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 static 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 max, 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 max = vq->vring.num; 1082 1083 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 1084 MemoryRegionCache *desc_cache = &caches->desc; 1085 unsigned int num_bufs; 1086 VRingDesc desc; 1087 unsigned int i; 1088 1089 num_bufs = total_bufs; 1090 1091 if (!virtqueue_get_head(vq, idx++, &i)) { 1092 goto err; 1093 } 1094 1095 vring_split_desc_read(vdev, &desc, desc_cache, i); 1096 1097 if (desc.flags & VRING_DESC_F_INDIRECT) { 1098 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1099 virtio_error(vdev, "Invalid size for indirect buffer table"); 1100 goto err; 1101 } 1102 1103 /* If we've got too many, that implies a descriptor loop. */ 1104 if (num_bufs >= max) { 1105 virtio_error(vdev, "Looped descriptor"); 1106 goto err; 1107 } 1108 1109 /* loop over the indirect descriptor table */ 1110 len = address_space_cache_init(&indirect_desc_cache, 1111 vdev->dma_as, 1112 desc.addr, desc.len, false); 1113 desc_cache = &indirect_desc_cache; 1114 if (len < desc.len) { 1115 virtio_error(vdev, "Cannot map indirect buffer"); 1116 goto err; 1117 } 1118 1119 max = desc.len / sizeof(VRingDesc); 1120 num_bufs = i = 0; 1121 vring_split_desc_read(vdev, &desc, desc_cache, i); 1122 } 1123 1124 do { 1125 /* If we've got too many, that implies a descriptor loop. */ 1126 if (++num_bufs > max) { 1127 virtio_error(vdev, "Looped descriptor"); 1128 goto err; 1129 } 1130 1131 if (desc.flags & VRING_DESC_F_WRITE) { 1132 in_total += desc.len; 1133 } else { 1134 out_total += desc.len; 1135 } 1136 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1137 goto done; 1138 } 1139 1140 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); 1141 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1142 1143 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1144 goto err; 1145 } 1146 1147 if (desc_cache == &indirect_desc_cache) { 1148 address_space_cache_destroy(&indirect_desc_cache); 1149 total_bufs++; 1150 } else { 1151 total_bufs = num_bufs; 1152 } 1153 } 1154 1155 if (rc < 0) { 1156 goto err; 1157 } 1158 1159 done: 1160 address_space_cache_destroy(&indirect_desc_cache); 1161 if (in_bytes) { 1162 *in_bytes = in_total; 1163 } 1164 if (out_bytes) { 1165 *out_bytes = out_total; 1166 } 1167 return; 1168 1169 err: 1170 in_total = out_total = 0; 1171 goto done; 1172 } 1173 1174 static int virtqueue_packed_read_next_desc(VirtQueue *vq, 1175 VRingPackedDesc *desc, 1176 MemoryRegionCache 1177 *desc_cache, 1178 unsigned int max, 1179 unsigned int *next, 1180 bool indirect) 1181 { 1182 /* If this descriptor says it doesn't chain, we're done. */ 1183 if (!indirect && !(desc->flags & VRING_DESC_F_NEXT)) { 1184 return VIRTQUEUE_READ_DESC_DONE; 1185 } 1186 1187 ++*next; 1188 if (*next == max) { 1189 if (indirect) { 1190 return VIRTQUEUE_READ_DESC_DONE; 1191 } else { 1192 (*next) -= vq->vring.num; 1193 } 1194 } 1195 1196 vring_packed_desc_read(vq->vdev, desc, desc_cache, *next, false); 1197 return VIRTQUEUE_READ_DESC_MORE; 1198 } 1199 1200 /* Called within rcu_read_lock(). */ 1201 static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, 1202 unsigned int *in_bytes, 1203 unsigned int *out_bytes, 1204 unsigned max_in_bytes, 1205 unsigned max_out_bytes, 1206 VRingMemoryRegionCaches *caches) 1207 { 1208 VirtIODevice *vdev = vq->vdev; 1209 unsigned int max, idx; 1210 unsigned int total_bufs, in_total, out_total; 1211 MemoryRegionCache *desc_cache; 1212 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1213 int64_t len = 0; 1214 VRingPackedDesc desc; 1215 bool wrap_counter; 1216 1217 idx = vq->last_avail_idx; 1218 wrap_counter = vq->last_avail_wrap_counter; 1219 total_bufs = in_total = out_total = 0; 1220 1221 max = vq->vring.num; 1222 1223 for (;;) { 1224 unsigned int num_bufs = total_bufs; 1225 unsigned int i = idx; 1226 int rc; 1227 1228 desc_cache = &caches->desc; 1229 vring_packed_desc_read(vdev, &desc, desc_cache, idx, true); 1230 if (!is_desc_avail(desc.flags, wrap_counter)) { 1231 break; 1232 } 1233 1234 if (desc.flags & VRING_DESC_F_INDIRECT) { 1235 if (desc.len % sizeof(VRingPackedDesc)) { 1236 virtio_error(vdev, "Invalid size for indirect buffer table"); 1237 goto err; 1238 } 1239 1240 /* If we've got too many, that implies a descriptor loop. */ 1241 if (num_bufs >= max) { 1242 virtio_error(vdev, "Looped descriptor"); 1243 goto err; 1244 } 1245 1246 /* loop over the indirect descriptor table */ 1247 len = address_space_cache_init(&indirect_desc_cache, 1248 vdev->dma_as, 1249 desc.addr, desc.len, false); 1250 desc_cache = &indirect_desc_cache; 1251 if (len < desc.len) { 1252 virtio_error(vdev, "Cannot map indirect buffer"); 1253 goto err; 1254 } 1255 1256 max = desc.len / sizeof(VRingPackedDesc); 1257 num_bufs = i = 0; 1258 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1259 } 1260 1261 do { 1262 /* If we've got too many, that implies a descriptor loop. */ 1263 if (++num_bufs > max) { 1264 virtio_error(vdev, "Looped descriptor"); 1265 goto err; 1266 } 1267 1268 if (desc.flags & VRING_DESC_F_WRITE) { 1269 in_total += desc.len; 1270 } else { 1271 out_total += desc.len; 1272 } 1273 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 1274 goto done; 1275 } 1276 1277 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, 1278 &i, desc_cache == 1279 &indirect_desc_cache); 1280 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1281 1282 if (desc_cache == &indirect_desc_cache) { 1283 address_space_cache_destroy(&indirect_desc_cache); 1284 total_bufs++; 1285 idx++; 1286 } else { 1287 idx += num_bufs - total_bufs; 1288 total_bufs = num_bufs; 1289 } 1290 1291 if (idx >= vq->vring.num) { 1292 idx -= vq->vring.num; 1293 wrap_counter ^= 1; 1294 } 1295 } 1296 1297 /* Record the index and wrap counter for a kick we want */ 1298 vq->shadow_avail_idx = idx; 1299 vq->shadow_avail_wrap_counter = wrap_counter; 1300 done: 1301 address_space_cache_destroy(&indirect_desc_cache); 1302 if (in_bytes) { 1303 *in_bytes = in_total; 1304 } 1305 if (out_bytes) { 1306 *out_bytes = out_total; 1307 } 1308 return; 1309 1310 err: 1311 in_total = out_total = 0; 1312 goto done; 1313 } 1314 1315 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 1316 unsigned int *out_bytes, 1317 unsigned max_in_bytes, unsigned max_out_bytes) 1318 { 1319 uint16_t desc_size; 1320 VRingMemoryRegionCaches *caches; 1321 1322 RCU_READ_LOCK_GUARD(); 1323 1324 if (unlikely(!vq->vring.desc)) { 1325 goto err; 1326 } 1327 1328 caches = vring_get_region_caches(vq); 1329 if (!caches) { 1330 goto err; 1331 } 1332 1333 desc_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED) ? 1334 sizeof(VRingPackedDesc) : sizeof(VRingDesc); 1335 if (caches->desc.len < vq->vring.num * desc_size) { 1336 virtio_error(vq->vdev, "Cannot map descriptor ring"); 1337 goto err; 1338 } 1339 1340 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1341 virtqueue_packed_get_avail_bytes(vq, in_bytes, out_bytes, 1342 max_in_bytes, max_out_bytes, 1343 caches); 1344 } else { 1345 virtqueue_split_get_avail_bytes(vq, in_bytes, out_bytes, 1346 max_in_bytes, max_out_bytes, 1347 caches); 1348 } 1349 1350 return; 1351 err: 1352 if (in_bytes) { 1353 *in_bytes = 0; 1354 } 1355 if (out_bytes) { 1356 *out_bytes = 0; 1357 } 1358 } 1359 1360 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 1361 unsigned int out_bytes) 1362 { 1363 unsigned int in_total, out_total; 1364 1365 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 1366 return in_bytes <= in_total && out_bytes <= out_total; 1367 } 1368 1369 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 1370 hwaddr *addr, struct iovec *iov, 1371 unsigned int max_num_sg, bool is_write, 1372 hwaddr pa, size_t sz) 1373 { 1374 bool ok = false; 1375 unsigned num_sg = *p_num_sg; 1376 assert(num_sg <= max_num_sg); 1377 1378 if (!sz) { 1379 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 1380 goto out; 1381 } 1382 1383 while (sz) { 1384 hwaddr len = sz; 1385 1386 if (num_sg == max_num_sg) { 1387 virtio_error(vdev, "virtio: too many write descriptors in " 1388 "indirect table"); 1389 goto out; 1390 } 1391 1392 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 1393 is_write ? 1394 DMA_DIRECTION_FROM_DEVICE : 1395 DMA_DIRECTION_TO_DEVICE, 1396 MEMTXATTRS_UNSPECIFIED); 1397 if (!iov[num_sg].iov_base) { 1398 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 1399 goto out; 1400 } 1401 1402 iov[num_sg].iov_len = len; 1403 addr[num_sg] = pa; 1404 1405 sz -= len; 1406 pa += len; 1407 num_sg++; 1408 } 1409 ok = true; 1410 1411 out: 1412 *p_num_sg = num_sg; 1413 return ok; 1414 } 1415 1416 /* Only used by error code paths before we have a VirtQueueElement (therefore 1417 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 1418 * yet. 1419 */ 1420 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 1421 struct iovec *iov) 1422 { 1423 unsigned int i; 1424 1425 for (i = 0; i < out_num + in_num; i++) { 1426 int is_write = i >= out_num; 1427 1428 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 1429 iov++; 1430 } 1431 } 1432 1433 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 1434 hwaddr *addr, unsigned int num_sg, 1435 bool is_write) 1436 { 1437 unsigned int i; 1438 hwaddr len; 1439 1440 for (i = 0; i < num_sg; i++) { 1441 len = sg[i].iov_len; 1442 sg[i].iov_base = dma_memory_map(vdev->dma_as, 1443 addr[i], &len, is_write ? 