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