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 "qemu-common.h" 17 #include "cpu.h" 18 #include "trace.h" 19 #include "exec/address-spaces.h" 20 #include "qemu/error-report.h" 21 #include "hw/virtio/virtio.h" 22 #include "qemu/atomic.h" 23 #include "hw/virtio/virtio-bus.h" 24 #include "migration/migration.h" 25 #include "hw/virtio/virtio-access.h" 26 #include "sysemu/dma.h" 27 28 /* 29 * The alignment to use between consumer and producer parts of vring. 30 * x86 pagesize again. This is the default, used by transports like PCI 31 * which don't provide a means for the guest to tell the host the alignment. 32 */ 33 #define VIRTIO_PCI_VRING_ALIGN 4096 34 35 typedef struct VRingDesc 36 { 37 uint64_t addr; 38 uint32_t len; 39 uint16_t flags; 40 uint16_t next; 41 } VRingDesc; 42 43 typedef struct VRingAvail 44 { 45 uint16_t flags; 46 uint16_t idx; 47 uint16_t ring[0]; 48 } VRingAvail; 49 50 typedef struct VRingUsedElem 51 { 52 uint32_t id; 53 uint32_t len; 54 } VRingUsedElem; 55 56 typedef struct VRingUsed 57 { 58 uint16_t flags; 59 uint16_t idx; 60 VRingUsedElem ring[0]; 61 } VRingUsed; 62 63 typedef struct VRing 64 { 65 unsigned int num; 66 unsigned int num_default; 67 unsigned int align; 68 hwaddr desc; 69 hwaddr avail; 70 hwaddr used; 71 } VRing; 72 73 struct VirtQueue 74 { 75 VRing vring; 76 77 /* Next head to pop */ 78 uint16_t last_avail_idx; 79 80 /* Last avail_idx read from VQ. */ 81 uint16_t shadow_avail_idx; 82 83 uint16_t used_idx; 84 85 /* Last used index value we have signalled on */ 86 uint16_t signalled_used; 87 88 /* Last used index value we have signalled on */ 89 bool signalled_used_valid; 90 91 /* Notification enabled? */ 92 bool notification; 93 94 uint16_t queue_index; 95 96 unsigned int inuse; 97 98 uint16_t vector; 99 VirtIOHandleOutput handle_output; 100 VirtIOHandleOutput handle_aio_output; 101 VirtIODevice *vdev; 102 EventNotifier guest_notifier; 103 EventNotifier host_notifier; 104 QLIST_ENTRY(VirtQueue) node; 105 }; 106 107 /* virt queue functions */ 108 void virtio_queue_update_rings(VirtIODevice *vdev, int n) 109 { 110 VRing *vring = &vdev->vq[n].vring; 111 112 if (!vring->desc) { 113 /* not yet setup -> nothing to do */ 114 return; 115 } 116 vring->avail = vring->desc + vring->num * sizeof(VRingDesc); 117 vring->used = vring_align(vring->avail + 118 offsetof(VRingAvail, ring[vring->num]), 119 vring->align); 120 } 121 122 static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc, 123 hwaddr desc_pa, int i) 124 { 125 address_space_read(vdev->dma_as, desc_pa + i * sizeof(VRingDesc), 126 MEMTXATTRS_UNSPECIFIED, (void *)desc, sizeof(VRingDesc)); 127 virtio_tswap64s(vdev, &desc->addr); 128 virtio_tswap32s(vdev, &desc->len); 129 virtio_tswap16s(vdev, &desc->flags); 130 virtio_tswap16s(vdev, &desc->next); 131 } 132 133 static inline uint16_t vring_avail_flags(VirtQueue *vq) 134 { 135 hwaddr pa; 136 pa = vq->vring.avail + offsetof(VRingAvail, flags); 137 return virtio_lduw_phys(vq->vdev, pa); 138 } 139 140 static inline uint16_t vring_avail_idx(VirtQueue *vq) 141 { 142 hwaddr pa; 143 pa = vq->vring.avail + offsetof(VRingAvail, idx); 144 vq->shadow_avail_idx = virtio_lduw_phys(vq->vdev, pa); 145 return vq->shadow_avail_idx; 146 } 147 148 static inline uint16_t vring_avail_ring(VirtQueue *vq, int i) 149 { 150 hwaddr pa; 151 pa = vq->vring.avail + offsetof(VRingAvail, ring[i]); 152 return virtio_lduw_phys(vq->vdev, pa); 153 } 154 155 static inline uint16_t vring_get_used_event(VirtQueue *vq) 156 { 157 return vring_avail_ring(vq, vq->vring.num); 158 } 159 160 static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, 161 int i) 162 { 163 hwaddr pa; 164 virtio_tswap32s(vq->vdev, &uelem->id); 165 virtio_tswap32s(vq->vdev, &uelem->len); 166 pa = vq->vring.used + offsetof(VRingUsed, ring[i]); 167 address_space_write(vq->vdev->dma_as, pa, MEMTXATTRS_UNSPECIFIED, 168 (void *)uelem, sizeof(VRingUsedElem)); 169 } 170 171 static uint16_t vring_used_idx(VirtQueue *vq) 172 { 173 hwaddr pa; 174 pa = vq->vring.used + offsetof(VRingUsed, idx); 175 return virtio_lduw_phys(vq->vdev, pa); 176 } 177 178 static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val) 179 { 180 hwaddr pa; 181 pa = vq->vring.used + offsetof(VRingUsed, idx); 182 virtio_stw_phys(vq->vdev, pa, val); 183 vq->used_idx = val; 184 } 185 186 static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask) 187 { 188 VirtIODevice *vdev = vq->vdev; 189 hwaddr pa; 190 pa = vq->vring.used + offsetof(VRingUsed, flags); 191 virtio_stw_phys(vdev, pa, virtio_lduw_phys(vdev, pa) | mask); 192 } 193 194 static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask) 195 { 196 VirtIODevice *vdev = vq->vdev; 197 hwaddr pa; 198 pa = vq->vring.used + offsetof(VRingUsed, flags); 199 virtio_stw_phys(vdev, pa, virtio_lduw_phys(vdev, pa) & ~mask); 200 } 201 202 static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) 203 { 204 hwaddr pa; 205 if (!vq->notification) { 206 return; 207 } 208 pa = vq->vring.used + offsetof(VRingUsed, ring[vq->vring.num]); 209 virtio_stw_phys(vq->vdev, pa, val); 210 } 211 212 void virtio_queue_set_notification(VirtQueue *vq, int enable) 213 { 214 vq->notification = enable; 215 if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) { 216 vring_set_avail_event(vq, vring_avail_idx(vq)); 217 } else if (enable) { 218 vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); 219 } else { 220 vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); 221 } 222 if (enable) { 223 /* Expose avail event/used flags before caller checks the avail idx. */ 224 smp_mb(); 225 } 226 } 227 228 int virtio_queue_ready(VirtQueue *vq) 229 { 230 return vq->vring.avail != 0; 231 } 232 233 /* Fetch avail_idx from VQ memory only when we really need to know if 234 * guest has added some buffers. */ 235 int virtio_queue_empty(VirtQueue *vq) 236 { 237 if (vq->shadow_avail_idx != vq->last_avail_idx) { 238 return 0; 239 } 240 241 return vring_avail_idx(vq) == vq->last_avail_idx; 242 } 243 244 static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 245 unsigned int len) 246 { 247 AddressSpace *dma_as = vq->vdev->dma_as; 248 unsigned int offset; 249 int i; 250 251 offset = 0; 252 for (i = 0; i < elem->in_num; i++) { 253 size_t size = MIN(len - offset, elem->in_sg[i].iov_len); 254 255 dma_memory_unmap(dma_as, elem->in_sg[i].iov_base, 256 elem->in_sg[i].iov_len, 257 DMA_DIRECTION_FROM_DEVICE, size); 258 259 offset += size; 260 } 261 262 for (i = 0; i < elem->out_num; i++) 263 dma_memory_unmap(dma_as, elem->out_sg[i].iov_base, 264 elem->out_sg[i].iov_len, 265 DMA_DIRECTION_TO_DEVICE, 266 elem->out_sg[i].iov_len); 267 } 268 269 /* virtqueue_detach_element: 270 * @vq: The #VirtQueue 271 * @elem: The #VirtQueueElement 272 * @len: number of bytes written 273 * 274 * Detach the element from the virtqueue. This function is suitable for device 275 * reset or other situations where a #VirtQueueElement is simply freed and will 276 * not be pushed or discarded. 277 */ 278 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 279 unsigned int len) 280 { 281 vq->inuse--; 282 virtqueue_unmap_sg(vq, elem, len); 283 } 284 285 /* virtqueue_unpop: 286 * @vq: The #VirtQueue 287 * @elem: The #VirtQueueElement 288 * @len: number of bytes written 289 * 290 * Pretend the most recent element wasn't popped from the virtqueue. The next 291 * call to virtqueue_pop() will refetch the element. 292 */ 293 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 294 unsigned int len) 295 { 296 vq->last_avail_idx--; 297 virtqueue_detach_element(vq, elem, len); 298 } 299 300 /* virtqueue_rewind: 301 * @vq: The #VirtQueue 302 * @num: Number of elements to push back 303 * 304 * Pretend that elements weren't popped from the virtqueue. The next 305 * virtqueue_pop() will refetch the oldest element. 306 * 307 * Use virtqueue_unpop() instead if you have a VirtQueueElement. 308 * 309 * Returns: true on success, false if @num is greater than the number of in use 310 * elements. 