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 "qapi/qapi-commands-virtio.h" 17 #include "trace.h" 18 #include "qemu/error-report.h" 19 #include "qemu/log.h" 20 #include "qemu/main-loop.h" 21 #include "qemu/module.h" 22 #include "qom/object_interfaces.h" 23 #include "hw/core/cpu.h" 24 #include "hw/virtio/virtio.h" 25 #include "hw/virtio/vhost.h" 26 #include "migration/qemu-file-types.h" 27 #include "qemu/atomic.h" 28 #include "hw/virtio/virtio-bus.h" 29 #include "hw/qdev-properties.h" 30 #include "hw/virtio/virtio-access.h" 31 #include "sysemu/dma.h" 32 #include "sysemu/runstate.h" 33 #include "virtio-qmp.h" 34 35 #include "standard-headers/linux/virtio_ids.h" 36 #include "standard-headers/linux/vhost_types.h" 37 #include "standard-headers/linux/virtio_blk.h" 38 #include "standard-headers/linux/virtio_console.h" 39 #include "standard-headers/linux/virtio_gpu.h" 40 #include "standard-headers/linux/virtio_net.h" 41 #include "standard-headers/linux/virtio_scsi.h" 42 #include "standard-headers/linux/virtio_i2c.h" 43 #include "standard-headers/linux/virtio_balloon.h" 44 #include "standard-headers/linux/virtio_iommu.h" 45 #include "standard-headers/linux/virtio_mem.h" 46 #include "standard-headers/linux/virtio_vsock.h" 47 48 /* 49 * Maximum size of virtio device config space 50 */ 51 #define VHOST_USER_MAX_CONFIG_SIZE 256 52 53 /* 54 * The alignment to use between consumer and producer parts of vring. 55 * x86 pagesize again. This is the default, used by transports like PCI 56 * which don't provide a means for the guest to tell the host the alignment. 57 */ 58 #define VIRTIO_PCI_VRING_ALIGN 4096 59 60 typedef struct VRingDesc 61 { 62 uint64_t addr; 63 uint32_t len; 64 uint16_t flags; 65 uint16_t next; 66 } VRingDesc; 67 68 typedef struct VRingPackedDesc { 69 uint64_t addr; 70 uint32_t len; 71 uint16_t id; 72 uint16_t flags; 73 } VRingPackedDesc; 74 75 typedef struct VRingAvail 76 { 77 uint16_t flags; 78 uint16_t idx; 79 uint16_t ring[]; 80 } VRingAvail; 81 82 typedef struct VRingUsedElem 83 { 84 uint32_t id; 85 uint32_t len; 86 } VRingUsedElem; 87 88 typedef struct VRingUsed 89 { 90 uint16_t flags; 91 uint16_t idx; 92 VRingUsedElem ring[]; 93 } VRingUsed; 94 95 typedef struct VRingMemoryRegionCaches { 96 struct rcu_head rcu; 97 MemoryRegionCache desc; 98 MemoryRegionCache avail; 99 MemoryRegionCache used; 100 } VRingMemoryRegionCaches; 101 102 typedef struct VRing 103 { 104 unsigned int num; 105 unsigned int num_default; 106 unsigned int align; 107 hwaddr desc; 108 hwaddr avail; 109 hwaddr used; 110 VRingMemoryRegionCaches *caches; 111 } VRing; 112 113 typedef struct VRingPackedDescEvent { 114 uint16_t off_wrap; 115 uint16_t flags; 116 } VRingPackedDescEvent ; 117 118 struct VirtQueue 119 { 120 VRing vring; 121 VirtQueueElement *used_elems; 122 123 /* Next head to pop */ 124 uint16_t last_avail_idx; 125 bool last_avail_wrap_counter; 126 127 /* Last avail_idx read from VQ. */ 128 uint16_t shadow_avail_idx; 129 bool shadow_avail_wrap_counter; 130 131 uint16_t used_idx; 132 bool used_wrap_counter; 133 134 /* Last used index value we have signalled on */ 135 uint16_t signalled_used; 136 137 /* Last used index value we have signalled on */ 138 bool signalled_used_valid; 139 140 /* Notification enabled? */ 141 bool notification; 142 143 uint16_t queue_index; 144 145 unsigned int inuse; 146 147 uint16_t vector; 148 VirtIOHandleOutput handle_output; 149 VirtIODevice *vdev; 150 EventNotifier guest_notifier; 151 EventNotifier host_notifier; 152 bool host_notifier_enabled; 153 QLIST_ENTRY(VirtQueue) node; 154 }; 155 156 const char *virtio_device_names[] = { 157 [VIRTIO_ID_NET] = "virtio-net", 158 [VIRTIO_ID_BLOCK] = "virtio-blk", 159 [VIRTIO_ID_CONSOLE] = "virtio-serial", 160 [VIRTIO_ID_RNG] = "virtio-rng", 161 [VIRTIO_ID_BALLOON] = "virtio-balloon", 162 [VIRTIO_ID_IOMEM] = "virtio-iomem", 163 [VIRTIO_ID_RPMSG] = "virtio-rpmsg", 164 [VIRTIO_ID_SCSI] = "virtio-scsi", 165 [VIRTIO_ID_9P] = "virtio-9p", 166 [VIRTIO_ID_MAC80211_WLAN] = "virtio-mac-wlan", 167 [VIRTIO_ID_RPROC_SERIAL] = "virtio-rproc-serial", 168 [VIRTIO_ID_CAIF] = "virtio-caif", 169 [VIRTIO_ID_MEMORY_BALLOON] = "virtio-mem-balloon", 170 [VIRTIO_ID_GPU] = "virtio-gpu", 171 [VIRTIO_ID_CLOCK] = "virtio-clk", 172 [VIRTIO_ID_INPUT] = "virtio-input", 173 [VIRTIO_ID_VSOCK] = "vhost-vsock", 174 [VIRTIO_ID_CRYPTO] = "virtio-crypto", 175 [VIRTIO_ID_SIGNAL_DIST] = "virtio-signal", 176 [VIRTIO_ID_PSTORE] = "virtio-pstore", 177 [VIRTIO_ID_IOMMU] = "virtio-iommu", 178 [VIRTIO_ID_MEM] = "virtio-mem", 179 [VIRTIO_ID_SOUND] = "virtio-sound", 180 [VIRTIO_ID_FS] = "virtio-user-fs", 181 [VIRTIO_ID_PMEM] = "virtio-pmem", 182 [VIRTIO_ID_RPMB] = "virtio-rpmb", 183 [VIRTIO_ID_MAC80211_HWSIM] = "virtio-mac-hwsim", 184 [VIRTIO_ID_VIDEO_ENCODER] = "virtio-vid-encoder", 185 [VIRTIO_ID_VIDEO_DECODER] = "virtio-vid-decoder", 186 [VIRTIO_ID_SCMI] = "virtio-scmi", 187 [VIRTIO_ID_NITRO_SEC_MOD] = "virtio-nitro-sec-mod", 188 [VIRTIO_ID_I2C_ADAPTER] = "vhost-user-i2c", 189 [VIRTIO_ID_WATCHDOG] = "virtio-watchdog", 190 [VIRTIO_ID_CAN] = "virtio-can", 191 [VIRTIO_ID_DMABUF] = "virtio-dmabuf", 192 [VIRTIO_ID_PARAM_SERV] = "virtio-param-serv", 193 [VIRTIO_ID_AUDIO_POLICY] = "virtio-audio-pol", 194 [VIRTIO_ID_BT] = "virtio-bluetooth", 195 [VIRTIO_ID_GPIO] = "virtio-gpio" 196 }; 197 198 static const char *virtio_id_to_name(uint16_t device_id) 199 { 200 assert(device_id < G_N_ELEMENTS(virtio_device_names)); 201 const char *name = virtio_device_names[device_id]; 202 assert(name != NULL); 203 return name; 204 } 205 206 /* Called within call_rcu(). */ 207 static void virtio_free_region_cache(VRingMemoryRegionCaches *caches) 208 { 209 assert(caches != NULL); 210 address_space_cache_destroy(&caches->desc); 211 address_space_cache_destroy(&caches->avail); 212 address_space_cache_destroy(&caches->used); 213 g_free(caches); 214 } 215 216 static void virtio_virtqueue_reset_region_cache(struct VirtQueue *vq) 217 { 218 VRingMemoryRegionCaches *caches; 219 220 caches = qatomic_read(&vq->vring.caches); 221 qatomic_rcu_set(&vq->vring.caches, NULL); 222 if (caches) { 223 call_rcu(caches, virtio_free_region_cache, rcu); 224 } 225 } 226 227 void virtio_init_region_cache(VirtIODevice *vdev, int n) 228 { 229 VirtQueue *vq = &vdev->vq[n]; 230 VRingMemoryRegionCaches *old = vq->vring.caches; 231 VRingMemoryRegionCaches *new = NULL; 232 hwaddr addr, size; 233 int64_t len; 234 bool packed; 235 236 237 addr = vq->vring.desc; 238 if (!addr) { 239 goto out_no_cache; 240 } 241 new = g_new0(VRingMemoryRegionCaches, 1); 242 size = virtio_queue_get_desc_size(vdev, n); 243 packed = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ? 244 true : false; 245 len = address_space_cache_init(&new->desc, vdev->dma_as, 246 addr, size, packed); 247 if (len < size) { 248 virtio_error(vdev, "Cannot map desc"); 249 goto err_desc; 250 } 251 252 size = virtio_queue_get_used_size(vdev, n); 253 len = address_space_cache_init(&new->used, vdev->dma_as, 254 vq->vring.used, size, true); 255 if (len < size) { 256 virtio_error(vdev, "Cannot map used"); 257 goto err_used; 258 } 259 260 size = virtio_queue_get_avail_size(vdev, n); 261 len = address_space_cache_init(&new->avail, vdev->dma_as, 262 vq->vring.avail, size, false); 263 if (len < size) { 264 virtio_error(vdev, "Cannot map avail"); 265 goto err_avail; 266 } 267 268 qatomic_rcu_set(&vq->vring.caches, new); 269 if (old) { 270 call_rcu(old, virtio_free_region_cache, rcu); 271 } 272 return; 273 274 err_avail: 275 address_space_cache_destroy(&new->avail); 276 err_used: 277 address_space_cache_destroy(&new->used); 278 err_desc: 279 address_space_cache_destroy(&new->desc); 280 out_no_cache: 281 g_free(new); 282 virtio_virtqueue_reset_region_cache(vq); 283 } 284 285 /* virt queue functions */ 286 void virtio_queue_update_rings(VirtIODevice *vdev, int n) 287 { 288 VRing *vring = &vdev->vq[n].vring; 289 290 if (!vring->num || !vring->desc || !vring->align) { 291 /* not yet setup -> nothing to do */ 292 return; 293 } 294 vring->avail = vring->desc + vring->num * sizeof(VRingDesc); 295 vring->used = vring_align(vring->avail + 296 offsetof(VRingAvail, ring[vring->num]), 297 vring->align); 298 virtio_init_region_cache(vdev, n); 299 } 300 301 /* Called within rcu_read_lock(). */ 302 static void vring_split_desc_read(VirtIODevice *vdev, VRingDesc *desc, 303 MemoryRegionCache *cache, int i) 304 { 305 address_space_read_cached(cache, i * sizeof(VRingDesc), 306 desc, sizeof(VRingDesc)); 307 virtio_tswap64s(vdev, &desc->addr); 308 virtio_tswap32s(vdev, &desc->len); 309 virtio_tswap16s(vdev, &desc->flags); 310 virtio_tswap16s(vdev, &desc->next); 311 } 312 313 static void vring_packed_event_read(VirtIODevice *vdev, 314 MemoryRegionCache *cache, 315 VRingPackedDescEvent *e) 316 { 317 hwaddr off_off = offsetof(VRingPackedDescEvent, off_wrap); 318 hwaddr off_flags = offsetof(VRingPackedDescEvent, flags); 319 320 e->flags = virtio_lduw_phys_cached(vdev, cache, off_flags); 321 /* Make sure flags is seen before off_wrap */ 322 smp_rmb(); 323 e->off_wrap = virtio_lduw_phys_cached(vdev, cache, off_off); 324 virtio_tswap16s(vdev, &e->flags); 325 } 326 327 static void vring_packed_off_wrap_write(VirtIODevice *vdev, 328 MemoryRegionCache *cache, 329 uint16_t off_wrap) 330 { 331 hwaddr off = offsetof(VRingPackedDescEvent, off_wrap); 332 333 virtio_stw_phys_cached(vdev, cache, off, off_wrap); 334 address_space_cache_invalidate(cache, off, sizeof(off_wrap)); 335 } 336 337 static void vring_packed_flags_write(VirtIODevice *vdev, 338 MemoryRegionCache *cache, uint16_t flags) 339 { 340 hwaddr off = offsetof(VRingPackedDescEvent, flags); 341 342 virtio_stw_phys_cached(vdev, cache, off, flags); 343 address_space_cache_invalidate(cache, off, sizeof(flags)); 344 } 345 346 /* Called within rcu_read_lock(). */ 347 static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq) 348 { 349 return qatomic_rcu_read(&vq->vring.caches); 350 } 351 352 /* Called within rcu_read_lock(). */ 353 static inline uint16_t vring_avail_flags(VirtQueue *vq) 354 { 355 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 356 hwaddr pa = offsetof(VRingAvail, flags); 357 358 if (!caches) { 359 return 0; 360 } 361 362 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 363 } 364 365 /* Called within rcu_read_lock(). */ 366 static inline uint16_t vring_avail_idx(VirtQueue *vq) 367 { 368 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 369 hwaddr pa = offsetof(VRingAvail, idx); 370 371 if (!caches) { 372 return 0; 373 } 374 375 vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 376 return vq->shadow_avail_idx; 377 } 378 379 /* Called within rcu_read_lock(). */ 380 static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) 381 { 382 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 383 hwaddr pa = offsetof(VRingAvail, ring[i]); 384 385 if (!caches) { 386 return 0; 387 } 388 389 return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa); 390 } 391 392 /* Called within rcu_read_lock(). */ 393 static inline uint16_t vring_get_used_event(VirtQueue *vq) 394 { 395 return vring_avail_ring(vq, vq->vring.num); 396 } 397 398 /* Called within rcu_read_lock(). */ 399 static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, 400 int i) 401 { 402 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 403 hwaddr pa = offsetof(VRingUsed, ring[i]); 404 405 if (!caches) { 406 return; 407 } 408 409 virtio_tswap32s(vq->vdev, &uelem->id); 410 virtio_tswap32s(vq->vdev, &uelem->len); 411 address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem)); 412 address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem)); 413 } 414 415 /* Called within rcu_read_lock(). */ 416 static inline uint16_t vring_used_flags(VirtQueue *vq) 417 { 418 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 419 hwaddr pa = offsetof(VRingUsed, flags); 420 421 if (!caches) { 422 return 0; 423 } 424 425 return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 426 } 427 428 /* Called within rcu_read_lock(). */ 429 static uint16_t vring_used_idx(VirtQueue *vq) 430 { 431 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 432 hwaddr pa = offsetof(VRingUsed, idx); 433 434 if (!caches) { 435 return 0; 436 } 437 438 return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 439 } 440 441 /* Called within rcu_read_lock(). */ 442 static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val) 443 { 444 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 445 hwaddr pa = offsetof(VRingUsed, idx); 446 447 if (caches) { 448 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 449 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 450 } 451 452 vq->used_idx = val; 453 } 454 455 /* Called within rcu_read_lock(). */ 456 static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) 457 { 458 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 459 VirtIODevice *vdev = vq->vdev; 460 hwaddr pa = offsetof(VRingUsed, flags); 461 uint16_t flags; 462 463 if (!caches) { 464 return; 465 } 466 467 flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 468 virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask); 469 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 470 } 471 472 /* Called within rcu_read_lock(). */ 473 static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) 474 { 475 VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); 476 VirtIODevice *vdev = vq->vdev; 477 hwaddr pa = offsetof(VRingUsed, flags); 478 uint16_t flags; 479 480 if (!caches) { 481 return; 482 } 483 484 flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); 485 virtio_stw_phys_cached(vdev, &caches->used, pa, flags & ~mask); 486 address_space_cache_invalidate(&caches->used, pa, sizeof(flags)); 487 } 488 489 /* Called within rcu_read_lock(). */ 490 static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) 491 { 492 VRingMemoryRegionCaches *caches; 493 hwaddr pa; 494 if (!vq->notification) { 495 return; 496 } 497 498 caches = vring_get_region_caches(vq); 499 if (!caches) { 500 return; 501 } 502 503 pa = offsetof(VRingUsed, ring[vq->vring.num]); 504 virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val); 505 address_space_cache_invalidate(&caches->used, pa, sizeof(val)); 506 } 507 508 static void virtio_queue_split_set_notification(VirtQueue *vq, int enable) 509 { 510 RCU_READ_LOCK_GUARD(); 511 512 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 513 vring_set_avail_event(vq, vring_avail_idx(vq)); 514 } else if (enable) { 515 