1444 DMA_DIRECTION_FROM_DEVICE : 1445 DMA_DIRECTION_TO_DEVICE, 1446 MEMTXATTRS_UNSPECIFIED); 1447 if (!sg[i].iov_base) { 1448 error_report("virtio: error trying to map MMIO memory"); 1449 exit(1); 1450 } 1451 if (len != sg[i].iov_len) { 1452 error_report("virtio: unexpected memory split"); 1453 exit(1); 1454 } 1455 } 1456 } 1457 1458 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 1459 { 1460 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, true); 1461 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 1462 false); 1463 } 1464 1465 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 1466 { 1467 VirtQueueElement *elem; 1468 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 1469 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 1470 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 1471 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 1472 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 1473 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 1474 1475 assert(sz >= sizeof(VirtQueueElement)); 1476 elem = g_malloc(out_sg_end); 1477 trace_virtqueue_alloc_element(elem, sz, in_num, out_num); 1478 elem->out_num = out_num; 1479 elem->in_num = in_num; 1480 elem->in_addr = (void *)elem + in_addr_ofs; 1481 elem->out_addr = (void *)elem + out_addr_ofs; 1482 elem->in_sg = (void *)elem + in_sg_ofs; 1483 elem->out_sg = (void *)elem + out_sg_ofs; 1484 return elem; 1485 } 1486 1487 static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) 1488 { 1489 unsigned int i, head, max; 1490 VRingMemoryRegionCaches *caches; 1491 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1492 MemoryRegionCache *desc_cache; 1493 int64_t len; 1494 VirtIODevice *vdev = vq->vdev; 1495 VirtQueueElement *elem = NULL; 1496 unsigned out_num, in_num, elem_entries; 1497 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1498 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1499 VRingDesc desc; 1500 int rc; 1501 1502 RCU_READ_LOCK_GUARD(); 1503 if (virtio_queue_empty_rcu(vq)) { 1504 goto done; 1505 } 1506 /* Needed after virtio_queue_empty(), see comment in 1507 * virtqueue_num_heads(). */ 1508 smp_rmb(); 1509 1510 /* When we start there are none of either input nor output. */ 1511 out_num = in_num = elem_entries = 0; 1512 1513 max = vq->vring.num; 1514 1515 if (vq->inuse >= vq->vring.num) { 1516 virtio_error(vdev, "Virtqueue size exceeded"); 1517 goto done; 1518 } 1519 1520 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 1521 goto done; 1522 } 1523 1524 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1525 vring_set_avail_event(vq, vq->last_avail_idx); 1526 } 1527 1528 i = head; 1529 1530 caches = vring_get_region_caches(vq); 1531 if (!caches) { 1532 virtio_error(vdev, "Region caches not initialized"); 1533 goto done; 1534 } 1535 1536 if (caches->desc.len < max * sizeof(VRingDesc)) { 1537 virtio_error(vdev, "Cannot map descriptor ring"); 1538 goto done; 1539 } 1540 1541 desc_cache = &caches->desc; 1542 vring_split_desc_read(vdev, &desc, desc_cache, i); 1543 if (desc.flags & VRING_DESC_F_INDIRECT) { 1544 if (!desc.len || (desc.len % sizeof(VRingDesc))) { 1545 virtio_error(vdev, "Invalid size for indirect buffer table"); 1546 goto done; 1547 } 1548 1549 /* loop over the indirect descriptor table */ 1550 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1551 desc.addr, desc.len, false); 1552 desc_cache = &indirect_desc_cache; 1553 if (len < desc.len) { 1554 virtio_error(vdev, "Cannot map indirect buffer"); 1555 goto done; 1556 } 1557 1558 max = desc.len / sizeof(VRingDesc); 1559 i = 0; 1560 vring_split_desc_read(vdev, &desc, desc_cache, i); 1561 } 1562 1563 /* Collect all the descriptors */ 1564 do { 1565 bool map_ok; 1566 1567 if (desc.flags & VRING_DESC_F_WRITE) { 1568 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1569 iov + out_num, 1570 VIRTQUEUE_MAX_SIZE - out_num, true, 1571 desc.addr, desc.len); 1572 } else { 1573 if (in_num) { 1574 virtio_error(vdev, "Incorrect order for descriptors"); 1575 goto err_undo_map; 1576 } 1577 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1578 VIRTQUEUE_MAX_SIZE, false, 1579 desc.addr, desc.len); 1580 } 1581 if (!map_ok) { 1582 goto err_undo_map; 1583 } 1584 1585 /* If we've got too many, that implies a descriptor loop. */ 1586 if (++elem_entries > max) { 1587 virtio_error(vdev, "Looped descriptor"); 1588 goto err_undo_map; 1589 } 1590 1591 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); 1592 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1593 1594 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 1595 goto err_undo_map; 1596 } 1597 1598 /* Now copy what we have collected and mapped */ 1599 elem = virtqueue_alloc_element(sz, out_num, in_num); 1600 elem->index = head; 1601 elem->ndescs = 1; 1602 for (i = 0; i < out_num; i++) { 1603 elem->out_addr[i] = addr[i]; 1604 elem->out_sg[i] = iov[i]; 1605 } 1606 for (i = 0; i < in_num; i++) { 1607 elem->in_addr[i] = addr[out_num + i]; 1608 elem->in_sg[i] = iov[out_num + i]; 1609 } 1610 1611 vq->inuse++; 1612 1613 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1614 done: 1615 address_space_cache_destroy(&indirect_desc_cache); 1616 1617 return elem; 1618 1619 err_undo_map: 1620 virtqueue_undo_map_desc(out_num, in_num, iov); 1621 goto done; 1622 } 1623 1624 static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) 1625 { 1626 unsigned int i, max; 1627 VRingMemoryRegionCaches *caches; 1628 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 1629 MemoryRegionCache *desc_cache; 1630 int64_t len; 1631 VirtIODevice *vdev = vq->vdev; 1632 VirtQueueElement *elem = NULL; 1633 unsigned out_num, in_num, elem_entries; 1634 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 1635 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 1636 VRingPackedDesc desc; 1637 uint16_t id; 1638 int rc; 1639 1640 RCU_READ_LOCK_GUARD(); 1641 if (virtio_queue_packed_empty_rcu(vq)) { 1642 goto done; 1643 } 1644 1645 /* When we start there are none of either input nor output. */ 1646 out_num = in_num = elem_entries = 0; 1647 1648 max = vq->vring.num; 1649 1650 if (vq->inuse >= vq->vring.num) { 1651 virtio_error(vdev, "Virtqueue size exceeded"); 1652 goto done; 1653 } 1654 1655 i = vq->last_avail_idx; 1656 1657 caches = vring_get_region_caches(vq); 1658 if (!caches) { 1659 virtio_error(vdev, "Region caches not initialized"); 1660 goto done; 1661 } 1662 1663 if (caches->desc.len < max * sizeof(VRingDesc)) { 1664 virtio_error(vdev, "Cannot map descriptor ring"); 1665 goto done; 1666 } 1667 1668 desc_cache = &caches->desc; 1669 vring_packed_desc_read(vdev, &desc, desc_cache, i, true); 1670 id = desc.id; 1671 if (desc.flags & VRING_DESC_F_INDIRECT) { 1672 if (desc.len % sizeof(VRingPackedDesc)) { 1673 virtio_error(vdev, "Invalid size for indirect buffer table"); 1674 goto done; 1675 } 1676 1677 /* loop over the indirect descriptor table */ 1678 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 1679 desc.addr, desc.len, false); 1680 desc_cache = &indirect_desc_cache; 1681 if (len < desc.len) { 1682 virtio_error(vdev, "Cannot map indirect buffer"); 1683 goto done; 1684 } 1685 1686 max = desc.len / sizeof(VRingPackedDesc); 1687 i = 0; 1688 vring_packed_desc_read(vdev, &desc, desc_cache, i, false); 1689 } 1690 1691 /* Collect all the descriptors */ 1692 do { 1693 bool map_ok; 1694 1695 if (desc.flags & VRING_DESC_F_WRITE) { 1696 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 1697 iov + out_num, 1698 VIRTQUEUE_MAX_SIZE - out_num, true, 1699 desc.addr, desc.len); 1700 } else { 1701 if (in_num) { 1702 virtio_error(vdev, "Incorrect order for descriptors"); 1703 goto err_undo_map; 1704 } 1705 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 1706 VIRTQUEUE_MAX_SIZE, false, 1707 desc.addr, desc.len); 1708 } 1709 if (!map_ok) { 1710 goto err_undo_map; 1711 } 1712 1713 /* If we've got too many, that implies a descriptor loop. */ 1714 if (++elem_entries > max) { 1715 virtio_error(vdev, "Looped descriptor"); 1716 goto err_undo_map; 1717 } 1718 1719 rc = virtqueue_packed_read_next_desc(vq, &desc, desc_cache, max, &i, 1720 desc_cache == 1721 &indirect_desc_cache); 1722 } while (rc == VIRTQUEUE_READ_DESC_MORE); 1723 1724 /* Now copy what we have collected and mapped */ 1725 elem = virtqueue_alloc_element(sz, out_num, in_num); 1726 for (i = 0; i < out_num; i++) { 1727 elem->out_addr[i] = addr[i]; 1728 elem->out_sg[i] = iov[i]; 1729 } 1730 for (i = 0; i < in_num; i++) { 1731 elem->in_addr[i] = addr[out_num + i]; 1732 elem->in_sg[i] = iov[out_num + i]; 1733 } 1734 1735 elem->index = id; 1736 elem->ndescs = (desc_cache == &indirect_desc_cache) ? 1 : elem_entries; 1737 vq->last_avail_idx += elem->ndescs; 1738 vq->inuse += elem->ndescs; 1739 1740 if (vq->last_avail_idx >= vq->vring.num) { 1741 vq->last_avail_idx -= vq->vring.num; 1742 vq->last_avail_wrap_counter ^= 1; 1743 } 1744 1745 vq->shadow_avail_idx = vq->last_avail_idx; 1746 vq->shadow_avail_wrap_counter = vq->last_avail_wrap_counter; 1747 1748 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 1749 done: 1750 address_space_cache_destroy(&indirect_desc_cache); 1751 1752 return elem; 1753 1754 err_undo_map: 1755 virtqueue_undo_map_desc(out_num, in_num, iov); 1756 goto done; 1757 } 1758 1759 void *virtqueue_pop(VirtQueue *vq, size_t sz) 1760 { 1761 if (virtio_device_disabled(vq->vdev)) { 1762 return NULL; 1763 } 1764 1765 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) { 1766 return virtqueue_packed_pop(vq, sz); 1767 } else { 1768 return virtqueue_split_pop(vq, sz); 1769 } 1770 } 1771 1772 static unsigned int virtqueue_packed_drop_all(VirtQueue *vq) 1773 { 1774 VRingMemoryRegionCaches *caches; 1775 MemoryRegionCache *desc_cache; 1776 unsigned int dropped = 0; 1777 VirtQueueElement elem = {}; 1778 VirtIODevice *vdev = vq->vdev; 1779 VRingPackedDesc desc; 1780 1781 RCU_READ_LOCK_GUARD(); 1782 1783 caches = vring_get_region_caches(vq); 1784 if (!caches) { 1785 return 0; 1786 } 1787 1788 desc_cache = &caches->desc; 1789 1790 virtio_queue_set_notification(vq, 0); 1791 1792 while (vq->inuse < vq->vring.num) { 1793 unsigned int idx = vq->last_avail_idx; 1794 /* 1795 * works similar to virtqueue_pop but does not map buffers 1796 * and does not allocate any memory. 1797 */ 1798 vring_packed_desc_read(vdev, &desc, desc_cache, 1799 vq->last_avail_idx , true); 1800 if (!is_desc_avail(desc.flags, vq->last_avail_wrap_counter)) { 1801 break; 1802 } 1803 elem.index = desc.id; 1804 elem.ndescs = 1; 1805 while (virtqueue_packed_read_next_desc(vq, &desc, desc_cache, 1806 vq->vring.num, &idx, false)) { 1807 ++elem.ndescs; 1808 } 1809 /* 1810 * immediately push the element, nothing to unmap 1811 * as both in_num and out_num are set to 0. 1812 */ 1813 virtqueue_push(vq, &elem, 0); 1814 dropped++; 1815 vq->last_avail_idx += elem.ndescs; 1816 if (vq->last_avail_idx >= vq->vring.num) { 1817 vq->last_avail_idx -= vq->vring.num; 1818 vq->last_avail_wrap_counter ^= 1; 1819 } 1820 } 1821 1822 return dropped; 1823 } 1824 1825 static unsigned int virtqueue_split_drop_all(VirtQueue *vq) 1826 { 1827 unsigned int dropped = 0; 1828 VirtQueueElement elem = {}; 1829 VirtIODevice *vdev = vq->vdev; 1830 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 1831 1832 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 1833 /* works similar to virtqueue_pop but does not map buffers 1834 * and does not allocate any memory */ 1835 smp_rmb(); 1836 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 1837 break; 1838 } 1839 vq->inuse++; 1840 vq->last_avail_idx++; 1841 if (fEventIdx) { 1842 vring_set_avail_event(vq, vq->last_avail_idx); 1843 } 1844 /* immediately push the element, nothing to unmap 1845 * as both in_num and out_num are set to 0 */ 1846 virtqueue_push(vq, &elem, 0); 1847 dropped++; 1848 } 1849 1850 return dropped; 1851 } 1852 1853 /* virtqueue_drop_all: 1854 * @vq: The #VirtQueue 1855 * Drops all queued buffers and indicates them to the guest 1856 * as if they are done. Useful when buffers can not be 1857 * processed but must be returned to the guest. 