311 */ 312 bool virtqueue_rewind(VirtQueue *vq, unsigned int num) 313 { 314 if (num > vq->inuse) { 315 return false; 316 } 317 vq->last_avail_idx -= num; 318 vq->inuse -= num; 319 return true; 320 } 321 322 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 323 unsigned int len, unsigned int idx) 324 { 325 VRingUsedElem uelem; 326 327 trace_virtqueue_fill(vq, elem, len, idx); 328 329 virtqueue_unmap_sg(vq, elem, len); 330 331 if (unlikely(vq->vdev->broken)) { 332 return; 333 } 334 335 idx = (idx + vq->used_idx) % vq->vring.num; 336 337 uelem.id = elem->index; 338 uelem.len = len; 339 vring_used_write(vq, &uelem, idx); 340 } 341 342 void virtqueue_flush(VirtQueue *vq, unsigned int count) 343 { 344 uint16_t old, new; 345 346 if (unlikely(vq->vdev->broken)) { 347 vq->inuse -= count; 348 return; 349 } 350 351 /* Make sure buffer is written before we update index. */ 352 smp_wmb(); 353 trace_virtqueue_flush(vq, count); 354 old = vq->used_idx; 355 new = old + count; 356 vring_used_idx_set(vq, new); 357 vq->inuse -= count; 358 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) 359 vq->signalled_used_valid = false; 360 } 361 362 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 363 unsigned int len) 364 { 365 virtqueue_fill(vq, elem, len, 0); 366 virtqueue_flush(vq, 1); 367 } 368 369 static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) 370 { 371 uint16_t num_heads = vring_avail_idx(vq) - idx; 372 373 /* Check it isn't doing very strange things with descriptor numbers. */ 374 if (num_heads > vq->vring.num) { 375 virtio_error(vq->vdev, "Guest moved used index from %u to %u", 376 idx, vq->shadow_avail_idx); 377 return -EINVAL; 378 } 379 /* On success, callers read a descriptor at vq->last_avail_idx. 380 * Make sure descriptor read does not bypass avail index read. */ 381 if (num_heads) { 382 smp_rmb(); 383 } 384 385 return num_heads; 386 } 387 388 static bool virtqueue_get_head(VirtQueue *vq, unsigned int idx, 389 unsigned int *head) 390 { 391 /* Grab the next descriptor number they're advertising, and increment 392 * the index we've seen. */ 393 *head = vring_avail_ring(vq, idx % vq->vring.num); 394 395 /* If their number is silly, that's a fatal mistake. */ 396 if (*head >= vq->vring.num) { 397 virtio_error(vq->vdev, "Guest says index %u is available", *head); 398 return false; 399 } 400 401 return true; 402 } 403 404 enum { 405 VIRTQUEUE_READ_DESC_ERROR = -1, 406 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 407 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 408 }; 409 410 static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, 411 hwaddr desc_pa, unsigned int max, 412 unsigned int *next) 413 { 414 /* If this descriptor says it doesn't chain, we're done. */ 415 if (!(desc->flags & VRING_DESC_F_NEXT)) { 416 return VIRTQUEUE_READ_DESC_DONE; 417 } 418 419 /* Check they're not leading us off end of descriptors. */ 420 *next = desc->next; 421 /* Make sure compiler knows to grab that: we don't want it changing! */ 422 smp_wmb(); 423 424 if (*next >= max) { 425 virtio_error(vdev, "Desc next is %u", *next); 426 return VIRTQUEUE_READ_DESC_ERROR; 427 } 428 429 vring_desc_read(vdev, desc, desc_pa, *next); 430 return VIRTQUEUE_READ_DESC_MORE; 431 } 432 433 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 434 unsigned int *out_bytes, 435 unsigned max_in_bytes, unsigned max_out_bytes) 436 { 437 unsigned int idx; 438 unsigned int total_bufs, in_total, out_total; 439 int rc; 440 441 idx = vq->last_avail_idx; 442 443 total_bufs = in_total = out_total = 0; 444 while ((rc = virtqueue_num_heads(vq, idx)) > 0) { 445 VirtIODevice *vdev = vq->vdev; 446 unsigned int max, num_bufs, indirect = 0; 447 VRingDesc desc; 448 hwaddr desc_pa; 449 unsigned int i; 450 451 max = vq->vring.num; 452 num_bufs = total_bufs; 453 454 if (!virtqueue_get_head(vq, idx++, &i)) { 455 goto err; 456 } 457 458 desc_pa = vq->vring.desc; 459 vring_desc_read(vdev, &desc, desc_pa, i); 460 461 if (desc.flags & VRING_DESC_F_INDIRECT) { 462 if (desc.len % sizeof(VRingDesc)) { 463 virtio_error(vdev, "Invalid size for indirect buffer table"); 464 goto err; 465 } 466 467 /* If we've got too many, that implies a descriptor loop. */ 468 if (num_bufs >= max) { 469 virtio_error(vdev, "Looped descriptor"); 470 goto err; 471 } 472 473 /* loop over the indirect descriptor table */ 474 indirect = 1; 475 max = desc.len / sizeof(VRingDesc); 476 desc_pa = desc.addr; 477 num_bufs = i = 0; 478 vring_desc_read(vdev, &desc, desc_pa, i); 479 } 480 481 do { 482 /* If we've got too many, that implies a descriptor loop. */ 483 if (++num_bufs > max) { 484 virtio_error(vdev, "Looped descriptor"); 485 goto err; 486 } 487 488 if (desc.flags & VRING_DESC_F_WRITE) { 489 in_total += desc.len; 490 } else { 491 out_total += desc.len; 492 } 493 if (in_total >= max_in_bytes && out_total >= max_out_bytes) { 494 goto done; 495 } 496 497 rc = virtqueue_read_next_desc(vdev, &desc, desc_pa, max, &i); 498 } while (rc == VIRTQUEUE_READ_DESC_MORE); 499 500 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 501 goto err; 502 } 503 504 if (!indirect) 505 total_bufs = num_bufs; 506 else 507 total_bufs++; 508 } 509 510 if (rc < 0) { 511 goto err; 512 } 513 514 done: 515 if (in_bytes) { 516 *in_bytes = in_total; 517 } 518 if (out_bytes) { 519 *out_bytes = out_total; 520 } 521 return; 522 523 err: 524 in_total = out_total = 0; 525 goto done; 526 } 527 528 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 529 unsigned int out_bytes) 530 { 531 unsigned int in_total, out_total; 532 533 virtqueue_get_avail_bytes(vq, &in_total, &out_total, in_bytes, out_bytes); 534 return in_bytes <= in_total && out_bytes <= out_total; 535 } 536 537 static bool virtqueue_map_desc(VirtIODevice *vdev, unsigned int *p_num_sg, 538 hwaddr *addr, struct iovec *iov, 539 unsigned int max_num_sg, bool is_write, 540 hwaddr pa, size_t sz) 541 { 542 bool ok = false; 543 unsigned num_sg = *p_num_sg; 544 assert(num_sg <= max_num_sg); 545 546 if (!sz) { 547 virtio_error(vdev, "virtio: zero sized buffers are not allowed"); 548 goto out; 549 } 550 551 while (sz) { 552 hwaddr len = sz; 553 554 if (num_sg == max_num_sg) { 555 virtio_error(vdev, "virtio: too many write descriptors in " 556 "indirect table"); 557 goto out; 558 } 559 560 iov[num_sg].iov_base = dma_memory_map(vdev->dma_as, pa, &len, 561 is_write ? 562 DMA_DIRECTION_FROM_DEVICE : 563 DMA_DIRECTION_TO_DEVICE); 564 if (!iov[num_sg].iov_base) { 565 virtio_error(vdev, "virtio: bogus descriptor or out of resources"); 566 goto out; 567 } 568 569 iov[num_sg].iov_len = len; 570 addr[num_sg] = pa; 571 572 sz -= len; 573 pa += len; 574 num_sg++; 575 } 576 ok = true; 577 578 out: 579 *p_num_sg = num_sg; 580 return ok; 581 } 582 583 /* Only used by error code paths before we have a VirtQueueElement (therefore 584 * virtqueue_unmap_sg() can't be used). Assumes buffers weren't written to 585 * yet. 586 */ 587 static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num, 588 struct iovec *iov) 589 { 590 unsigned int i; 591 592 for (i = 0; i < out_num + in_num; i++) { 593 int is_write = i >= out_num; 594 595 cpu_physical_memory_unmap(iov->iov_base, iov->iov_len, is_write, 0); 596 iov++; 597 } 598 } 599 600 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg, 601 hwaddr *addr, unsigned int *num_sg, 602 unsigned int max_size, int is_write) 603 { 604 unsigned int i; 605 hwaddr len; 606 607 /* Note: this function MUST validate input, some callers 608 * are passing in num_sg values received over the network. 609 */ 610 /* TODO: teach all callers that this can fail, and return failure instead 611 * of asserting here. 612 * When we do, we might be able to re-enable NDEBUG below. 613 */ 614 #ifdef NDEBUG 615 #error building with NDEBUG is not supported 616 #endif 617 assert(*num_sg <= max_size); 618 619 for (i = 0; i < *num_sg; i++) { 620 len = sg[i].iov_len; 621 sg[i].iov_base = dma_memory_map(vdev->dma_as, 622 addr[i], &len, is_write ? 