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); 516 } else { 517 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); 518 } 519 if (enable) { 520 /* Expose avail event/used flags before caller checks the avail idx. */ 521 smp_mb(); 522 } 523 } 524 525 static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) 526 { 527 uint16_t off_wrap; 528 VRingPackedDescEvent e; 529 VRingMemoryRegionCaches *caches; 530 531 RCU_READ_LOCK_GUARD(); 532 caches = vring_get_region_caches(vq); 533 if (!caches) { 534 return; 535 } 536 537 vring_packed_event_read(vq->vdev, &caches->used, &e); 538 539 if (!enable) { 540 e.flags = VRING_PACKED_EVENT_FLAG_DISABLE; 541 } else if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 542 off_wrap = vq->shadow_avail_idx | vq->shadow_avail_wrap_counter << 15; 543 vring_packed_off_wrap_write(vq->vdev, &caches->used, off_wrap); 544 /* Make sure off_wrap is wrote before flags */ 545 smp_wmb(); 546 e.flags = VRING_PACKED_EVENT_FLAG_DESC; 547 } else { 548 e.flags = VRING_PACKED_EVENT_FLAG_ENABLE; 549 } 550 551 vring_packed_flags_write(vq->vdev, &caches->used, e.flags); 552 if (enable) { 553 /* Expose avail event/used flags before caller checks the avail idx. */ 554 smp_mb(); 555 } 556 } 557 558 bool virtio_queue_get_notification(VirtQueue *vq) 559 { 560 return vq->notification; 561 } 562 563 void virtio_queue_set_notification(VirtQueue *vq, int enable) 564 { 565 vq->notification = enable; 566 567 if (!vq->vring.desc) { 568 return; 569 } 570 571 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 572 virtio_queue_packed_set_notification(vq, enable); 573 } else { 574 virtio_queue_split_set_notification(vq, enable); 575 } 576 } 577 578 int virtio_queue_ready(VirtQueue *vq) 579 { 580 return vq->vring.avail != 0; 581 } 582 583 static void vring_packed_desc_read_flags(VirtIODevice *vdev, 584 uint16_t *flags, 585 MemoryRegionCache *cache, 586 int i) 587 { 588 hwaddr off = i * sizeof(VRingPackedDesc) + offsetof(VRingPackedDesc, flags); 589 590 *flags = virtio_lduw_phys_cached(vdev, cache, off); 591 } 592 593 static void vring_packed_desc_read(VirtIODevice *vdev, 594 VRingPackedDesc *desc, 595 MemoryRegionCache *cache, 596 int i, bool strict_order) 597 { 598 hwaddr off = i * sizeof(VRingPackedDesc); 599 600 vring_packed_desc_read_flags(vdev, &desc->flags, cache, i); 601 602 if (strict_order) { 603 /* Make sure flags is read before the rest fields. */ 604 smp_rmb(); 605 } 606 607 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, addr), 608 &desc->addr, sizeof(desc->addr)); 609 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, id), 610 &desc->id, sizeof(desc->id)); 611 address_space_read_cached(cache, off + offsetof(VRingPackedDesc, len), 612 &desc->len, sizeof(desc->len)); 613 virtio_tswap64s(vdev, &desc->addr); 614 virtio_tswap16s(vdev, &desc->id); 615 virtio_tswap32s(vdev, &desc->len); 616 } 617 618 static void vring_packed_desc_write_data(VirtIODevice *vdev, 619 VRingPackedDesc *desc, 620 MemoryRegionCache *cache, 621 int i) 622 { 623 hwaddr off_id = i * sizeof(VRingPackedDesc) + 624 offsetof(VRingPackedDesc, id); 625 hwaddr off_len = i * sizeof(VRingPackedDesc) + 626 offsetof(VRingPackedDesc, len); 627 628 virtio_tswap32s(vdev, &desc->len); 629 virtio_tswap16s(vdev, &desc->id); 630 address_space_write_cached(cache, off_id, &desc->id, sizeof(desc->id)); 631 address_space_cache_invalidate(cache, off_id, sizeof(desc->id)); 632 address_space_write_cached(cache, off_len, &desc->len, sizeof(desc->len)); 633 address_space_cache_invalidate(cache, off_len, sizeof(desc->len)); 634 } 635 636 static void vring_packed_desc_write_flags(VirtIODevice *vdev, 637 VRingPackedDesc *desc, 638 MemoryRegionCache *cache, 639 int i) 640 { 641 hwaddr off = i * sizeof(VRingPackedDesc) + offsetof(VRingPackedDesc, flags); 642 643 virtio_stw_phys_cached(vdev, cache, off, desc->flags); 644 address_space_cache_invalidate(cache, off, sizeof(desc->flags)); 645 } 646 647 static void vring_packed_desc_write(VirtIODevice *vdev, 648 VRingPackedDesc *desc, 649 MemoryRegionCache *cache, 650 int i, bool strict_order) 651 { 652 vring_packed_desc_write_data(vdev, desc, cache, i); 653 if (strict_order) { 654 /* Make sure data is wrote before flags. */ 655 smp_wmb(); 656 } 657 vring_packed_desc_write_flags(vdev, desc, cache, i); 658 } 659 660 static inline bool is_desc_avail(uint16_t flags, bool wrap_counter) 661 { 662 bool avail, used; 663 664 avail = !!(flags & (1 << VRING_PACKED_DESC_F_AVAIL)); 665 used = !!(flags & (1 << VRING_PACKED_DESC_F_USED)); 666 return (avail != used) && (avail == wrap_counter); 667 } 668 669 /* Fetch avail_idx from VQ memory only when we really need to know if 670 * guest has added some buffers. 671 * Called within rcu_read_lock(). */ 672 static int virtio_queue_empty_rcu(VirtQueue *vq) 673 { 674 if (virtio_device_disabled(vq->vdev)) { 675 return 1; 676 } 677 678 if (unlikely(!vq->vring.avail)) { 679 return 1; 680 } 681 682 if (vq->shadow_avail_idx != vq->last_avail_idx) { 683 return 0; 684 } 685 686 return vring_avail_idx(vq) == vq->last_avail_idx; 687 } 688 689 static int virtio_queue_split_empty(VirtQueue *vq) 690 { 691 bool empty; 692 693 if (virtio_device_disabled(vq->vdev)) { 694 return 1; 695 } 696 697 if (unlikely(!vq->vring.avail)) { 698 return 1; 699 } 700 701 if (vq->shadow_avail_idx != vq->last_avail_idx) { 702 return 0; 703 } 704 705 RCU_READ_LOCK_GUARD(); 706 empty = vring_avail_idx(vq) == vq->last_avail_idx; 707 return empty; 708 } 709 710 /* Called within rcu_read_lock(). */ 711 static int virtio_queue_packed_empty_rcu(VirtQueue *vq) 712 { 713 struct VRingPackedDesc desc; 714 VRingMemoryRegionCaches *cache; 715 716 if (unlikely(!vq->vring.desc)) { 717 return 1; 718 } 719 720 cache = vring_get_region_caches(vq); 721 if (!cache) { 722 return 1; 723 } 724 725 vring_packed_desc_read_flags(vq->vdev, &desc.flags, &cache->desc, 726 vq->last_avail_idx); 727 728 return !is_desc_avail(desc.flags, vq->last_avail_wrap_counter); 729 } 730 731 static int virtio_queue_packed_empty(VirtQueue *vq) 732 { 733 RCU_READ_LOCK_GUARD(); 734 return virtio_queue_packed_empty_rcu(vq); 735 } 736 737 int virtio_queue_empty(VirtQueue *vq) 738 { 739 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 740 return virtio_queue_packed_empty(vq); 741 } else { 742 return virtio_queue_split_empty(vq); 743 } 744 } 745 746 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 747 unsigned int len) 748 { 749 AddressSpace *dma_as = vq->vdev->dma_as; 750 unsigned int offset; 751 int i; 752 753 offset = 0; 754 for (i = 0; i < elem->in_num; i++) { 755 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 756 757 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 758 elem->in_sg[i].iov_len, 759 DMA_DIRECTION_FROM_DEVICE, size); 760 761 offset += size; 762 } 763 764 for (i = 0; i < elem->out_num; i++) 765 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 766 elem->out_sg[i].iov_len, 767 DMA_DIRECTION_TO_DEVICE, 768 elem->out_sg[i].iov_len); 769 } 770 771 /* virtqueue_detach_element: 772 * @vq: The #VirtQueue 773 * @elem: The #VirtQueueElement 774 * @len: number of bytes written 775 * 776 * Detach the element from the virtqueue. This function is suitable for device 777 * reset or other situations where a #VirtQueueElement is simply freed and will 778 * not be pushed or discarded. 779 */ 780 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 781 unsigned int len) 782 { 783 vq->inuse -= elem->ndescs; 784 virtqueue_unmap_sg(vq, elem, len); 785 } 786 787 static void virtqueue_split_rewind(VirtQueue *vq, unsigned int num) 788 { 789 vq->last_avail_idx -= num; 790 } 791 792 static void virtqueue_packed_rewind(VirtQueue *vq, unsigned int num) 793 { 794 if (vq->last_avail_idx < num) { 795 vq->last_avail_idx = vq->vring.num + vq->last_avail_idx - num; 796 vq->last_avail_wrap_counter ^= 1; 797 } else { 798 vq->last_avail_idx -= num; 799 } 800 } 801 802 /* virtqueue_unpop: 803 * @vq: The #VirtQueue 804 * @elem: The #VirtQueueElement 805 * @len: number of bytes written 806 * 807 * Pretend the most recent element wasn't popped from the virtqueue. The next 808 * call to virtqueue_pop() will refetch the element. 809 */ 810 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 811 unsigned int len) 812 { 813 814 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 815 virtqueue_packed_rewind(vq, 1); 816 } else { 817 virtqueue_split_rewind(vq, 1); 818 } 819 820 virtqueue_detach_element(vq, elem, len); 821 } 822 823 /* virtqueue_rewind: 824 * @vq: The #VirtQueue 825 * @num: Number of elements to push back 826 * 827 * Pretend that elements weren't popped from the virtqueue. The next 828 * virtqueue_pop() will refetch the oldest element. 829 * 830 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 831 * 832 * Returns: true on success, false if @num is greater than the number of in use 833 * elements. 834 */ 835 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 836 { 837 if (num > vq->inuse) { 838 return false; 839 } 840 841 vq->inuse -= num; 842 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 843 virtqueue_packed_rewind(vq, num); 844 } else { 845 virtqueue_split_rewind(vq, num); 846 } 847 return true; 848 } 849 850 static void virtqueue_split_fill(VirtQueue *vq, const VirtQueueElement *elem, 851 unsigned int len, unsigned int idx) 852 { 853 VRingUsedElem uelem; 854 855 if (unlikely(!vq->vring.used)) { 856 return; 857 } 858 859 idx = (idx + vq->used_idx) % vq->vring.num; 860 861 uelem.id = elem->index; 862 uelem.len = len; 863 vring_used_write(vq, &uelem, idx); 864 } 865 866 static void virtqueue_packed_fill(VirtQueue *vq, const VirtQueueElement *elem, 867 unsigned int len, unsigned int idx) 868 { 869 vq->used_elems[idx].index = elem->index; 870 vq->used_elems[idx].len = len; 871 vq->used_elems[idx].ndescs = elem->ndescs; 872 } 873 874 static void virtqueue_packed_fill_desc(VirtQueue *vq, 875 const VirtQueueElement *elem, 876 unsigned int idx, 877 bool strict_order) 878 { 879 uint16_t head; 880 VRingMemoryRegionCaches *caches; 881 VRingPackedDesc desc = { 882 .id = elem->index, 883 .len = elem->len, 884 }; 885 bool wrap_counter = vq->used_wrap_counter; 886 887 if (unlikely(!vq->vring.desc)) { 888 return; 889 } 890 891 head = vq->used_idx + idx; 892 if (head >= vq->vring.num) { 893 head -= vq->vring.num; 894 wrap_counter ^= 1; 895 } 896 if (wrap_counter) { 897 desc.flags |= (1 << VRING_PACKED_DESC_F_AVAIL); 898 desc.flags |= (1 << VRING_PACKED_DESC_F_USED); 899 } else { 900 desc.flags &= ~(1 << VRING_PACKED_DESC_F_AVAIL); 901 desc.flags &= ~(1 << VRING_PACKED_DESC_F_USED); 902 } 903 904 caches = vring_get_region_caches(vq); 905 if (!caches) { 906 return; 907 } 908 909 vring_packed_desc_write(vq->vdev, &desc, &caches->desc, head, strict_order); 910 } 911 912 /* Called within rcu_read_lock(). */ 913 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 914 unsigned int len, unsigned int idx) 915 { 916 trace_virtqueue_fill(vq, elem, len, idx); 917 918 virtqueue_unmap_sg(vq, elem, len); 919 920 if (virtio_device_disabled(vq->vdev)) { 921 return; 922 } 923 924 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 925 virtqueue_packed_fill(vq, elem, len, idx); 926 } else { 927 virtqueue_split_fill(vq, elem, len, idx); 928 } 929 } 930 931 /* Called within rcu_read_lock(). */ 932 static void virtqueue_split_flush(VirtQueue *vq, unsigned int count) 933 { 934 uint16_t old, new; 935 936 if (unlikely(!vq->vring.used)) { 937 return; 938 } 939 940 /* Make sure buffer is written before we update index. */ 941 smp_wmb(); 942 trace_virtqueue_flush(vq, count); 943 old = vq->used_idx; 944 new = old + count; 945 vring_used_idx_set(vq, new); 946 vq->inuse -= count; 947 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 948 vq->signalled_used_valid = false; 949 } 950 951 static void virtqueue_packed_flush(VirtQueue *vq, unsigned int count) 952 { 953 unsigned int i, ndescs = 0; 954 955 if (unlikely(!vq->vring.desc)) { 956 return; 957 } 958 959 for (i = 1; i < count; i++) { 960 virtqueue_packed_fill_desc(vq, &vq->used_elems[i], i, false); 961 ndescs += vq->used_elems[i].ndescs; 962 } 963 virtqueue_packed_fill_desc(vq, &vq->used_elems[0], 0, true); 964 ndescs += vq->used_elems[0].ndescs; 965 966 vq->inuse -= ndescs; 967 vq->used_idx += ndescs; 968 if (vq->used_idx >= vq->vring.num) { 969 vq->used_idx -= vq->vring.num; 970 vq->used_wrap_counter ^= 1; 971 vq->signalled_used_valid = false; 972 } 973 } 974 975 void virtqueue_flush(VirtQueue *vq, unsigned int count) 976 { 977 if (virtio_device_disabled(vq->vdev)) { 978 vq->inuse -= count; 979 return; 980 } 981 982 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 983 virtqueue_packed_flush(vq, count); 984 } else { 985 virtqueue_split_flush(vq, count); 986 } 987 } 988 989 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 990 unsigned int len) 991 { 992 RCU_READ_LOCK_GUARD(); 993 virtqueue_fill(vq, elem, len, 0); 994 virtqueue_flush(vq, 1); 995 } 996 997 /* Called within rcu_read_lock(). */ 998 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 999 { 1000 uint16_t avail_idx, num_heads; 1001 1002 /* Use shadow index whenever possible. */ 1003 avail_idx = (vq->shadow_avail_idx != idx) ? vq->shadow_avail_idx 1004 : vring_avail_idx(vq); 1005 num_heads = avail_idx - idx; 1006 1007 /* Check it isn't doing very strange things with descriptor numbers. */ 1008 if (num_heads > vq->vring.num) { 1009 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 1010 idx, vq->shadow_avail_idx); 1011 return -EINVAL; 1012 } 1013 /* 1014 * On success, callers read a descriptor at vq->last_avail_idx. 1015 * Make sure descriptor read does not bypass avail index read. 1016 * 1017 * This is necessary even if we are using a shadow index, since 1018 * the shadow index could have been initialized by calling 1019 * vring_avail_idx() outside of this function, i.e., by a guest 1020 * memory read not accompanied by a barrier. 1021 */ 1022 if (num_heads) { 1023 smp_rmb(); 1024 } 1025 1026 return num_heads; 1027 } 1028 1029 /* Called within rcu_read_lock(). */ 1030 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 1031 unsigned int *head) 1032 { 1033 /* Grab the next descriptor number they're advertising, and increment 1034 * the index we've seen. */ 1035 *head = vring_avail_ring(vq, idx % vq->vring.num); 1036 1037 /* If their number is silly, that's a fatal mistake. */ 1038 if (*head >= vq->vring.num) { 1039 virtio_error(vq->vdev, "Guest says index %u is available", *head); 1040 return false; 1041 } 1042 1043 return true; 1044 } 1045 1046 enum { 1047 VIRTQUEUE_READ_DESC_ERROR = -1, 1048 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 1049 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 1050 }; 1051 1052 /* Reads the 'desc->next' descriptor into '*desc'. */ 1053 static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 1054 MemoryRegionCache *desc_cache, 1055 unsigned int max) 1056 { 1057 /* If this descriptor says it doesn't chain, we're done. */ 1058 if (!