1858 */ 1859 unsigned int virtqueue_drop_all(VirtQueue *vq) 1860 { 1861 struct VirtIODevice *vdev = vq->vdev; 1862 1863 if (virtio_device_disabled(vq->vdev)) { 1864 return 0; 1865 } 1866 1867 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1868 return virtqueue_packed_drop_all(vq); 1869 } else { 1870 return virtqueue_split_drop_all(vq); 1871 } 1872 } 1873 1874 /* Reading and writing a structure directly to QEMUFile is *awful*, but 1875 * it is what QEMU has always done by mistake. We can change it sooner 1876 * or later by bumping the version number of the affected vm states. 1877 * In the meanwhile, since the in-memory layout of VirtQueueElement 1878 * has changed, we need to marshal to and from the layout that was 1879 * used before the change. 1880 */ 1881 typedef struct VirtQueueElementOld { 1882 unsigned int index; 1883 unsigned int out_num; 1884 unsigned int in_num; 1885 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 1886 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 1887 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 1888 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 1889 } VirtQueueElementOld; 1890 1891 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 1892 { 1893 VirtQueueElement *elem; 1894 VirtQueueElementOld data; 1895 int i; 1896 1897 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1898 1899 /* TODO: teach all callers that this can fail, and return failure instead 1900 * of asserting here. 1901 * This is just one thing (there are probably more) that must be 1902 * fixed before we can allow NDEBUG compilation. 1903 */ 1904 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 1905 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 1906 1907 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 1908 elem->index = data.index; 1909 1910 for (i = 0; i < elem->in_num; i++) { 1911 elem->in_addr[i] = data.in_addr[i]; 1912 } 1913 1914 for (i = 0; i < elem->out_num; i++) { 1915 elem->out_addr[i] = data.out_addr[i]; 1916 } 1917 1918 for (i = 0; i < elem->in_num; i++) { 1919 /* Base is overwritten by virtqueue_map. */ 1920 elem->in_sg[i].iov_base = 0; 1921 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 1922 } 1923 1924 for (i = 0; i < elem->out_num; i++) { 1925 /* Base is overwritten by virtqueue_map. */ 1926 elem->out_sg[i].iov_base = 0; 1927 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 1928 } 1929 1930 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1931 qemu_get_be32s(f, &elem->ndescs); 1932 } 1933 1934 virtqueue_map(vdev, elem); 1935 return elem; 1936 } 1937 1938 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 1939 VirtQueueElement *elem) 1940 { 1941 VirtQueueElementOld data; 1942 int i; 1943 1944 memset(&data, 0, sizeof(data)); 1945 data.index = elem->index; 1946 data.in_num = elem->in_num; 1947 data.out_num = elem->out_num; 1948 1949 for (i = 0; i < elem->in_num; i++) { 1950 data.in_addr[i] = elem->in_addr[i]; 1951 } 1952 1953 for (i = 0; i < elem->out_num; i++) { 1954 data.out_addr[i] = elem->out_addr[i]; 1955 } 1956 1957 for (i = 0; i < elem->in_num; i++) { 1958 /* Base is overwritten by virtqueue_map when loading. Do not 1959 * save it, as it would leak the QEMU address space layout. */ 1960 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 1961 } 1962 1963 for (i = 0; i < elem->out_num; i++) { 1964 /* Do not save iov_base as above. */ 1965 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 1966 } 1967 1968 if (virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 1969 qemu_put_be32s(f, &elem->ndescs); 1970 } 1971 1972 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 1973 } 1974 1975 /* virtio device */ 1976 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 1977 { 1978 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1979 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1980 1981 if (virtio_device_disabled(vdev)) { 1982 return; 1983 } 1984 1985 if (k->notify) { 1986 k->notify(qbus->parent, vector); 1987 } 1988 } 1989 1990 void virtio_update_irq(VirtIODevice *vdev) 1991 { 1992 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1993 } 1994 1995 static int virtio_validate_features(VirtIODevice *vdev) 1996 { 1997 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1998 1999 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 2000 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 2001 return -EFAULT; 2002 } 2003 2004 if (k->validate_features) { 2005 return k->validate_features(vdev); 2006 } else { 2007 return 0; 2008 } 2009 } 2010 2011 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 2012 { 2013 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2014 trace_virtio_set_status(vdev, val); 2015 2016 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2017 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 2018 val & VIRTIO_CONFIG_S_FEATURES_OK) { 2019 int ret = virtio_validate_features(vdev); 2020 2021 if (ret) { 2022 return ret; 2023 } 2024 } 2025 } 2026 2027 if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) != 2028 (val & VIRTIO_CONFIG_S_DRIVER_OK)) { 2029 virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK); 2030 } 2031 2032 if (k->set_status) { 2033 k->set_status(vdev, val); 2034 } 2035 vdev->status = val; 2036 2037 return 0; 2038 } 2039 2040 static enum virtio_device_endian virtio_default_endian(void) 2041 { 2042 if (target_words_bigendian()) { 2043 return VIRTIO_DEVICE_ENDIAN_BIG; 2044 } else { 2045 return VIRTIO_DEVICE_ENDIAN_LITTLE; 2046 } 2047 } 2048 2049 static enum virtio_device_endian virtio_current_cpu_endian(void) 2050 { 2051 if (cpu_virtio_is_big_endian(current_cpu)) { 2052 return VIRTIO_DEVICE_ENDIAN_BIG; 2053 } else { 2054 return VIRTIO_DEVICE_ENDIAN_LITTLE; 2055 } 2056 } 2057 2058 static void __virtio_queue_reset(VirtIODevice *vdev, uint32_t i) 2059 { 2060 vdev->vq[i].vring.desc = 0; 2061 vdev->vq[i].vring.avail = 0; 2062 vdev->vq[i].vring.used = 0; 2063 vdev->vq[i].last_avail_idx = 0; 2064 vdev->vq[i].shadow_avail_idx = 0; 2065 vdev->vq[i].used_idx = 0; 2066 vdev->vq[i].last_avail_wrap_counter = true; 2067 vdev->vq[i].shadow_avail_wrap_counter = true; 2068 vdev->vq[i].used_wrap_counter = true; 2069 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 2070 vdev->vq[i].signalled_used = 0; 2071 vdev->vq[i].signalled_used_valid = false; 2072 vdev->vq[i].notification = true; 2073 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 2074 vdev->vq[i].inuse = 0; 2075 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 2076 } 2077 2078 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index) 2079 { 2080 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2081 2082 if (k->queue_reset) { 2083 k->queue_reset(vdev, queue_index); 2084 } 2085 2086 __virtio_queue_reset(vdev, queue_index); 2087 } 2088 2089 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index) 2090 { 2091 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2092 2093 /* 2094 * TODO: Seabios is currently out of spec and triggering this error. 2095 * So this needs to be fixed in Seabios, then this can 2096 * be re-enabled for new machine types only, and also after 2097 * being converted to LOG_GUEST_ERROR. 2098 * 2099 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2100 error_report("queue_enable is only suppported in devices of virtio " 2101 "1.0 or later."); 2102 } 2103 */ 2104 2105 if (k->queue_enable) { 2106 k->queue_enable(vdev, queue_index); 2107 } 2108 } 2109 2110 void virtio_reset(void *opaque) 2111 { 2112 VirtIODevice *vdev = opaque; 2113 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2114 int i; 2115 2116 virtio_set_status(vdev, 0); 2117 if (current_cpu) { 2118 /* Guest initiated reset */ 2119 vdev->device_endian = virtio_current_cpu_endian(); 2120 } else { 2121 /* System reset */ 2122 vdev->device_endian = virtio_default_endian(); 2123 } 2124 2125 if (k->reset) { 2126 k->reset(vdev); 2127 } 2128 2129 vdev->start_on_kick = false; 2130 vdev->started = false; 2131 vdev->broken = false; 2132 vdev->guest_features = 0; 2133 vdev->queue_sel = 0; 2134 vdev->status = 0; 2135 vdev->disabled = false; 2136 qatomic_set(&vdev->isr, 0); 2137 vdev->config_vector = VIRTIO_NO_VECTOR; 2138 virtio_notify_vector(vdev, vdev->config_vector); 2139 2140 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2141 __virtio_queue_reset(vdev, i); 2142 } 2143 } 2144 2145 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 2146 { 2147 if (!vdev->vq[n].vring.num) { 2148 return; 2149 } 2150 vdev->vq[n].vring.desc = addr; 2151 virtio_queue_update_rings(vdev, n); 2152 } 2153 2154 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 2155 { 2156 return vdev->vq[n].vring.desc; 2157 } 2158 2159 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 2160 hwaddr avail, hwaddr used) 2161 { 2162 if (!vdev->vq[n].vring.num) { 2163 return; 2164 } 2165 vdev->vq[n].vring.desc = desc; 2166 vdev->vq[n].vring.avail = avail; 2167 vdev->vq[n].vring.used = used; 2168 virtio_init_region_cache(vdev, n); 2169 } 2170 2171 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 2172 { 2173 /* Don't allow guest to flip queue between existent and 2174 * nonexistent states, or to set it to an invalid size. 2175 */ 2176 if (!!num != !!vdev->vq[n].vring.num || 2177 num > VIRTQUEUE_MAX_SIZE || 2178 num < 0) { 2179 return; 2180 } 2181 vdev->vq[n].vring.num = num; 2182 } 2183 2184 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 2185 { 2186 return QLIST_FIRST(&vdev->vector_queues[vector]); 2187 } 2188 2189 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 2190 { 2191 return QLIST_NEXT(vq, node); 2192 } 2193 2194 int virtio_queue_get_num(VirtIODevice *vdev, int n) 2195 { 2196 return vdev->vq[n].vring.num; 2197 } 2198 2199 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 2200 { 2201 return vdev->vq[n].vring.num_default; 2202 } 2203 2204 int virtio_get_num_queues(VirtIODevice *vdev) 2205 { 2206 int i; 2207 2208 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2209 if (!virtio_queue_get_num(vdev, i)) { 2210 break; 2211 } 2212 } 2213 2214 return i; 2215 } 2216 2217 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 2218 { 2219 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2220 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2221 2222 /* virtio-1 compliant devices cannot change the alignment */ 2223 