623 DMA_DIRECTION_FROM_DEVICE : 624 DMA_DIRECTION_TO_DEVICE); 625 if (!sg[i].iov_base) { 626 error_report("virtio: error trying to map MMIO memory"); 627 exit(1); 628 } 629 if (len != sg[i].iov_len) { 630 error_report("virtio: unexpected memory split"); 631 exit(1); 632 } 633 } 634 } 635 636 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 637 { 638 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num, 639 MIN(ARRAY_SIZE(elem->in_sg), ARRAY_SIZE(elem->in_addr)), 640 1); 641 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num, 642 MIN(ARRAY_SIZE(elem->out_sg), 643 ARRAY_SIZE(elem->out_addr)), 644 0); 645 } 646 647 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 648 { 649 VirtQueueElement *elem; 650 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 651 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 652 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 653 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 654 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 655 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 656 657 assert(sz >= sizeof(VirtQueueElement)); 658 elem = g_malloc(out_sg_end); 659 elem->out_num = out_num; 660 elem->in_num = in_num; 661 elem->in_addr = (void *)elem + in_addr_ofs; 662 elem->out_addr = (void *)elem + out_addr_ofs; 663 elem->in_sg = (void *)elem + in_sg_ofs; 664 elem->out_sg = (void *)elem + out_sg_ofs; 665 return elem; 666 } 667 668 void *virtqueue_pop(VirtQueue *vq, size_t sz) 669 { 670 unsigned int i, head, max; 671 hwaddr desc_pa = vq->vring.desc; 672 VirtIODevice *vdev = vq->vdev; 673 VirtQueueElement *elem; 674 unsigned out_num, in_num; 675 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 676 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 677 VRingDesc desc; 678 int rc; 679 680 if (unlikely(vdev->broken)) { 681 return NULL; 682 } 683 if (virtio_queue_empty(vq)) { 684 return NULL; 685 } 686 /* Needed after virtio_queue_empty(), see comment in 687 * virtqueue_num_heads(). */ 688 smp_rmb(); 689 690 /* When we start there are none of either input nor output. */ 691 out_num = in_num = 0; 692 693 max = vq->vring.num; 694 695 if (vq->inuse >= vq->vring.num) { 696 virtio_error(vdev, "Virtqueue size exceeded"); 697 return NULL; 698 } 699 700 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 701 return NULL; 702 } 703 704 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 705 vring_set_avail_event(vq, vq->last_avail_idx); 706 } 707 708 i = head; 709 vring_desc_read(vdev, &desc, desc_pa, i); 710 if (desc.flags & VRING_DESC_F_INDIRECT) { 711 if (desc.len % sizeof(VRingDesc)) { 712 virtio_error(vdev, "Invalid size for indirect buffer table"); 713 return NULL; 714 } 715 716 /* loop over the indirect descriptor table */ 717 max = desc.len / sizeof(VRingDesc); 718 desc_pa = desc.addr; 719 i = 0; 720 vring_desc_read(vdev, &desc, desc_pa, i); 721 } 722 723 /* Collect all the descriptors */ 724 do { 725 bool map_ok; 726 727 if (desc.flags & VRING_DESC_F_WRITE) { 728 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 729 iov + out_num, 730 VIRTQUEUE_MAX_SIZE - out_num, true, 731 desc.addr, desc.len); 732 } else { 733 if (in_num) { 734 virtio_error(vdev, "Incorrect order for descriptors"); 735 goto err_undo_map; 736 } 737 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 738 VIRTQUEUE_MAX_SIZE, false, 739 desc.addr, desc.len); 740 } 741 if (!map_ok) { 742 goto err_undo_map; 743 } 744 745 /* If we've got too many, that implies a descriptor loop. */ 746 if ((in_num + out_num) > max) { 747 virtio_error(vdev, "Looped descriptor"); 748 goto err_undo_map; 749 } 750 751 rc = virtqueue_read_next_desc(vdev, &desc, desc_pa, max, &i); 752 } while (rc == VIRTQUEUE_READ_DESC_MORE); 753 754 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 755 goto err_undo_map; 756 } 757 758 /* Now copy what we have collected and mapped */ 759 elem = virtqueue_alloc_element(sz, out_num, in_num); 760 elem->index = head; 761 for (i = 0; i < out_num; i++) { 762 elem->out_addr[i] = addr[i]; 763 elem->out_sg[i] = iov[i]; 764 } 765 for (i = 0; i < in_num; i++) { 766 elem->in_addr[i] = addr[out_num + i]; 767 elem->in_sg[i] = iov[out_num + i]; 768 } 769 770 vq->inuse++; 771 772 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 773 return elem; 774 775 err_undo_map: 776 virtqueue_undo_map_desc(out_num, in_num, iov); 777 return NULL; 778 } 779 780 /* virtqueue_drop_all: 781 * @vq: The #VirtQueue 782 * Drops all queued buffers and indicates them to the guest 783 * as if they are done. Useful when buffers can not be 784 * processed but must be returned to the guest. 785 */ 786 unsigned int virtqueue_drop_all(VirtQueue *vq) 787 { 788 unsigned int dropped = 0; 789 VirtQueueElement elem = {}; 790 VirtIODevice *vdev = vq->vdev; 791 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 792 793 if (unlikely(vdev->broken)) { 794 return 0; 795 } 796 797 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 798 /* works similar to virtqueue_pop but does not map buffers 799 * and does not allocate any memory */ 800 smp_rmb(); 801 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 802 break; 803 } 804 vq->inuse++; 805 vq->last_avail_idx++; 806 if (fEventIdx) { 807 vring_set_avail_event(vq, vq->last_avail_idx); 808 } 809 /* immediately push the element, nothing to unmap 810 * as both in_num and out_num are set to 0 */ 811 virtqueue_push(vq, &elem, 0); 812 dropped++; 813 } 814 815 return dropped; 816 } 817 818 /* Reading and writing a structure directly to QEMUFile is *awful*, but 819 * it is what QEMU has always done by mistake. We can change it sooner 820 * or later by bumping the version number of the affected vm states. 821 * In the meanwhile, since the in-memory layout of VirtQueueElement 822 * has changed, we need to marshal to and from the layout that was 823 * used before the change. 824 */ 825 typedef struct VirtQueueElementOld { 826 unsigned int index; 827 unsigned int out_num; 828 unsigned int in_num; 829 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 830 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 831 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 832 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 833 } VirtQueueElementOld; 834 835 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 836 { 837 VirtQueueElement *elem; 838 VirtQueueElementOld data; 839 int i; 840 841 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 842 843 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 844 elem->index = data.index; 845 846 for (i = 0; i < elem->in_num; i++) { 847 elem->in_addr[i] = data.in_addr[i]; 848 } 849 850 for (i = 0; i < elem->out_num; i++) { 851 elem->out_addr[i] = data.out_addr[i]; 852 } 853 854 for (i = 0; i < elem->in_num; i++) { 855 /* Base is overwritten by virtqueue_map. */ 856 elem->in_sg[i].iov_base = 0; 857 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 858 } 859 860 for (i = 0; i < elem->out_num; i++) { 861 /* Base is overwritten by virtqueue_map. */ 862 elem->out_sg[i].iov_base = 0; 863 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 864 } 865 866 virtqueue_map(vdev, elem); 867 return elem; 868 } 869 870 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem) 871 { 872 VirtQueueElementOld data; 873 int i; 874 875 memset(&data, 0, sizeof(data)); 876 data.index = elem->index; 877 data.in_num = elem->in_num; 878 data.out_num = elem->out_num; 879 880 for (i = 0; i < elem->in_num; i++) { 881 data.in_addr[i] = elem->in_addr[i]; 882 } 883 884 for (i = 0; i < elem->out_num; i++) { 885 data.out_addr[i] = elem->out_addr[i]; 886 } 887 888 for (i = 0; i < elem->in_num; i++) { 889 /* Base is overwritten by virtqueue_map when loading. Do not 890 * save it, as it would leak the QEMU address space layout. */ 891 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 892 } 893 894 for (i = 0; i < elem->out_num; i++) { 895 /* Do not save iov_base as above. */ 896 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 897 } 898 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 899 } 900 901 /* virtio device */ 902 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 903 { 904 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 905 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 906 907 if (unlikely(vdev->broken)) { 908 return; 909 } 910 911 if (k->notify) { 912 k->notify(qbus->parent, vector); 913 } 914 } 915 916 void virtio_update_irq(VirtIODevice *vdev) 917 { 918 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 919 } 920 921 static int virtio_validate_features(VirtIODevice *vdev) 922 { 923 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 924 925 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 926 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 927 return -EFAULT; 928 } 929 930 if (k->validate_features) { 931 return k->validate_features(vdev); 932 } else { 933 return 0; 934 } 935 } 936 937 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 938 { 939 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 940 trace_virtio_set_status(vdev, val); 941 942 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 943 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 944 val & VIRTIO_CONFIG_S_FEATURES_OK) { 945 int ret = virtio_validate_features(vdev); 946 947 if (ret) { 948 return ret; 949 } 950 } 951 } 952 if (k->set_status) { 953 k->set_status(vdev, val); 954 } 955 vdev->status = val; 956 return 0; 957 } 958 959 bool target_words_bigendian(void); 960 static enum virtio_device_endian virtio_default_endian(void) 961 { 962 if (target_words_bigendian()) { 963 return VIRTIO_DEVICE_ENDIAN_BIG; 964 } else { 965 return VIRTIO_DEVICE_ENDIAN_LITTLE; 966 } 967 } 968 969 static enum virtio_device_endian virtio_current_cpu_endian(void) 970 { 971 CPUClass *cc = CPU_GET_CLASS(current_cpu); 972 973 if (cc->virtio_is_big_endian(current_cpu)) { 974 return VIRTIO_DEVICE_ENDIAN_BIG; 975 } else { 976 return VIRTIO_DEVICE_ENDIAN_LITTLE; 977 } 978 } 979 980 void virtio_reset(void *opaque) 981 { 982 VirtIODevice *vdev = opaque; 983 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 984 int i; 985 986 virtio_set_status(vdev, 0); 987 if (current_cpu) { 988 /* Guest initiated reset */ 989 vdev->device_endian = virtio_current_cpu_endian(); 990 } else { 991 /* System reset */ 992 vdev->device_endian = virtio_default_endian(); 993 } 994 995 if (k->reset) { 996 k->reset(vdev); 997 } 998 999 vdev->broken = false; 1000 vdev->guest_features = 0; 1001 vdev->queue_sel = 0; 1002 vdev->status = 0; 1003 atomic_set(&vdev->isr, 0); 1004 vdev->config_vector = VIRTIO_NO_VECTOR; 1005 virtio_notify_vector(vdev, vdev->config_vector); 1006 1007 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1008 vdev->vq[i].vring.desc = 0; 1009 vdev->vq[i].vring.avail = 0; 1010 vdev->vq[i].vring.used = 0; 1011 vdev->vq[i].last_avail_idx = 0; 1012 vdev->vq[i].shadow_avail_idx = 0; 1013 vdev->vq[i].used_idx = 0; 1014 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1015 vdev->vq[i].signalled_used = 0; 1016 vdev->vq[i].signalled_used_valid = false; 1017 vdev->vq[i].notification = true; 1018 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1019 vdev->vq[i].inuse = 0; 1020 } 1021 } 1022 1023 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1024 { 1025 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1026 uint8_t val; 1027 1028 if (addr + sizeof(val) > vdev->config_len) { 1029 return (uint32_t)-1; 1030 } 1031 1032 k->get_config(vdev, vdev->config); 1033 1034 val = ldub_p(vdev->config + addr); 1035 return val; 1036 } 1037 1038 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1039 { 1040 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1041 uint16_t val; 1042 1043 if (addr + sizeof(val) > vdev->config_len) { 1044 return (uint32_t)-1; 1045 } 1046 1047 k->get_config(vdev, vdev->config); 1048 1049 val = lduw_p(vdev->config + addr); 1050 return val; 1051 } 1052 1053 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1054 { 1055 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1056 uint32_t val; 1057 1058 if (addr + sizeof(val) > vdev->config_len) { 1059 return (uint32_t)-1; 1060 } 1061 1062 k->get_config(vdev, vdev->config); 1063 1064 val = ldl_p(vdev->config + addr); 1065 return val; 1066 } 1067 1068 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1069 { 1070 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1071 uint8_t val = data; 1072 1073 if (addr + sizeof(val) > vdev->config_len) { 1074 return; 1075 } 1076 1077 stb_p(vdev->config + addr, val); 1078 1079 if (k->set_config) { 1080 k->set_config(vdev, vdev->config); 1081 } 1082 } 1083 1084 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1085 { 1086 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1087 uint16_t val = data; 1088 1089 if (addr + sizeof(val) > vdev->config_len) { 1090 return; 1091 } 1092 1093 stw_p(vdev->config + addr, val); 1094 1095 if (k->set_config) { 1096 k->set_config(vdev, vdev->config); 1097 } 1098 } 1099 1100 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1101 { 1102 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1103 uint32_t val = data; 1104 1105 if (addr + sizeof(val) > vdev->config_len) { 1106 return; 1107 } 1108 1109 stl_p(vdev->config + addr, val); 1110 1111 if (k->set_config) { 1112 k->set_config(vdev, vdev->config); 1113 } 1114 } 1115 1116 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 1117 { 1118 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1119 uint8_t val; 1120 1121 if (addr + sizeof(val) > vdev->config_len) { 1122 return (uint32_t)-1; 1123 } 1124 1125 k->get_config(vdev, vdev->config); 1126 1127 val = ldub_p(vdev->config + addr); 1128 return val; 1129 } 1130 1131 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 1132 { 1133 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1134 uint16_t val; 1135 1136 if (addr + sizeof(val) > vdev->config_len) { 1137 return (uint32_t)-1; 1138 } 1139 1140 k->get_config(vdev, vdev->config); 1141 1142 val = lduw_le_p(vdev->config + addr); 1143 return val; 1144 } 1145 1146 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 1147 { 1148 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1149 uint32_t val; 1150 1151 if (addr + sizeof(val) > vdev->config_len) { 1152 return (uint32_t)-1; 1153 } 1154 1155 k->get_config(vdev, vdev->config); 1156 1157 val = ldl_le_p(vdev->config + addr); 1158 return val; 1159 } 1160 1161 void virtio_config_modern_writeb(VirtIODevice *vdev, 1162 uint32_t addr, uint32_t data) 1163 { 1164 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1165 uint8_t val = data; 1166 1167 if (addr + sizeof(val) > vdev->config_len) { 1168 return; 1169 } 1170 1171 stb_p(vdev->config + addr, val); 1172 1173 if (k->set_config) { 1174 k->set_config(vdev, vdev->config); 1175 } 1176 } 1177 1178 void virtio_config_modern_writew(VirtIODevice *vdev, 1179 uint32_t addr, uint32_t data) 1180 { 1181 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1182 uint16_t val = data; 1183 1184 if (addr + sizeof(val) > vdev->config_len) { 1185 return; 1186 } 1187 1188 stw_le_p(vdev->config + addr, val); 1189 1190 if (k->set_config) { 1191 k->set_config(vdev, vdev->config); 1192 } 1193 } 1194 1195 void virtio_config_modern_writel(VirtIODevice *vdev, 1196 uint32_t addr, uint32_t data) 1197 { 1198 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1199 uint32_t val = data; 1200 1201 if (addr + sizeof(val) > vdev->config_len) { 1202 return; 1203 } 1204 1205 stl_le_p(vdev->config + addr, val); 1206 1207 if (k->set_config) { 1208 k->set_config(vdev, vdev->config); 1209 } 1210 } 1211 1212 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 1213 { 1214 vdev->vq[n].vring.desc = addr; 1215 virtio_queue_update_rings(vdev, n); 1216 } 1217 1218 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 1219 { 1220 return vdev->vq[n].vring.desc; 1221 } 1222 1223 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 1224 hwaddr avail, hwaddr used) 1225 { 1226 vdev->vq[n].vring.desc = desc; 1227 vdev->vq[n].vring.avail = avail; 1228 vdev->vq[n].vring.used = used; 1229 } 1230 1231 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 1232 { 1233 /* Don't allow guest to flip queue between existent and 1234 * nonexistent states, or to set it to an invalid size. 1235 */ 1236 if (!!num != !!vdev->vq[n].vring.num || 1237 num > VIRTQUEUE_MAX_SIZE || 1238 num < 0) { 1239 return; 1240 } 1241 vdev->vq[n].vring.num = num; 1242 } 1243 1244 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 1245 { 1246 return QLIST_FIRST(&vdev->vector_queues[vector]); 