(desc->flags & VRING_DESC_F_NEXT)) { 1059 return VIRTQUEUE_READ_DESC_DONE; 1060 } 1061 1062 /* Check they're not leading us off end of descriptors. */ 1063 if (desc->next >= max) { 1064 virtio_error(vdev, "Desc next is %u", desc->next); 1065 return VIRTQUEUE_READ_DESC_ERROR; 1066 } 1067 1068 vring_split_desc_read(vdev, desc, desc_cache, desc->next); 1069 return VIRTQUEUE_READ_DESC_MORE; 1070 } 1071 1072 /* Called within rcu_read_lock(). */ 1073 static void virtqueue_split_get_avail_bytes(VirtQueue *vq, 1074 unsigned int *in_bytes, unsigned int *out_bytes, 1075 unsigned max_in_bytes, unsigned max_out_bytes, 1076 VRingMemoryRegionCaches *caches) 1077 { 1078 VirtIODevice *vdev = vq->vdev; 1079 unsigned int idx; 1080 unsigned int total_bufs, in_total, out_total; 1081 MemoryRegionCache indirect_desc_cache; 1082 int64_t len = 0; 1083 int rc; 1084 1085 address_space_cache_init_empty(&indirect_desc_cache); 1086 1087 idx = vq->last_avail_idx; 1088 total_bufs = in_total = out_total = 0; 1089 1090 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 1091 MemoryRegionCache *desc_cache = &caches->desc; 1092 unsigned int num_bufs; 1093 VRingDesc desc; 1094 unsigned int i; 1095 unsigned int max = vq->vring.num; 1096 1097 num_bufs = total_bufs; 1098 1099 if (!virtqueue_get_head(vq, idx++, &i)) { 1100 goto err; 1101 } 1102 1103 vring_split_desc_read(vdev, &desc, desc_cache, i); 1104 1105 if (desc.flags & VRING_DESC_F_INDIRECT) { 1106 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1107 virtio_error(vdev, "Invalid size for indirect buffer table"); 1108 goto err; 1109 } 1110 1111 /* If we've got too many, that implies a descriptor loop. */ 1112 if (num_bufs >= max) { 1113 virtio_error(vdev, "Looped descriptor"); 1114 goto err; 1115 } 1116 1117 /* loop over the indirect descriptor table */ 1118 len = address_space_cache_init(&indirect_desc_cache, 1119 vdev->dma_as, 1120 desc.addr, desc.len, false); 1121 desc_cache = &indirect_desc_cache; 1122 if (len < desc.len) { 1123 virtio_error(vdev, "Cannot map indirect buffer"); 1124 goto err; 1125 } 1126 1127 max = desc.len / sizeof(VRingDesc); 1128 num_bufs = i = 0; 1129 vring_split_desc_read(vdev, &desc, desc_cache, i); 1130 } 1131 1132 do { 1133 /* If we've got too many, that implies a descriptor loop. */ 1134 if (++num_bufs > max) { 1135 virtio_error(vdev, "Looped descriptor"); 1136 goto err; 1137 } 1138 1139 if (desc.flags & VRING_DESC_F_WRITE) { 1140 in_total += desc.len; 1141 } else { 1142 out_total += desc.len; 1143 } 1144 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1145 goto done; 1146 } 1147 1148 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max); 1149 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1150 1151 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1152 goto err; 1153 } 1154 1155 if (desc_cache == &indirect_desc_cache) { 1156 address_space_cache_destroy(&indirect_desc_cache); 1157 total_bufs++; 1158 } else { 1159 total_bufs = num_bufs; 1160 } 1161 } 1162 1163 if (rc < 0) { 1164 goto err; 1165 } 1166 1167 done: 1168 address_space_cache_destroy(&indirect_desc_cache); 1169 if (in_bytes) { 1170 *in_bytes = in_total; 1171 } 1172 if (out_bytes) { 1173 *out_bytes = out_total; 1174 } 1175 return; 1176 1177 err: 1178 in_total = out_total = 0; 1179 goto done; 1180 } 1181 1182 static int virtqueue_packed_read_next_desc(VirtQueue *vq, 1183 VRingPackedDesc *desc, 1184 MemoryRegionCache 1185 *desc_cache, 1186 unsigned int max, 1187 unsigned int *next, 1188 bool indirect) 1189 { 1190 /* If this descriptor says it doesn't chain, we're done. */ 1191 if (!indirect && !(desc->flags & VRING_DESC_F_NEXT)) { 1192 return VIRTQUEUE_READ_DESC_DONE; 1193 } 1194 1195 ++*next; 1196 if (*next == max) { 1197 if (indirect) { 1198 return VIRTQUEUE_READ_DESC_DONE; 1199 } else { 1200 (*next) -= vq->vring.num; 1201 } 1202 } 1203 1204 vring_packed_desc_read(vq->vdev, desc, desc_cache, *next, false); 1205 return VIRTQUEUE_READ_DESC_MORE; 1206 } 1207 1208 /* Called within rcu_read_lock(). */ 1209 static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, 1210 unsigned int *in_bytes, 1211 unsigned int *out_bytes, 1212 unsigned max_in_bytes, 1213 unsigned max_out_bytes, 1214 VRingMemoryRegionCaches *caches) 1215 { 1216 VirtIODevice *vdev = vq->vdev; 1217 unsigned int idx; 1218 unsigned int total_bufs, in_total, out_total; 1219 MemoryRegionCache indirect_desc_cache; 1220 MemoryRegionCache *desc_cache; 1221 int64_t len = 0; 1222 VRingPackedDesc desc; 1223 bool wrap_counter; 1224 1225 address_space_cache_init_empty(&indirect_desc_cache); 1226 1227 idx = vq->last_avail_idx; 1228 wrap_counter = vq->last_avail_wrap_counter; 1229 total_bufs = in_total = out_total = 0; 1230 1231 for (;;) { 1232 unsigned int num_bufs = total_bufs; 1233 unsigned int i = idx; 1234 int rc; 1235 unsigned int max = vq->vring.num; 1236 1237 desc_cache = &caches->desc; 1238 1239 vring_packed_desc_read(vdev, &desc, desc_cache, idx, true); 1240 if (!is_desc_avail(desc.flags, wrap_counter)) { 1241 break; 1242 } 1243 1244 if (desc.flags & VRING_DESC_F_INDIRECT) { 1245 if (desc.len % sizeof(VRingPackedDesc)) { 1246 virtio_error(vdev, "Invalid size for indirect buffer table"); 1247 goto err; 1248 } 1249 1250 /* If we've got too many, that implies a descriptor loop. */ 1251 if (num_bufs >= max) { 1252 virtio_error(vdev, "Looped descriptor"); 1253 goto err; 1254 } 1255 1256 /* loop over the indirect descriptor table */ 1257 len = address_space_cache_init(&indirect_desc_cache, 1258 vdev->dma_as, 1259 desc.addr, desc.len, false); 1260 desc_cache = &indirect_desc_cache; 1261 if (len < desc.len) { 1262 virtio_error(vdev, "Cannot map indirect buffer"); 1263 goto err; 1264 } 1265 1266 max = desc.len / sizeof(VRingPackedDesc); 1267 num_bufs = i = 0; 1268 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1269 } 1270 1271 do { 1272 /* If we've got too many, that implies a descriptor loop. */ 1273 if (++num_bufs > max) { 1274 virtio_error(vdev, "Looped descriptor"); 1275 goto err; 1276 } 1277 1278 if (desc.flags & VRING_DESC_F_WRITE) { 1279 in_total += desc.len; 1280 } else { 1281 out_total += desc.len; 1282 } 1283 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1284 goto done; 1285 } 1286 1287 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, 1288 &i, desc_cache == 1289 &indirect_desc_cache); 1290 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1291 1292 if (desc_cache == &indirect_desc_cache) { 1293 address_space_cache_destroy(&indirect_desc_cache); 1294 total_bufs++; 1295 idx++; 1296 } else { 1297 idx += num_bufs - total_bufs; 1298 total_bufs = num_bufs; 1299 } 1300 1301 if (idx >= vq->vring.num) { 1302 idx -= vq->vring.num; 1303 wrap_counter ^= 1; 1304 } 1305 } 1306 1307 /* Record the index and wrap counter for a kick we want */ 1308 vq->shadow_avail_idx = idx; 1309 vq->shadow_avail_wrap_counter = wrap_counter; 1310 done: 1311 address_space_cache_destroy(&indirect_desc_cache); 1312 if (in_bytes) { 1313 *in_bytes = in_total; 1314 } 1315 if (out_bytes) { 1316 *out_bytes = out_total; 1317 } 1318 return; 1319 1320 err: 1321 in_total = out_total = 0; 1322 goto done; 1323 } 1324 1325 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 1326 unsigned int *out_bytes, 1327 unsigned max_in_bytes, unsigned max_out_bytes) 1328 { 1329 uint16_t desc_size; 1330 VRingMemoryRegionCaches *caches; 1331 1332 RCU_READ_LOCK_GUARD(); 1333 1334 if (unlikely(!vq->vring.desc)) { 1335 goto err; 1336 } 1337 1338 caches = vring_get_region_caches(vq); 1339 if (!caches) { 1340 goto err; 1341 } 1342 1343 desc_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ? 1344 sizeof(VRingPackedDesc) : sizeof(VRingDesc); 1345 if (caches->desc.len < vq->vring.num * desc_size) { 1346 virtio_error(vq->vdev, "Cannot map descriptor ring"); 1347 goto err; 1348 } 1349 1350 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1351 virtqueue_packed_get_avail_bytes(vq, in_bytes, out_bytes, 1352 max_in_bytes, max_out_bytes, 1353 caches); 1354 } else { 1355 virtqueue_split_get_avail_bytes(vq, in_bytes, out_bytes, 1356 max_in_bytes, max_out_bytes, 1357 caches); 1358 } 1359 1360 return; 1361 err: 1362 if (in_bytes) { 1363 *in_bytes = 0; 1364 } 1365 if (out_bytes) { 1366 *out_bytes = 0; 1367 } 1368 } 1369 1370 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 1371 unsigned int out_bytes) 1372 { 1373 unsigned int in_total, out_total; 1374 1375 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 1376 return in_bytes <= in_total && out_bytes <= out_total; 1377 } 1378 1379 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 1380 hwaddr *addr, struct iovec *iov, 1381 unsigned int max_num_sg, bool is_write, 1382 hwaddr pa, size_t sz) 1383 { 1384 bool ok = false; 1385 unsigned num_sg = *p_num_sg; 1386 assert(num_sg <= max_num_sg); 1387 1388 if (!sz) { 1389 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 1390 goto out; 1391 } 1392 1393 while (sz) { 1394 hwaddr len = sz; 1395 1396 if (num_sg == max_num_sg) { 1397 virtio_error(vdev, "virtio: too many write descriptors in " 1398 "indirect table"); 1399 goto out; 1400 } 1401 1402 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 1403 is_write ? 1404 DMA_DIRECTION_FROM_DEVICE : 1405 DMA_DIRECTION_TO_DEVICE, 1406 MEMTXATTRS_UNSPECIFIED); 1407 if (!iov[num_sg].iov_base) { 1408 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 1409 goto out; 1410 } 1411 1412 iov[num_sg].iov_len = len; 1413 addr[num_sg] = pa; 1414 1415 sz -= len; 1416 pa += len; 1417 num_sg++; 1418 } 1419 ok = true; 1420 1421 out: 1422 *p_num_sg = num_sg; 1423 return ok; 1424 } 1425 1426 /* Only used by error code paths before we have a VirtQueueElement (therefore 1427 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 1428 * yet. 1429 */ 1430 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 1431 struct iovec *iov) 1432 { 1433 unsigned int i; 1434 1435 for (i = 0; i < out_num + in_num; i++) { 1436 int is_write = i >= out_num; 1437 1438 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 1439 iov++; 1440 } 1441 } 1442 1443 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 1444 hwaddr *addr, unsigned int num_sg, 1445 bool is_write) 1446 { 1447 unsigned int i; 1448 hwaddr len; 1449 1450 for (i = 0; i < num_sg; i++) { 1451 len = sg[i].iov_len; 1452 sg[i].iov_base = dma_memory_map(vdev->dma_as, 1453 addr[i], &len, is_write ? 1454 DMA_DIRECTION_FROM_DEVICE : 1455 DMA_DIRECTION_TO_DEVICE, 1456 MEMTXATTRS_UNSPECIFIED); 1457 if (!sg[i].iov_base) { 1458 error_report("virtio: error trying to map MMIO memory"); 1459 exit(1); 1460 } 1461 if (len != sg[i].iov_len) { 1462 error_report("virtio: unexpected memory split"); 1463 exit(1); 1464 } 1465 } 1466 } 1467 1468 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 1469 { 1470 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, true); 1471 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 1472 false); 1473 } 1474 1475 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 1476 { 1477 VirtQueueElement *elem; 1478 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 1479 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 1480 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 1481 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 1482 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 1483 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 1484 1485 assert(sz >= sizeof(VirtQueueElement)); 1486 elem = g_malloc(out_sg_end); 1487 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 1488 elem->out_num = out_num; 1489 elem->in_num = in_num; 1490 elem->in_addr = (void *)elem + in_addr_ofs; 1491 elem->out_addr = (void *)elem + out_addr_ofs; 1492 elem->in_sg = (void *)elem + in_sg_ofs; 1493 elem->out_sg = (void *)elem + out_sg_ofs; 1494 return elem; 1495 } 1496 1497 static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) 1498 { 1499 unsigned int i, head, max; 1500 VRingMemoryRegionCaches *caches; 1501 MemoryRegionCache indirect_desc_cache; 1502 MemoryRegionCache *desc_cache; 1503 int64_t len; 1504 VirtIODevice *vdev = vq->vdev; 1505 VirtQueueElement *elem = NULL; 1506 unsigned out_num, in_num, elem_entries; 1507 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1508 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1509 VRingDesc desc; 1510 int rc; 1511 1512 address_space_cache_init_empty(&indirect_desc_cache); 1513 1514 RCU_READ_LOCK_GUARD(); 1515 if (virtio_queue_empty_rcu(vq)) { 1516 goto done; 1517 } 1518 /* Needed after virtio_queue_empty(), see comment in 1519 * virtqueue_num_heads(). */ 1520 smp_rmb(); 1521 1522 /* When we start there are none of either input nor output. */ 1523 out_num = in_num = elem_entries = 0; 1524 1525 max = vq->vring.num; 1526 1527 if (vq->inuse >= vq->vring.num) { 1528 virtio_error(vdev, "Virtqueue size exceeded"); 1529 goto done; 1530 } 1531 1532 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 1533 goto done; 1534 } 1535 1536 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1537 vring_set_avail_event(vq, vq->last_avail_idx); 1538 } 1539 1540 i = head; 1541 1542 caches = vring_get_region_caches(vq); 1543 if (!caches) { 1544 virtio_error(vdev, "Region caches not initialized"); 1545 goto done; 1546 } 1547 1548 if (caches->desc.len < max * sizeof(VRingDesc)) { 1549 virtio_error(vdev, "Cannot map descriptor ring"); 1550 goto done; 1551 } 1552 1553 desc_cache = &caches->desc; 1554 vring_split_desc_read(vdev, &desc, desc_cache, i); 1555 if (desc.flags & VRING_DESC_F_INDIRECT) { 1556 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1557 virtio_error(vdev, "Invalid size for indirect buffer table"); 1558 goto done; 1559 } 1560 1561 /* loop over the indirect descriptor table */ 1562 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1563 desc.addr, desc.len, false); 1564 desc_cache = &indirect_desc_cache; 1565 if (len < desc.len) { 1566 virtio_error(vdev, "Cannot map indirect buffer"); 1567 goto done; 1568 } 1569 1570 max = desc.len / sizeof(VRingDesc); 1571 i = 0; 1572 vring_split_desc_read(vdev, &desc, desc_cache, i); 