out_num; i++) { 1576 elem->out_addr[i] = addr[i]; 1577 elem->out_sg[i] = iov[i]; 1578 } 1579 for (i = 0; i < in_num; i++) { 1580 elem->in_addr[i] = addr[out_num + i]; 1581 elem->in_sg[i] = iov[out_num + i]; 1582 } 1583 1584 elem->index = id; 1585 elem->ndescs = (desc_cache == &indirect_desc_cache) ? 1 : elem_entries; 1586 vq->last_avail_idx += elem->ndescs; 1587 vq->inuse += elem->ndescs; 1588 1589 if (vq->last_avail_idx >= vq->vring.num) { 1590 vq->last_avail_idx -= vq->vring.num; 1591 vq->last_avail_wrap_counter ^= 1; 1592 } 1593 1594 vq->shadow_avail_idx = vq->last_avail_idx; 1595 vq->shadow_avail_wrap_counter = vq->last_avail_wrap_counter; 1596 1597 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1598 done: 1599 address_space_cache_destroy(&indirect_desc_cache); 1600 1601 return elem; 1602 1603 err_undo_map: 1604 virtqueue_undo_map_desc(out_num, in_num, iov); 1605 goto done; 1606 } 1607 1608 void *virtqueue_pop(VirtQueue *vq, size_t sz) 1609 { 1610 if (virtio_device_disabled(vq->vdev)) { 1611 return NULL; 1612 } 1613 1614 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1615 return virtqueue_packed_pop(vq, sz); 1616 } else { 1617 return virtqueue_split_pop(vq, sz); 1618 } 1619 } 1620 1621 static unsigned int virtqueue_packed_drop_all(VirtQueue *vq) 1622 { 1623 VRingMemoryRegionCaches *caches; 1624 MemoryRegionCache *desc_cache; 1625 unsigned int dropped = 0; 1626 VirtQueueElement elem = {}; 1627 VirtIODevice *vdev = vq->vdev; 1628 VRingPackedDesc desc; 1629 1630 caches = vring_get_region_caches(vq); 1631 desc_cache = &caches->desc; 1632 1633 virtio_queue_set_notification(vq, 0); 1634 1635 while (vq->inuse < vq->vring.num) { 1636 unsigned int idx = vq->last_avail_idx; 1637 /* 1638 * works similar to virtqueue_pop but does not map buffers 1639 * and does not allocate any memory. 1640 */ 1641 vring_packed_desc_read(vdev, &desc, desc_cache, 1642 vq->last_avail_idx , true); 1643 if (!is_desc_avail(desc.flags, vq->last_avail_wrap_counter)) { 1644 break; 1645 } 1646 elem.index = desc.id; 1647 elem.ndescs = 1; 1648 while (virtqueue_packed_read_next_desc(vq, &desc, desc_cache, 1649 vq->vring.num, &idx, false)) { 1650 ++elem.ndescs; 1651 } 1652 /* 1653 * immediately push the element, nothing to unmap 1654 * as both in_num and out_num are set to 0. 1655 */ 1656 virtqueue_push(vq, &elem, 0); 1657 dropped++; 1658 vq->last_avail_idx += elem.ndescs; 1659 if (vq->last_avail_idx >= vq->vring.num) { 1660 vq->last_avail_idx -= vq->vring.num; 1661 vq->last_avail_wrap_counter ^= 1; 1662 } 1663 } 1664 1665 return dropped; 1666 } 1667 1668 static unsigned int virtqueue_split_drop_all(VirtQueue *vq) 1669 { 1670 unsigned int dropped = 0; 1671 VirtQueueElement elem = {}; 1672 VirtIODevice *vdev = vq->vdev; 1673 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 1674 1675 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 1676 /* works similar to virtqueue_pop but does not map buffers 1677 * and does not allocate any memory */ 1678 smp_rmb(); 1679 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 1680 break; 1681 } 1682 vq->inuse++; 1683 vq->last_avail_idx++; 1684 if (fEventIdx) { 1685 vring_set_avail_event(vq, vq->last_avail_idx); 1686 } 1687 /* immediately push the element, nothing to unmap 1688 * as both in_num and out_num are set to 0 */ 1689 virtqueue_push(vq, &elem, 0); 1690 dropped++; 1691 } 1692 1693 return dropped; 1694 } 1695 1696 /* virtqueue_drop_all: 1697 * @vq: The #VirtQueue 1698 * Drops all queued buffers and indicates them to the guest 1699 * as if they are done. Useful when buffers can not be 1700 * processed but must be returned to the guest. 1701 */ 1702 unsigned int virtqueue_drop_all(VirtQueue *vq) 1703 { 1704 struct VirtIODevice *vdev = vq->vdev; 1705 1706 if (virtio_device_disabled(vq->vdev)) { 1707 return 0; 1708 } 1709 1710 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1711 return virtqueue_packed_drop_all(vq); 1712 } else { 1713 return virtqueue_split_drop_all(vq); 1714 } 1715 } 1716 1717 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1718 * it is what QEMU has always done by mistake. We can change it sooner 1719 * or later by bumping the version number of the affected vm states. 1720 * In the meanwhile, since the in-memory layout of VirtQueueElement 1721 * has changed, we need to marshal to and from the layout that was 1722 * used before the change. 1723 */ 1724 typedef struct VirtQueueElementOld { 1725 unsigned int index; 1726 unsigned int out_num; 1727 unsigned int in_num; 1728 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1729 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1730 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1731 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1732 } VirtQueueElementOld; 1733 1734 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1735 { 1736 VirtQueueElement *elem; 1737 VirtQueueElementOld data; 1738 int i; 1739 1740 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1741 1742 /* TODO: teach all callers that this can fail, and return failure instead 1743 * of asserting here. 1744 * This is just one thing (there are probably more) that must be 1745 * fixed before we can allow NDEBUG compilation. 1746 */ 1747 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1748 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1749 1750 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1751 elem->index = data.index; 1752 1753 for (i = 0; i < elem->in_num; i++) { 1754 elem->in_addr[i] = data.in_addr[i]; 1755 } 1756 1757 for (i = 0; i < elem->out_num; i++) { 1758 elem->out_addr[i] = data.out_addr[i]; 1759 } 1760 1761 for (i = 0; i < elem->in_num; i++) { 1762 /* Base is overwritten by virtqueue_map. */ 1763 elem->in_sg[i].iov_base = 0; 1764 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1765 } 1766 1767 for (i = 0; i < elem->out_num; i++) { 1768 /* Base is overwritten by virtqueue_map. */ 1769 elem->out_sg[i].iov_base = 0; 1770 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1771 } 1772 1773 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1774 qemu_get_be32s(f, &elem->ndescs); 1775 } 1776 1777 virtqueue_map(vdev, elem); 1778 return elem; 1779 } 1780 1781 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 1782 VirtQueueElement *elem) 1783 { 1784 VirtQueueElementOld data; 1785 int i; 1786 1787 memset(&data, 0, sizeof(data)); 1788 data.index = elem->index; 1789 data.in_num = elem->in_num; 1790 data.out_num = elem->out_num; 1791 1792 for (i = 0; i < elem->in_num; i++) { 1793 data.in_addr[i] = elem->in_addr[i]; 1794 } 1795 1796 for (i = 0; i < elem->out_num; i++) { 1797 data.out_addr[i] = elem->out_addr[i]; 1798 } 1799 1800 for (i = 0; i < elem->in_num; i++) { 1801 /* Base is overwritten by virtqueue_map when loading. Do not 1802 * save it, as it would leak the QEMU address space layout. */ 1803 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1804 } 1805 1806 for (i = 0; i < elem->out_num; i++) { 1807 /* Do not save iov_base as above. */ 1808 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1809 } 1810 1811 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1812 qemu_put_be32s(f, &elem->ndescs); 1813 } 1814 1815 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1816 } 1817 1818 /* virtio device */ 1819 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1820 { 1821 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1822 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1823 1824 if (virtio_device_disabled(vdev)) { 1825 return; 1826 } 1827 1828 if (k->notify) { 1829 k->notify(qbus->parent, vector); 1830 } 1831 } 1832 1833 void