1247 } 1248 1249 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 1250 { 1251 return QLIST_NEXT(vq, node); 1252 } 1253 1254 int virtio_queue_get_num(VirtIODevice *vdev, int n) 1255 { 1256 return vdev->vq[n].vring.num; 1257 } 1258 1259 int virtio_get_num_queues(VirtIODevice *vdev) 1260 { 1261 int i; 1262 1263 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1264 if (!virtio_queue_get_num(vdev, i)) { 1265 break; 1266 } 1267 } 1268 1269 return i; 1270 } 1271 1272 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 1273 { 1274 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1275 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1276 1277 /* virtio-1 compliant devices cannot change the alignment */ 1278 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1279 error_report("tried to modify queue alignment for virtio-1 device"); 1280 return; 1281 } 1282 /* Check that the transport told us it was going to do this 1283 * (so a buggy transport will immediately assert rather than 1284 * silently failing to migrate this state) 1285 */ 1286 assert(k->has_variable_vring_alignment); 1287 1288 vdev->vq[n].vring.align = align; 1289 virtio_queue_update_rings(vdev, n); 1290 } 1291 1292 static void virtio_queue_notify_aio_vq(VirtQueue *vq) 1293 { 1294 if (vq->vring.desc && vq->handle_aio_output) { 1295 VirtIODevice *vdev = vq->vdev; 1296 1297 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1298 vq->handle_aio_output(vdev, vq); 1299 } 1300 } 1301 1302 static void virtio_queue_notify_vq(VirtQueue *vq) 1303 { 1304 if (vq->vring.desc && vq->handle_output) { 1305 VirtIODevice *vdev = vq->vdev; 1306 1307 if (unlikely(vdev->broken)) { 1308 return; 1309 } 1310 1311 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1312 vq->handle_output(vdev, vq); 1313 } 1314 } 1315 1316 void virtio_queue_notify(VirtIODevice *vdev, int n) 1317 { 1318 virtio_queue_notify_vq(&vdev->vq[n]); 1319 } 1320 1321 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 1322 { 1323 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 1324 VIRTIO_NO_VECTOR; 1325 } 1326 1327 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 1328 { 1329 VirtQueue *vq = &vdev->vq[n]; 1330 1331 if (n < VIRTIO_QUEUE_MAX) { 1332 if (vdev->vector_queues && 1333 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 1334 QLIST_REMOVE(vq, node); 1335 } 1336 vdev->vq[n].vector = vector; 1337 if (vdev->vector_queues && 1338 vector != VIRTIO_NO_VECTOR) { 1339 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 1340 } 1341 } 1342 } 1343 1344 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 1345 VirtIOHandleOutput handle_output) 1346 { 1347 int i; 1348 1349 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1350 if (vdev->vq[i].vring.num == 0) 1351 break; 1352 } 1353 1354 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 1355 abort(); 1356 1357 vdev->vq[i].vring.num = queue_size; 1358 vdev->vq[i].vring.num_default = queue_size; 1359 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 1360 vdev->vq[i].handle_output = handle_output; 1361 vdev->vq[i].handle_aio_output = NULL; 1362 1363 return &vdev->vq[i]; 1364 } 1365 1366 void virtio_del_queue(VirtIODevice *vdev, int n) 1367 { 1368 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 1369 abort(); 1370 } 1371 1372 vdev->vq[n].vring.num = 0; 1373 vdev->vq[n].vring.num_default = 0; 1374 } 1375 1376 static void virtio_set_isr(VirtIODevice *vdev, int value) 1377 { 1378 uint8_t old = atomic_read(&vdev->isr); 1379 1380 /* Do not write ISR if it does not change, so that its cacheline remains 1381 * shared in the common case where the guest does not read it. 1382 */ 1383 if ((old & value) != value) { 1384 atomic_or(&vdev->isr, value); 1385 } 1386 } 1387 1388 bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 1389 { 1390 uint16_t old, new; 1391 bool v; 1392 /* We need to expose used array entries before checking used event. */ 1393 smp_mb(); 1394 /* Always notify when queue is empty (when feature acknowledge) */ 1395 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 1396 !vq->inuse && virtio_queue_empty(vq)) { 1397 return true; 1398 } 1399 1400 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1401 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 1402 } 1403 1404 v = vq->signalled_used_valid; 1405 vq->signalled_used_valid = true; 1406 old = vq->signalled_used; 1407 new = vq->signalled_used = vq->used_idx; 1408 return !v || vring_need_event(vring_get_used_event(vq), new, old); 1409 } 1410 1411 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 1412 { 1413 if (!virtio_should_notify(vdev, vq)) { 1414 return; 1415 } 1416 1417 trace_virtio_notify_irqfd(vdev, vq); 1418 1419 /* 1420 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 1421 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 1422 * incorrectly polling this bit during crashdump and hibernation 1423 * in MSI mode, causing a hang if this bit is never updated. 1424 * Recent releases of Windows do not really shut down, but rather 1425 * log out and hibernate to make the next startup faster. Hence, 1426 * this manifested as a more serious hang during shutdown with 1427 * 1428 * Next driver release from 2016 fixed this problem, so working around it 1429 * is not a must, but it's easy to do so let's do it here. 1430 * 1431 * Note: it's safe to update ISR from any thread as it was switched 1432 * to an atomic operation. 1433 */ 1434 virtio_set_isr(vq->vdev, 0x1); 1435 event_notifier_set(&vq->guest_notifier); 1436 } 1437 1438 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 1439 { 1440 if (!virtio_should_notify(vdev, vq)) { 1441 return; 1442 } 1443 1444 trace_virtio_notify(vdev, vq); 1445 virtio_set_isr(vq->vdev, 0x1); 1446 virtio_notify_vector(vdev, vq->vector); 1447 } 1448 1449 void virtio_notify_config(VirtIODevice *vdev) 1450 { 1451 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 1452 return; 1453 1454 virtio_set_isr(vdev, 0x3); 1455 vdev->generation++; 1456 virtio_notify_vector(vdev, vdev->config_vector); 1457 } 1458 1459 static bool virtio_device_endian_needed(void *opaque) 1460 { 1461 VirtIODevice *vdev = opaque; 1462 1463 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 1464 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1465 return vdev->device_endian != virtio_default_endian(); 1466 } 1467 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 1468 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 1469 } 1470 1471 static bool virtio_64bit_features_needed(void *opaque) 1472 { 1473 VirtIODevice *vdev = opaque; 1474 1475 return (vdev->host_features >> 32) != 0; 1476 } 1477 1478 static bool virtio_virtqueue_needed(void *opaque) 1479 { 1480 VirtIODevice *vdev = opaque; 1481 1482 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 1483 } 1484 1485 static bool virtio_ringsize_needed(void *opaque) 1486 { 1487 VirtIODevice *vdev = opaque; 1488 int i; 1489 1490 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1491 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 1492 return true; 1493 } 1494 } 1495 return false; 1496 } 1497 1498 static bool virtio_extra_state_needed(void *opaque) 1499 { 1500 VirtIODevice *vdev = opaque; 1501 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1502 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1503 1504 return k->has_extra_state && 1505 k->has_extra_state(qbus->parent); 1506 } 1507 1508 static bool virtio_broken_needed(void *opaque) 1509 { 1510 VirtIODevice *vdev = opaque; 1511 1512 return vdev->broken; 1513 } 1514 1515 static const VMStateDescription vmstate_virtqueue = { 1516 .name = "virtqueue_state", 1517 .version_id = 1, 1518 .minimum_version_id = 1, 1519 .fields = (VMStateField[]) { 1520 VMSTATE_UINT64(vring.avail, struct VirtQueue), 1521 VMSTATE_UINT64(vring.used, struct VirtQueue), 1522 VMSTATE_END_OF_LIST() 1523 } 1524 }; 1525 1526 static const VMStateDescription vmstate_virtio_virtqueues = { 1527 .name = "virtio/virtqueues", 1528 .version_id = 1, 1529 .minimum_version_id = 1, 1530 .needed = &virtio_virtqueue_needed, 1531 .fields = (VMStateField[]) { 1532 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1533 