1573 } 1574 1575 /* Collect all the descriptors */ 1576 do { 1577 bool map_ok; 1578 1579 if (desc.flags & VRING_DESC_F_WRITE) { 1580 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1581 iov + out_num, 1582 VIRTQUEUE_MAX_SIZE - out_num, true, 1583 desc.addr, desc.len); 1584 } else { 1585 if (in_num) { 1586 virtio_error(vdev, "Incorrect order for descriptors"); 1587 goto err_undo_map; 1588 } 1589 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1590 VIRTQUEUE_MAX_SIZE, false, 1591 desc.addr, desc.len); 1592 } 1593 if (!map_ok) { 1594 goto err_undo_map; 1595 } 1596 1597 /* If we've got too many, that implies a descriptor loop. */ 1598 if (++elem_entries > max) { 1599 virtio_error(vdev, "Looped descriptor"); 1600 goto err_undo_map; 1601 } 1602 1603 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max); 1604 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1605 1606 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1607 goto err_undo_map; 1608 } 1609 1610 /* Now copy what we have collected and mapped */ 1611 elem = virtqueue_alloc_element(sz, out_num, in_num); 1612 elem->index = head; 1613 elem->ndescs = 1; 1614 for (i = 0; i < out_num; i++) { 1615 elem->out_addr[i] = addr[i]; 1616 elem->out_sg[i] = iov[i]; 1617 } 1618 for (i = 0; i < in_num; i++) { 1619 elem->in_addr[i] = addr[out_num + i]; 1620 elem->in_sg[i] = iov[out_num + i]; 1621 } 1622 1623 vq->inuse++; 1624 1625 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1626 done: 1627 address_space_cache_destroy(&indirect_desc_cache); 1628 1629 return elem; 1630 1631 err_undo_map: 1632 virtqueue_undo_map_desc(out_num, in_num, iov); 1633 goto done; 1634 } 1635 1636 static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) 1637 { 1638 unsigned int i, max; 1639 VRingMemoryRegionCaches *caches; 1640 MemoryRegionCache indirect_desc_cache; 1641 MemoryRegionCache *desc_cache; 1642 int64_t len; 1643 VirtIODevice *vdev = vq->vdev; 1644 VirtQueueElement *elem = NULL; 1645 unsigned out_num, in_num, elem_entries; 1646 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1647 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1648 VRingPackedDesc desc; 1649 uint16_t id; 1650 int rc; 1651 1652 address_space_cache_init_empty(&indirect_desc_cache); 1653 1654 RCU_READ_LOCK_GUARD(); 1655 if (virtio_queue_packed_empty_rcu(vq)) { 1656 goto done; 1657 } 1658 1659 /* When we start there are none of either input nor output. */ 1660 out_num = in_num = elem_entries = 0; 1661 1662 max = vq->vring.num; 1663 1664 if (vq->inuse >= vq->vring.num) { 1665 virtio_error(vdev, "Virtqueue size exceeded"); 1666 goto done; 1667 } 1668 1669 i = vq->last_avail_idx; 1670 1671 caches = vring_get_region_caches(vq); 1672 if (!caches) { 1673 virtio_error(vdev, "Region caches not initialized"); 1674 goto done; 1675 } 1676 1677 if (caches->desc.len < max * sizeof(VRingDesc)) { 1678 virtio_error(vdev, "Cannot map descriptor ring"); 1679 goto done; 1680 } 1681 1682 desc_cache = &caches->desc; 1683 vring_packed_desc_read(vdev, &desc, desc_cache, i, true); 1684 id = desc.id; 1685 if (desc.flags & VRING_DESC_F_INDIRECT) { 1686 if (desc.len % sizeof(VRingPackedDesc)) { 1687 virtio_error(vdev, "Invalid size for indirect buffer table"); 1688 goto done; 1689 } 1690 1691 /* loop over the indirect descriptor table */ 1692 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1693 desc.addr, desc.len, false); 1694 desc_cache = &indirect_desc_cache; 1695 if (len < desc.len) { 1696 virtio_error(vdev, "Cannot map indirect buffer"); 1697 goto done; 1698 } 1699 1700 max = desc.len / sizeof(VRingPackedDesc); 1701 i = 0; 1702 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1703 } 1704 1705 /* Collect all the descriptors */ 1706 do { 1707 bool map_ok; 1708 1709 if (desc.flags & VRING_DESC_F_WRITE) { 1710 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1711 iov + out_num, 1712 VIRTQUEUE_MAX_SIZE - out_num, true, 1713 desc.addr, desc.len); 1714 } else { 1715 if (in_num) { 1716 virtio_error(vdev, "Incorrect order for descriptors"); 1717 goto err_undo_map; 1718 } 1719 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1720 VIRTQUEUE_MAX_SIZE, false, 1721 desc.addr, desc.len); 1722 } 1723 if (!map_ok) { 1724 goto err_undo_map; 1725 } 1726 1727 /* If we've got too many, that implies a descriptor loop. */ 1728 if (++elem_entries > max) { 1729 virtio_error(vdev, "Looped descriptor"); 1730 goto err_undo_map; 1731 } 1732 1733 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, &i, 1734 desc_cache == 1735 &indirect_desc_cache); 1736 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1737 1738 /* Now copy what we have collected and mapped */ 1739 elem = virtqueue_alloc_element(sz, out_num, in_num); 1740 for (i = 0; i < out_num; i++) { 1741 elem->out_addr[i] = addr[i]; 1742 elem->out_sg[i] = iov[i]; 1743 } 1744 for (i = 0; i < in_num; i++) { 1745 elem->in_addr[i] = addr[out_num + i]; 1746 elem->in_sg[i] = iov[out_num + i]; 1747 } 1748 1749 elem->index = id; 1750 elem->ndescs = (desc_cache == &indirect_desc_cache) ? 1 : elem_entries; 1751 vq->last_avail_idx += elem->ndescs; 1752 vq->inuse += elem->ndescs; 1753 1754 if (vq->last_avail_idx >= vq->vring.num) { 1755 vq->last_avail_idx -= vq->vring.num; 1756 vq->last_avail_wrap_counter ^= 1; 1757 } 1758 1759 vq->shadow_avail_idx = vq->last_avail_idx; 1760 vq->shadow_avail_wrap_counter = vq->last_avail_wrap_counter; 1761 1762 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1763 done: 1764 address_space_cache_destroy(&indirect_desc_cache); 1765 1766 return elem; 1767 1768 err_undo_map: 1769 virtqueue_undo_map_desc(out_num, in_num, iov); 1770 goto done; 1771 } 1772 1773 void *virtqueue_pop(VirtQueue *vq, size_t sz) 1774 { 1775 if (virtio_device_disabled(vq->vdev)) { 1776 return NULL; 1777 } 1778 1779 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1780 return virtqueue_packed_pop(vq, sz); 1781 } else { 1782 return virtqueue_split_pop(vq, sz); 1783 } 1784 } 1785 1786 static unsigned int virtqueue_packed_drop_all(VirtQueue *vq) 1787 { 1788 VRingMemoryRegionCaches *caches; 1789 MemoryRegionCache *desc_cache; 1790 unsigned int dropped = 0; 1791 VirtQueueElement elem = {}; 1792 VirtIODevice *vdev = vq->vdev; 1793 VRingPackedDesc desc; 1794 1795 RCU_READ_LOCK_GUARD(); 1796 1797 caches = vring_get_region_caches(vq); 1798 if (!caches) { 1799 return 0; 1800 } 1801 1802 desc_cache = &caches->desc; 1803 1804 virtio_queue_set_notification(vq, 0); 1805 1806 while (vq->inuse < vq->vring.num) { 1807 unsigned int idx = vq->last_avail_idx; 1808 /* 1809 * works similar to virtqueue_pop but does not map buffers 1810 * and does not allocate any memory. 1811 */ 1812 vring_packed_desc_read(vdev, &desc, desc_cache, 1813 vq->last_avail_idx , true); 1814 if (!is_desc_avail(desc.flags, vq->last_avail_wrap_counter)) { 1815 break; 1816 } 1817 elem.index = desc.id; 1818 elem.ndescs = 1; 1819 while (virtqueue_packed_read_next_desc(vq, &desc, desc_cache, 1820 vq->vring.num, &idx, false)) { 1821 ++elem.ndescs; 1822 } 1823 /* 1824 * immediately push the element, nothing to unmap 1825 * as both in_num and out_num are set to 0. 1826 */ 1827 virtqueue_push(vq, &elem, 0); 1828 dropped++; 1829 vq->last_avail_idx += elem.ndescs; 1830 if (vq->last_avail_idx >= vq->vring.num) { 1831 vq->last_avail_idx -= vq->vring.num; 1832 vq->last_avail_wrap_counter ^= 1; 1833 } 1834 } 1835 1836 return dropped; 1837 } 1838 1839 static unsigned int virtqueue_split_drop_all(VirtQueue *vq) 1840 { 1841 unsigned int dropped = 0; 1842 VirtQueueElement elem = {}; 1843 VirtIODevice *vdev = vq->vdev; 1844 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 1845 1846 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 1847 /* works similar to virtqueue_pop but does not map buffers 1848 * and does not allocate any memory */ 1849 smp_rmb(); 1850 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 1851 break; 1852 } 1853 vq->inuse++; 1854 vq->last_avail_idx++; 1855 if (fEventIdx) { 1856 vring_set_avail_event(vq, vq->last_avail_idx); 1857 } 1858 /* immediately push the element, nothing to unmap 1859 * as both in_num and out_num are set to 0 */ 1860 virtqueue_push(vq, &elem, 0); 1861 dropped++; 1862 } 1863 1864 return dropped; 1865 } 1866 1867 /* virtqueue_drop_all: 1868 * @vq: The #VirtQueue 1869 * Drops all queued buffers and indicates them to the guest 1870 * as if they are done. Useful when buffers can not be 1871 * processed but must be returned to the guest. 1872 */ 1873 unsigned int virtqueue_drop_all(VirtQueue *vq) 1874 { 1875 struct VirtIODevice *vdev = vq->vdev; 1876 1877 if (virtio_device_disabled(vq->vdev)) { 1878 return 0; 1879 } 1880 1881 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1882 return virtqueue_packed_drop_all(vq); 1883 } else { 1884 return virtqueue_split_drop_all(vq); 1885 } 1886 } 1887 1888 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1889 * it is what QEMU has always done by mistake. We can change it sooner 1890 * or later by bumping the version number of the affected vm states. 1891 * In the meanwhile, since the in-memory layout of VirtQueueElement 1892 * has changed, we need to marshal to and from the layout that was 1893 * used before the change. 1894 */ 1895 typedef struct VirtQueueElementOld { 1896 unsigned int index; 1897 unsigned int out_num; 1898 unsigned int in_num; 1899 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1900 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1901 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1902 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1903 } VirtQueueElementOld; 1904 1905 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1906 { 1907 VirtQueueElement *elem; 1908 VirtQueueElementOld data; 1909 int i; 1910 1911 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1912 1913 /* TODO: teach all callers that this can fail, and return failure instead 1914 * of asserting here. 1915 * This is just one thing (there are probably more) that must be 1916 * fixed before we can allow NDEBUG compilation. 1917 */ 1918 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1919 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1920 1921 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1922 elem->index = data.index; 1923 1924 for (i = 0; i < elem->in_num; i++) { 1925 elem->in_addr[i] = data.in_addr[i]; 1926 } 1927 1928 for (i = 0; i < elem->out_num; i++) { 1929 elem->out_addr[i] = data.out_addr[i]; 1930 } 1931 1932 for (i = 0; i < elem->in_num; i++) { 1933 /* Base is overwritten by virtqueue_map. */ 1934 elem->in_sg[i].iov_base = 0; 1935 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1936 } 1937 1938 for (i = 0; i < elem->out_num; i++) { 1939 /* Base is overwritten by virtqueue_map. */ 1940 elem->out_sg[i].iov_base = 0; 1941 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1942 } 1943 1944 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1945 qemu_get_be32s(f, &elem->ndescs); 1946 } 1947 1948 virtqueue_map(vdev, elem); 1949 return elem; 1950 } 1951 1952 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 1953 VirtQueueElement *elem) 1954 { 1955 VirtQueueElementOld data; 1956 int i; 1957 1958 memset(&data, 0, sizeof(data)); 1959 data.index = elem->index; 1960 data.in_num = elem->in_num; 1961 data.out_num = elem->out_num; 1962 1963 for (i = 0; i < elem->in_num; i++) { 1964 data.in_addr[i] = elem->in_addr[i]; 1965 } 1966 1967 for (i = 0; i < elem->out_num; i++) { 1968 data.out_addr[i] = elem->out_addr[i]; 1969 } 1970 1971 for (i = 0; i < elem->in_num; i++) { 1972 /* Base is overwritten by virtqueue_map when loading. Do not 1973 * save it, as it would leak the QEMU address space layout. */ 1974 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1975 } 1976 1977 for (i = 0; i < elem->out_num; i++) { 1978 /* Do not save iov_base as above. */ 1979 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1980 } 1981 1982 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1983 qemu_put_be32s(f, &elem->ndescs); 1984 } 1985 1986 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1987 } 1988 1989 /* virtio device */ 1990 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1991 { 1992 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1993 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1994 1995 if (virtio_device_disabled(vdev)) { 1996 return; 1997 } 1998 1999 if (k->notify) { 2000 k->notify(qbus->parent, vector); 2001 } 2002 } 2003 2004 void virtio_update_irq(VirtIODevice *vdev) 2005 { 2006 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 2007 } 2008 2009 static int virtio_validate_features(VirtIODevice *vdev) 2010 { 2011 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2012 2013 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 2014 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 2015 return -EFAULT; 2016 } 2017 2018 if (k->validate_features) { 2019 return k->validate_features(vdev); 2020 } else { 2021 return 0; 2022 } 2023 } 2024 2025 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 2026 { 2027 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2028 trace_virtio_set_status(vdev, val); 2029 2030 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2031 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 2032 val & VIRTIO_CONFIG_S_FEATURES_OK) { 2033 int ret = virtio_validate_features(vdev); 2034 2035 if (ret) { 2036 return ret; 2037 } 2038 } 2039 } 2040 2041 if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) != 2042 (val & VIRTIO_CONFIG_S_DRIVER_OK)) { 2043 virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK); 2044 } 2045 2046 if (k->set_status) { 2047 k->set_status(vdev, val); 2048 } 2049 vdev->status = val; 2050 2051 return 0; 2052 } 2053 2054 static enum virtio_device_endian virtio_default_endian(void) 2055 { 2056 if (target_words_bigendian()) { 2057 return VIRTIO_DEVICE_ENDIAN_BIG; 2058 } else { 2059 return VIRTIO_DEVICE_ENDIAN_LITTLE; 2060 } 2061 } 2062 2063 static enum virtio_device_endian virtio_current_cpu_endian(void) 2064 { 2065 if (cpu_virtio_is_big_endian(current_cpu)) { 2066 return VIRTIO_DEVICE_ENDIAN_BIG; 2067 } else { 2068 return VIRTIO_DEVICE_ENDIAN_LITTLE; 2069 } 2070 } 2071 2072 static void __virtio_queue_reset(VirtIODevice *vdev, uint32_t i) 2073 { 2074 vdev->vq[i].vring.desc = 0; 2075 vdev->vq[i].vring.avail = 0; 2076 vdev->vq[i].vring.used = 0; 2077 vdev->vq[i].last_avail_idx = 0; 2078 vdev->vq[i].shadow_avail_idx = 0; 2079 vdev->vq[i].used_idx = 0; 2080 vdev->vq[i].last_avail_wrap_counter = true; 2081 vdev->vq[i].shadow_avail_wrap_counter = true; 2082 vdev->vq[i].used_wrap_counter = true; 2083 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 2084 vdev->vq[i].signalled_used = 0; 2085 vdev->vq[i].signalled_used_valid = false; 2086 vdev->vq[i].notification = true; 2087 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 2088 vdev->vq[i].inuse = 0; 2089 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2090 } 2091 2092 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index) 2093 { 2094 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2095 2096 if (k->queue_reset) { 2097 k->queue_reset(vdev, queue_index); 2098 } 2099 2100 __virtio_queue_reset(vdev, queue_index); 2101 } 2102 2103 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index) 2104 { 2105 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2106 2107 /* 2108 * TODO: Seabios is currently out of spec and triggering this error. 