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2224 error_report("tried to modify queue alignment for virtio-1 device"); 2225 return; 2226 } 2227 /* Check that the transport told us it was going to do this 2228 * (so a buggy transport will immediately assert rather than 2229 * silently failing to migrate this state) 2230 */ 2231 assert(k->has_variable_vring_alignment); 2232 2233 if (align) { 2234 vdev->vq[n].vring.align = align; 2235 virtio_queue_update_rings(vdev, n); 2236 } 2237 } 2238 2239 static void virtio_queue_notify_vq(VirtQueue *vq) 2240 { 2241 if (vq->vring.desc && vq->handle_output) { 2242 VirtIODevice *vdev = vq->vdev; 2243 2244 if (unlikely(vdev->broken)) { 2245 return; 2246 } 2247 2248 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2249 vq->handle_output(vdev, vq); 2250 2251 if (unlikely(vdev->start_on_kick)) { 2252 virtio_set_started(vdev, true); 2253 } 2254 } 2255 } 2256 2257 void virtio_queue_notify(VirtIODevice *vdev, int n) 2258 { 2259 VirtQueue *vq = &vdev->vq[n]; 2260 2261 if (unlikely(!vq->vring.desc || vdev->broken)) { 2262 return; 2263 } 2264 2265 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 2266 if (vq->host_notifier_enabled) { 2267 event_notifier_set(&vq->host_notifier); 2268 } else if (vq->handle_output) { 2269 vq->handle_output(vdev, vq); 2270 2271 if (unlikely(vdev->start_on_kick)) { 2272 virtio_set_started(vdev, true); 2273 } 2274 } 2275 } 2276 2277 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 2278 { 2279 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 2280 VIRTIO_NO_VECTOR; 2281 } 2282 2283 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 2284 { 2285 VirtQueue *vq = &vdev->vq[n]; 2286 2287 if (n < VIRTIO_QUEUE_MAX) { 2288 if (vdev->vector_queues && 2289 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 2290 QLIST_REMOVE(vq, node); 2291 } 2292 vdev->vq[n].vector = vector; 2293 if (vdev->vector_queues && 2294 vector != VIRTIO_NO_VECTOR) { 2295 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 2296 } 2297 } 2298 } 2299 2300 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 2301 VirtIOHandleOutput handle_output) 2302 { 2303 int i; 2304 2305 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2306 if (vdev->vq[i].vring.num == 0) 2307 break; 2308 } 2309 2310 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 2311 abort(); 2312 2313 vdev->vq[i].vring.num = queue_size; 2314 vdev->vq[i].vring.num_default = queue_size; 2315 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 2316 vdev->vq[i].handle_output = handle_output; 2317 vdev->vq[i].used_elems = g_new0(VirtQueueElement, queue_size); 2318 2319 return &vdev->vq[i]; 2320 } 2321 2322 void virtio_delete_queue(VirtQueue *vq) 2323 { 2324 vq->vring.num = 0; 2325 vq->vring.num_default = 0; 2326 vq->handle_output = NULL; 2327 g_free(vq->used_elems); 2328 vq->used_elems = NULL; 2329 virtio_virtqueue_reset_region_cache(vq); 2330 } 2331 2332 void virtio_del_queue(VirtIODevice *vdev, int n) 2333 { 2334 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 2335 abort(); 2336 } 2337 2338 virtio_delete_queue(&vdev->vq[n]); 2339 } 2340 2341 static void virtio_set_isr(VirtIODevice *vdev, int value) 2342 { 2343 uint8_t old = qatomic_read(&vdev->isr); 2344 2345 /* Do not write ISR if it does not change, so that its cacheline remains 2346 * shared in the common case where the guest does not read it. 2347 */ 2348 if ((old & value) != value) { 2349 qatomic_or(&vdev->isr, value); 2350 } 2351 } 2352 2353 /* Called within rcu_read_lock(). */ 2354 static bool virtio_split_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2355 { 2356 uint16_t old, new; 2357 bool v; 2358 /* We need to expose used array entries before checking used event. */ 2359 smp_mb(); 2360 /* Always notify when queue is empty (when feature acknowledge) */ 2361 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 2362 !vq->inuse && virtio_queue_empty(vq)) { 2363 return true; 2364 } 2365 2366 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2367 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 2368 } 2369 2370 v = vq->signalled_used_valid; 2371 vq->signalled_used_valid = true; 2372 old = vq->signalled_used; 2373 new = vq->signalled_used = vq->used_idx; 2374 return !v || vring_need_event(vring_get_used_event(vq), new, old); 2375 } 2376 2377 static bool vring_packed_need_event(VirtQueue *vq, bool wrap, 2378 uint16_t off_wrap, uint16_t new, 2379 uint16_t old) 2380 { 2381 int off = off_wrap & ~(1 << 15); 2382 2383 if (wrap != off_wrap >> 15) { 2384 off -= vq->vring.num; 2385 } 2386 2387 return vring_need_event(off, new, old); 2388 } 2389 2390 /* Called within rcu_read_lock(). */ 2391 static bool virtio_packed_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2392 { 2393 VRingPackedDescEvent e; 2394 uint16_t old, new; 2395 bool v; 2396 VRingMemoryRegionCaches *caches; 2397 2398 caches = vring_get_region_caches(vq); 2399 if (!caches) { 2400 return false; 2401 } 2402 2403 vring_packed_event_read(vdev, &caches->avail, &e); 2404 2405 old = vq->signalled_used; 2406 new = vq->signalled_used = vq->used_idx; 2407 v = vq->signalled_used_valid; 2408 vq->signalled_used_valid = true; 2409 2410 if (e.flags == VRING_PACKED_EVENT_FLAG_DISABLE) { 2411 return false; 2412 } else if (e.flags == VRING_PACKED_EVENT_FLAG_ENABLE) { 2413 return true; 2414 } 2415 2416 return !v || vring_packed_need_event(vq, vq->used_wrap_counter, 2417 e.off_wrap, new, old); 2418 } 2419 2420 /* Called within rcu_read_lock(). */ 2421 static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 2422 { 2423 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 2424 return virtio_packed_should_notify(vdev, vq); 2425 } else { 2426 return virtio_split_should_notify(vdev, vq); 2427 } 2428 } 2429 2430 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 2431 { 2432 WITH_RCU_READ_LOCK_GUARD() { 2433 if (!virtio_should_notify(vdev, vq)) { 2434 return; 2435 } 2436 } 2437 2438 trace_virtio_notify_irqfd(vdev, vq); 2439 2440 /* 2441 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 2442 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 2443 * incorrectly polling this bit during crashdump and hibernation 2444 * in MSI mode, causing a hang if this bit is never updated. 2445 * Recent releases of Windows do not really shut down, but rather 2446 * log out and hibernate to make the next startup faster. Hence, 2447 * this manifested as a more serious hang during shutdown with 2448 * 2449 * Next driver release from 2016 fixed this problem, so working around it 2450 * is not a must, but it's easy to do so let's do it here. 2451 * 2452 * Note: it's safe to update ISR from any thread as it was switched 2453 * to an atomic operation. 2454 */ 2455 virtio_set_isr(vq->vdev, 0x1); 2456 event_notifier_set(&vq->guest_notifier); 2457 } 2458 2459 static void virtio_irq(VirtQueue *vq) 2460 { 2461 virtio_set_isr(vq->vdev, 0x1); 2462 virtio_notify_vector(vq->vdev, vq->vector); 2463 } 2464 2465 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 2466 { 2467 WITH_RCU_READ_LOCK_GUARD() { 2468 if (!virtio_should_notify(vdev, vq)) { 2469 return; 2470 } 2471 } 2472 2473 trace_virtio_notify(vdev, vq); 2474 virtio_irq(vq); 2475 } 2476 2477 void virtio_notify_config(VirtIODevice *vdev) 2478 { 2479 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 2480 return; 2481 2482 virtio_set_isr(vdev, 0x3); 2483 vdev->generation++; 2484 virtio_notify_vector(vdev, vdev->config_vector); 2485 } 2486 2487 static bool virtio_device_endian_needed(void *opaque) 2488 { 2489 VirtIODevice *vdev = opaque; 2490 2491 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 2492 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2493 return vdev->device_endian != virtio_default_endian(); 2494 } 2495 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 2496 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 2497 } 2498 2499 static bool virtio_64bit_features_needed(void *opaque) 2500 { 2501 VirtIODevice *vdev = opaque; 2502 2503 return (vdev->host_features >> 32) != 0; 2504 } 2505 2506 static bool virtio_virtqueue_needed(void *opaque) 2507 { 2508 VirtIODevice *vdev = opaque; 2509 2510 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 2511 } 2512 2513 static bool virtio_packed_virtqueue_needed(void *opaque) 2514 { 2515 VirtIODevice *vdev = opaque; 2516 2517 return virtio_host_has_feature(vdev, VIRTIO_F_RING_PACKED); 2518 } 2519 2520 static bool virtio_ringsize_needed(void *opaque) 2521 { 2522 VirtIODevice *vdev = opaque; 2523 int i; 2524 2525 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2526 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 2527 return true; 2528 } 2529 } 2530 return false; 2531 } 2532 2533 static bool virtio_extra_state_needed(void *opaque) 2534 { 2535 VirtIODevice *vdev = opaque; 2536 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2537 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2538 2539 return k->has_extra_state && 2540 k->has_extra_state(qbus->parent); 2541 } 2542 2543 static bool virtio_broken_needed(void *opaque) 2544 { 2545 VirtIODevice *vdev = opaque; 2546 2547 return vdev->broken; 2548 } 2549 2550 static bool virtio_started_needed(void *opaque) 2551 { 2552 VirtIODevice *vdev = opaque; 2553 2554 return vdev->started; 2555 } 2556 2557 static bool virtio_disabled_needed(void *opaque) 2558 { 2559 VirtIODevice *vdev = opaque; 2560 2561 return vdev->disabled; 2562 } 2563 2564 static const VMStateDescription vmstate_virtqueue = { 2565 .name = "virtqueue_state", 2566 .version_id = 1, 2567 .minimum_version_id = 1, 2568 .fields = (VMStateField[]) { 2569 VMSTATE_UINT64(vring.avail, struct VirtQueue), 2570 VMSTATE_UINT64(vring.used, struct VirtQueue), 2571 VMSTATE_END_OF_LIST() 2572 } 2573 }; 2574 2575 static const VMStateDescription vmstate_packed_virtqueue = { 2576 .name = "packed_virtqueue_state", 2577 .version_id = 1, 2578 .minimum_version_id = 1, 2579 .fields = (VMStateField[]) { 2580 VMSTATE_UINT16(last_avail_idx, struct VirtQueue), 2581 VMSTATE_BOOL(last_avail_wrap_counter, struct VirtQueue), 2582 VMSTATE_UINT16(used_idx, struct VirtQueue), 2583 VMSTATE_BOOL(used_wrap_counter, struct VirtQueue), 2584 VMSTATE_UINT32(inuse, struct VirtQueue), 2585 VMSTATE_END_OF_LIST() 2586 } 2587 }; 2588 2589 static const VMStateDescription vmstate_virtio_virtqueues = { 2590 .name = "virtio/virtqueues", 2591 .version_id = 1, 2592 .minimum_version_id = 1, 2593 .needed = &virtio_virtqueue_needed, 2594 .fields = (VMStateField[]) { 2595 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2596 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 2597 VMSTATE_END_OF_LIST() 