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 1534 VMSTATE_END_OF_LIST() 1535 } 1536 }; 1537 1538 static const VMStateDescription vmstate_ringsize = { 1539 .name = "ringsize_state", 1540 .version_id = 1, 1541 .minimum_version_id = 1, 1542 .fields = (VMStateField[]) { 1543 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 1544 VMSTATE_END_OF_LIST() 1545 } 1546 }; 1547 1548 static const VMStateDescription vmstate_virtio_ringsize = { 1549 .name = "virtio/ringsize", 1550 .version_id = 1, 1551 .minimum_version_id = 1, 1552 .needed = &virtio_ringsize_needed, 1553 .fields = (VMStateField[]) { 1554 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1555 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 1556 VMSTATE_END_OF_LIST() 1557 } 1558 }; 1559 1560 static int get_extra_state(QEMUFile *f, void *pv, size_t size) 1561 { 1562 VirtIODevice *vdev = pv; 1563 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1564 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1565 1566 if (!k->load_extra_state) { 1567 return -1; 1568 } else { 1569 return k->load_extra_state(qbus->parent, f); 1570 } 1571 } 1572 1573 static void put_extra_state(QEMUFile *f, void *pv, size_t size) 1574 { 1575 VirtIODevice *vdev = pv; 1576 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1577 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1578 1579 k->save_extra_state(qbus->parent, f); 1580 } 1581 1582 static const VMStateInfo vmstate_info_extra_state = { 1583 .name = "virtqueue_extra_state", 1584 .get = get_extra_state, 1585 .put = put_extra_state, 1586 }; 1587 1588 static const VMStateDescription vmstate_virtio_extra_state = { 1589 .name = "virtio/extra_state", 1590 .version_id = 1, 1591 .minimum_version_id = 1, 1592 .needed = &virtio_extra_state_needed, 1593 .fields = (VMStateField[]) { 1594 { 1595 .name = "extra_state", 1596 .version_id = 0, 1597 .field_exists = NULL, 1598 .size = 0, 1599 .info = &vmstate_info_extra_state, 1600 .flags = VMS_SINGLE, 1601 .offset = 0, 1602 }, 1603 VMSTATE_END_OF_LIST() 1604 } 1605 }; 1606 1607 static const VMStateDescription vmstate_virtio_device_endian = { 1608 .name = "virtio/device_endian", 1609 .version_id = 1, 1610 .minimum_version_id = 1, 1611 .needed = &virtio_device_endian_needed, 1612 .fields = (VMStateField[]) { 1613 VMSTATE_UINT8(device_endian, VirtIODevice), 1614 VMSTATE_END_OF_LIST() 1615 } 1616 }; 1617 1618 static const VMStateDescription vmstate_virtio_64bit_features = { 1619 .name = "virtio/64bit_features", 1620 .version_id = 1, 1621 .minimum_version_id = 1, 1622 .needed = &virtio_64bit_features_needed, 1623 .fields = (VMStateField[]) { 1624 VMSTATE_UINT64(guest_features, VirtIODevice), 1625 VMSTATE_END_OF_LIST() 1626 } 1627 }; 1628 1629 static const VMStateDescription vmstate_virtio_broken = { 1630 .name = "virtio/broken", 1631 .version_id = 1, 1632 .minimum_version_id = 1, 1633 .needed = &virtio_broken_needed, 1634 .fields = (VMStateField[]) { 1635 VMSTATE_BOOL(broken, VirtIODevice), 1636 VMSTATE_END_OF_LIST() 1637 } 1638 }; 1639 1640 static const VMStateDescription vmstate_virtio = { 1641 .name = "virtio", 1642 .version_id = 1, 1643 .minimum_version_id = 1, 1644 .minimum_version_id_old = 1, 1645 .fields = (VMStateField[]) { 1646 VMSTATE_END_OF_LIST() 1647 }, 1648 .subsections = (const VMStateDescription*[]) { 1649 &vmstate_virtio_device_endian, 1650 &vmstate_virtio_64bit_features, 1651 &vmstate_virtio_virtqueues, 1652 &vmstate_virtio_ringsize, 1653 &vmstate_virtio_broken, 1654 &vmstate_virtio_extra_state, 1655 NULL 1656 } 1657 }; 1658 1659 void virtio_save(VirtIODevice *vdev, QEMUFile *f) 1660 { 1661 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1662 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1663 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1664 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 1665 int i; 1666 1667 if (k->save_config) { 1668 k->save_config(qbus->parent, f); 1669 } 1670 1671 qemu_put_8s(f, &vdev->status); 1672 qemu_put_8s(f, &vdev->isr); 1673 qemu_put_be16s(f, &vdev->queue_sel); 1674 qemu_put_be32s(f, &guest_features_lo); 1675 qemu_put_be32(f, vdev->config_len); 1676 qemu_put_buffer(f, vdev->config, vdev->config_len); 1677 1678 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1679 if (vdev->vq[i].vring.num == 0) 1680 break; 1681 } 1682 1683 qemu_put_be32(f, i); 1684 1685 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1686 if (vdev->vq[i].vring.num == 0) 1687 break; 1688 1689 qemu_put_be32(f, vdev->vq[i].vring.num); 1690 if (k->has_variable_vring_alignment) { 1691 qemu_put_be32(f, vdev->vq[i].vring.align); 1692 } 1693 /* XXX virtio-1 devices */ 1694 qemu_put_be64(f, vdev->vq[i].vring.desc); 1695 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 1696 if (k->save_queue) { 1697 k->save_queue(qbus->parent, i, f); 1698 } 1699 } 1700 1701 if (vdc->save != NULL) { 1702 vdc->save(vdev, f); 1703 } 1704 1705 if (vdc->vmsd) { 1706 vmstate_save_state(f, vdc->vmsd, vdev, NULL); 1707 } 1708 1709 /* Subsections */ 1710 vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 1711 } 1712 1713 /* A wrapper for use as a VMState .put function */ 1714 static void virtio_device_put(QEMUFile *f, void *opaque, size_t size) 1715 { 1716 virtio_save(VIRTIO_DEVICE(opaque), f); 1717 } 1718 1719 /* A wrapper for use as a VMState .get function */ 1720 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size) 1721 { 1722 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1723 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 1724 1725 return virtio_load(vdev, f, dc->vmsd->version_id); 1726 } 1727 1728 const VMStateInfo virtio_vmstate_info = { 1729 .name = "virtio", 1730 .get = virtio_device_get, 1731 .put = virtio_device_put, 1732 }; 1733 1734 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 1735 { 1736 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1737 bool bad = (val & ~(vdev->host_features)) != 0; 1738 1739 val &= vdev->host_features; 1740 if (k->set_features) { 1741 k->set_features(vdev, val); 1742 } 1743 vdev->guest_features = val; 1744 return bad ? -1 : 0; 1745 } 1746 1747 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 1748 { 1749 /* 1750 * The driver must not attempt to set features after feature negotiation 1751 * has finished. 1752 */ 1753 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 1754 return -EINVAL; 1755 } 1756 return virtio_set_features_nocheck(vdev, val); 1757 } 1758 1759 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 1760 { 1761 int i, ret; 1762 int32_t config_len; 1763 uint32_t num; 1764 uint32_t features; 1765 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1766 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1767 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1768 1769 /* 1770 * We poison the endianness to ensure it does not get used before 1771 * subsections have been loaded. 1772 */ 1773 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 1774 1775 if (k->load_config) { 1776 ret = k->load_config(qbus->parent, f); 1777 if (ret) 1778 return ret; 1779 } 1780 1781 qemu_get_8s(f, &vdev->status); 1782 qemu_get_8s(f, &vdev->isr); 1783 qemu_get_be16s(f, &vdev->queue_sel); 1784 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 1785 return -1; 1786 } 1787 qemu_get_be32s(f, &features); 1788 1789 /* 1790 * Temporarily set guest_features low bits - needed by 1791 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 1792 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 1793 * 1794 * Note: devices should always test host features in future - don't create 1795 * new dependencies like this. 1796 */ 1797 vdev->guest_features = features; 1798 1799 config_len = qemu_get_be32(f); 1800 1801 /* 1802 * There are cases where the incoming config can be bigger or smaller 1803 * than what we have; so load what we have space for, and skip 1804 * any excess that's in the stream. 