virtio_update_irq(VirtIODevice *vdev) 1834 { 1835 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1836 } 1837 1838 static int virtio_validate_features(VirtIODevice *vdev) 1839 { 1840 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1841 1842 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 1843 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 1844 return -EFAULT; 1845 } 1846 1847 if (k->validate_features) { 1848 return k->validate_features(vdev); 1849 } else { 1850 return 0; 1851 } 1852 } 1853 1854 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 1855 { 1856 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1857 trace_virtio_set_status(vdev, val); 1858 1859 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1860 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 1861 val & VIRTIO_CONFIG_S_FEATURES_OK) { 1862 int ret = virtio_validate_features(vdev); 1863 1864 if (ret) { 1865 return ret; 1866 } 1867 } 1868 } 1869 1870 if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) != 1871 (val & VIRTIO_CONFIG_S_DRIVER_OK)) { 1872 virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK); 1873 } 1874 1875 if (k->set_status) { 1876 k->set_status(vdev, val); 1877 } 1878 vdev->status = val; 1879 1880 return 0; 1881 } 1882 1883 static enum virtio_device_endian virtio_default_endian(void) 1884 { 1885 if (target_words_bigendian()) { 1886 return VIRTIO_DEVICE_ENDIAN_BIG; 1887 } else { 1888 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1889 } 1890 } 1891 1892 static enum virtio_device_endian virtio_current_cpu_endian(void) 1893 { 1894 CPUClass *cc = CPU_GET_CLASS(current_cpu); 1895 1896 if (cc->virtio_is_big_endian(current_cpu)) { 1897 return VIRTIO_DEVICE_ENDIAN_BIG; 1898 } else { 1899 return VIRTIO_DEVICE_ENDIAN_LITTLE; 1900 } 1901 } 1902 1903 void virtio_reset(void *opaque) 1904 { 1905 VirtIODevice *vdev = opaque; 1906 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1907 int i; 1908 1909 virtio_set_status(vdev, 0); 1910 if (current_cpu) { 1911 /* Guest initiated reset */ 1912 vdev->device_endian = virtio_current_cpu_endian(); 1913 } else { 1914 /* System reset */ 1915 vdev->device_endian = virtio_default_endian(); 1916 } 1917 1918 if (k->reset) { 1919 k->reset(vdev); 1920 } 1921 1922 vdev->start_on_kick = false; 1923 vdev->started = false; 1924 vdev->broken = false; 1925 vdev->guest_features = 0; 1926 vdev->queue_sel = 0; 1927 vdev->status = 0; 1928 vdev->disabled = false; 1929 atomic_set(&vdev->isr, 0); 1930 vdev->config_vector = VIRTIO_NO_VECTOR; 1931 virtio_notify_vector(vdev, vdev->config_vector); 1932 1933 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1934 vdev->vq[i].vring.desc = 0; 1935 vdev->vq[i].vring.avail = 0; 1936 vdev->vq[i].vring.used = 0; 1937 vdev->vq[i].last_avail_idx = 0; 1938 vdev->vq[i].shadow_avail_idx = 0; 1939 vdev->vq[i].used_idx = 0; 1940 vdev->vq[i].last_avail_wrap_counter = true; 1941 vdev->vq[i].shadow_avail_wrap_counter = true; 1942 vdev->vq[i].used_wrap_counter = true; 1943 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1944 vdev->vq[i].signalled_used = 0; 1945 vdev->vq[i].signalled_used_valid = false; 1946 vdev->vq[i].notification = true; 1947 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1948 vdev->vq[i].inuse = 0; 1949 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 1950 } 1951 } 1952 1953 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1954 { 1955 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1956 uint8_t val; 1957 1958 if (addr + sizeof(val) > vdev->config_len) { 1959 return (uint32_t)-1; 1960 } 1961 1962 k->get_config(vdev, vdev->config); 1963 1964 val = ldub_p(vdev->config + addr); 1965 return val; 1966 } 1967 1968 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1969 { 1970 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1971 uint16_t val; 1972 1973 if (addr + sizeof(val) > vdev->config_len) { 1974 return (uint32_t)-1; 1975 } 1976 1977 k->get_config(vdev, vdev->config); 1978 1979 val = lduw_p(vdev->config + addr); 1980 return val; 1981 } 1982 1983 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1984 { 1985 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1986 uint32_t val; 1987 1988 if (addr + sizeof(val) > vdev->config_len) { 1989 return (uint32_t)-1; 1990 } 1991 1992 k->get_config(vdev, vdev->config); 1993 1994 val = ldl_p(vdev->config + addr); 1995 return val; 1996 } 1997 1998 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1999 { 2000 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2001 uint8_t val = data; 2002 2003 if (addr + sizeof(val) > vdev->config_len) { 2004 return; 2005 } 2006 2007 stb_p(vdev->config + addr, val); 2008 2009 if (k->set_config) { 2010 k->set_config(vdev, vdev->config); 2011 } 2012 } 2013 2014 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 2015 { 2016 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2017 uint16_t val = data; 2018 2019 if (addr + sizeof(val) > vdev->config_len) { 2020 return; 2021 } 2022 2023 stw_p(vdev->config + addr, val); 2024 2025 if (k->set_config) { 2026 k->set_config(vdev, vdev->config); 2027 } 2028 } 2029 2030 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 2031 { 2032 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2033 uint32_t val = data; 2034 2035 if (addr + sizeof(val) > vdev->config_len) { 2036 return; 2037 } 2038 2039 stl_p(vdev->config + addr, val); 2040 2041 if (k->set_config) { 2042 k->set_config(vdev, vdev->config); 2043 } 2044 } 2045 2046 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 2047 { 2048 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2049 uint8_t val; 2050 2051 if (addr + sizeof(val) > vdev->config_len) { 2052 return (uint32_t)-1; 2053 } 2054 2055 k->get_config(vdev, vdev->config); 2056 2057 val = ldub_p(vdev->config + addr); 2058 return val; 2059 } 2060 2061 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 2062 { 2063 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2064 uint16_t val; 2065 2066 if (addr + sizeof(val) > vdev->config_len) { 2067 return (uint32_t)-1; 2068 } 2069 2070 k->get_config(vdev, vdev->config); 2071 2072 val = lduw_le_p(vdev->config + addr); 2073 return val; 2074 } 2075 2076 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 2077 { 2078 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2079 uint32_t val; 2080 2081 if (addr + sizeof(val) > vdev->config_len) { 2082 return (uint32_t)-1; 2083 } 2084 2085 k->get_config(vdev, vdev->config); 2086 2087 val = ldl_le_p(vdev->config + addr); 2088 return val; 2089 } 2090 2091 void virtio_config_modern_writeb(VirtIODevice *vdev, 2092 uint32_t addr, uint32_t data) 2093 { 2094 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2095 uint8_t val = data; 2096 2097 if (addr + sizeof(val) > vdev->config_len) { 2098 return; 2099 } 2100 2101 stb_p(vdev->config + addr, val); 2102 2103 if (k->set_config) { 2104 k->set_config(vdev, vdev->config); 2105 } 2106 } 2107 2108 void virtio_config_modern_writew(VirtIODevice *vdev, 2109 uint32_t addr, uint32_t data) 2110 { 2111 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2112 uint16_t val = data; 2113 2114 if (addr + sizeof(val) > vdev->config_len) { 2115 return; 2116 } 2117 2118 stw_le_p(vdev->config + addr, val); 2119 2120 if (k->set_config) { 2121 k->set_config(vdev, vdev->config); 2122 } 2123 } 2124 2125 void virtio_config_modern_writel(VirtIODevice *vdev, 2126 uint32_t addr, uint32_t data) 2127 { 2128 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2129 uint32_t val = data; 2130 2131 if (addr + sizeof(val) > vdev->config_len) { 2132 return; 2133 } 2134 2135 stl_le_p(vdev->config + addr, val); 2136 2137 if (k->set_config) { 