2598 } 2599 }; 2600 2601 static const VMStateDescription vmstate_virtio_packed_virtqueues = { 2602 .name = "virtio/packed_virtqueues", 2603 .version_id = 1, 2604 .minimum_version_id = 1, 2605 .needed = &virtio_packed_virtqueue_needed, 2606 .fields = (VMStateField[]) { 2607 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2608 VIRTIO_QUEUE_MAX, 0, vmstate_packed_virtqueue, VirtQueue), 2609 VMSTATE_END_OF_LIST() 2610 } 2611 }; 2612 2613 static const VMStateDescription vmstate_ringsize = { 2614 .name = "ringsize_state", 2615 .version_id = 1, 2616 .minimum_version_id = 1, 2617 .fields = (VMStateField[]) { 2618 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 2619 VMSTATE_END_OF_LIST() 2620 } 2621 }; 2622 2623 static const VMStateDescription vmstate_virtio_ringsize = { 2624 .name = "virtio/ringsize", 2625 .version_id = 1, 2626 .minimum_version_id = 1, 2627 .needed = &virtio_ringsize_needed, 2628 .fields = (VMStateField[]) { 2629 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 2630 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 2631 VMSTATE_END_OF_LIST() 2632 } 2633 }; 2634 2635 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 2636 const VMStateField *field) 2637 { 2638 VirtIODevice *vdev = pv; 2639 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2640 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2641 2642 if (!k->load_extra_state) { 2643 return -1; 2644 } else { 2645 return k->load_extra_state(qbus->parent, f); 2646 } 2647 } 2648 2649 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 2650 const VMStateField *field, JSONWriter *vmdesc) 2651 { 2652 VirtIODevice *vdev = pv; 2653 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2654 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2655 2656 k->save_extra_state(qbus->parent, f); 2657 return 0; 2658 } 2659 2660 static const VMStateInfo vmstate_info_extra_state = { 2661 .name = "virtqueue_extra_state", 2662 .get = get_extra_state, 2663 .put = put_extra_state, 2664 }; 2665 2666 static const VMStateDescription vmstate_virtio_extra_state = { 2667 .name = "virtio/extra_state", 2668 .version_id = 1, 2669 .minimum_version_id = 1, 2670 .needed = &virtio_extra_state_needed, 2671 .fields = (VMStateField[]) { 2672 { 2673 .name = "extra_state", 2674 .version_id = 0, 2675 .field_exists = NULL, 2676 .size = 0, 2677 .info = &vmstate_info_extra_state, 2678 .flags = VMS_SINGLE, 2679 .offset = 0, 2680 }, 2681 VMSTATE_END_OF_LIST() 2682 } 2683 }; 2684 2685 static const VMStateDescription vmstate_virtio_device_endian = { 2686 .name = "virtio/device_endian", 2687 .version_id = 1, 2688 .minimum_version_id = 1, 2689 .needed = &virtio_device_endian_needed, 2690 .fields = (VMStateField[]) { 2691 VMSTATE_UINT8(device_endian, VirtIODevice), 2692 VMSTATE_END_OF_LIST() 2693 } 2694 }; 2695 2696 static const VMStateDescription vmstate_virtio_64bit_features = { 2697 .name = "virtio/64bit_features", 2698 .version_id = 1, 2699 .minimum_version_id = 1, 2700 .needed = &virtio_64bit_features_needed, 2701 .fields = (VMStateField[]) { 2702 VMSTATE_UINT64(guest_features, VirtIODevice), 2703 VMSTATE_END_OF_LIST() 2704 } 2705 }; 2706 2707 static const VMStateDescription vmstate_virtio_broken = { 2708 .name = "virtio/broken", 2709 .version_id = 1, 2710 .minimum_version_id = 1, 2711 .needed = &virtio_broken_needed, 2712 .fields = (VMStateField[]) { 2713 VMSTATE_BOOL(broken, VirtIODevice), 2714 VMSTATE_END_OF_LIST() 2715 } 2716 }; 2717 2718 static const VMStateDescription vmstate_virtio_started = { 2719 .name = "virtio/started", 2720 .version_id = 1, 2721 .minimum_version_id = 1, 2722 .needed = &virtio_started_needed, 2723 .fields = (VMStateField[]) { 2724 VMSTATE_BOOL(started, VirtIODevice), 2725 VMSTATE_END_OF_LIST() 2726 } 2727 }; 2728 2729 static const VMStateDescription vmstate_virtio_disabled = { 2730 .name = "virtio/disabled", 2731 .version_id = 1, 2732 .minimum_version_id = 1, 2733 .needed = &virtio_disabled_needed, 2734 .fields = (VMStateField[]) { 2735 VMSTATE_BOOL(disabled, VirtIODevice), 2736 VMSTATE_END_OF_LIST() 2737 } 2738 }; 2739 2740 static const VMStateDescription vmstate_virtio = { 2741 .name = "virtio", 2742 .version_id = 1, 2743 .minimum_version_id = 1, 2744 .fields = (VMStateField[]) { 2745 VMSTATE_END_OF_LIST() 2746 }, 2747 .subsections = (const VMStateDescription*[]) { 2748 &vmstate_virtio_device_endian, 2749 &vmstate_virtio_64bit_features, 2750 &vmstate_virtio_virtqueues, 2751 &vmstate_virtio_ringsize, 2752 &vmstate_virtio_broken, 2753 &vmstate_virtio_extra_state, 2754 &vmstate_virtio_started, 2755 &vmstate_virtio_packed_virtqueues, 2756 &vmstate_virtio_disabled, 2757 NULL 2758 } 2759 }; 2760 2761 int virtio_save(VirtIODevice *vdev, QEMUFile *f) 2762 { 2763 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2764 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2765 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2766 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 2767 int i; 2768 2769 if (k->save_config) { 2770 k->save_config(qbus->parent, f); 2771 } 2772 2773 qemu_put_8s(f, &vdev->status); 2774 qemu_put_8s(f, &vdev->isr); 2775 qemu_put_be16s(f, &vdev->queue_sel); 2776 qemu_put_be32s(f, &guest_features_lo); 2777 qemu_put_be32(f, vdev->config_len); 2778 qemu_put_buffer(f, vdev->config, vdev->config_len); 2779 2780 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2781 if (vdev->vq[i].vring.num == 0) 2782 break; 2783 } 2784 2785 qemu_put_be32(f, i); 2786 2787 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2788 if (vdev->vq[i].vring.num == 0) 2789 break; 2790 2791 qemu_put_be32(f, vdev->vq[i].vring.num); 2792 if (k->has_variable_vring_alignment) { 2793 qemu_put_be32(f, vdev->vq[i].vring.align); 2794 } 2795 /* 2796 * Save desc now, the rest of the ring addresses are saved in 2797 * subsections for VIRTIO-1 devices. 2798 */ 2799 qemu_put_be64(f, vdev->vq[i].vring.desc); 2800 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 2801 if (k->save_queue) { 2802 k->save_queue(qbus->parent, i, f); 2803 } 2804 } 2805 2806 if (vdc->save != NULL) { 2807 vdc->save(vdev, f); 2808 } 2809 2810 if (vdc->vmsd) { 2811 int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL); 2812 if (ret) { 2813 return ret; 2814 } 2815 } 2816 2817 /* Subsections */ 2818 return vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 2819 } 2820 2821 /* A wrapper for use as a VMState .put function */ 2822 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 2823 const VMStateField *field, JSONWriter *vmdesc) 2824 { 2825 return virtio_save(VIRTIO_DEVICE(opaque), f); 2826 } 2827 2828 /* A wrapper for use as a VMState .get function */ 2829 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 2830 const VMStateField *field) 2831 { 2832 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 2833 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 2834 2835 return virtio_load(vdev, f, dc->vmsd->version_id); 2836 } 2837 2838 const VMStateInfo virtio_vmstate_info = { 2839 .name = "virtio", 2840 .get = virtio_device_get, 2841 .put = virtio_device_put, 2842 }; 2843 2844 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 2845 { 2846 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 2847 bool bad = (val & ~(vdev->host_features)) != 0; 2848 2849 val &= vdev->host_features; 2850 if (k->set_features) { 2851 k->set_features(vdev, val); 2852 } 2853 vdev->guest_features = val; 2854 return bad ? -1 : 0; 2855 } 2856 2857 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 2858 { 2859 int ret; 2860 /* 2861 * The driver must not attempt to set features after feature negotiation 2862 * has finished. 2863 */ 2864 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 2865 return -EINVAL; 2866 } 2867 2868 if (val & (1ull << VIRTIO_F_BAD_FEATURE)) { 2869 qemu_log_mask(LOG_GUEST_ERROR, 2870 "%s: guest driver for %s has enabled UNUSED(30) feature bit!\n", 2871 __func__, vdev->name); 2872 } 2873 2874 ret = virtio_set_features_nocheck(vdev, val); 2875 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 2876 /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */ 2877 int i; 2878 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 2879 if (vdev->vq[i].vring.num != 0) { 2880 virtio_init_region_cache(vdev, i); 2881 } 2882 } 2883 } 2884 if (!ret) { 2885 if (!virtio_device_started(vdev, vdev->status) && 2886 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2887 vdev->start_on_kick = true; 2888 } 2889 } 2890 return ret; 2891 } 2892 2893 size_t virtio_get_config_size(const VirtIOConfigSizeParams *params, 2894 uint64_t host_features) 2895 { 2896 size_t config_size = params->min_size; 2897 const VirtIOFeature *feature_sizes = params->feature_sizes; 2898 size_t i; 2899 2900 for (i = 0; feature_sizes[i].flags != 0; i++) { 2901 if (host_features & feature_sizes[i].flags) { 2902 config_size = MAX(feature_sizes[i].end, config_size); 2903 } 2904 } 2905 2906 assert(config_size <= params->max_size); 2907 return config_size; 2908 } 2909 2910 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 2911 { 2912 int i, ret; 2913 int32_t config_len; 2914 uint32_t num; 2915 uint32_t features; 2916 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2917 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 2918 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 2919 2920 /* 2921 * We poison the endianness to ensure it does not get used before 2922 * subsections have been loaded. 2923 */ 2924 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 2925 2926 if (k->load_config) { 2927 ret = k->load_config(qbus->parent, f); 2928 if (ret) 2929 return ret; 2930 } 2931 2932 qemu_get_8s(f, &vdev->status); 2933 qemu_get_8s(f, &vdev->isr); 2934 qemu_get_be16s(f, &vdev->queue_sel); 2935 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 2936 return -1; 2937 } 2938 qemu_get_be32s(f, &features); 2939 2940 /* 2941 * Temporarily set guest_features low bits - needed by 2942 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2943 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 2944 * 2945 * Note: devices should always test host features in future - don't create 2946 * new dependencies like this. 2947 */ 2948 vdev->guest_features = features; 2949 2950 config_len = qemu_get_be32(f); 2951 2952 /* 2953 * There are cases where the incoming config can be bigger or smaller 2954 * than what we have; so load what we have space for, and skip 2955 * any excess that's in the stream. 