1805 */ 1806 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 1807 1808 while (config_len > vdev->config_len) { 1809 qemu_get_byte(f); 1810 config_len--; 1811 } 1812 1813 num = qemu_get_be32(f); 1814 1815 if (num > VIRTIO_QUEUE_MAX) { 1816 error_report("Invalid number of virtqueues: 0x%x", num); 1817 return -1; 1818 } 1819 1820 for (i = 0; i < num; i++) { 1821 vdev->vq[i].vring.num = qemu_get_be32(f); 1822 if (k->has_variable_vring_alignment) { 1823 vdev->vq[i].vring.align = qemu_get_be32(f); 1824 } 1825 vdev->vq[i].vring.desc = qemu_get_be64(f); 1826 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 1827 vdev->vq[i].signalled_used_valid = false; 1828 vdev->vq[i].notification = true; 1829 1830 if (vdev->vq[i].vring.desc) { 1831 /* XXX virtio-1 devices */ 1832 virtio_queue_update_rings(vdev, i); 1833 } else if (vdev->vq[i].last_avail_idx) { 1834 error_report("VQ %d address 0x0 " 1835 "inconsistent with Host index 0x%x", 1836 i, vdev->vq[i].last_avail_idx); 1837 return -1; 1838 } 1839 if (k->load_queue) { 1840 ret = k->load_queue(qbus->parent, i, f); 1841 if (ret) 1842 return ret; 1843 } 1844 } 1845 1846 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1847 1848 if (vdc->load != NULL) { 1849 ret = vdc->load(vdev, f, version_id); 1850 if (ret) { 1851 return ret; 1852 } 1853 } 1854 1855 if (vdc->vmsd) { 1856 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 1857 if (ret) { 1858 return ret; 1859 } 1860 } 1861 1862 /* Subsections */ 1863 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 1864 if (ret) { 1865 return ret; 1866 } 1867 1868 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 1869 vdev->device_endian = virtio_default_endian(); 1870 } 1871 1872 if (virtio_64bit_features_needed(vdev)) { 1873 /* 1874 * Subsection load filled vdev->guest_features. Run them 1875 * through virtio_set_features to sanity-check them against 1876 * host_features. 1877 */ 1878 uint64_t features64 = vdev->guest_features; 1879 if (virtio_set_features_nocheck(vdev, features64) < 0) { 1880 error_report("Features 0x%" PRIx64 " unsupported. " 1881 "Allowed features: 0x%" PRIx64, 1882 features64, vdev->host_features); 1883 return -1; 1884 } 1885 } else { 1886 if (virtio_set_features_nocheck(vdev, features) < 0) { 1887 error_report("Features 0x%x unsupported. " 1888 "Allowed features: 0x%" PRIx64, 1889 features, vdev->host_features); 1890 return -1; 1891 } 1892 } 1893 1894 for (i = 0; i < num; i++) { 1895 if (vdev->vq[i].vring.desc) { 1896 uint16_t nheads; 1897 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 1898 /* Check it isn't doing strange things with descriptor numbers. */ 1899 if (nheads > vdev->vq[i].vring.num) { 1900 error_report("VQ %d size 0x%x Guest index 0x%x " 1901 "inconsistent with Host index 0x%x: delta 0x%x", 1902 i, vdev->vq[i].vring.num, 1903 vring_avail_idx(&vdev->vq[i]), 1904 vdev->vq[i].last_avail_idx, nheads); 1905 return -1; 1906 } 1907 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 1908 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 1909 1910 /* 1911 * Some devices migrate VirtQueueElements that have been popped 1912 * from the avail ring but not yet returned to the used ring. 1913 * Since max ring size < UINT16_MAX it's safe to use modulo 1914 * UINT16_MAX + 1 subtraction. 1915 */ 1916 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 1917 vdev->vq[i].used_idx); 1918 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 1919 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 1920 "used_idx 0x%x", 1921 i, vdev->vq[i].vring.num, 1922 vdev->vq[i].last_avail_idx, 1923 vdev->vq[i].used_idx); 1924 return -1; 1925 } 1926 } 1927 } 1928 1929 return 0; 1930 } 1931 1932 void virtio_cleanup(VirtIODevice *vdev) 1933 { 1934 qemu_del_vm_change_state_handler(vdev->vmstate); 1935 g_free(vdev->config); 1936 g_free(vdev->vq); 1937 g_free(vdev->vector_queues); 1938 } 1939 1940 static void virtio_vmstate_change(void *opaque, int running, RunState state) 1941 { 1942 VirtIODevice *vdev = opaque; 1943 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1944 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1945 bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK); 1946 vdev->vm_running = running; 1947 1948 if (backend_run) { 1949 virtio_set_status(vdev, vdev->status); 1950 } 1951 1952 if (k->vmstate_change) { 1953 k->vmstate_change(qbus->parent, backend_run); 1954 } 1955 1956 if (!backend_run) { 1957 virtio_set_status(vdev, vdev->status); 1958 } 1959 } 1960 1961 void virtio_instance_init_common(Object *proxy_obj, void *data, 1962 size_t vdev_size, const char *vdev_name) 1963 { 1964 DeviceState *vdev = data; 1965 1966 object_initialize(vdev, vdev_size, vdev_name); 1967 object_property_add_child(proxy_obj, "virtio-backend", OBJECT(vdev), NULL); 1968 object_unref(OBJECT(vdev)); 1969 qdev_alias_all_properties(vdev, proxy_obj); 1970 } 1971 1972 void virtio_init(VirtIODevice *vdev, const char *name, 1973 uint16_t device_id, size_t config_size) 1974 { 1975 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1976 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1977 int i; 1978 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 1979 1980 if (nvectors) { 1981 vdev->vector_queues = 1982 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 1983 } 1984 1985 vdev->device_id = device_id; 1986 vdev->status = 0; 1987 atomic_set(&vdev->isr, 0); 1988 vdev->queue_sel = 0; 1989 vdev->config_vector = VIRTIO_NO_VECTOR; 1990 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 1991 vdev->vm_running = runstate_is_running(); 1992 vdev->broken = false; 1993 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1994 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 1995 vdev->vq[i].vdev = vdev; 1996 vdev->vq[i].queue_index = i; 1997 } 1998 1999 vdev->name = name; 2000 vdev->config_len = config_size; 2001 if (vdev->config_len) { 2002 vdev->config = g_malloc0(config_size); 2003 } else { 2004 vdev->config = NULL; 2005 } 2006 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, 2007 vdev); 2008 vdev->device_endian = virtio_default_endian(); 2009 vdev->use_guest_notifier_mask = true; 2010 } 2011 2012 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 2013 { 2014 return vdev->vq[n].vring.desc; 2015 } 2016 2017 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 2018 { 2019 return vdev->vq[n].vring.avail; 2020 } 2021 2022 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 2023 { 2024 return vdev->vq[n].vring.used; 2025 } 2026 2027 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 2028 { 2029 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 2030 } 2031 2032 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 2033 { 2034 return offsetof(VRingAvail, ring) + 2035 sizeof(uint16_t) * vdev->vq[n].vring.num; 2036 } 2037 2038 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 2039 { 2040 return offsetof(VRingUsed, ring) + 2041 sizeof(VRingUsedElem) * vdev->vq[n].vring.num; 2042 } 2043 2044 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 2045 { 2046 return vdev->vq[n].last_avail_idx; 2047 } 2048 2049 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) 2050 { 2051 vdev->vq[n].last_avail_idx = idx; 2052 vdev->vq[n].shadow_avail_idx = idx; 2053 } 2054 2055 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 2056 { 2057 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 2058 } 2059 2060 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 2061 { 2062 vdev->vq[n].signalled_used_valid = false; 2063 } 2064 2065 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 2066 { 2067 return vdev->vq + n; 2068 } 2069 2070 uint16_t virtio_get_queue_index(VirtQueue *vq) 2071 { 2072 return vq->queue_index; 2073 } 2074 2075 static void virtio_queue_guest_notifier_read(EventNotifier *n) 2076 { 2077 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 2078 if (event_notifier_test_and_clear(n)) { 2079 virtio_notify_vector(vq->vdev, vq->vector); 2080 } 2081 } 2082 2083 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 2084 bool with_irqfd) 2085 { 2086 if (assign && !with_irqfd) { 2087 event_notifier_set_handler(&vq->guest_notifier, false, 2088 virtio_queue_guest_notifier_read); 2089 } else { 2090 event_notifier_set_handler(&vq->guest_notifier, false, NULL); 2091 } 2092 if (!assign) { 2093 /* Test and clear notifier