2138 k->set_config(vdev, vdev->config); 2139 } 2140 } 2141 2142 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 2143 { 2144 if (!vdev->vq[n].vring.num) { 2145 return; 2146 } 2147 vdev->vq[n].vring.desc = addr; 2148 virtio_queue_update_rings(vdev, n); 2149 } 2150 2151 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 2152 { 2153 return vdev->vq[n].vring.desc; 2154 } 2155 2156 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 2157 hwaddr avail, hwaddr used) 2158 { 2159 if (!vdev->vq[n].vring.num) { 2160 return; 2161 } 2162 vdev->vq[n].vring.desc = desc; 2163 vdev->vq[n].vring.avail = avail; 2164 vdev->vq[n].vring.used = used; 2165 virtio_init_region_cache(vdev, n); 2166 } 2167 2168 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 2169 { 2170 /* Don't allow guest to flip queue between existent and 2171 * nonexistent states, or to set it to an invalid size. 2172 */ 2173 if (!!num != !!vdev->vq[n].vring.num || 2174 num > VIRTQUEUE_MAX_SIZE || 2175 num < 0) { 2176 return; 2177 } 2178 vdev->vq[n].vring.num = num; 2179 } 2180 2181 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 2182 { 2183 return QLIST_FIRST(&vdev->vector_queues[vector]); 2184 } 2185 2186 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 2187 { 2188 return QLIST_NEXT(vq, node); 2189 } 2190 2191 int virtio_queue_get_num(VirtIODevice *vdev, int n) 2192 { 2193 return vdev->vq[n].vring.num; 2194 } 2195 2196 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 2197 { 2198 return vdev->vq[n].vring.num_default; 2199 } 2200 2201 int virtio_get_num_queues(VirtIODevice *vdev) 2202 { 2203 int i; 2204 2205 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2206 if (!virtio_queue_get_num(vdev, i)) { 2207 break; 2208 } 2209 } 2210 2211 return i; 2212 } 2213 2214 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 2215 { 2216 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2217 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2218 2219 /* virtio-1 compliant devices cannot change the alignment */ 2220 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2221 error_report("tried to modify queue alignment for virtio-1 device"); 2222 return; 2223 } 2224 /* Check that the transport told us it was going to do this 2225 * (so a buggy transport will immediately assert rather than 2226 * silently failing to migrate this state) 2227 */ 2228 assert(k->has_variable_vring_alignment); 2229 2230 if (align) { 2231 vdev->vq[n].vring.align = align; 2232 virtio_queue_update_rings(vdev, n); 2233 } 2234 } 2235 2236 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) 2237 { 2238 bool ret = false; 2239 2240 if (vq->vring.desc && vq->handle_aio_output) { 2241 VirtIODevice *vdev = vq->vdev; 2242 2243 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2244 ret = vq->handle_aio_output(vdev, vq); 2245 2246 if (unlikely(vdev->start_on_kick)) { 2247 virtio_set_started(vdev, true); 2248 } 2249 } 2250 2251 return ret; 2252 } 2253 2254 static void virtio_queue_notify_vq(VirtQueue *vq) 2255 { 2256 if (vq->vring.desc && vq->handle_output) { 2257 VirtIODevice *vdev = vq->vdev; 2258 2259 if (unlikely(vdev->broken)) { 2260 return; 2261 } 2262 2263 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2264 vq->handle_output(vdev, vq); 2265 2266 if (unlikely(vdev->start_on_kick)) { 2267 virtio_set_started(vdev, true); 2268 } 2269 } 2270 } 2271 2272 void virtio_queue_notify(VirtIODevice *vdev, int n) 2273 { 2274 VirtQueue *vq = &vdev->vq[n]; 2275 2276 if (unlikely(!vq->vring.desc || vdev->broken)) { 2277 return; 2278 } 2279 2280 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2281 if (vq->host_notifier_enabled) { 2282 event_notifier_set(&vq->host_notifier); 2283 } else if (vq->handle_output) { 2284 vq->handle_output(vdev, vq); 2285 2286 if (unlikely(vdev->start_on_kick)) { 2287 virtio_set_started(vdev, true); 2288 } 2289 } 2290 } 2291 2292 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 2293 { 2294 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 2295 VIRTIO_NO_VECTOR; 2296 } 2297 2298 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 2299 { 2300 VirtQueue *vq = &vdev->vq[n]; 2301 2302 if (n < VIRTIO_QUEUE_MAX) { 2303 if (vdev->vector_queues && 2304 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 2305 QLIST_REMOVE(vq, node); 2306 } 2307 vdev->vq[n].vector = vector; 2308 if (vdev->vector_queues && 2309 vector != VIRTIO_NO_VECTOR) { 2310 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 2311 } 2312 } 2313 } 2314 2315 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 2316 VirtIOHandleOutput handle_output) 2317 { 2318 int i; 2319 2320 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2321 if (vdev->vq[i].vring.num == 0) 2322 break; 2323 } 2324 2325 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 2326 abort(); 2327 2328 vdev->vq[i].vring.num = queue_size; 2329 vdev->vq[i].vring.num_default = queue_size; 2330 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 2331 vdev->vq[i].handle_output = handle_output; 2332 vdev->vq[i].handle_aio_output = NULL; 2333 vdev->vq[i].used_elems = g_malloc0(sizeof(VirtQueueElement) * 2334 queue_size); 2335 2336 return &vdev->vq[i]; 2337 } 2338 2339 void virtio_delete_queue(VirtQueue *vq) 2340 { 2341 vq->vring.num = 0; 2342 vq->vring.num_default = 0; 2343 vq->handle_output = NULL; 2344 vq->handle_aio_output = NULL; 2345 g_free(vq->used_elems); 2346 vq->used_elems = NULL; 2347 virtio_virtqueue_reset_region_cache(vq); 2348 } 2349 2350 void virtio_del_queue(VirtIODevice *vdev, int n) 2351 { 2352 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 2353 abort(); 2354 } 2355 2356 virtio_delete_queue(&vdev->vq[n]); 2357 } 2358 2359 static void virtio_set_isr(VirtIODevice *vdev, int value) 2360 { 2361 uint8_t old = atomic_read(&vdev->isr); 2362 2363 /* Do not write ISR if it does not change, so that its cacheline remains 2364 * shared in the common case where the guest does not read it. 2365 */ 2366 if ((old & value) != value) { 2367 atomic_or(&vdev->isr, value); 2368 } 2369 } 2370 2371 static bool virtio_split_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2372 { 2373 uint16_t old, new; 2374 bool v; 2375 /* We need to expose used array entries before checking used event. */ 2376 smp_mb(); 2377 /* Always notify when queue is empty (when feature acknowledge) */ 2378 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 2379 !vq->inuse && virtio_queue_empty(vq)) { 2380 return true; 2381 } 2382 2383 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2384 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 2385 } 2386 2387 v = vq->signalled_used_valid; 2388 vq->signalled_used_valid = true; 2389 old = vq->signalled_used; 2390 new = vq->signalled_used = vq->used_idx; 2391 return !v || vring_need_event(vring_get_used_event(vq), new, old); 2392 } 2393 2394 static bool vring_packed_need_event(VirtQueue *vq, bool wrap, 2395 uint16_t off_wrap, uint16_t new, 2396 uint16_t old) 2397 { 2398 int off = off_wrap & ~(1 << 15); 2399 2400 if (wrap != off_wrap >> 15) { 2401 off -= vq->vring.num; 2402 } 2403 2404 return vring_need_event(off, new, old); 2405 } 2406 2407 static bool virtio_packed_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2408 { 2409 VRingPackedDescEvent e; 2410 uint16_t old, new; 2411 bool v; 2412 VRingMemoryRegionCaches *caches; 2413 2414 caches = vring_get_region_caches(vq); 2415 vring_packed_event_read(vdev, &caches->avail, &e); 2416 2417 old = vq->signalled_used; 2418 new = vq->signalled_used = vq->used_idx; 2419 v = vq->signalled_used_valid; 2420 vq->signalled_used_valid = true; 2421 2422 if (e.flags == VRING_PACKED_EVENT_FLAG_DISABLE) { 2423 return false; 2424 } else if (e.flags == VRING_PACKED_EVENT_FLAG_ENABLE) { 2425 return true; 2426 } 2427 2428 return !v || vring_packed_need_event(vq, vq->used_wrap_counter, 2429 e.off_wrap, new, old); 2430 } 2431 2432 /* Called within rcu_read_lock(). */ 2433 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2434 { 2435 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 2436 return virtio_packed_should_notify(vdev, vq); 2437 } else { 2438 return virtio_split_should_notify(vdev, vq); 2439 } 2440 } 2441 2442 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 2443 { 2444 WITH_RCU_READ_LOCK_GUARD() { 2445 if (!virtio_should_notify(vdev, vq)) { 2446 return; 2447 } 2448 } 2449 2450 trace_virtio_notify_irqfd(vdev, vq); 2451 2452 /* 2453 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 2454 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 2455 * incorrectly polling this bit during crashdump and hibernation 2456 * in MSI mode, causing a hang if this bit is never updated. 