2956 */ 2957 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 2958 2959 while (config_len > vdev->config_len) { 2960 qemu_get_byte(f); 2961 config_len--; 2962 } 2963 2964 num = qemu_get_be32(f); 2965 2966 if (num > VIRTIO_QUEUE_MAX) { 2967 error_report("Invalid number of virtqueues: 0x%x", num); 2968 return -1; 2969 } 2970 2971 for (i = 0; i < num; i++) { 2972 vdev->vq[i].vring.num = qemu_get_be32(f); 2973 if (k->has_variable_vring_alignment) { 2974 vdev->vq[i].vring.align = qemu_get_be32(f); 2975 } 2976 vdev->vq[i].vring.desc = qemu_get_be64(f); 2977 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 2978 vdev->vq[i].signalled_used_valid = false; 2979 vdev->vq[i].notification = true; 2980 2981 if (!vdev->vq[i].vring.desc && vdev->vq[i].last_avail_idx) { 2982 error_report("VQ %d address 0x0 " 2983 "inconsistent with Host index 0x%x", 2984 i, vdev->vq[i].last_avail_idx); 2985 return -1; 2986 } 2987 if (k->load_queue) { 2988 ret = k->load_queue(qbus->parent, i, f); 2989 if (ret) 2990 return ret; 2991 } 2992 } 2993 2994 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 2995 2996 if (vdc->load != NULL) { 2997 ret = vdc->load(vdev, f, version_id); 2998 if (ret) { 2999 return ret; 3000 } 3001 } 3002 3003 if (vdc->vmsd) { 3004 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 3005 if (ret) { 3006 return ret; 3007 } 3008 } 3009 3010 /* Subsections */ 3011 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 3012 if (ret) { 3013 return ret; 3014 } 3015 3016 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 3017 vdev->device_endian = virtio_default_endian(); 3018 } 3019 3020 if (virtio_64bit_features_needed(vdev)) { 3021 /* 3022 * Subsection load filled vdev->guest_features. Run them 3023 * through virtio_set_features to sanity-check them against 3024 * host_features. 3025 */ 3026 uint64_t features64 = vdev->guest_features; 3027 if (virtio_set_features_nocheck(vdev, features64) < 0) { 3028 error_report("Features 0x%" PRIx64 " unsupported. " 3029 "Allowed features: 0x%" PRIx64, 3030 features64, vdev->host_features); 3031 return -1; 3032 } 3033 } else { 3034 if (virtio_set_features_nocheck(vdev, features) < 0) { 3035 error_report("Features 0x%x unsupported. " 3036 "Allowed features: 0x%" PRIx64, 3037 features, vdev->host_features); 3038 return -1; 3039 } 3040 } 3041 3042 if (!virtio_device_started(vdev, vdev->status) && 3043 !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3044 vdev->start_on_kick = true; 3045 } 3046 3047 RCU_READ_LOCK_GUARD(); 3048 for (i = 0; i < num; i++) { 3049 if (vdev->vq[i].vring.desc) { 3050 uint16_t nheads; 3051 3052 /* 3053 * VIRTIO-1 devices migrate desc, used, and avail ring addresses so 3054 * only the region cache needs to be set up. Legacy devices need 3055 * to calculate used and avail ring addresses based on the desc 3056 * address. 3057 */ 3058 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3059 virtio_init_region_cache(vdev, i); 3060 } else { 3061 virtio_queue_update_rings(vdev, i); 3062 } 3063 3064 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3065 vdev->vq[i].shadow_avail_idx = vdev->vq[i].last_avail_idx; 3066 vdev->vq[i].shadow_avail_wrap_counter = 3067 vdev->vq[i].last_avail_wrap_counter; 3068 continue; 3069 } 3070 3071 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 3072 /* Check it isn't doing strange things with descriptor numbers. */ 3073 if (nheads > vdev->vq[i].vring.num) { 3074 virtio_error(vdev, "VQ %d size 0x%x Guest index 0x%x " 3075 "inconsistent with Host index 0x%x: delta 0x%x", 3076 i, vdev->vq[i].vring.num, 3077 vring_avail_idx(&vdev->vq[i]), 3078 vdev->vq[i].last_avail_idx, nheads); 3079 vdev->vq[i].used_idx = 0; 3080 vdev->vq[i].shadow_avail_idx = 0; 3081 vdev->vq[i].inuse = 0; 3082 continue; 3083 } 3084 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 3085 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 3086 3087 /* 3088 * Some devices migrate VirtQueueElements that have been popped 3089 * from the avail ring but not yet returned to the used ring. 3090 * Since max ring size < UINT16_MAX it's safe to use modulo 3091 * UINT16_MAX + 1 subtraction. 3092 */ 3093 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 3094 vdev->vq[i].used_idx); 3095 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 3096 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 3097 "used_idx 0x%x", 3098 i, vdev->vq[i].vring.num, 3099 vdev->vq[i].last_avail_idx, 3100 vdev->vq[i].used_idx); 3101 return -1; 3102 } 3103 } 3104 } 3105 3106 if (vdc->post_load) { 3107 ret = vdc->post_load(vdev); 3108 if (ret) { 3109 return ret; 3110 } 3111 } 3112 3113 return 0; 3114 } 3115 3116 void virtio_cleanup(VirtIODevice *vdev) 3117 { 3118 qemu_del_vm_change_state_handler(vdev->vmstate); 3119 } 3120 3121 static void virtio_vmstate_change(void *opaque, bool running, RunState state) 3122 { 3123 VirtIODevice *vdev = opaque; 3124 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3125 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3126 bool backend_run = running && virtio_device_started(vdev, vdev->status); 3127 vdev->vm_running = running; 3128 3129 if (backend_run) { 3130 virtio_set_status(vdev, vdev->status); 3131 } 3132 3133 if (k->vmstate_change) { 3134 k->vmstate_change(qbus->parent, backend_run); 3135 } 3136 3137 if (!backend_run) { 3138 virtio_set_status(vdev, vdev->status); 3139 } 3140 } 3141 3142 void virtio_instance_init_common(Object *proxy_obj, void *data, 3143 size_t vdev_size, const char *vdev_name) 3144 { 3145 DeviceState *vdev = data; 3146 3147 object_initialize_child_with_props(proxy_obj, "virtio-backend", vdev, 3148 vdev_size, vdev_name, &error_abort, 3149 NULL); 3150 qdev_alias_all_properties(vdev, proxy_obj); 3151 } 3152 3153 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size) 3154 { 3155 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3156 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3157 int i; 3158 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 3159 3160 if (nvectors) { 3161 vdev->vector_queues = 3162 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 3163 } 3164 3165 vdev->start_on_kick = false; 3166 vdev->started = false; 3167 vdev->vhost_started = false; 3168 vdev->device_id = device_id; 3169 vdev->status = 0; 3170 qatomic_set(&vdev->isr, 0); 3171 vdev->queue_sel = 0; 3172 vdev->config_vector = VIRTIO_NO_VECTOR; 3173 vdev->vq = g_new0(VirtQueue, VIRTIO_QUEUE_MAX); 3174 vdev->vm_running = runstate_is_running(); 3175 vdev->broken = false; 3176 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3177 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 3178 vdev->vq[i].vdev = vdev; 3179 vdev->vq[i].queue_index = i; 3180 vdev->vq[i].host_notifier_enabled = false; 3181 } 3182 3183 vdev->name = virtio_id_to_name(device_id); 3184 vdev->config_len = config_size; 3185 if (vdev->config_len) { 3186 vdev->config = g_malloc0(config_size); 3187 } else { 3188 vdev->config = NULL; 3189 } 3190 vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev), 3191 virtio_vmstate_change, vdev); 3192 vdev->device_endian = virtio_default_endian(); 3193 vdev->use_guest_notifier_mask = true; 3194 } 3195 3196 /* 3197 * Only devices that have already been around prior to defining the virtio 3198 * standard support legacy mode; this includes devices not specified in the 3199 * standard. All newer devices conform to the virtio standard only. 3200 */ 3201 bool virtio_legacy_allowed(VirtIODevice *vdev) 3202 { 3203 switch (vdev->device_id) { 3204 case VIRTIO_ID_NET: 3205 case VIRTIO_ID_BLOCK: 3206 case VIRTIO_ID_CONSOLE: 3207 case VIRTIO_ID_RNG: 3208 case VIRTIO_ID_BALLOON: 3209 case VIRTIO_ID_RPMSG: 3210 case VIRTIO_ID_SCSI: 3211 case VIRTIO_ID_9P: 3212 case VIRTIO_ID_RPROC_SERIAL: 3213 case VIRTIO_ID_CAIF: 3214 return true; 3215 default: 3216 return false; 3217 } 3218 } 3219 3220 bool virtio_legacy_check_disabled(VirtIODevice *vdev) 3221 { 3222 return vdev->disable_legacy_check; 3223 } 3224 3225 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 3226 { 3227 return vdev->vq[n].vring.desc; 3228 } 3229 3230 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n) 3231 { 3232 return virtio_queue_get_desc_addr(vdev, n) != 0; 3233 } 3234 3235 bool virtio_queue_enabled(VirtIODevice *vdev, int n) 3236 { 3237 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3238 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3239 3240 if (k->queue_enabled) { 3241 return k->queue_enabled(qbus->parent, n); 3242 } 3243 return virtio_queue_enabled_legacy(vdev, n); 3244 } 3245 3246 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 3247 { 3248 return vdev->vq[n].vring.avail; 3249 } 3250 3251 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 3252 { 3253 return vdev->vq[n].vring.used; 3254 } 3255 3256 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 3257 { 3258 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 3259 } 3260 3261 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 3262 { 3263 int s; 3264 3265 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3266 return sizeof(struct VRingPackedDescEvent); 3267 } 3268 3269 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3270 return offsetof(VRingAvail, ring) + 3271 sizeof(uint16_t) * vdev->vq[n].vring.num + s; 3272 } 3273 3274 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 3275 { 3276 int s; 3277 3278 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3279 return sizeof(struct VRingPackedDescEvent); 3280 } 3281 3282 s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; 3283 return offsetof(VRingUsed, ring) + 3284 sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s; 3285 } 3286 3287 static unsigned int virtio_queue_packed_get_last_avail_idx(VirtIODevice *vdev, 3288 int n) 3289 { 3290 unsigned int avail, used; 3291 3292 avail = vdev->vq[n].last_avail_idx; 3293 avail |= ((uint16_t)vdev->vq[n].last_avail_wrap_counter) << 15; 3294 3295 used = vdev->vq[n].used_idx; 3296 used |= ((uint16_t)vdev->vq[n].used_wrap_counter) << 15; 3297 3298 return avail | used << 16; 3299 } 3300 3301 static uint16_t virtio_queue_split_get_last_avail_idx(VirtIODevice *vdev, 3302 int n) 3303 { 3304 return vdev->vq[n].last_avail_idx; 3305 } 3306 3307 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 3308 { 3309 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3310 return virtio_queue_packed_get_last_avail_idx(vdev, n); 3311 } else { 3312 return virtio_queue_split_get_last_avail_idx(vdev, n); 3313 } 3314 } 3315 3316 static void virtio_queue_packed_set_last_avail_idx(VirtIODevice *vdev, 3317 int n, unsigned int idx) 3318 { 3319 struct VirtQueue *vq = &vdev->vq[n]; 3320 3321 vq->last_avail_idx = vq->shadow_avail_idx = idx & 0x7fff; 3322 vq->last_avail_wrap_counter = 3323 vq->shadow_avail_wrap_counter = !!