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