2457 * Recent releases of Windows do not really shut down, but rather 2458 * log out and hibernate to make the next startup faster. Hence, 2459 * this manifested as a more serious hang during shutdown with 2460 * 2461 * Next driver release from 2016 fixed this problem, so working around it 2462 * is not a must, but it's easy to do so let's do it here. 2463 * 2464 * Note: it's safe to update ISR from any thread as it was switched 2465 * to an atomic operation. 2466 */ 2467 virtio_set_isr(vq->vdev, 0x1); 2468 event_notifier_set(&vq->guest_notifier); 2469 } 2470 2471 static void virtio_irq(VirtQueue *vq) 2472 { 2473 virtio_set_isr(vq->vdev, 0x1); 2474 virtio_notify_vector(vq->vdev, vq->vector); 2475 } 2476 2477 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 2478 { 2479 WITH_RCU_READ_LOCK_GUARD() { 2480 if (!virtio_should_notify(vdev, vq)) { 2481 return; 2482 } 2483 } 2484 2485 trace_virtio_notify(vdev, vq); 2486 virtio_irq(vq); 2487 } 2488 2489 void virtio_notify_config(VirtIODevice *vdev) 2490 { 2491 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 2492 return; 2493 2494 virtio_set_isr(vdev, 0x3); 2495 vdev->generation++; 2496 virtio_notify_vector(vdev, vdev->config_vector); 2497 } 2498 2499 static bool virtio_device_endian_needed(void *opaque) 2500 { 2501 VirtIODevice *vdev = opaque; 2502 2503 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 2504 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2505 return vdev->device_endian != virtio_default_endian(); 2506 } 2507 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 2508 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 2509 } 2510 2511 static bool virtio_64bit_features_needed(void *opaque) 2512 { 2513 VirtIODevice *vdev = opaque; 2514 2515 return (vdev->host_features >> 32) != 0; 2516 } 2517 2518 static bool virtio_virtqueue_needed(void *opaque) 2519 { 2520 VirtIODevice *vdev = opaque; 2521 2522 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 2523 } 2524 2525 static bool virtio_packed_virtqueue_needed(void *opaque) 2526 { 2527 VirtIODevice *vdev = opaque; 2528 2529 return virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED); 2530 } 2531 2532 static bool virtio_ringsize_needed(void *opaque) 2533 { 2534 VirtIODevice *vdev = opaque; 2535 int i; 2536 2537 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2538 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 2539 return true; 2540 } 2541 } 2542 return false; 2543 } 2544 2545 static bool virtio_extra_state_needed(void *opaque) 2546 { 2547 VirtIODevice *vdev = opaque; 2548 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2549 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2550 2551 return k->has_extra_state && 2552 k->has_extra_state(qbus->parent); 2553 } 2554 2555 static bool virtio_broken_needed(void *opaque) 2556 { 2557 VirtIODevice *vdev = opaque; 2558 2559 return vdev->broken; 2560 } 2561 2562 static bool virtio_started_needed(void *opaque) 2563 { 2564 VirtIODevice *vdev = opaque; 2565 2566 return vdev->started; 2567 } 2568 2569 static bool virtio_disabled_needed(void *opaque) 2570 { 2571 VirtIODevice *vdev = opaque; 2572 2573 return vdev->disabled; 2574 } 2575 2576 static const VMStateDescription vmstate_virtqueue = { 2577 .name = "virtqueue_state", 2578 .version_id = 1, 2579 .minimum_version_id = 1, 2580 .fields = (VMStateField[]) { 2581 VMSTATE_UINT64(vring.avail, struct VirtQueue), 2582 VMSTATE_UINT64(vring.used, struct VirtQueue), 2583 VMSTATE_END_OF_LIST() 2584 } 2585 }; 2586 2587 static const VMStateDescription vmstate_packed_virtqueue = { 2588 .name = "packed_virtqueue_state", 2589 .version_id = 1, 2590 .minimum_version_id = 1, 2591 .fields = (VMStateField[]) { 2592 VMSTATE_UINT16(last_avail_idx, struct VirtQueue), 2593 VMSTATE_BOOL(last_avail_wrap_counter, struct VirtQueue), 2594 VMSTATE_UINT16(used_idx, struct VirtQueue), 2595 VMSTATE_BOOL(used_wrap_counter, struct VirtQueue), 2596 VMSTATE_UINT32(inuse, struct VirtQueue), 2597 VMSTATE_END_OF_LIST() 2598 } 2599 }; 2600 2601 static const VMStateDescription vmstate_virtio_virtqueues = { 2602 .name = "virtio/virtqueues", 2603 .version_id = 1, 2604 .minimum_version_id = 1, 2605 .needed = &virtio_virtqueue_needed, 2606 .fields = (VMStateField[]) { 2607 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2608 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 2609 VMSTATE_END_OF_LIST() 2610 } 2611 }; 2612 2613 static const VMStateDescription vmstate_virtio_packed_virtqueues = { 2614 .name = "virtio/packed_virtqueues", 2615 .version_id = 1, 2616 .minimum_version_id = 1, 2617 .needed = &virtio_packed_virtqueue_needed, 2618 .fields = (VMStateField[]) { 2619 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2620 VIRTIO_QUEUE_MAX, 0, vmstate_packed_virtqueue, VirtQueue), 2621 VMSTATE_END_OF_LIST() 2622 } 2623 }; 2624 2625 static const VMStateDescription vmstate_ringsize = { 2626 .name = "ringsize_state", 2627 .version_id = 1, 2628 .minimum_version_id = 1, 2629 .fields = (VMStateField[]) { 2630 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 2631 VMSTATE_END_OF_LIST() 2632 } 2633 }; 2634 2635 static const VMStateDescription vmstate_virtio_ringsize = { 2636 .name = "virtio/ringsize", 2637 .version_id = 1, 2638 .minimum_version_id = 1, 2639 .needed = &virtio_ringsize_needed, 2640 .fields = (VMStateField[]) { 2641 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2642 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 2643 VMSTATE_END_OF_LIST() 2644 } 2645 }; 2646 2647 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 2648 const VMStateField *field) 2649 { 2650 VirtIODevice *vdev = pv; 2651 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2652 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2653 2654 if (!k->load_extra_state) { 2655 return -1; 2656 } else { 2657 return k->load_extra_state(qbus->parent, f); 2658 } 2659 } 2660 2661 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 2662 const VMStateField *field, QJSON *vmdesc) 2663 { 2664 VirtIODevice *vdev = pv; 2665 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2666 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2667 2668 k->save_extra_state(qbus->parent, f); 2669 return 0; 2670 } 2671 2672 static const VMStateInfo vmstate_info_extra_state = { 2673 .name = "virtqueue_extra_state", 2674 .get = get_extra_state, 2675 .put = put_extra_state, 2676 }; 2677 2678 static const VMStateDescription vmstate_virtio_extra_state = { 2679 .name = "virtio/extra_state", 2680 .version_id = 1, 2681 .minimum_version_id = 1, 2682 .needed = &virtio_extra_state_needed, 2683 .fields = (VMStateField[]) { 