2109 * So this needs to be fixed in Seabios, then this can 2110 * be re-enabled for new machine types only, and also after 2111 * being converted to LOG_GUEST_ERROR. 2112 * 2113 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2114 error_report("queue_enable is only supported in devices of virtio " 2115 "1.0 or later."); 2116 } 2117 */ 2118 2119 if (k->queue_enable) { 2120 k->queue_enable(vdev, queue_index); 2121 } 2122 } 2123 2124 void virtio_reset(void *opaque) 2125 { 2126 VirtIODevice *vdev = opaque; 2127 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2128 int i; 2129 2130 virtio_set_status(vdev, 0); 2131 if (current_cpu) { 2132 /* Guest initiated reset */ 2133 vdev->device_endian = virtio_current_cpu_endian(); 2134 } else { 2135 /* System reset */ 2136 vdev->device_endian = virtio_default_endian(); 2137 } 2138 2139 if (k->reset) { 2140 k->reset(vdev); 2141 } 2142 2143 vdev->start_on_kick = false; 2144 vdev->started = false; 2145 vdev->broken = false; 2146 vdev->guest_features = 0; 2147 vdev->queue_sel = 0; 2148 vdev->status = 0; 2149 vdev->disabled = false; 2150 qatomic_set(&vdev->isr, 0); 2151 vdev->config_vector = VIRTIO_NO_VECTOR; 2152 virtio_notify_vector(vdev, vdev->config_vector); 2153 2154 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2155 __virtio_queue_reset(vdev, i); 2156 } 2157 } 2158 2159 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 2160 { 2161 if (!vdev->vq[n].vring.num) { 2162 return; 2163 } 2164 vdev->vq[n].vring.desc = addr; 2165 virtio_queue_update_rings(vdev, n); 2166 } 2167 2168 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 2169 { 2170 return vdev->vq[n].vring.desc; 2171 } 2172 2173 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 2174 hwaddr avail, hwaddr used) 2175 { 2176 if (!vdev->vq[n].vring.num) { 2177 return; 2178 } 2179 vdev->vq[n].vring.desc = desc; 2180 vdev->vq[n].vring.avail = avail; 2181 vdev->vq[n].vring.used = used; 2182 virtio_init_region_cache(vdev, n); 2183 } 2184 2185 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 2186 { 2187 /* Don't allow guest to flip queue between existent and 2188 * nonexistent states, or to set it to an invalid size. 2189 */ 2190 if (!!num != !!vdev->vq[n].vring.num || 2191 num > VIRTQUEUE_MAX_SIZE || 2192 num < 0) { 2193 return; 2194 } 2195 vdev->vq[n].vring.num = num; 2196 } 2197 2198 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 2199 { 2200 return QLIST_FIRST(&vdev->vector_queues[vector]); 2201 } 2202 2203 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 2204 { 2205 return QLIST_NEXT(vq, node); 2206 } 2207 2208 int virtio_queue_get_num(VirtIODevice *vdev, int n) 2209 { 2210 return vdev->vq[n].vring.num; 2211 } 2212 2213 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 2214 { 2215 return vdev->vq[n].vring.num_default; 2216 } 2217 2218 int virtio_get_num_queues(VirtIODevice *vdev) 2219 { 2220 int i; 2221 2222 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2223 if (!virtio_queue_get_num(vdev, i)) { 2224 break; 2225 } 2226 } 2227 2228 return i; 2229 } 2230 2231 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 2232 { 2233 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2234 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2235 2236 /* virtio-1 compliant devices cannot change the alignment */ 2237 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2238 error_report("tried to modify queue alignment for virtio-1 device"); 2239 return; 2240 } 2241 /* Check that the transport told us it was going to do this 2242 * (so a buggy transport will immediately assert rather than 2243 * silently failing to migrate this state) 2244 */ 2245 assert(k->has_variable_vring_alignment); 2246 2247 if (align) { 2248 vdev->vq[n].vring.align = align; 2249 virtio_queue_update_rings(vdev, n); 2250 } 2251 } 2252 2253 static void virtio_queue_notify_vq(VirtQueue *vq) 2254 { 2255 if (vq->vring.desc && vq->handle_output) { 2256 VirtIODevice *vdev = vq->vdev; 2257 2258 if (unlikely(vdev->broken)) { 2259 return; 2260 } 2261 2262 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2263 vq->handle_output(vdev, vq); 2264 2265 if (unlikely(vdev->start_on_kick)) { 2266 virtio_set_started(vdev, true); 2267 } 2268 } 2269 } 2270 2271 void virtio_queue_notify(VirtIODevice *vdev, int n) 2272 { 2273 VirtQueue *vq = &vdev->vq[n]; 2274 2275 if (unlikely(!vq->vring.desc || vdev->broken)) { 2276 return; 2277 } 2278 2279 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2280 if (vq->host_notifier_enabled) { 2281 event_notifier_set(&vq->host_notifier); 2282 } else if (vq->handle_output) { 2283 vq->handle_output(vdev, vq); 2284 2285 if (unlikely(vdev->start_on_kick)) { 2286 virtio_set_started(vdev, true); 2287 } 2288 } 2289 } 2290 2291 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 2292 { 2293 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 2294 VIRTIO_NO_VECTOR; 2295 } 2296 2297 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 2298 { 2299 VirtQueue *vq = &vdev->vq[n]; 2300 2301 if (n < VIRTIO_QUEUE_MAX) { 2302 if (vdev->vector_queues && 2303 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 2304 QLIST_REMOVE(vq, node); 2305 } 2306 vdev->vq[n].vector = vector; 2307 if (vdev->vector_queues && 2308 vector != VIRTIO_NO_VECTOR) { 2309 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 2310 } 2311 } 2312 } 2313 2314 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 2315 VirtIOHandleOutput handle_output) 2316 { 2317 int i; 2318 2319 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2320 if (vdev->vq[i].vring.num == 0) 2321 break; 2322 } 2323 2324 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 2325 abort(); 2326 2327 vdev->vq[i].vring.num = queue_size; 2328 vdev->vq[i].vring.num_default = queue_size; 2329 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 2330 vdev->vq[i].handle_output = handle_output; 2331 vdev->vq[i].used_elems = g_new0(VirtQueueElement, queue_size); 2332 2333 return &vdev->vq[i]; 2334 } 2335 2336 void virtio_delete_queue(VirtQueue *vq) 2337 { 2338 vq->vring.num = 0; 2339 vq->vring.num_default = 0; 2340 vq->handle_output = NULL; 2341 g_free(vq->used_elems); 2342 vq->used_elems = NULL; 2343 virtio_virtqueue_reset_region_cache(vq); 2344 } 2345 2346 void virtio_del_queue(VirtIODevice *vdev, int n) 2347 { 2348 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 2349 abort(); 2350 } 2351 2352 virtio_delete_queue(&vdev->vq[n]); 2353 } 2354 2355 static void virtio_set_isr(VirtIODevice *vdev, int value) 2356 { 2357 uint8_t old = qatomic_read(&vdev->isr); 2358 2359 /* Do not write ISR if it does not change, so that its cacheline remains 2360 * shared in the common case where the guest does not read it. 2361 */ 2362 if ((old & value) != value) { 2363 qatomic_or(&vdev->isr, value); 2364 } 2365 } 2366 2367 /* Called within rcu_read_lock(). */ 2368 static bool virtio_split_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2369 { 2370 uint16_t old, new; 2371 bool v; 2372 /* We need to expose used array entries before checking used event. */ 2373 smp_mb(); 2374 /* Always notify when queue is empty (when feature acknowledge) */ 2375 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 2376 !vq->inuse && virtio_queue_empty(vq)) { 2377 return true; 2378 } 2379 2380 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2381 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 2382 } 2383 2384 v = vq->signalled_used_valid; 2385 vq->signalled_used_valid = true; 2386 old = vq->signalled_used; 2387 new = vq->signalled_used = vq->used_idx; 2388 return !v || vring_need_event(vring_get_used_event(vq), new, old); 2389 } 2390 2391 static bool vring_packed_need_event(VirtQueue *vq, bool wrap, 2392 uint16_t off_wrap, uint16_t new, 2393 uint16_t old) 2394 { 2395 int off = off_wrap & ~(1 << 15); 2396 2397 if (wrap != off_wrap >> 15) { 2398 off -= vq->vring.num; 2399 } 2400 2401 return vring_need_event(off, new, old); 2402 } 2403 2404 /* Called within rcu_read_lock(). */ 2405 static bool virtio_packed_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2406 { 2407 VRingPackedDescEvent e; 2408 uint16_t old, new; 2409 bool v; 2410 VRingMemoryRegionCaches *caches; 2411 2412 caches = vring_get_region_caches(vq); 2413 if (!caches) { 2414 return false; 2415 } 2416 2417 vring_packed_event_read(vdev, &caches->avail, &e); 2418 2419 old = vq->signalled_used; 2420 new = vq->signalled_used = vq->used_idx; 2421 v = vq->signalled_used_valid; 2422 vq->signalled_used_valid = true; 2423 2424 if (e.flags == VRING_PACKED_EVENT_FLAG_DISABLE) { 2425 return false; 2426 } else if (e.flags == VRING_PACKED_EVENT_FLAG_ENABLE) { 2427 return true; 2428 } 2429 2430 return !v || vring_packed_need_event(vq, vq->used_wrap_counter, 2431 e.off_wrap, new, old); 2432 } 2433 2434 /* Called within rcu_read_lock(). */ 2435 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2436 { 2437 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 2438 return virtio_packed_should_notify(vdev, vq); 2439 } else { 2440 return virtio_split_should_notify(vdev, vq); 2441 } 2442 } 2443 2444 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 2445 { 2446 WITH_RCU_READ_LOCK_GUARD() { 2447 if (!virtio_should_notify(vdev, vq)) { 2448 return; 2449 } 2450 } 2451 2452 trace_virtio_notify_irqfd(vdev, vq); 2453 2454 /* 2455 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 2456 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 2457 * incorrectly polling this bit during crashdump and hibernation 2458 * in MSI mode, causing a hang if this bit is never updated. 2459 * Recent releases of Windows do not really shut down, but rather 2460 * log out and hibernate to make the next startup faster. Hence, 2461 * this manifested as a more serious hang during shutdown with 2462 * 2463 * Next driver release from 2016 fixed this problem, so working around it 2464 * is not a must, but it's easy to do so let's do it here. 2465 * 2466 * Note: it's safe to update ISR from any thread as it was switched 2467 * to an atomic operation. 2468 */ 2469 virtio_set_isr(vq->vdev, 0x1); 2470 event_notifier_set(&vq->guest_notifier); 2471 } 2472 2473 static void virtio_irq(VirtQueue *vq) 2474 { 2475 virtio_set_isr(vq->vdev, 0x1); 2476 virtio_notify_vector(vq->vdev, vq->vector); 2477 } 2478 2479 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 2480 { 2481 WITH_RCU_READ_LOCK_GUARD() { 2482 if (!virtio_should_notify(vdev, vq)) { 2483 return; 2484 } 2485 } 2486 2487 trace_virtio_notify(vdev, vq); 2488 virtio_irq(vq); 2489 } 2490 2491 void virtio_notify_config(VirtIODevice *vdev) 2492 { 2493 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 2494 return; 2495 2496 virtio_set_isr(vdev, 0x3); 2497 vdev->generation++; 2498 virtio_notify_vector(vdev, vdev->config_vector); 2499 } 2500 2501 static bool virtio_device_endian_needed(void *opaque) 2502 { 2503 VirtIODevice *vdev = opaque; 2504 2505 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 2506 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2507 return vdev->device_endian != virtio_default_endian(); 2508 } 2509 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 2510 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 2511 } 2512 2513 static bool virtio_64bit_features_needed(void *opaque) 2514 { 2515 VirtIODevice *vdev = opaque; 2516 2517 return (vdev->host_features >> 32) != 0; 2518 } 2519 2520 static bool virtio_virtqueue_needed(void *opaque) 2521 { 2522 VirtIODevice *vdev = opaque; 2523 2524 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 2525 } 2526 2527 static bool virtio_packed_virtqueue_needed(void *opaque) 2528 { 2529 VirtIODevice *vdev = opaque; 2530 2531 return virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED); 2532 } 2533 2534 static bool virtio_ringsize_needed(void *opaque) 2535 { 2536 VirtIODevice *vdev = opaque; 2537 int i; 2538 2539 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2540 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 2541 return true; 2542 } 2543 } 2544 return false; 2545 } 2546 2547 static bool virtio_extra_state_needed(void *opaque) 2548 { 2549 VirtIODevice *vdev = opaque; 2550 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2551 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2552 2553 return k->has_extra_state && 2554 k->has_extra_state(qbus->parent); 2555 } 2556 2557 static bool virtio_broken_needed(void *opaque) 2558 { 2559 VirtIODevice *vdev = opaque; 2560 2561 return vdev->broken; 2562 } 2563 2564 static bool virtio_started_needed(void *opaque) 2565 { 2566 VirtIODevice *vdev = opaque; 2567 2568 return vdev->started; 2569 } 2570 2571 static bool virtio_disabled_needed(void *opaque) 2572 { 2573 VirtIODevice *vdev = opaque; 2574 2575 return vdev->disabled; 2576 } 2577 2578 static const VMStateDescription vmstate_virtqueue = { 2579 .name = "virtqueue_state", 2580 .version_id = 1, 2581 .minimum_version_id = 1, 2582 .fields = (VMStateField[]) { 2583 VMSTATE_UINT64(vring.avail, struct VirtQueue), 2584 VMSTATE_UINT64(vring.used, struct VirtQueue), 2585 VMSTATE_END_OF_LIST() 2586 } 2587 }; 2588 2589 static const VMStateDescription vmstate_packed_virtqueue = { 2590 .name = "packed_virtqueue_state", 2591 .version_id = 1, 2592 .minimum_version_id = 1, 2593 .fields = (VMStateField[]) { 2594 VMSTATE_UINT16(last_avail_idx, struct VirtQueue), 2595 VMSTATE_BOOL(last_avail_wrap_counter, struct VirtQueue), 2596 VMSTATE_UINT16(used_idx, struct VirtQueue), 2597 VMSTATE_BOOL(used_wrap_counter, struct VirtQueue), 2598 VMSTATE_UINT32(inuse, struct VirtQueue), 2599 VMSTATE_END_OF_LIST() 