before closing it, 2094 * in case poll callback didn't have time to run. */ 2095 virtio_queue_guest_notifier_read(&vq->guest_notifier); 2096 } 2097 } 2098 2099 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 2100 { 2101 return &vq->guest_notifier; 2102 } 2103 2104 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 2105 { 2106 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2107 if (event_notifier_test_and_clear(n)) { 2108 virtio_queue_notify_aio_vq(vq); 2109 } 2110 } 2111 2112 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 2113 { 2114 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2115 2116 virtio_queue_set_notification(vq, 0); 2117 } 2118 2119 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 2120 { 2121 EventNotifier *n = opaque; 2122 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2123 2124 if (virtio_queue_empty(vq)) { 2125 return false; 2126 } 2127 2128 virtio_queue_notify_aio_vq(vq); 2129 2130 /* In case the handler function re-enabled notifications */ 2131 virtio_queue_set_notification(vq, 0); 2132 return true; 2133 } 2134 2135 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 2136 { 2137 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2138 2139 /* Caller polls once more after this to catch requests that race with us */ 2140 virtio_queue_set_notification(vq, 1); 2141 } 2142 2143 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 2144 VirtIOHandleOutput handle_output) 2145 { 2146 if (handle_output) { 2147 vq->handle_aio_output = handle_output; 2148 aio_set_event_notifier(ctx, &vq->host_notifier, true, 2149 virtio_queue_host_notifier_aio_read, 2150 virtio_queue_host_notifier_aio_poll); 2151 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 2152 virtio_queue_host_notifier_aio_poll_begin, 2153 virtio_queue_host_notifier_aio_poll_end); 2154 } else { 2155 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 2156 /* Test and clear notifier before after disabling event, 2157 * in case poll callback didn't have time to run. */ 2158 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 2159 vq->handle_aio_output = NULL; 2160 } 2161 } 2162 2163 void virtio_queue_host_notifier_read(EventNotifier *n) 2164 { 2165 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2166 if (event_notifier_test_and_clear(n)) { 2167 virtio_queue_notify_vq(vq); 2168 } 2169 } 2170 2171 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 2172 { 2173 return &vq->host_notifier; 2174 } 2175 2176 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 2177 { 2178 g_free(vdev->bus_name); 2179 vdev->bus_name = g_strdup(bus_name); 2180 } 2181 2182 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 2183 { 2184 va_list ap; 2185 2186 va_start(ap, fmt); 2187 error_vreport(fmt, ap); 2188 va_end(ap); 2189 2190 vdev->broken = true; 2191 2192 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2193 virtio_set_status(vdev, vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET); 2194 virtio_notify_config(vdev); 2195 } 2196 } 2197 2198 static void virtio_device_realize(DeviceState *dev, Error **errp) 2199 { 2200 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2201 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2202 Error *err = NULL; 2203 2204 /* Devices should either use vmsd or the load/save methods */ 2205 assert(!vdc->vmsd || !vdc->load); 2206 2207 if (vdc->realize != NULL) { 2208 vdc->realize(dev, &err); 2209 if (err != NULL) { 2210 error_propagate(errp, err); 2211 return; 2212 } 2213 } 2214 2215 virtio_bus_device_plugged(vdev, &err); 2216 if (err != NULL) { 2217 error_propagate(errp, err); 2218 return; 2219 } 2220 } 2221 2222 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 2223 { 2224 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2225 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2226 Error *err = NULL; 2227 2228 virtio_bus_device_unplugged(vdev); 2229 2230 if (vdc->unrealize != NULL) { 2231 vdc->unrealize(dev, &err); 2232 if (err != NULL) { 2233 error_propagate(errp, err); 2234 return; 2235 } 2236 } 2237 2238 g_free(vdev->bus_name); 2239 vdev->bus_name = NULL; 2240 } 2241 2242 static Property virtio_properties[] = { 2243 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 2244 DEFINE_PROP_END_OF_LIST(), 2245 }; 2246 2247 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 2248 { 2249 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2250 int n, r, err; 2251 2252 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2253 VirtQueue *vq = &vdev->vq[n]; 2254 if (!virtio_queue_get_num(vdev, n)) { 2255 continue; 2256 } 2257 r = virtio_bus_set_host_notifier(qbus, n, true); 2258 if (r < 0) { 2259 err = r; 2260 goto assign_error; 2261 } 2262 event_notifier_set_handler(&vq->host_notifier, true, 2263 virtio_queue_host_notifier_read); 2264 } 2265 2266 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2267 /* Kick right away to begin processing requests already in vring */ 2268 VirtQueue *vq = &vdev->vq[n]; 2269 if (!vq->vring.num) { 2270 continue; 2271 } 2272 event_notifier_set(&vq->host_notifier); 2273 } 2274 return 0; 2275 2276 assign_error: 2277 while (--n >= 0) { 2278 VirtQueue *vq = &vdev->vq[n]; 2279 if (!virtio_queue_get_num(vdev, n)) { 2280 continue; 2281 } 2282 2283 event_notifier_set_handler(&vq->host_notifier, true, NULL); 2284 r = virtio_bus_set_host_notifier(qbus, n, false); 2285 assert(r >= 0); 2286 } 2287 return err; 2288 } 2289 2290 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 2291 { 2292 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2293 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2294 2295 return virtio_bus_start_ioeventfd(vbus); 2296 } 2297 2298 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 2299 { 2300 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2301 int n, r; 2302 2303 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2304 VirtQueue *vq = &vdev->vq[n]; 2305 2306 if (!virtio_queue_get_num(vdev, n)) { 2307 continue; 2308 } 2309 event_notifier_set_handler(&vq->host_notifier, true, NULL); 2310 r = virtio_bus_set_host_notifier(qbus, n, false); 2311 assert(r >= 0); 2312 } 2313 } 2314 2315 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) 2316 { 2317 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2318 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2319 2320 virtio_bus_stop_ioeventfd(vbus); 2321 } 2322 2323 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 2324 { 2325 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2326 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2327 2328 return virtio_bus_grab_ioeventfd(vbus); 2329 } 2330 2331 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 2332 { 2333 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2334 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2335 2336 virtio_bus_release_ioeventfd(vbus); 2337 } 2338 2339 static void virtio_device_class_init(ObjectClass *klass, void *data) 2340 { 2341 /* Set the default value here. */ 2342 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 2343 DeviceClass *dc = DEVICE_CLASS(klass); 2344 2345 dc->realize = virtio_device_realize; 2346 dc->unrealize = virtio_device_unrealize; 2347 dc->bus_type = TYPE_VIRTIO_BUS; 2348 dc->props = virtio_properties; 2349 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 2350 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 2351 2352 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 2353 } 2354 2355 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 2356 { 2357 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2358 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2359 2360 return virtio_bus_ioeventfd_enabled(vbus); 2361 } 2362 2363 static const TypeInfo virtio_device_info = { 2364 .name = TYPE_VIRTIO_DEVICE, 2365 .parent = TYPE_DEVICE, 2366 .instance_size = sizeof(VirtIODevice), 2367 .class_init = virtio_device_class_init, 2368 .abstract = true, 2369 .class_size = sizeof(VirtioDeviceClass), 2370 }; 2371 2372 static void virtio_register_types(void) 2373 { 2374 type_register_static(&virtio_device_info); 2375 } 2376 2377 type_init(virtio_register_types) 2378