2684 { 2685 .name = "extra_state", 2686 .version_id = 0, 2687 .field_exists = NULL, 2688 .size = 0, 2689 .info = &vmstate_info_extra_state, 2690 .flags = VMS_SINGLE, 2691 .offset = 0, 2692 }, 2693 VMSTATE_END_OF_LIST() 2694 } 2695 }; 2696 2697 static const VMStateDescription vmstate_virtio_device_endian = { 2698 .name = "virtio/device_endian", 2699 .version_id = 1, 2700 .minimum_version_id = 1, 2701 .needed = &virtio_device_endian_needed, 2702 .fields = (VMStateField[]) { 2703 VMSTATE_UINT8(device_endian, VirtIODevice), 2704 VMSTATE_END_OF_LIST() 2705 } 2706 }; 2707 2708 static const VMStateDescription vmstate_virtio_64bit_features = { 2709 .name = "virtio/64bit_features", 2710 .version_id = 1, 2711 .minimum_version_id = 1, 2712 .needed = &virtio_64bit_features_needed, 2713 .fields = (VMStateField[]) { 2714 VMSTATE_UINT64(guest_features, VirtIODevice), 2715 VMSTATE_END_OF_LIST() 2716 } 2717 }; 2718 2719 static const VMStateDescription vmstate_virtio_broken = { 2720 .name = "virtio/broken", 2721 .version_id = 1, 2722 .minimum_version_id = 1, 2723 .needed = &virtio_broken_needed, 2724 .fields = (VMStateField[]) { 2725 VMSTATE_BOOL(broken, VirtIODevice), 2726 VMSTATE_END_OF_LIST() 2727 } 2728 }; 2729 2730 static const VMStateDescription vmstate_virtio_started = { 2731 .name = "virtio/started", 2732 .version_id = 1, 2733 .minimum_version_id = 1, 2734 .needed = &virtio_started_needed, 2735 .fields = (VMStateField[]) { 2736 VMSTATE_BOOL(started, VirtIODevice), 2737 VMSTATE_END_OF_LIST() 2738 } 2739 }; 2740 2741 static const VMStateDescription vmstate_virtio_disabled = { 2742 .name = "virtio/disabled", 2743 .version_id = 1, 2744 .minimum_version_id = 1, 2745 .needed = &virtio_disabled_needed, 2746 .fields = (VMStateField[]) { 2747 VMSTATE_BOOL(disabled, VirtIODevice), 2748 VMSTATE_END_OF_LIST() 2749 } 2750 }; 2751 2752 static const VMStateDescription vmstate_virtio = { 2753 .name = "virtio", 2754 .version_id = 1, 2755 .minimum_version_id = 1, 2756 .minimum_version_id_old = 1, 2757 .fields = (VMStateField[]) { 2758 VMSTATE_END_OF_LIST() 2759 }, 2760 .subsections = (const VMStateDescription*[]) { 2761 &vmstate_virtio_device_endian, 2762 &vmstate_virtio_64bit_features, 2763 &vmstate_virtio_virtqueues, 2764 &vmstate_virtio_ringsize, 2765 &vmstate_virtio_broken, 2766 &vmstate_virtio_extra_state, 2767 &vmstate_virtio_started, 2768 &vmstate_virtio_packed_virtqueues, 2769 &vmstate_virtio_disabled, 2770 NULL 2771 } 2772 }; 2773 2774 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 2775 { 2776 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2777 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2778 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2779 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 2780 int i; 2781 2782 if (k->save_config) { 2783 k->save_config(qbus->parent, f); 2784 } 2785 2786 qemu_put_8s(f, &vdev->status); 2787 qemu_put_8s(f, &vdev->isr); 2788 qemu_put_be16s(f, &vdev->queue_sel); 2789 qemu_put_be32s(f, &guest_features_lo); 2790 qemu_put_be32(f, vdev->config_len); 2791 qemu_put_buffer(f, vdev->config, vdev->config_len); 2792 2793 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2794 if (vdev->vq[i].vring.num == 0) 2795 break; 2796 } 2797 2798 qemu_put_be32(f, i); 2799 2800 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2801 if (vdev->vq[i].vring.num == 0) 2802 break; 2803 2804 qemu_put_be32(f, vdev->vq[i].vring.num); 2805 if (k->has_variable_vring_alignment) { 2806 qemu_put_be32(f, vdev->vq[i].vring.align); 2807 } 2808 /* 2809 * Save desc now, the rest of the ring addresses are saved in 2810 * subsections for VIRTIO-1 devices. 2811 */ 2812 qemu_put_be64(f, vdev->vq[i].vring.desc); 2813 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 2814 if (k->save_queue) { 2815 k->save_queue(qbus->parent, i, f); 2816 } 2817 } 2818 2819 if (vdc->save != NULL) { 2820 vdc->save(vdev, f); 2821 } 2822 2823 if (vdc->vmsd) { 2824 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 2825 if (ret) { 2826 return ret; 2827 } 2828 } 2829 2830 /* Subsections */ 2831 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 2832 } 2833 2834 /* A wrapper for use as a VMState .put function */ 2835 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 2836 const VMStateField *field, QJSON *vmdesc) 2837 { 2838 return virtio_save(VIRTIO_DEVICE(opaque), f); 2839 } 2840 2841 /* A wrapper for use as a VMState .get function */ 2842 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 2843 const VMStateField *field) 2844 { 2845 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 2846 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 2847 2848 return virtio_load(vdev, f, dc->vmsd->version_id); 2849 } 2850 2851 const VMStateInfo virtio_vmstate_info = { 2852 .name = "virtio", 2853 .get = virtio_device_get, 2854 .put = virtio_device_put, 2855 }; 2856 2857 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 2858 { 2859 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2860 bool bad = (val & ~(vdev->host_features)) != 0; 2861 2862 val &= vdev->host_features; 2863 if (k->set_features) { 2864 k->set_features(vdev, val); 2865 } 2866 vdev->guest_features = val; 2867 return bad ? -1 : 0; 2868 } 2869 2870 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2871 { 2872 int ret; 2873 /* 2874 * The driver must not attempt to set features after feature negotiation 2875 * has finished. 2876 */ 2877 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2878 return -EINVAL; 2879 } 2880 ret = virtio_set_features_nocheck(vdev, val); 2881 if (!ret) { 2882 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2883 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ 2884 int i; 2885 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2886 if (vdev->vq[i].vring.num != 0) { 2887 virtio_init_region_cache(vdev, i); 2888 } 2889 } 2890 } 2891 2892 if (!virtio_device_started(vdev, vdev->status) && 2893 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2894 vdev->start_on_kick = true; 2895 } 2896 } 2897 return ret; 2898 } 2899 2900 size_t virtio_feature_get_config_size(VirtIOFeature *feature_sizes, 2901 uint64_t host_features) 2902 { 2903 size_t config_size = 0; 2904 int i; 2905 2906 for (i = 0; feature_sizes[i].flags != 0; i++) { 2907 if (host_features & feature_sizes[i].flags) { 2908 config_size = MAX(feature_sizes[i].end, config_size); 2909 } 2910 } 2911 2912 return config_size; 2913 } 2914 2915 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2916 { 2917 int i, ret; 2918 int32_t config_len; 2919 uint32_t num; 2920 uint32_t features; 2921 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2922 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2923 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2924 2925 /* 2926 * We poison the endianness to ensure it does not get used before 2927 * subsections have been loaded. 2928 */ 2929 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2930 2931 if (k->load_config) { 2932 ret = k->load_config(qbus->parent, f); 2933 if (ret) 2934 return ret; 2935 } 2936 2937 qemu_get_8s(f, &vdev->status); 2938 qemu_get_8s(f, &vdev->isr); 2939 qemu_get_be16s(f, &vdev->queue_sel); 2940 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2941 return -1; 2942 } 2943 qemu_get_be32s(f, &features); 2944 2945 /* 2946 * Temporarily set guest_features low bits - needed by 2947 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2948 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2949 * 2950 * Note: devices should always test host features in future - don't create 2951 * new dependencies like this. 2952 */ 2953 vdev->guest_features = features; 2954 2955 config_len = qemu_get_be32(f); 2956 2957 /* 2958 * There are cases where the incoming config can be bigger or smaller 2959 * than what we have; so load what we have space for, and skip 2960 * any excess that's in the stream. 