(idx & 0x8000); 3324 idx >>= 16; 3325 vq->used_idx = idx & 0x7ffff; 3326 vq->used_wrap_counter = !!(idx & 0x8000); 3327 } 3328 3329 static void virtio_queue_split_set_last_avail_idx(VirtIODevice *vdev, 3330 int n, unsigned int idx) 3331 { 3332 vdev->vq[n].last_avail_idx = idx; 3333 vdev->vq[n].shadow_avail_idx = idx; 3334 } 3335 3336 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 3337 unsigned int idx) 3338 { 3339 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3340 virtio_queue_packed_set_last_avail_idx(vdev, n, idx); 3341 } else { 3342 virtio_queue_split_set_last_avail_idx(vdev, n, idx); 3343 } 3344 } 3345 3346 static void virtio_queue_packed_restore_last_avail_idx(VirtIODevice *vdev, 3347 int n) 3348 { 3349 /* We don't have a reference like avail idx in shared memory */ 3350 return; 3351 } 3352 3353 static void virtio_queue_split_restore_last_avail_idx(VirtIODevice *vdev, 3354 int n) 3355 { 3356 RCU_READ_LOCK_GUARD(); 3357 if (vdev->vq[n].vring.desc) { 3358 vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); 3359 vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; 3360 } 3361 } 3362 3363 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) 3364 { 3365 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3366 virtio_queue_packed_restore_last_avail_idx(vdev, n); 3367 } else { 3368 virtio_queue_split_restore_last_avail_idx(vdev, n); 3369 } 3370 } 3371 3372 static void virtio_queue_packed_update_used_idx(VirtIODevice *vdev, int n) 3373 { 3374 /* used idx was updated through set_last_avail_idx() */ 3375 return; 3376 } 3377 3378 static void virtio_split_packed_update_used_idx(VirtIODevice *vdev, int n) 3379 { 3380 RCU_READ_LOCK_GUARD(); 3381 if (vdev->vq[n].vring.desc) { 3382 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 3383 } 3384 } 3385 3386 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 3387 { 3388 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3389 return virtio_queue_packed_update_used_idx(vdev, n); 3390 } else { 3391 return virtio_split_packed_update_used_idx(vdev, n); 3392 } 3393 } 3394 3395 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 3396 { 3397 vdev->vq[n].signalled_used_valid = false; 3398 } 3399 3400 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 3401 { 3402 return vdev->vq + n; 3403 } 3404 3405 uint16_t virtio_get_queue_index(VirtQueue *vq) 3406 { 3407 return vq->queue_index; 3408 } 3409 3410 static void virtio_queue_guest_notifier_read(EventNotifier *n) 3411 { 3412 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 3413 if (event_notifier_test_and_clear(n)) { 3414 virtio_irq(vq); 3415 } 3416 } 3417 static void virtio_config_guest_notifier_read(EventNotifier *n) 3418 { 3419 VirtIODevice *vdev = container_of(n, VirtIODevice, config_notifier); 3420 3421 if (event_notifier_test_and_clear(n)) { 3422 virtio_notify_config(vdev); 3423 } 3424 } 3425 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 3426 bool with_irqfd) 3427 { 3428 if (assign && !with_irqfd) { 3429 event_notifier_set_handler(&vq->guest_notifier, 3430 virtio_queue_guest_notifier_read); 3431 } else { 3432 event_notifier_set_handler(&vq->guest_notifier, NULL); 3433 } 3434 if (!assign) { 3435 /* Test and clear notifier before closing it, 3436 * in case poll callback didn't have time to run. */ 3437 virtio_queue_guest_notifier_read(&vq->guest_notifier); 3438 } 3439 } 3440 3441 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev, 3442 bool assign, bool with_irqfd) 3443 { 3444 EventNotifier *n; 3445 n = &vdev->config_notifier; 3446 if (assign && !with_irqfd) { 3447 event_notifier_set_handler(n, virtio_config_guest_notifier_read); 3448 } else { 3449 event_notifier_set_handler(n, NULL); 3450 } 3451 if (!assign) { 3452 /* Test and clear notifier before closing it,*/ 3453 /* in case poll callback didn't have time to run. */ 3454 virtio_config_guest_notifier_read(n); 3455 } 3456 } 3457 3458 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 3459 { 3460 return &vq->guest_notifier; 3461 } 3462 3463 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 3464 { 3465 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3466 3467 virtio_queue_set_notification(vq, 0); 3468 } 3469 3470 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 3471 { 3472 EventNotifier *n = opaque; 3473 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3474 3475 return vq->vring.desc && !virtio_queue_empty(vq); 3476 } 3477 3478 static void virtio_queue_host_notifier_aio_poll_ready(EventNotifier *n) 3479 { 3480 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3481 3482 virtio_queue_notify_vq(vq); 3483 } 3484 3485 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 3486 { 3487 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3488 3489 /* Caller polls once more after this to catch requests that race with us */ 3490 virtio_queue_set_notification(vq, 1); 3491 } 3492 3493 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx) 3494 { 3495 aio_set_event_notifier(ctx, &vq->host_notifier, true, 3496 virtio_queue_host_notifier_read, 3497 virtio_queue_host_notifier_aio_poll, 3498 virtio_queue_host_notifier_aio_poll_ready); 3499 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 3500 virtio_queue_host_notifier_aio_poll_begin, 3501 virtio_queue_host_notifier_aio_poll_end); 3502 } 3503 3504 /* 3505 * Same as virtio_queue_aio_attach_host_notifier() but without polling. Use 3506 * this for rx virtqueues and similar cases where the virtqueue handler 3507 * function does not pop all elements. When the virtqueue is left non-empty 3508 * polling consumes CPU cycles and should not be used. 3509 */ 3510 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx) 3511 { 3512 aio_set_event_notifier(ctx, &vq->host_notifier, true, 3513 virtio_queue_host_notifier_read, 3514 NULL, NULL); 3515 } 3516 3517 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx) 3518 { 3519 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL, NULL); 3520 /* Test and clear notifier before after disabling event, 3521 * in case poll callback didn't have time to run. */ 3522 virtio_queue_host_notifier_read(&vq->host_notifier); 3523 } 3524 3525 void virtio_queue_host_notifier_read(EventNotifier *n) 3526 { 3527 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 3528 if (event_notifier_test_and_clear(n)) { 3529 virtio_queue_notify_vq(vq); 3530 } 3531 } 3532 3533 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 3534 { 3535 return &vq->host_notifier; 3536 } 3537 3538 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev) 3539 { 3540 return &vdev->config_notifier; 3541 } 3542 3543 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled) 3544 { 3545 vq->host_notifier_enabled = enabled; 3546 } 3547 3548 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 3549 MemoryRegion *mr, bool assign) 3550 { 3551 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3552 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 3553 3554 if (k->set_host_notifier_mr) { 3555 return k->set_host_notifier_mr(qbus->parent, n, mr, assign); 3556 } 3557 3558 return -1; 3559 } 3560 3561 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 3562 { 3563 g_free(vdev->bus_name); 3564 vdev->bus_name = g_strdup(bus_name); 3565 } 3566 3567 void G_GNUC_PRINTF(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 3568 { 3569 va_list ap; 3570 3571 va_start(ap, fmt); 3572 error_vreport(fmt, ap); 3573 va_end(ap); 3574 3575 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 3576 vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET; 3577 virtio_notify_config(vdev); 3578 } 3579 3580 vdev->broken = true; 3581 } 3582 3583 static void virtio_memory_listener_commit(MemoryListener *listener) 3584 { 3585 VirtIODevice *vdev = container_of(listener, VirtIODevice, listener); 3586 int i; 3587 3588 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3589 if (vdev->vq[i].vring.num == 0) { 3590 break; 3591 } 3592 virtio_init_region_cache(vdev, i); 3593 } 3594 } 3595 3596 static void virtio_device_realize(DeviceState *dev, Error **errp) 3597 { 3598 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3599 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3600 Error *err = NULL; 3601 3602 /* Devices should either use vmsd or the load/save methods */ 3603 assert(!vdc->vmsd || !vdc->load); 3604 3605 if (vdc->realize != NULL) { 3606 vdc->realize(dev, &err); 3607 if (err != NULL) { 3608 error_propagate(errp, err); 3609 return; 3610 } 3611 } 3612 3613 virtio_bus_device_plugged(vdev, &err); 3614 if (err != NULL) { 3615 error_propagate(errp, err); 3616 vdc->unrealize(dev); 3617 return; 3618 } 3619 3620 vdev->listener.commit = virtio_memory_listener_commit; 3621 vdev->listener.name = "virtio"; 3622 memory_listener_register(&vdev->listener, vdev->dma_as); 3623 QTAILQ_INSERT_TAIL(&virtio_list, vdev, next); 3624 } 3625 3626 static void virtio_device_unrealize(DeviceState *dev) 3627 { 3628 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 3629 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 3630 3631 memory_listener_unregister(&vdev->listener); 3632 virtio_bus_device_unplugged(vdev); 3633 3634 if (vdc->unrealize != NULL) { 3635 vdc->unrealize(dev); 3636 } 3637 3638 QTAILQ_REMOVE(&virtio_list, vdev, next); 3639 g_free(vdev->bus_name); 3640 vdev->bus_name = NULL; 3641 } 3642 3643 static void virtio_device_free_virtqueues(VirtIODevice *vdev) 3644 { 3645 int i; 3646 if (!vdev->vq) { 3647 return; 3648 } 3649 3650 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 3651 if (vdev->vq[i].vring.num == 0) { 3652 break; 3653 } 3654 virtio_virtqueue_reset_region_cache(&vdev->vq[i]); 3655 } 3656 g_free(vdev->vq); 3657 } 3658 3659 static void virtio_device_instance_finalize(Object *obj) 3660 { 3661 VirtIODevice *vdev = VIRTIO_DEVICE(obj); 3662 3663 virtio_device_free_virtqueues(vdev); 3664 3665 g_free(vdev->config); 3666 g_free(vdev->vector_queues); 3667 } 3668 3669 static Property virtio_properties[] = { 3670 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 3671 DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true), 3672 DEFINE_PROP_BOOL("use-disabled-flag", VirtIODevice, use_disabled_flag, true), 3673 DEFINE_PROP_BOOL("x-disable-legacy-check", VirtIODevice, 3674 disable_legacy_check, false), 3675 DEFINE_PROP_END_OF_LIST(), 3676 }; 3677 3678 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 3679 { 3680 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3681 int i, n, r, err; 3682 3683 /* 3684 * Batch all the host notifiers in a single transaction to avoid 3685 * quadratic time complexity in address_space_update_ioeventfds(). 