2600 } 2601 }; 2602 2603 static const VMStateDescription vmstate_virtio_virtqueues = { 2604 .name = "virtio/virtqueues", 2605 .version_id = 1, 2606 .minimum_version_id = 1, 2607 .needed = &virtio_virtqueue_needed, 2608 .fields = (VMStateField[]) { 2609 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2610 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 2611 VMSTATE_END_OF_LIST() 2612 } 2613 }; 2614 2615 static const VMStateDescription vmstate_virtio_packed_virtqueues = { 2616 .name = "virtio/packed_virtqueues", 2617 .version_id = 1, 2618 .minimum_version_id = 1, 2619 .needed = &virtio_packed_virtqueue_needed, 2620 .fields = (VMStateField[]) { 2621 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2622 VIRTIO_QUEUE_MAX, 0, vmstate_packed_virtqueue, VirtQueue), 2623 VMSTATE_END_OF_LIST() 2624 } 2625 }; 2626 2627 static const VMStateDescription vmstate_ringsize = { 2628 .name = "ringsize_state", 2629 .version_id = 1, 2630 .minimum_version_id = 1, 2631 .fields = (VMStateField[]) { 2632 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 2633 VMSTATE_END_OF_LIST() 2634 } 2635 }; 2636 2637 static const VMStateDescription vmstate_virtio_ringsize = { 2638 .name = "virtio/ringsize", 2639 .version_id = 1, 2640 .minimum_version_id = 1, 2641 .needed = &virtio_ringsize_needed, 2642 .fields = (VMStateField[]) { 2643 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2644 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 2645 VMSTATE_END_OF_LIST() 2646 } 2647 }; 2648 2649 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 2650 const VMStateField *field) 2651 { 2652 VirtIODevice *vdev = pv; 2653 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2654 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2655 2656 if (!k->load_extra_state) { 2657 return -1; 2658 } else { 2659 return k->load_extra_state(qbus->parent, f); 2660 } 2661 } 2662 2663 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 2664 const VMStateField *field, JSONWriter *vmdesc) 2665 { 2666 VirtIODevice *vdev = pv; 2667 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2668 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2669 2670 k->save_extra_state(qbus->parent, f); 2671 return 0; 2672 } 2673 2674 static const VMStateInfo vmstate_info_extra_state = { 2675 .name = "virtqueue_extra_state", 2676 .get = get_extra_state, 2677 .put = put_extra_state, 2678 }; 2679 2680 static const VMStateDescription vmstate_virtio_extra_state = { 2681 .name = "virtio/extra_state", 2682 .version_id = 1, 2683 .minimum_version_id = 1, 2684 .needed = &virtio_extra_state_needed, 2685 .fields = (VMStateField[]) { 2686 { 2687 .name = "extra_state", 2688 .version_id = 0, 2689 .field_exists = NULL, 2690 .size = 0, 2691 .info = &vmstate_info_extra_state, 2692 .flags = VMS_SINGLE, 2693 .offset = 0, 2694 }, 2695 VMSTATE_END_OF_LIST() 2696 } 2697 }; 2698 2699 static const VMStateDescription vmstate_virtio_device_endian = { 2700 .name = "virtio/device_endian", 2701 .version_id = 1, 2702 .minimum_version_id = 1, 2703 .needed = &virtio_device_endian_needed, 2704 .fields = (VMStateField[]) { 2705 VMSTATE_UINT8(device_endian, VirtIODevice), 2706 VMSTATE_END_OF_LIST() 2707 } 2708 }; 2709 2710 static const VMStateDescription vmstate_virtio_64bit_features = { 2711 .name = "virtio/64bit_features", 2712 .version_id = 1, 2713 .minimum_version_id = 1, 2714 .needed = &virtio_64bit_features_needed, 2715 .fields = (VMStateField[]) { 2716 VMSTATE_UINT64(guest_features, VirtIODevice), 2717 VMSTATE_END_OF_LIST() 2718 } 2719 }; 2720 2721 static const VMStateDescription vmstate_virtio_broken = { 2722 .name = "virtio/broken", 2723 .version_id = 1, 2724 .minimum_version_id = 1, 2725 .needed = &virtio_broken_needed, 2726 .fields = (VMStateField[]) { 2727 VMSTATE_BOOL(broken, VirtIODevice), 2728 VMSTATE_END_OF_LIST() 2729 } 2730 }; 2731 2732 static const VMStateDescription vmstate_virtio_started = { 2733 .name = "virtio/started", 2734 .version_id = 1, 2735 .minimum_version_id = 1, 2736 .needed = &virtio_started_needed, 2737 .fields = (VMStateField[]) { 2738 VMSTATE_BOOL(started, VirtIODevice), 2739 VMSTATE_END_OF_LIST() 2740 } 2741 }; 2742 2743 static const VMStateDescription vmstate_virtio_disabled = { 2744 .name = "virtio/disabled", 2745 .version_id = 1, 2746 .minimum_version_id = 1, 2747 .needed = &virtio_disabled_needed, 2748 .fields = (VMStateField[]) { 2749 VMSTATE_BOOL(disabled, VirtIODevice), 2750 VMSTATE_END_OF_LIST() 2751 } 2752 }; 2753 2754 static const VMStateDescription vmstate_virtio = { 2755 .name = "virtio", 2756 .version_id = 1, 2757 .minimum_version_id = 1, 2758 .fields = (VMStateField[]) { 2759 VMSTATE_END_OF_LIST() 2760 }, 2761 .subsections = (const VMStateDescription*[]) { 2762 &vmstate_virtio_device_endian, 2763 &vmstate_virtio_64bit_features, 2764 &vmstate_virtio_virtqueues, 2765 &vmstate_virtio_ringsize, 2766 &vmstate_virtio_broken, 2767 &vmstate_virtio_extra_state, 2768 &vmstate_virtio_started, 2769 &vmstate_virtio_packed_virtqueues, 2770 &vmstate_virtio_disabled, 2771 NULL 2772 } 2773 }; 2774 2775 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 2776 { 2777 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2778 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2779 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2780 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 2781 int i; 2782 2783 if (k->save_config) { 2784 k->save_config(qbus->parent, f); 2785 } 2786 2787 qemu_put_8s(f, &vdev->status); 2788 qemu_put_8s(f, &vdev->isr); 2789 qemu_put_be16s(f, &vdev->queue_sel); 2790 qemu_put_be32s(f, &guest_features_lo); 2791 qemu_put_be32(f, vdev->config_len); 2792 qemu_put_buffer(f, vdev->config, vdev->config_len); 2793 2794 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2795 if (vdev->vq[i].vring.num == 0) 2796 break; 2797 } 2798 2799 qemu_put_be32(f, i); 2800 2801 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2802 if (vdev->vq[i].vring.num == 0) 2803 break; 2804 2805 qemu_put_be32(f, vdev->vq[i].vring.num); 2806 if (k->has_variable_vring_alignment) { 2807 qemu_put_be32(f, vdev->vq[i].vring.align); 2808 } 2809 /* 2810 * Save desc now, the rest of the ring addresses are saved in 2811 * subsections for VIRTIO-1 devices. 2812 */ 2813 qemu_put_be64(f, vdev->vq[i].vring.desc); 2814 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 2815 if (k->save_queue) { 2816 k->save_queue(qbus->parent, i, f); 2817 } 2818 } 2819 2820 if (vdc->save != NULL) { 2821 vdc->save(vdev, f); 2822 } 2823 2824 if (vdc->vmsd) { 2825 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 2826 if (ret) { 2827 return ret; 2828 } 2829 } 2830 2831 /* Subsections */ 2832 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 2833 } 2834 2835 /* A wrapper for use as a VMState .put function */ 2836 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 2837 const VMStateField *field, JSONWriter *vmdesc) 2838 { 2839 return virtio_save(VIRTIO_DEVICE(opaque), f); 2840 } 2841 2842 /* A wrapper for use as a VMState .get function */ 2843 static int coroutine_mixed_fn 2844 virtio_device_get(QEMUFile *f, void *opaque, size_t size, 2845 const VMStateField *field) 2846 { 2847 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 2848 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 2849 2850 return virtio_load(vdev, f, dc->vmsd->version_id); 2851 } 2852 2853 const VMStateInfo virtio_vmstate_info = { 2854 .name = "virtio", 2855 .get = virtio_device_get, 2856 .put = virtio_device_put, 2857 }; 2858 2859 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 2860 { 2861 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2862 bool bad = (val & ~(vdev->host_features)) != 0; 2863 2864 val &= vdev->host_features; 2865 if (k->set_features) { 2866 k->set_features(vdev, val); 2867 } 2868 vdev->guest_features = val; 2869 return bad ? -1 : 0; 2870 } 2871 2872 typedef struct VirtioSetFeaturesNocheckData { 2873 Coroutine *co; 2874 VirtIODevice *vdev; 2875 uint64_t val; 2876 int ret; 2877 } VirtioSetFeaturesNocheckData; 2878 2879 static void virtio_set_features_nocheck_bh(void *opaque) 2880 { 2881 VirtioSetFeaturesNocheckData *data = opaque; 2882 2883 data->ret = virtio_set_features_nocheck(data->vdev, data->val); 2884 aio_co_wake(data->co); 2885 } 2886 2887 static int coroutine_mixed_fn 2888 virtio_set_features_nocheck_maybe_co(VirtIODevice *vdev, uint64_t val) 2889 { 2890 if (qemu_in_coroutine()) { 2891 VirtioSetFeaturesNocheckData data = { 2892 .co = qemu_coroutine_self(), 2893 .vdev = vdev, 2894 .val = val, 2895 }; 2896 aio_bh_schedule_oneshot(qemu_get_current_aio_context(), 2897 virtio_set_features_nocheck_bh, &data); 2898 qemu_coroutine_yield(); 2899 return data.ret; 2900 } else { 2901 return virtio_set_features_nocheck(vdev, val); 2902 } 2903 } 2904 2905 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2906 { 2907 int ret; 2908 /* 2909 * The driver must not attempt to set features after feature negotiation 2910 * has finished. 2911 */ 2912 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2913 return -EINVAL; 2914 } 2915 2916 if (val & (1ull << VIRTIO_F_BAD_FEATURE)) { 2917 qemu_log_mask(LOG_GUEST_ERROR, 2918 "%s: guest driver for %s has enabled UNUSED(30) feature bit!\n", 2919 __func__, vdev->name); 2920 } 2921 2922 ret = virtio_set_features_nocheck(vdev, val); 2923 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2924 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ 2925 int i; 2926 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2927 if (vdev->vq[i].vring.num != 0) { 2928 virtio_init_region_cache(vdev, i); 2929 } 2930 } 2931 } 2932 if (!ret) { 2933 if (!virtio_device_started(vdev, vdev->status) && 2934 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2935 vdev->start_on_kick = true; 2936 } 2937 } 2938 return ret; 2939 } 2940 2941 size_t virtio_get_config_size(const VirtIOConfigSizeParams *params, 2942 uint64_t host_features) 2943 { 2944 size_t config_size = params->min_size; 2945 const VirtIOFeature *feature_sizes = params->feature_sizes; 2946 size_t i; 2947 2948 for (i = 0; feature_sizes[i].flags != 0; i++) { 2949 if (host_features & feature_sizes[i].flags) { 2950 config_size = MAX(feature_sizes[i].end, config_size); 2951 } 2952 } 2953 2954 assert(config_size <= params->max_size); 2955 return config_size; 2956 } 2957 2958 int coroutine_mixed_fn 2959 virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2960 { 2961 int i, ret; 2962 int32_t config_len; 2963 uint32_t num; 2964 uint32_t features; 2965 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2966 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2967 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2968 2969 /* 2970 * We poison the endianness to ensure it does not get used before 2971 * subsections have been loaded. 2972 */ 2973 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2974 2975 if (k->load_config) { 2976 ret = k->load_config(qbus->parent, f); 2977 if (ret) 2978 return ret; 2979 } 2980 2981 qemu_get_8s(f, &vdev->status); 2982 qemu_get_8s(f, &vdev->isr); 2983 qemu_get_be16s(f, &vdev->queue_sel); 2984 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2985 return -1; 2986 } 2987 qemu_get_be32s(f, &features); 2988 2989 /* 2990 * Temporarily set guest_features low bits - needed by 2991 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2992 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2993 * 2994 * Note: devices should always test host features in future - don't create 2995 * new dependencies like this. 2996 */ 2997 vdev->guest_features = features; 2998 2999 config_len = qemu_get_be32(f); 3000 3001 /* 3002 * There are cases where the incoming config can be bigger or smaller 3003 * than what we have; so load what we have space for, and skip 3004 * any excess that's in the stream. 3005 */ 3006 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 3007 3008 while (config_len > vdev->config_len) { 3009 qemu_get_byte(f); 3010 config_len--; 3011 } 3012 3013 num = qemu_get_be32(f); 3014 3015 if (num > VIRTIO_QUEUE_MAX) { 3016 error_report("Invalid number of virtqueues: 0x%x", num); 3017 return -1; 3018 } 3019 3020 for (i = 0; i < num; i++) { 3021 vdev->vq[i].vring.num = qemu_get_be32(f); 3022 if (k->has_variable_vring_alignment) { 3023 vdev->vq[i].vring.align = qemu_get_be32(f); 3024 } 3025 vdev->vq[i].vring.desc = qemu_get_be64(f); 3026 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 3027 vdev->vq[i].signalled_used_valid = false; 3028 vdev->vq[i].notification = true; 3029 3030 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 3031 error_report("VQ %d address 0x0 " 3032 "inconsistent with Host index 0x%x", 3033 i, vdev->vq[i].last_avail_idx); 3034 return -1; 3035 } 3036 if (k->load_queue) { 3037 ret = k->load_queue(qbus->parent, i, f); 3038 if (ret) 3039 return ret; 3040 } 3041 } 3042 3043 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 3044 3045 if (vdc->load != NULL) { 3046 ret = vdc->load(vdev, f, version_id); 3047 if (ret) { 3048 return ret; 3049 } 3050 } 3051 3052 if (vdc->vmsd) { 3053 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 3054 if (ret) { 3055 return ret; 3056 } 3057 } 3058 3059 /* Subsections */ 3060 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 3061 if (ret) { 3062 return ret; 3063 } 3064 3065 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 3066 vdev->device_endian = virtio_default_endian(); 3067 } 3068 3069 if (virtio_64bit_features_needed(vdev)) { 3070 /* 3071 * Subsection load filled vdev->guest_features. Run them 3072 * through virtio_set_features to sanity-check them against 3073 * host_features. 3074 */ 3075 uint64_t features64 = vdev->guest_features; 3076 if (virtio_set_features_nocheck_maybe_co(vdev, features64) < 0) { 3077 error_report("Features 0x%" PRIx64 " unsupported. " 3078 "Allowed features: 0x%" PRIx64, 3079 features64, vdev->host_features); 3080 return -1; 3081 } 3082 } else { 3083 if (virtio_set_features_nocheck_maybe_co(vdev, features) < 0) { 3084 error_report("Features 0x%x unsupported. " 3085 "Allowed features: 0x%" PRIx64, 3086 features, vdev->host_features); 3087 return -1; 3088 } 3089 } 3090 3091 if (!virtio_device_started(vdev, vdev->status) && 3092 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3093 vdev->start_on_kick = true; 3094 } 3095 3096 RCU_READ_LOCK_GUARD(); 3097 for (i = 0; i < num; i++) { 3098 if (vdev->vq[i].vring.desc) { 3099 uint16_t nheads; 3100 3101 /* 3102 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 3103 * only the region cache needs to be set up. Legacy devices need 3104 * to calculate used and avail ring addresses based on the desc 3105 * address. 