2961 */ 2962 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 2963 2964 while (config_len > vdev->config_len) { 2965 qemu_get_byte(f); 2966 config_len--; 2967 } 2968 2969 num = qemu_get_be32(f); 2970 2971 if (num > VIRTIO_QUEUE_MAX) { 2972 error_report("Invalid number of virtqueues: 0x%x", num); 2973 return -1; 2974 } 2975 2976 for (i = 0; i < num; i++) { 2977 vdev->vq[i].vring.num = qemu_get_be32(f); 2978 if (k->has_variable_vring_alignment) { 2979 vdev->vq[i].vring.align = qemu_get_be32(f); 2980 } 2981 vdev->vq[i].vring.desc = qemu_get_be64(f); 2982 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 2983 vdev->vq[i].signalled_used_valid = false; 2984 vdev->vq[i].notification = true; 2985 2986 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 2987 error_report("VQ %d address 0x0 " 2988 "inconsistent with Host index 0x%x", 2989 i, vdev->vq[i].last_avail_idx); 2990 return -1; 2991 } 2992 if (k->load_queue) { 2993 ret = k->load_queue(qbus->parent, i, f); 2994 if (ret) 2995 return ret; 2996 } 2997 } 2998 2999 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 3000 3001 if (vdc->load != NULL) { 3002 ret = vdc->load(vdev, f, version_id); 3003 if (ret) { 3004 return ret; 3005 } 3006 } 3007 3008 if (vdc->vmsd) { 3009 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 3010 if (ret) { 3011 return ret; 3012 } 3013 } 3014 3015 /* Subsections */ 3016 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 3017 if (ret) { 3018 return ret; 3019 } 3020 3021 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 3022 vdev->device_endian = virtio_default_endian(); 3023 } 3024 3025 if (virtio_64bit_features_needed(vdev)) { 3026 /* 3027 * Subsection load filled vdev->guest_features. Run them 3028 * through virtio_set_features to sanity-check them against 3029 * host_features. 3030 */ 3031 uint64_t features64 = vdev->guest_features; 3032 if (virtio_set_features_nocheck(vdev, features64) < 0) { 3033 error_report("Features 0x%" PRIx64 " unsupported. " 3034 "Allowed features: 0x%" PRIx64, 3035 features64, vdev->host_features); 3036 return -1; 3037 } 3038 } else { 3039 if (virtio_set_features_nocheck(vdev, features) < 0) { 3040 error_report("Features 0x%x unsupported. " 3041 "Allowed features: 0x%" PRIx64, 3042 features, vdev->host_features); 3043 return -1; 3044 } 3045 } 3046 3047 if (!virtio_device_started(vdev, vdev->status) && 3048 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3049 vdev->start_on_kick = true; 3050 } 3051 3052 RCU_READ_LOCK_GUARD(); 3053 for (i = 0; i < num; i++) { 3054 if (vdev->vq[i].vring.desc) { 3055 uint16_t nheads; 3056 3057 /* 3058 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 3059 * only the region cache needs to be set up. Legacy devices need 3060 * to calculate used and avail ring addresses based on the desc 3061 * address. 3062 */ 3063 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3064 virtio_init_region_cache(vdev, i); 3065 } else { 3066 virtio_queue_update_rings(vdev, i); 3067 } 3068 3069 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3070 vdev->vq[i].shadow_avail_idx = vdev->vq[i].last_avail_idx; 3071 vdev->vq[i].shadow_avail_wrap_counter = 3072 vdev->vq[i].last_avail_wrap_counter; 3073 continue; 3074 } 3075 3076 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 3077 /* Check it isn't doing strange things with descriptor numbers. */ 3078 if (nheads > vdev->vq[i].vring.num) { 3079 error_report("VQ %d size 0x%x Guest index 0x%x " 3080 "inconsistent with Host index 0x%x: delta 0x%x", 3081 i, vdev->vq[i].vring.num, 3082 vring_avail_idx(&vdev->vq[i]), 3083 vdev->vq[i].last_avail_idx, nheads); 3084 return -1; 3085 } 3086 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 3087 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 3088 3089 /* 3090 * Some devices migrate VirtQueueElements that have been popped 3091 * from the avail ring but not yet returned to the used ring. 3092 * Since max ring size < UINT16_MAX it's safe to use modulo 3093 * UINT16_MAX + 1 subtraction. 3094 */ 3095 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 3096 vdev->vq[i].used_idx); 3097 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 3098 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 3099 "used_idx 0x%x", 3100 i, vdev->vq[i].vring.num, 3101 vdev->vq[i].last_avail_idx, 3102 vdev->vq[i].used_idx); 3103 return -1; 3104 } 3105 } 3106 } 3107 3108 if (vdc->post_load) { 3109 ret = vdc->post_load(vdev); 3110 if (ret) { 3111 return ret; 3112 } 3113 } 3114 3115 return 0; 3116 } 3117 3118 void virtio_cleanup(VirtIODevice *vdev) 3119 { 3120 qemu_del_vm_change_state_handler(vdev->vmstate); 3121 } 3122 3123 static void virtio_vmstate_change(void *opaque, int running, RunState state) 3124 { 3125 VirtIODevice *vdev = opaque; 3126 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3127 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3128 bool backend_run = running && virtio_device_started(vdev, vdev->status); 3129 vdev->vm_running = running; 3130 3131 if (backend_run) { 3132 virtio_set_status(vdev, vdev->status); 3133 } 3134 3135 if (k->vmstate_change) { 3136 k->vmstate_change(qbus->parent, backend_run); 3137 } 3138 3139 if (!backend_run) { 3140 virtio_set_status(vdev, vdev->status); 3141 } 3142 } 3143 3144 void virtio_instance_init_common(Object *proxy_obj, void *data, 3145 size_t vdev_size, const char *vdev_name) 3146 { 3147 DeviceState *vdev = data; 3148 3149 object_initialize_child(proxy_obj, "virtio-backend", vdev, vdev_size, 3150 vdev_name, &error_abort, NULL); 3151 qdev_alias_all_properties(vdev, proxy_obj); 3152 } 3153 3154 void virtio_init(VirtIODevice *vdev, const char *name, 3155 uint16_t device_id, size_t config_size) 3156 { 3157 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3158 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3159 int i; 3160 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 3161 3162 if (nvectors) { 3163 vdev->vector_queues = 3164 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 3165 } 3166 3167 vdev->start_on_kick = false; 3168 vdev->started = false; 3169 vdev->device_id = device_id; 3170 vdev->status = 0; 3171 atomic_set(&vdev->isr, 0); 3172 vdev->queue_sel = 0; 3173 vdev->config_vector = VIRTIO_NO_VECTOR; 3174 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 3175 vdev->vm_running = runstate_is_running(); 3176 vdev->broken = false; 3177 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3178 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 3179 vdev->vq[i].vdev = vdev; 3180 vdev->vq[i].queue_index = i; 3181 vdev->vq[i].host_notifier_enabled = false; 3182 } 3183 3184 vdev->name = name; 3185 vdev->config_len = config_size; 3186 if (vdev->config_len) { 3187 vdev->config = g_malloc0(config_size); 3188 } else { 3189 vdev->config = NULL; 3190 } 3191 vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev), 3192 virtio_vmstate_change, vdev); 3193 vdev->device_endian = virtio_default_endian(); 3194 vdev->use_guest_notifier_mask = true; 3195 } 3196 3197 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 3198 { 3199 return vdev->vq[n].vring.desc; 3200 } 3201 3202 bool virtio_queue_enabled(VirtIODevice *vdev, int n) 3203 { 3204 return virtio_queue_get_desc_addr(vdev, n) != 0; 3205 } 3206 3207 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 3208 { 3209 return vdev->vq[n].vring.avail; 3210 } 3211 3212 