3686 */ 3687 memory_region_transaction_begin(); 3688 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3689 VirtQueue *vq = &vdev->vq[n]; 3690 if (!virtio_queue_get_num(vdev, n)) { 3691 continue; 3692 } 3693 r = virtio_bus_set_host_notifier(qbus, n, true); 3694 if (r < 0) { 3695 err = r; 3696 goto assign_error; 3697 } 3698 event_notifier_set_handler(&vq->host_notifier, 3699 virtio_queue_host_notifier_read); 3700 } 3701 3702 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3703 /* Kick right away to begin processing requests already in vring */ 3704 VirtQueue *vq = &vdev->vq[n]; 3705 if (!vq->vring.num) { 3706 continue; 3707 } 3708 event_notifier_set(&vq->host_notifier); 3709 } 3710 memory_region_transaction_commit(); 3711 return 0; 3712 3713 assign_error: 3714 i = n; /* save n for a second iteration after transaction is committed. */ 3715 while (--n >= 0) { 3716 VirtQueue *vq = &vdev->vq[n]; 3717 if (!virtio_queue_get_num(vdev, n)) { 3718 continue; 3719 } 3720 3721 event_notifier_set_handler(&vq->host_notifier, NULL); 3722 r = virtio_bus_set_host_notifier(qbus, n, false); 3723 assert(r >= 0); 3724 } 3725 /* 3726 * The transaction expects the ioeventfds to be open when it 3727 * commits. Do it now, before the cleanup loop. 3728 */ 3729 memory_region_transaction_commit(); 3730 3731 while (--i >= 0) { 3732 if (!virtio_queue_get_num(vdev, i)) { 3733 continue; 3734 } 3735 virtio_bus_cleanup_host_notifier(qbus, i); 3736 } 3737 return err; 3738 } 3739 3740 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 3741 { 3742 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3743 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3744 3745 return virtio_bus_start_ioeventfd(vbus); 3746 } 3747 3748 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 3749 { 3750 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 3751 int n, r; 3752 3753 /* 3754 * Batch all the host notifiers in a single transaction to avoid 3755 * quadratic time complexity in address_space_update_ioeventfds(). 3756 */ 3757 memory_region_transaction_begin(); 3758 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3759 VirtQueue *vq = &vdev->vq[n]; 3760 3761 if (!virtio_queue_get_num(vdev, n)) { 3762 continue; 3763 } 3764 event_notifier_set_handler(&vq->host_notifier, NULL); 3765 r = virtio_bus_set_host_notifier(qbus, n, false); 3766 assert(r >= 0); 3767 } 3768 /* 3769 * The transaction expects the ioeventfds to be open when it 3770 * commits. Do it now, before the cleanup loop. 3771 */ 3772 memory_region_transaction_commit(); 3773 3774 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 3775 if (!virtio_queue_get_num(vdev, n)) { 3776 continue; 3777 } 3778 virtio_bus_cleanup_host_notifier(qbus, n); 3779 } 3780 } 3781 3782 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 3783 { 3784 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3785 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3786 3787 return virtio_bus_grab_ioeventfd(vbus); 3788 } 3789 3790 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 3791 { 3792 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3793 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3794 3795 virtio_bus_release_ioeventfd(vbus); 3796 } 3797 3798 static void virtio_device_class_init(ObjectClass *klass, void *data) 3799 { 3800 /* Set the default value here. */ 3801 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 3802 DeviceClass *dc = DEVICE_CLASS(klass); 3803 3804 dc->realize = virtio_device_realize; 3805 dc->unrealize = virtio_device_unrealize; 3806 dc->bus_type = TYPE_VIRTIO_BUS; 3807 device_class_set_props(dc, virtio_properties); 3808 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 3809 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 3810 3811 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 3812 3813 QTAILQ_INIT(&virtio_list); 3814 } 3815 3816 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 3817 { 3818 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 3819 VirtioBusState *vbus = VIRTIO_BUS(qbus); 3820 3821 return virtio_bus_ioeventfd_enabled(vbus); 3822 } 3823 3824 VirtQueueStatus *qmp_x_query_virtio_queue_status(const char *path, 3825 uint16_t queue, 3826 Error **errp) 3827 { 3828 VirtIODevice *vdev; 3829 VirtQueueStatus *status; 3830 3831 vdev = qmp_find_virtio_device(path); 3832 if (vdev == NULL) { 3833 error_setg(errp, "Path %s is not a VirtIODevice", path); 3834 return NULL; 3835 } 3836 3837 if (queue >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, queue)) { 3838 error_setg(errp, "Invalid virtqueue number %d", queue); 3839 return NULL; 3840 } 3841 3842 status = g_new0(VirtQueueStatus, 1); 3843 status->name = g_strdup(vdev->name); 3844 status->queue_index = vdev->vq[queue].queue_index; 3845 status->inuse = vdev->vq[queue].inuse; 3846 status->vring_num = vdev->vq[queue].vring.num; 3847 status->vring_num_default = vdev->vq[queue].vring.num_default; 3848 status->vring_align = vdev->vq[queue].vring.align; 3849 status->vring_desc = vdev->vq[queue].vring.desc; 3850 status->vring_avail = vdev->vq[queue].vring.avail; 3851 status->vring_used = vdev->vq[queue].vring.used; 3852 status->used_idx = vdev->vq[queue].used_idx; 3853 status->signalled_used = vdev->vq[queue].signalled_used; 3854 status->signalled_used_valid = vdev->vq[queue].signalled_used_valid; 3855 3856 if (vdev->vhost_started) { 3857 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 3858 struct vhost_dev *hdev = vdc->get_vhost(vdev); 3859 3860 /* check if vq index exists for vhost as well */ 3861 if (queue >= hdev->vq_index && queue < hdev->vq_index + hdev->nvqs) { 3862 status->has_last_avail_idx = true; 3863 3864 int vhost_vq_index = 3865 hdev->vhost_ops->vhost_get_vq_index(hdev, queue); 3866 struct vhost_vring_state state = { 3867 .index = vhost_vq_index, 3868 }; 3869 3870 status->last_avail_idx = 3871 hdev->vhost_ops->vhost_get_vring_base(hdev, &state); 3872 } 3873 } else { 3874 status->has_shadow_avail_idx = true; 3875 status->has_last_avail_idx = true; 3876 status->last_avail_idx = vdev->vq[queue].last_avail_idx; 3877 status->shadow_avail_idx = vdev->vq[queue].shadow_avail_idx; 3878 } 3879 3880 return status; 3881 } 3882 3883 static strList *qmp_decode_vring_desc_flags(uint16_t flags) 3884 { 3885 strList *list = NULL; 3886 strList *node; 3887 int i; 3888 3889 struct { 3890 uint16_t flag; 3891 const char *value; 3892 } map[] = { 3893 { VRING_DESC_F_NEXT, "next" }, 3894 { VRING_DESC_F_WRITE, "write" }, 3895 { VRING_DESC_F_INDIRECT, "indirect" }, 3896 { 1 << VRING_PACKED_DESC_F_AVAIL, "avail" }, 3897 { 1 << VRING_PACKED_DESC_F_USED, "used" }, 3898 { 0, "" } 3899 }; 3900 3901 for (i = 0; map[i].flag; i++) { 3902 if ((map[i].flag & flags) == 0) { 3903 continue; 3904 } 3905 node = g_malloc0(sizeof(strList)); 3906 node->value = g_strdup(map[i].value); 3907 node->next = list; 3908 list = node; 3909 } 3910 3911 return list; 3912 } 3913 3914 VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path, 3915 uint16_t queue, 3916 bool has_index, 3917 uint16_t index, 3918 Error **errp) 3919 { 3920 VirtIODevice *vdev; 3921 VirtQueue *vq; 3922 VirtioQueueElement *element = NULL; 3923 3924 vdev = qmp_find_virtio_device(path); 3925 if (vdev == NULL) { 3926 error_setg(errp, "Path %s is not a VirtIO device", path); 3927 return NULL; 3928 } 3929 3930 if (queue >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, queue)) { 3931 error_setg(errp, "Invalid virtqueue number %d", queue); 3932 return NULL; 3933 } 3934 vq = &vdev->vq[queue]; 3935 3936 if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 3937 error_setg(errp, "Packed ring not supported"); 3938 return NULL; 3939 } else { 3940 unsigned int head, i, max; 3941 VRingMemoryRegionCaches *caches; 3942 MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; 3943 MemoryRegionCache *desc_cache; 3944 VRingDesc desc; 3945 VirtioRingDescList *list = NULL; 3946 VirtioRingDescList *node; 3947 int rc; int ndescs; 3948 3949 RCU_READ_LOCK_GUARD(); 3950 3951 max = vq->vring.num; 3952 3953 if (!has_index) { 3954 head = vring_avail_ring(vq, vq->last_avail_idx % vq->vring.num); 3955 } else { 3956 head = vring_avail_ring(vq, index % vq->vring.num); 3957 } 3958 i = head; 3959 3960 caches = vring_get_region_caches(vq); 3961 if (!caches) { 3962 error_setg(errp, "Region caches not initialized"); 3963 return NULL; 3964 } 3965 if (caches->desc.len < max * sizeof(VRingDesc)) { 3966 error_setg(errp, "Cannot map descriptor ring"); 3967 return NULL; 3968 } 3969 3970 desc_cache = &caches->desc; 3971 vring_split_desc_read(vdev, &desc, desc_cache, i); 3972 if (desc.flags & VRING_DESC_F_INDIRECT) { 3973 int64_t len; 3974 len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, 3975 desc.addr, desc.len, false); 3976 desc_cache = &indirect_desc_cache; 3977 if (len < desc.len) { 3978 error_setg(errp, "Cannot map indirect buffer"); 3979 goto done; 3980 } 3981 3982 max = desc.len / sizeof(VRingDesc); 3983 i = 0; 3984 vring_split_desc_read(vdev, &desc, desc_cache, i); 3985 } 3986 3987 element = g_new0(VirtioQueueElement, 1); 3988 element->avail = g_new0(VirtioRingAvail, 1); 3989 element->used = g_new0(VirtioRingUsed, 1); 3990 element->name = g_strdup(vdev->name); 3991 element->index = head; 3992 element->avail->flags = vring_avail_flags(vq); 3993 element->avail->idx = vring_avail_idx(vq); 3994 element->avail->ring = head; 3995 element->used->flags = vring_used_flags(vq); 3996 element->used->idx = vring_used_idx(vq); 3997 ndescs = 0; 3998 3999 do { 4000 /* A buggy driver may produce an infinite loop */ 4001 if (ndescs >= max) { 4002 break; 4003 } 4004 node = g_new0(VirtioRingDescList, 1); 4005 node->value = g_new0(VirtioRingDesc, 1); 4006 node->value->addr = desc.addr; 4007 node->value->len = desc.len; 4008 node->value->flags = qmp_decode_vring_desc_flags(desc.flags); 4009 node->next = list; 4010 list = node; 4011 4012 ndescs++; 4013 rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, 4014 max, &i); 4015 } while (rc == VIRTQUEUE_READ_DESC_MORE); 4016 element->descs = list; 4017 done: 4018 address_space_cache_destroy(&indirect_desc_cache); 4019 } 4020 4021 return element; 4022 } 4023 4024 static const TypeInfo virtio_device_info = { 4025 .name = TYPE_VIRTIO_DEVICE, 4026 .parent = TYPE_DEVICE, 4027 .instance_size = sizeof(VirtIODevice), 4028 .class_init = virtio_device_class_init, 4029 .instance_finalize = virtio_device_instance_finalize, 4030 .abstract = true, 4031 .class_size = sizeof(VirtioDeviceClass), 4032 }; 4033 4034 static void virtio_register_types(void) 4035 { 4036 type_register_static(&virtio_device_info); 4037 } 4038 4039 type_init(virtio_register_types) 4040