3106 */ 3107 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3108 virtio_init_region_cache(vdev, i); 3109 } else { 3110 virtio_queue_update_rings(vdev, i); 3111 } 3112 3113 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3114 vdev->vq[i].shadow_avail_idx = vdev->vq[i].last_avail_idx; 3115 vdev->vq[i].shadow_avail_wrap_counter = 3116 vdev->vq[i].last_avail_wrap_counter; 3117 continue; 3118 } 3119 3120 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 3121 /* Check it isn't doing strange things with descriptor numbers. */ 3122 if (nheads > vdev->vq[i].vring.num) { 3123 virtio_error(vdev, "VQ %d size 0x%x Guest index 0x%x " 3124 "inconsistent with Host index 0x%x: delta 0x%x", 3125 i, vdev->vq[i].vring.num, 3126 vring_avail_idx(&vdev->vq[i]), 3127 vdev->vq[i].last_avail_idx, nheads); 3128 vdev->vq[i].used_idx = 0; 3129 vdev->vq[i].shadow_avail_idx = 0; 3130 vdev->vq[i].inuse = 0; 3131 continue; 3132 } 3133 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 3134 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 3135 3136 /* 3137 * Some devices migrate VirtQueueElements that have been popped 3138 * from the avail ring but not yet returned to the used ring. 3139 * Since max ring size < UINT16_MAX it's safe to use modulo 3140 * UINT16_MAX + 1 subtraction. 3141 */ 3142 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 3143 vdev->vq[i].used_idx); 3144 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 3145 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 3146 "used_idx 0x%x", 3147 i, vdev->vq[i].vring.num, 3148 vdev->vq[i].last_avail_idx, 3149 vdev->vq[i].used_idx); 3150 return -1; 3151 } 3152 } 3153 } 3154 3155 if (vdc->post_load) { 3156 ret = vdc->post_load(vdev); 3157 if (ret) { 3158 return ret; 3159 } 3160 } 3161 3162 return 0; 3163 } 3164 3165 void virtio_cleanup(VirtIODevice *vdev) 3166 { 3167 qemu_del_vm_change_state_handler(vdev->vmstate); 3168 } 3169 3170 static void virtio_vmstate_change(void *opaque, bool running, RunState state) 3171 { 3172 VirtIODevice *vdev = opaque; 3173 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3174 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3175 bool backend_run = running && virtio_device_started(vdev, vdev->status); 3176 vdev->vm_running = running; 3177 3178 if (backend_run) { 3179 virtio_set_status(vdev, vdev->status); 3180 } 3181 3182 if (k->vmstate_change) { 3183 k->vmstate_change(qbus->parent, backend_run); 3184 } 3185 3186 if (!backend_run) { 3187 virtio_set_status(vdev, vdev->status); 3188 } 3189 } 3190 3191 void virtio_instance_init_common(Object *proxy_obj, void *data, 3192 size_t vdev_size, const char *vdev_name) 3193 { 3194 DeviceState *vdev = data; 3195 3196 object_initialize_child_with_props(proxy_obj, "virtio-backend", vdev, 3197 vdev_size, vdev_name, &error_abort, 3198 NULL); 3199 qdev_alias_all_properties(vdev, proxy_obj); 3200 } 3201 3202 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size) 3203 { 3204 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3205 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3206 int i; 3207 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 3208 3209 if (nvectors) { 3210 vdev->vector_queues = 3211 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 3212 } 3213 3214 vdev->start_on_kick = false; 3215 vdev->started = false; 3216 vdev->vhost_started = false; 3217 vdev->device_id = device_id; 3218 vdev->status = 0; 3219 qatomic_set(&vdev->isr, 0); 3220 vdev->queue_sel = 0; 3221 vdev->config_vector = VIRTIO_NO_VECTOR; 3222 vdev->vq = g_new0(VirtQueue, VIRTIO_QUEUE_MAX); 3223 vdev->vm_running = runstate_is_running(); 3224 vdev->broken = false; 3225 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3226 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 3227 vdev->vq[i].vdev = vdev; 3228 vdev->vq[i].queue_index = i; 3229 vdev->vq[i].host_notifier_enabled = false; 3230 } 3231 3232 vdev->name = virtio_id_to_name(device_id); 3233 vdev->config_len = config_size; 3234 if (vdev->config_len) { 3235 vdev->config = g_malloc0(config_size); 3236 } else { 3237 vdev->config = NULL; 3238 } 3239 vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev), 3240 virtio_vmstate_change, vdev); 3241 vdev->device_endian = virtio_default_endian(); 3242 vdev->use_guest_notifier_mask = true; 3243 } 3244 3245 /* 3246 * Only devices that have already been around prior to defining the virtio 3247 * standard support legacy mode; this includes devices not specified in the 3248 * standard. All newer devices conform to the virtio standard only. 3249 */ 3250 bool virtio_legacy_allowed(VirtIODevice *vdev) 3251 { 3252 switch (vdev->device_id) { 3253 case VIRTIO_ID_NET: 3254 case VIRTIO_ID_BLOCK: 3255 case VIRTIO_ID_CONSOLE: 3256 case VIRTIO_ID_RNG: 3257 case VIRTIO_ID_BALLOON: 3258 case VIRTIO_ID_RPMSG: 3259 case VIRTIO_ID_SCSI: 3260 case VIRTIO_ID_9P: 3261 case VIRTIO_ID_RPROC_SERIAL: 3262 case VIRTIO_ID_CAIF: 3263 return true; 3264 default: 3265 return false; 3266 } 3267 } 3268 3269 bool virtio_legacy_check_disabled(VirtIODevice *vdev) 3270 { 3271 return vdev->disable_legacy_check; 3272 } 3273 3274 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 3275 { 3276 return vdev->vq[n].vring.desc; 3277 } 3278 3279 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n) 3280 { 3281 return virtio_queue_get_desc_addr(vdev, n) != 0; 3282 } 3283 3284 bool virtio_queue_enabled(VirtIODevice *vdev, int n) 3285 { 3286 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3287 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3288 3289 if (k->queue_enabled) { 3290 return k->queue_enabled(qbus->parent, n); 3291 } 3292 return virtio_queue_enabled_legacy(vdev, n); 3293 } 3294 3295 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 3296 { 3297 return vdev->vq[n].vring.avail; 3298 } 3299 3300 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 3301 { 3302 return vdev->vq[n].vring.used; 3303 } 3304 3305 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 3306 { 3307 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 3308 } 3309 3310 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 3311 { 3312 int s; 3313 3314 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3315 return sizeof(struct VRingPackedDescEvent); 3316 } 3317 3318 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3319 return offsetof(VRingAvail, ring) + 3320 sizeof(uint16_t) * vdev->vq[n].vring.num + s; 3321 } 3322 3323 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 3324 { 3325 int s; 3326 3327 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3328 return sizeof(struct VRingPackedDescEvent); 3329 } 3330 3331 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3332 return offsetof(VRingUsed, ring) + 3333 sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s; 3334 } 3335 3336 static unsigned int virtio_queue_packed_get_last_avail_idx(VirtIODevice *vdev, 3337 int n) 3338 { 3339 unsigned int avail, used; 3340 3341 avail = vdev->vq[n].last_avail_idx; 3342 avail |= ((uint16_t)vdev->vq[n].last_avail_wrap_counter) << 15; 3343 3344 used = vdev->vq[n].used_idx; 3345 used |= ((uint16_t)vdev->vq[n].used_wrap_counter) << 15; 3346 3347 return avail | used << 16; 3348 } 3349 3350 static uint16_t virtio_queue_split_get_last_avail_idx(VirtIODevice *vdev, 3351 int n) 3352 { 3353 return vdev->vq[n].last_avail_idx; 3354 } 3355 3356 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 3357 { 3358 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3359 return virtio_queue_packed_get_last_avail_idx(vdev, n); 3360 } else { 3361 return virtio_queue_split_get_last_avail_idx(vdev, n); 3362 } 3363 } 3364 3365 static void virtio_queue_packed_set_last_avail_idx(VirtIODevice *vdev, 3366 int n, unsigned int idx) 3367 { 3368 struct VirtQueue *vq = &vdev->vq[n]; 3369 3370 vq->last_avail_idx = vq->shadow_avail_idx = idx & 0x7fff; 3371 vq->last_avail_wrap_counter = 3372 vq->shadow_avail_wrap_counter = !!(idx & 0x8000); 3373 idx >>= 16; 3374 vq->used_idx = idx & 0x7fff; 3375 vq->used_wrap_counter = !!(idx & 0x8000); 3376 } 3377 3378 static void virtio_queue_split_set_last_avail_idx(VirtIODevice *vdev, 3379 int n, unsigned int idx) 3380 { 3381 vdev->vq[n].last_avail_idx = idx; 3382 vdev->vq[n].shadow_avail_idx = idx; 3383 } 3384 3385 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 3386 unsigned int idx) 3387 { 3388 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3389 virtio_queue_packed_set_last_avail_idx(vdev, n, idx); 3390 } else { 3391 virtio_queue_split_set_last_avail_idx(vdev, n, idx); 3392 } 3393 } 3394 3395 static void virtio_queue_packed_restore_last_avail_idx(VirtIODevice *vdev, 3396 int n) 3397 { 3398 /* We don't have a reference like avail idx in shared memory */ 3399 return; 3400 } 3401 3402 static void virtio_queue_split_restore_last_avail_idx(VirtIODevice *vdev, 3403 int n) 3404 { 3405 RCU_READ_LOCK_GUARD(); 3406 if (vdev->vq[n].vring.desc) { 3407 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 3408 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 3409 } 3410 } 3411 3412 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 3413 { 3414 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3415 virtio_queue_packed_restore_last_avail_idx(vdev, n); 3416 } else { 3417 virtio_queue_split_restore_last_avail_idx(vdev, n); 3418 } 3419 } 3420 3421 static void virtio_queue_packed_update_used_idx(VirtIODevice *vdev, int n) 3422 { 3423 /* used idx was updated through set_last_avail_idx() */ 3424 return; 3425 } 3426 3427 static void virtio_split_packed_update_used_idx(VirtIODevice *vdev, int n) 3428 { 3429 RCU_READ_LOCK_GUARD(); 3430 if (vdev->vq[n].vring.desc) { 3431 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 3432 } 3433 } 3434 3435 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 3436 { 3437 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3438 return virtio_queue_packed_update_used_idx(vdev, n); 3439 } else { 3440 return virtio_split_packed_update_used_idx(vdev, n); 3441 } 3442 } 3443 3444 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 3445 { 3446 vdev->vq[n].signalled_used_valid = false; 3447 } 3448 3449 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 3450 { 3451 return vdev->vq + n; 3452 } 3453 3454 uint16_t virtio_get_queue_index(VirtQueue *vq) 3455 { 3456 return vq->queue_index; 3457 } 3458 3459 static void virtio_queue_guest_notifier_read(EventNotifier *n) 3460 { 3461 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 3462 if (event_notifier_test_and_clear(n)) { 3463 virtio_irq(vq); 3464 } 3465 } 3466 static void virtio_config_guest_notifier_read(EventNotifier *n) 3467 { 3468 VirtIODevice *vdev = container_of(n, VirtIODevice, config_notifier); 3469 3470 if (event_notifier_test_and_clear(n)) { 3471 virtio_notify_config(vdev); 3472 } 3473 } 3474 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 3475 bool with_irqfd) 3476 { 3477 if (assign && !with_irqfd) { 3478 event_notifier_set_handler(&vq->guest_notifier, 3479 virtio_queue_guest_notifier_read); 3480 } else { 3481 event_notifier_set_handler(&vq->guest_notifier, NULL); 3482 } 3483 if (!assign) { 3484 /* Test and clear notifier before closing it, 3485 * in case poll callback didn't have time to run. */ 3486 virtio_queue_guest_notifier_read(&vq->guest_notifier); 3487 } 3488 } 3489 3490 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev, 3491 bool assign, bool with_irqfd) 3492 { 3493 EventNotifier *n; 3494 n = &vdev->config_notifier; 3495 if (assign && !with_irqfd) { 3496 event_notifier_set_handler(n, virtio_config_guest_notifier_read); 3497 } else { 3498 event_notifier_set_handler(n, NULL); 3499 } 3500 if (!assign) { 3501 /* Test and clear notifier before closing it,*/ 3502 /* in case poll callback didn't have time to run. */ 3503 virtio_config_guest_notifier_read(n); 3504 } 3505 } 3506 3507 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 3508 { 3509 return &vq->guest_notifier; 3510 } 3511 3512 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 3513 { 3514 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3515 3516 virtio_queue_set_notification(vq, 0); 3517 } 3518 3519 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 3520 { 3521 EventNotifier *n = opaque; 3522 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3523 3524 return vq->vring.desc && !virtio_queue_empty(vq); 3525 } 3526 3527 static void virtio_queue_host_notifier_aio_poll_ready(EventNotifier *n) 3528 { 3529 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3530 3531 virtio_queue_notify_vq(vq); 3532 } 3533 3534 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 3535 { 3536 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3537 3538 /* Caller polls once more after this to catch requests that race with us */ 3539 virtio_queue_set_notification(vq, 1); 3540 } 3541 3542 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx) 3543 { 3544 aio_set_event_notifier(ctx, &vq->host_notifier, 3545 virtio_queue_host_notifier_read, 3546 virtio_queue_host_notifier_aio_poll, 3547 virtio_queue_host_notifier_aio_poll_ready); 3548 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 3549 virtio_queue_host_notifier_aio_poll_begin, 3550 virtio_queue_host_notifier_aio_poll_end); 3551 } 3552 3553 /* 3554 * Same as virtio_queue_aio_attach_host_notifier() but without polling. Use 3555 * this for rx virtqueues and similar cases where the virtqueue handler 3556 * function does not pop all elements. When the virtqueue is left non-empty 3557 * polling consumes CPU cycles and should not be used. 3558 */ 3559 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx) 3560 { 3561 aio_set_event_notifier(ctx, &vq->host_notifier, 3562 virtio_queue_host_notifier_read, 3563 NULL, NULL); 3564 } 3565 3566 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx) 3567 { 3568 aio_set_event_notifier(ctx, &vq->host_notifier, NULL, NULL, NULL); 3569 } 3570 3571 void virtio_queue_host_notifier_read(EventNotifier *n) 3572 { 3573 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3574 if (event_notifier_test_and_clear(n)) { 3575 virtio_queue_notify_vq(vq); 3576 } 3577 } 3578 3579 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 3580 { 3581 return &vq->host_notifier; 3582 } 3583 3584 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev) 3585 { 3586 return &vdev->config_notifier; 3587 } 3588 3589 