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 3213 { 3214 return vdev->vq[n].vring.used; 3215 } 3216 3217 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 3218 { 3219 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 3220 } 3221 3222 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 3223 { 3224 int s; 3225 3226 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3227 return sizeof(struct VRingPackedDescEvent); 3228 } 3229 3230 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3231 return offsetof(VRingAvail, ring) + 3232 sizeof(uint16_t) * vdev->vq[n].vring.num + s; 3233 } 3234 3235 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 3236 { 3237 int s; 3238 3239 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3240 return sizeof(struct VRingPackedDescEvent); 3241 } 3242 3243 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3244 return offsetof(VRingUsed, ring) + 3245 sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s; 3246 } 3247 3248 static unsigned int virtio_queue_packed_get_last_avail_idx(VirtIODevice *vdev, 3249 int n) 3250 { 3251 unsigned int avail, used; 3252 3253 avail = vdev->vq[n].last_avail_idx; 3254 avail |= ((uint16_t)vdev->vq[n].last_avail_wrap_counter) << 15; 3255 3256 used = vdev->vq[n].used_idx; 3257 used |= ((uint16_t)vdev->vq[n].used_wrap_counter) << 15; 3258 3259 return avail | used << 16; 3260 } 3261 3262 static uint16_t virtio_queue_split_get_last_avail_idx(VirtIODevice *vdev, 3263 int n) 3264 { 3265 return vdev->vq[n].last_avail_idx; 3266 } 3267 3268 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 3269 { 3270 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3271 return virtio_queue_packed_get_last_avail_idx(vdev, n); 3272 } else { 3273 return virtio_queue_split_get_last_avail_idx(vdev, n); 3274 } 3275 } 3276 3277 static void virtio_queue_packed_set_last_avail_idx(VirtIODevice *vdev, 3278 int n, unsigned int idx) 3279 { 3280 struct VirtQueue *vq = &vdev->vq[n]; 3281 3282 vq->last_avail_idx = vq->shadow_avail_idx = idx & 0x7fff; 3283 vq->last_avail_wrap_counter = 3284 vq->shadow_avail_wrap_counter = !!(idx & 0x8000); 3285 idx >>= 16; 3286 vq->used_idx = idx & 0x7ffff; 3287 vq->used_wrap_counter = !!(idx & 0x8000); 3288 } 3289 3290 static void virtio_queue_split_set_last_avail_idx(VirtIODevice *vdev, 3291 int n, unsigned int idx) 3292 { 3293 vdev->vq[n].last_avail_idx = idx; 3294 vdev->vq[n].shadow_avail_idx = idx; 3295 } 3296 3297 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 3298 unsigned int idx) 3299 { 3300 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3301 virtio_queue_packed_set_last_avail_idx(vdev, n, idx); 3302 } else { 3303 virtio_queue_split_set_last_avail_idx(vdev, n, idx); 3304 } 3305 } 3306 3307 static void virtio_queue_packed_restore_last_avail_idx(VirtIODevice *vdev, 3308 int n) 3309 { 3310 /* We don't have a reference like avail idx in shared memory */ 3311 return; 3312 } 3313 3314 static void virtio_queue_split_restore_last_avail_idx(VirtIODevice *vdev, 3315 int n) 3316 { 3317 RCU_READ_LOCK_GUARD(); 3318 if (vdev->vq[n].vring.desc) { 3319 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 3320 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 3321 } 3322 } 3323 3324 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 3325 { 3326 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3327 virtio_queue_packed_restore_last_avail_idx(vdev, n); 3328 } else { 3329 virtio_queue_split_restore_last_avail_idx(vdev, n); 3330 } 3331 } 3332 3333 static void virtio_queue_packed_update_used_idx(VirtIODevice *vdev, int n) 3334 { 3335 /* used idx was updated through set_last_avail_idx() */ 3336 return; 3337 } 3338 3339 static void virtio_split_packed_update_used_idx(VirtIODevice *vdev, int n) 3340 { 3341 RCU_READ_LOCK_GUARD(); 3342 if (vdev->vq[n].vring.desc) { 3343 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 3344 } 3345 } 3346 3347 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 3348 { 3349 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3350 return virtio_queue_packed_update_used_idx(vdev, n); 3351 } else { 3352 return virtio_split_packed_update_used_idx(vdev, n); 3353 } 3354 } 3355 3356 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 3357 { 3358 vdev->vq[n].signalled_used_valid = false; 3359 } 3360 3361 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 3362 { 3363 return vdev->vq + n; 3364 } 3365 3366 uint16_t virtio_get_queue_index(VirtQueue *vq) 3367 { 3368 return vq->queue_index; 3369 } 3370 3371 static void virtio_queue_guest_notifier_read(EventNotifier *n) 3372 { 3373 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 3374 if (event_notifier_test_and_clear(n)) { 3375 virtio_irq(vq); 3376 } 3377 } 3378 3379 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 3380 bool with_irqfd) 3381 { 3382 if (assign && !with_irqfd) { 3383 event_notifier_set_handler(&vq->guest_notifier, 3384 virtio_queue_guest_notifier_read); 3385 } else { 3386 event_notifier_set_handler(&vq->guest_notifier, NULL); 3387 } 3388 if (!assign) { 3389 /* Test and clear notifier before closing it, 3390 * in case poll callback didn't have time to run. */ 3391 virtio_queue_guest_notifier_read(&vq->guest_notifier); 3392 } 3393 } 3394 3395 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 3396 { 3397 return &vq->guest_notifier; 3398 } 3399 3400 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 3401 { 3402 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3403 if (event_notifier_test_and_clear(n)) { 3404 virtio_queue_notify_aio_vq(vq); 3405 } 3406 } 3407 3408 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 3409 { 3410 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3411 3412 virtio_queue_set_notification(vq, 0); 3413 } 3414 3415 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 3416 { 3417 EventNotifier *n = opaque; 3418 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3419 3420 if (!vq->vring.desc || virtio_queue_empty(vq)) { 3421 return false; 3422 } 3423 3424 return virtio_queue_notify_aio_vq(vq); 3425 } 3426 3427 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 3428 { 3429 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3430 3431 /* Caller polls once more after this to catch requests that race with us */ 3432 virtio_queue_set_notification(vq, 1); 3433 } 3434 3435 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 3436 VirtIOHandleAIOOutput handle_output) 3437 { 3438 if (handle_output) { 3439 vq->handle_aio_output = handle_output; 3440 aio_set_event_notifier(ctx, &vq->host_notifier, true, 3441 virtio_queue_host_notifier_aio_read, 3442 virtio_queue_host_notifier_aio_poll); 3443 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 3444 virtio_queue_host_notifier_aio_poll_begin, 3445 virtio_queue_host_notifier_aio_poll_end); 3446 } else { 3447 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 3448 /* Test and clear notifier before after disabling event, 3449 * in case poll callback didn't have time to run. */ 3450 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 3451 vq->handle_aio_output = NULL; 3452 } 3453 } 3454 3455 void virtio_queue_host_notifier_read(EventNotifier *n) 3456 { 3457 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3458 if (event_notifier_test_and_clear(n)) { 3459 virtio_queue_notify_vq(vq); 3460 } 3461 } 3462 3463 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 3464 { 3465 return &vq->host_notifier; 3466 } 3467 3468 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled) 3469 { 3470 vq->host_notifier_enabled = enabled; 3471 } 3472 3473 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 3474 MemoryRegion *mr, bool assign) 3475 { 3476 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3477 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3478 3479 if (k->set_host_notifier_mr) { 3480 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 3481 } 3482 3483 return -1; 3484 } 3485 3486 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 3487 { 3488 g_free(vdev->bus_name); 3489 vdev->bus_name = g_strdup(bus_name); 3490 } 3491 3492 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 3493 { 3494 va_list ap; 3495 3496 va_start(ap, fmt); 3497 error_vreport(fmt, ap); 3498 va_end(ap); 3499 3500 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3501 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 3502 virtio_notify_config(vdev); 3503 } 3504 3505 vdev->broken = true; 3506 } 3507 3508 static void virtio_memory_listener_commit(MemoryListener *listener) 3509 { 3510 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 3511 int i; 3512 3513 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3514 if (vdev->vq[i].vring.num == 0) { 3515 break; 3516 } 3517 virtio_init_region_cache(vdev, i); 3518 } 3519 } 3520 3521 static void virtio_device_realize(DeviceState *dev, Error **errp) 3522 { 3523 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3524 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3525 Error *err = NULL; 3526 3527 /* Devices should either use vmsd or the load/save methods */ 3528 assert(!vdc->vmsd || !vdc->load); 3529 3530 if (vdc->realize != NULL) { 3531 vdc->realize(dev, &err); 3532 if (err != NULL) { 3533 error_propagate(errp, err); 3534 return; 3535 } 3536 } 3537 3538 virtio_bus_device_plugged(vdev, &err); 3539 if (err != NULL) { 3540 error_propagate(errp, err); 3541 vdc->unrealize(dev, NULL); 3542 return; 3543 } 3544 3545 vdev->listener.commit = virtio_memory_listener_commit; 3546 memory_listener_register(&vdev->listener, vdev->dma_as); 3547 } 3548 3549 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 3550 { 3551 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3552 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3553 Error *err = NULL; 3554 3555 virtio_bus_device_unplugged(vdev); 3556 3557 if (vdc->unrealize != NULL) { 3558 vdc->unrealize(dev, &err); 3559 if (err != NULL) { 3560 error_propagate(errp, err); 3561 return; 3562 } 3563 } 3564 3565 g_free(vdev->bus_name); 3566 vdev->bus_name = NULL; 3567 } 3568 3569 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 3570 { 3571 int i; 3572 if (!vdev->vq) { 3573 return; 3574 } 3575 3576 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3577 if (vdev->vq[i].vring.num == 0) { 3578 break; 3579 } 3580 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 3581 } 3582 g_free(vdev->vq); 3583 } 3584 3585 static void virtio_device_instance_finalize(Object *obj) 3586 { 3587 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 3588 3589 memory_listener_unregister(&vdev->listener); 3590 virtio_device_free_virtqueues(vdev); 3591 3592 g_free(vdev->config); 3593 g_free(vdev->vector_queues); 3594 } 3595 3596 static Property virtio_properties[] = { 3597 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 3598 DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true), 3599 DEFINE_PROP_BOOL("use-disabled-flag", VirtIODevice, use_disabled_flag, true), 3600 DEFINE_PROP_END_OF_LIST(), 3601 }; 3602 3603 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 3604 { 3605 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3606 int i, n, r, err; 3607 3608 memory_region_transaction_begin(); 3609 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3610 VirtQueue *vq = &vdev->vq[n]; 3611 if (!virtio_queue_get_num(vdev, n)) { 3612 continue; 3613 } 3614 r = virtio_bus_set_host_notifier(qbus, n, true); 3615 if (r < 0) { 3616 err = r; 3617 goto assign_error; 3618 } 3619 event_notifier_set_handler(&vq->host_notifier, 3620 virtio_queue_host_notifier_read); 3621 } 3622 3623 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3624 /* Kick right away to begin processing requests already in vring */ 3625 VirtQueue *vq = &vdev->vq[n]; 3626 if (!vq->vring.num) { 3627 continue; 3628 } 3629 event_notifier_set(&vq->host_notifier); 3630 } 3631 memory_region_transaction_commit(); 3632 return 0; 3633 3634 assign_error: 3635 i = n; /* save n for a second iteration after transaction is committed. */ 3636 while (--n >= 0) { 3637 VirtQueue *vq = &vdev->vq[n]; 3638 if (!virtio_queue_get_num(vdev, n)) { 3639 continue; 3640 } 3641 3642 event_notifier_set_handler(&vq->host_notifier, NULL); 3643 r = virtio_bus_set_host_notifier(qbus, n, false); 3644 assert(r >= 0); 3645 } 3646 memory_region_transaction_commit(); 3647 3648 while (--i >= 0) { 3649 if (!virtio_queue_get_num(vdev, i)) { 3650 continue; 3651 } 3652 virtio_bus_cleanup_host_notifier(qbus, i); 3653 } 3654 return err; 3655 } 3656 3657 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 3658 { 3659 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3660 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3661 3662 return virtio_bus_start_ioeventfd(vbus); 3663 } 3664 3665 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 3666 { 3667 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3668 int n, r; 3669 3670 memory_region_transaction_begin(); 3671 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3672 VirtQueue *vq = &vdev->vq[n]; 3673 3674 if (!virtio_queue_get_num(vdev, n)) { 3675 continue; 3676 } 3677 event_notifier_set_handler(&vq->host_notifier, NULL); 3678 r = virtio_bus_set_host_notifier(qbus, n, false); 3679 assert(r >= 0); 3680 } 3681 memory_region_transaction_commit(); 3682 3683 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3684 if (!virtio_queue_get_num(vdev, n)) { 3685 continue; 3686 } 3687 virtio_bus_cleanup_host_notifier(qbus, n); 3688 } 3689 } 3690 3691 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 3692 { 3693 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3694 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3695 3696 return virtio_bus_grab_ioeventfd(vbus); 3697 } 3698 3699 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 3700 { 3701 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3702 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3703 3704 virtio_bus_release_ioeventfd(vbus); 3705 } 3706 3707 static void virtio_device_class_init(ObjectClass *klass, void *data) 3708 { 3709 /* Set the default value here. */ 3710 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 3711 DeviceClass *dc = DEVICE_CLASS(klass); 3712 3713 dc->realize = virtio_device_realize; 3714 dc->unrealize = virtio_device_unrealize; 3715 dc->bus_type = TYPE_VIRTIO_BUS; 3716 device_class_set_props(dc, virtio_properties); 3717 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 3718 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 3719 3720 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 3721 } 3722 3723 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 3724 { 3725 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3726 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3727 3728 return virtio_bus_ioeventfd_enabled(vbus); 3729 } 3730 3731 static const TypeInfo virtio_device_info = { 3732 .name = TYPE_VIRTIO_DEVICE, 3733 .parent = TYPE_DEVICE, 3734 .instance_size = sizeof(VirtIODevice), 3735 .class_init = virtio_device_class_init, 3736 .instance_finalize = virtio_device_instance_finalize, 3737 .abstract = true, 3738 .class_size = sizeof(VirtioDeviceClass), 3739 }; 3740 3741 static void virtio_register_types(void) 3742 { 3743 type_register_static(&virtio_device_info); 3744 } 3745 3746 type_init(virtio_register_types) 3747