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled) 3590 { 3591 vq->host_notifier_enabled = enabled; 3592 } 3593 3594 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 3595 MemoryRegion *mr, bool assign) 3596 { 3597 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3598 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3599 3600 if (k->set_host_notifier_mr) { 3601 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 3602 } 3603 3604 return -1; 3605 } 3606 3607 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 3608 { 3609 g_free(vdev->bus_name); 3610 vdev->bus_name = g_strdup(bus_name); 3611 } 3612 3613 void G_GNUC_PRINTF(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 3614 { 3615 va_list ap; 3616 3617 va_start(ap, fmt); 3618 error_vreport(fmt, ap); 3619 va_end(ap); 3620 3621 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3622 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 3623 virtio_notify_config(vdev); 3624 } 3625 3626 vdev->broken = true; 3627 } 3628 3629 static void virtio_memory_listener_commit(MemoryListener *listener) 3630 { 3631 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 3632 int i; 3633 3634 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3635 if (vdev->vq[i].vring.num == 0) { 3636 break; 3637 } 3638 virtio_init_region_cache(vdev, i); 3639 } 3640 } 3641 3642 static void virtio_device_realize(DeviceState *dev, Error **errp) 3643 { 3644 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3645 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3646 Error *err = NULL; 3647 3648 /* Devices should either use vmsd or the load/save methods */ 3649 assert(!vdc->vmsd || !vdc->load); 3650 3651 if (vdc->realize != NULL) { 3652 vdc->realize(dev, &err); 3653 if (err != NULL) { 3654 error_propagate(errp, err); 3655 return; 3656 } 3657 } 3658 3659 virtio_bus_device_plugged(vdev, &err); 3660 if (err != NULL) { 3661 error_propagate(errp, err); 3662 vdc->unrealize(dev); 3663 return; 3664 } 3665 3666 vdev->listener.commit = virtio_memory_listener_commit; 3667 vdev->listener.name = "virtio"; 3668 memory_listener_register(&vdev->listener, vdev->dma_as); 3669 } 3670 3671 static void virtio_device_unrealize(DeviceState *dev) 3672 { 3673 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3674 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3675 3676 memory_listener_unregister(&vdev->listener); 3677 virtio_bus_device_unplugged(vdev); 3678 3679 if (vdc->unrealize != NULL) { 3680 vdc->unrealize(dev); 3681 } 3682 3683 g_free(vdev->bus_name); 3684 vdev->bus_name = NULL; 3685 } 3686 3687 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 3688 { 3689 int i; 3690 if (!vdev->vq) { 3691 return; 3692 } 3693 3694 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3695 if (vdev->vq[i].vring.num == 0) { 3696 break; 3697 } 3698 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 3699 } 3700 g_free(vdev->vq); 3701 } 3702 3703 static void virtio_device_instance_finalize(Object *obj) 3704 { 3705 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 3706 3707 virtio_device_free_virtqueues(vdev); 3708 3709 g_free(vdev->config); 3710 g_free(vdev->vector_queues); 3711 } 3712 3713 static Property virtio_properties[] = { 3714 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 3715 DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true), 3716 DEFINE_PROP_BOOL("use-disabled-flag", VirtIODevice, use_disabled_flag, true), 3717 DEFINE_PROP_BOOL("x-disable-legacy-check", VirtIODevice, 3718 disable_legacy_check, false), 3719 DEFINE_PROP_END_OF_LIST(), 3720 }; 3721 3722 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 3723 { 3724 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3725 int i, n, r, err; 3726 3727 /* 3728 * Batch all the host notifiers in a single transaction to avoid 3729 * quadratic time complexity in address_space_update_ioeventfds(). 3730 */ 3731 memory_region_transaction_begin(); 3732 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3733 VirtQueue *vq = &vdev->vq[n]; 3734 if (!virtio_queue_get_num(vdev, n)) { 3735 continue; 3736 } 3737 r = virtio_bus_set_host_notifier(qbus, n, true); 3738 if (r < 0) { 3739 err = r; 3740 goto assign_error; 3741 } 3742 event_notifier_set_handler(&vq->host_notifier, 3743 virtio_queue_host_notifier_read); 3744 } 3745 3746 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3747 /* Kick right away to begin processing requests already in vring */ 3748 VirtQueue *vq = &vdev->vq[n]; 3749 if (!vq->vring.num) { 3750 continue; 3751 } 3752 event_notifier_set(&vq->host_notifier); 3753 } 3754 memory_region_transaction_commit(); 3755 return 0; 3756 3757 assign_error: 3758 i = n; /* save n for a second iteration after transaction is committed. */ 3759 while (--n >= 0) { 3760 VirtQueue *vq = &vdev->vq[n]; 3761 if (!virtio_queue_get_num(vdev, n)) { 3762 continue; 3763 } 3764 3765 event_notifier_set_handler(&vq->host_notifier, NULL); 3766 r = virtio_bus_set_host_notifier(qbus, n, false); 3767 assert(r >= 0); 3768 } 3769 /* 3770 * The transaction expects the ioeventfds to be open when it 3771 * commits. Do it now, before the cleanup loop. 3772 */ 3773 memory_region_transaction_commit(); 3774 3775 while (--i >= 0) { 3776 if (!virtio_queue_get_num(vdev, i)) { 3777 continue; 3778 } 3779 virtio_bus_cleanup_host_notifier(qbus, i); 3780 } 3781 return err; 3782 } 3783 3784 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 3785 { 3786 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3787 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3788 3789 return virtio_bus_start_ioeventfd(vbus); 3790 } 3791 3792 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 3793 { 3794 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3795 int n, r; 3796 3797 /* 3798 * Batch all the host notifiers in a single transaction to avoid 3799 * quadratic time complexity in address_space_update_ioeventfds(). 3800 */ 3801 memory_region_transaction_begin(); 3802 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3803 VirtQueue *vq = &vdev->vq[n]; 3804 3805 if (!virtio_queue_get_num(vdev, n)) { 3806 continue; 3807 } 3808 event_notifier_set_handler(&vq->host_notifier, NULL); 3809 r = virtio_bus_set_host_notifier(qbus, n, false); 3810 assert(r >= 0); 3811 } 3812 /* 3813 * The transaction expects the ioeventfds to be open when it 3814 * commits. Do it now, before the cleanup loop. 3815 */ 3816 memory_region_transaction_commit(); 3817 3818 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3819 if (!virtio_queue_get_num(vdev, n)) { 3820 continue; 3821 } 3822 virtio_bus_cleanup_host_notifier(qbus, n); 3823 } 3824 } 3825 3826 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 3827 { 3828 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3829 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3830 3831 return virtio_bus_grab_ioeventfd(vbus); 3832 } 3833 3834 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 3835 { 3836 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3837 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3838 3839 virtio_bus_release_ioeventfd(vbus); 3840 } 3841 3842 static void virtio_device_class_init(ObjectClass *klass, void *data) 3843 { 3844 /* Set the default value here. */ 3845 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 3846 DeviceClass *dc = DEVICE_CLASS(klass); 3847 3848 dc->realize = virtio_device_realize; 3849 dc->unrealize = virtio_device_unrealize; 3850 dc->bus_type = TYPE_VIRTIO_BUS; 3851 device_class_set_props(dc, virtio_properties); 3852 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 3853 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 3854 3855 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 3856 } 3857 3858 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 3859 { 3860 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3861 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3862 3863 return virtio_bus_ioeventfd_enabled(vbus); 3864 } 3865 3866 VirtQueueStatus *qmp_x_query_virtio_queue_status(const char *path, 3867 uint16_t queue, 3868 Error **errp) 3869 { 3870 VirtIODevice *vdev; 3871 VirtQueueStatus *status; 3872 3873 vdev = qmp_find_virtio_device(path); 3874 if (vdev == NULL) { 3875 error_setg(errp, "Path %s is not a VirtIODevice", path); 3876 return NULL; 3877 } 3878 3879 if (queue >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, queue)) { 3880 error_setg(errp, "Invalid virtqueue number %d", queue); 3881 return NULL; 3882 } 3883 3884 status = g_new0(VirtQueueStatus, 1); 3885 status->name = g_strdup(vdev->name); 3886 status->queue_index = vdev->vq[queue].queue_index; 3887 status->inuse = vdev->vq[queue].inuse; 3888 status->vring_num = vdev->vq[queue].vring.num; 3889 status->vring_num_default = vdev->vq[queue].vring.num_default; 3890 status->vring_align = vdev->vq[queue].vring.align; 3891 status->vring_desc = vdev->vq[queue].vring.desc; 3892 status->vring_avail = vdev->vq[queue].vring.avail; 3893 status->vring_used = vdev->vq[queue].vring.used; 3894 status->used_idx = vdev->vq[queue].used_idx; 3895 status->signalled_used = vdev->vq[queue].signalled_used; 3896 status->signalled_used_valid = vdev->vq[queue].signalled_used_valid; 3897 3898 if (vdev->vhost_started) { 3899 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 3900 struct vhost_dev *hdev = vdc->get_vhost(vdev); 3901 3902 /* check if vq index exists for vhost as well */ 3903 if (queue >= hdev->vq_index && queue < hdev->vq_index + hdev->nvqs) { 3904 status->has_last_avail_idx = true; 3905 3906 int vhost_vq_index = 3907 hdev->vhost_ops->vhost_get_vq_index(hdev, queue); 3908 struct vhost_vring_state state = { 3909 .index = vhost_vq_index, 3910 }; 3911 3912 status->last_avail_idx = 3913 hdev->vhost_ops->vhost_get_vring_base(hdev, &state); 3914 } 3915 } else { 3916 status->has_shadow_avail_idx = true; 3917 status->has_last_avail_idx = true; 3918 status->last_avail_idx = vdev->vq[queue].last_avail_idx; 3919 status->shadow_avail_idx = vdev->vq[queue].shadow_avail_idx; 3920 } 3921 3922 return status; 3923 } 3924 3925 static strList *qmp_decode_vring_desc_flags(uint16_t flags) 3926 { 3927 strList *list = NULL; 3928 strList *node; 3929 int i; 3930 3931 struct { 3932 uint16_t flag; 3933 const char *value; 3934 } map[] = { 3935 { VRING_DESC_F_NEXT, "next" }, 3936 { VRING_DESC_F_WRITE, "write" }, 3937 { VRING_DESC_F_INDIRECT, "indirect" }, 3938 { 1 << VRING_PACKED_DESC_F_AVAIL, "avail" }, 3939 { 1 << VRING_PACKED_DESC_F_USED, "used" }, 3940 { 0, "" } 3941 }; 3942 3943 for (i = 0; map[i].flag; i++) { 3944 if ((map[i].flag & flags) == 0) { 3945 continue; 3946 } 3947 node = g_malloc0(sizeof(strList)); 3948 node->value = g_strdup(map[i].value); 3949 node->next = list; 3950 list = node; 3951 } 3952 3953 return list; 3954 } 3955 3956 VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path, 3957 uint16_t queue, 3958 bool has_index, 3959 uint16_t index, 3960 Error **errp) 3961 { 3962 VirtIODevice *vdev; 3963 VirtQueue *vq; 3964 VirtioQueueElement *element = NULL; 3965 3966 vdev = qmp_find_virtio_device(path); 3967 if (vdev == NULL) { 3968 error_setg(errp, "Path %s is not a VirtIO device", path); 3969 return NULL; 3970 } 3971 3972 if (queue >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, queue)) { 3973 error_setg(errp, "Invalid virtqueue number %d", queue); 3974 return NULL; 3975 } 3976 vq = &vdev->vq[queue]; 3977 3978 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3979 error_setg(errp, "Packed ring not supported"); 3980 return NULL; 3981 } else { 3982 unsigned int head, i, max; 3983 VRingMemoryRegionCaches *caches; 3984 MemoryRegionCache indirect_desc_cache; 3985 MemoryRegionCache *desc_cache; 3986 VRingDesc desc; 3987 VirtioRingDescList *list = NULL; 3988 VirtioRingDescList *node; 3989 int rc; int ndescs; 3990 3991 address_space_cache_init_empty(&indirect_desc_cache); 3992 3993 RCU_READ_LOCK_GUARD(); 3994 3995 max = vq->vring.num; 3996 3997 if (!has_index) { 3998 head = vring_avail_ring(vq, vq->last_avail_idx % vq->vring.num); 3999 } else { 4000 head = vring_avail_ring(vq, index % vq->vring.num); 4001 } 4002 i = head; 4003 4004 caches = vring_get_region_caches(vq); 4005 if (!caches) { 4006 error_setg(errp, "Region caches not initialized"); 4007 return NULL; 4008 } 4009 if (caches->desc.len < max * sizeof(VRingDesc)) { 4010 error_setg(errp, "Cannot map descriptor ring"); 4011 return NULL; 4012 } 4013 4014 desc_cache = &caches->desc; 4015 vring_split_desc_read(vdev, &desc, desc_cache, i); 4016 if (desc.flags & VRING_DESC_F_INDIRECT) { 4017 int64_t len; 4018 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 4019 desc.addr, desc.len, false); 4020 desc_cache = &indirect_desc_cache; 4021 if (len < desc.len) { 4022 error_setg(errp, "Cannot map indirect buffer"); 4023 goto done; 4024 } 4025 4026 max = desc.len / sizeof(VRingDesc); 4027 i = 0; 4028 vring_split_desc_read(vdev, &desc, desc_cache, i); 4029 } 4030 4031 element = g_new0(VirtioQueueElement, 1); 4032 element->avail = g_new0(VirtioRingAvail, 1); 4033 element->used = g_new0(VirtioRingUsed, 1); 4034 element->name = g_strdup(vdev->name); 4035 element->index = head; 4036 element->avail->flags = vring_avail_flags(vq); 4037 element->avail->idx = vring_avail_idx(vq); 4038 element->avail->ring = head; 4039 element->used->flags = vring_used_flags(vq); 4040 element->used->idx = vring_used_idx(vq); 4041 ndescs = 0; 4042 4043 do { 4044 /* A buggy driver may produce an infinite loop */ 4045 if (ndescs >= max) { 4046 break; 4047 } 4048 node = g_new0(VirtioRingDescList, 1); 4049 node->value = g_new0(VirtioRingDesc, 1); 4050 node->value->addr = desc.addr; 4051 node->value->len = desc.len; 4052 node->value->flags = qmp_decode_vring_desc_flags(desc.flags); 4053 node->next = list; 4054 list = node; 4055 4056 ndescs++; 4057 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max); 4058 } while (rc == VIRTQUEUE_READ_DESC_MORE); 4059 element->descs = list; 4060 done: 4061 address_space_cache_destroy(&indirect_desc_cache); 4062 } 4063 4064 return element; 4065 } 4066 4067 static const TypeInfo virtio_device_info = { 4068 .name = TYPE_VIRTIO_DEVICE, 4069 .parent = TYPE_DEVICE, 4070 .instance_size = sizeof(VirtIODevice), 4071 .class_init = virtio_device_class_init, 4072 .instance_finalize = virtio_device_instance_finalize, 4073 .abstract = true, 4074 .class_size = sizeof(VirtioDeviceClass), 4075 }; 4076 4077 static void virtio_register_types(void) 4078 { 4079 type_register_static(&virtio_device_info); 4080 } 4081 4082 type_init(virtio_register_types) 4083