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 int is_write) 603 { 604 unsigned int i; 605 hwaddr len; 606 607 for (i = 0; i < *num_sg; i++) { 608 len = sg[i].iov_len; 609 sg[i].iov_base = dma_memory_map(vdev->dma_as, 610 addr[i], &len, is_write ? 611 DMA_DIRECTION_FROM_DEVICE : 612 DMA_DIRECTION_TO_DEVICE); 613 if (!sg[i].iov_base) { 614 error_report("virtio: error trying to map MMIO memory"); 615 exit(1); 616 } 617 if (len != sg[i].iov_len) { 618 error_report("virtio: unexpected memory split"); 619 exit(1); 620 } 621 } 622 } 623 624 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem) 625 { 626 virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num, 1); 627 virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num, 0); 628 } 629 630 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num) 631 { 632 VirtQueueElement *elem; 633 size_t in_addr_ofs = QEMU_ALIGN_UP(sz, __alignof__(elem->in_addr[0])); 634 size_t out_addr_ofs = in_addr_ofs + in_num * sizeof(elem->in_addr[0]); 635 size_t out_addr_end = out_addr_ofs + out_num * sizeof(elem->out_addr[0]); 636 size_t in_sg_ofs = QEMU_ALIGN_UP(out_addr_end, __alignof__(elem->in_sg[0])); 637 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 638 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 639 640 assert(sz >= sizeof(VirtQueueElement)); 641 elem = g_malloc(out_sg_end); 642 elem->out_num = out_num; 643 elem->in_num = in_num; 644 elem->in_addr = (void *)elem + in_addr_ofs; 645 elem->out_addr = (void *)elem + out_addr_ofs; 646 elem->in_sg = (void *)elem + in_sg_ofs; 647 elem->out_sg = (void *)elem + out_sg_ofs; 648 return elem; 649 } 650 651 void *virtqueue_pop(VirtQueue *vq, size_t sz) 652 { 653 unsigned int i, head, max; 654 hwaddr desc_pa = vq->vring.desc; 655 VirtIODevice *vdev = vq->vdev; 656 VirtQueueElement *elem; 657 unsigned out_num, in_num; 658 hwaddr addr[VIRTQUEUE_MAX_SIZE]; 659 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 660 VRingDesc desc; 661 int rc; 662 663 if (unlikely(vdev->broken)) { 664 return NULL; 665 } 666 if (virtio_queue_empty(vq)) { 667 return NULL; 668 } 669 /* Needed after virtio_queue_empty(), see comment in 670 * virtqueue_num_heads(). */ 671 smp_rmb(); 672 673 /* When we start there are none of either input nor output. */ 674 out_num = in_num = 0; 675 676 max = vq->vring.num; 677 678 if (vq->inuse >= vq->vring.num) { 679 virtio_error(vdev, "Virtqueue size exceeded"); 680 return NULL; 681 } 682 683 if (!virtqueue_get_head(vq, vq->last_avail_idx++, &head)) { 684 return NULL; 685 } 686 687 if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 688 vring_set_avail_event(vq, vq->last_avail_idx); 689 } 690 691 i = head; 692 vring_desc_read(vdev, &desc, desc_pa, i); 693 if (desc.flags & VRING_DESC_F_INDIRECT) { 694 if (desc.len % sizeof(VRingDesc)) { 695 virtio_error(vdev, "Invalid size for indirect buffer table"); 696 return NULL; 697 } 698 699 /* loop over the indirect descriptor table */ 700 max = desc.len / sizeof(VRingDesc); 701 desc_pa = desc.addr; 702 i = 0; 703 vring_desc_read(vdev, &desc, desc_pa, i); 704 } 705 706 /* Collect all the descriptors */ 707 do { 708 bool map_ok; 709 710 if (desc.flags & VRING_DESC_F_WRITE) { 711 map_ok = virtqueue_map_desc(vdev, &in_num, addr + out_num, 712 iov + out_num, 713 VIRTQUEUE_MAX_SIZE - out_num, true, 714 desc.addr, desc.len); 715 } else { 716 if (in_num) { 717 virtio_error(vdev, "Incorrect order for descriptors"); 718 goto err_undo_map; 719 } 720 map_ok = virtqueue_map_desc(vdev, &out_num, addr, iov, 721 VIRTQUEUE_MAX_SIZE, false, 722 desc.addr, desc.len); 723 } 724 if (!map_ok) { 725 goto err_undo_map; 726 } 727 728 /* If we've got too many, that implies a descriptor loop. */ 729 if ((in_num + out_num) > max) { 730 virtio_error(vdev, "Looped descriptor"); 731 goto err_undo_map; 732 } 733 734 rc = virtqueue_read_next_desc(vdev, &desc, desc_pa, max, &i); 735 } while (rc == VIRTQUEUE_READ_DESC_MORE); 736 737 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 738 goto err_undo_map; 739 } 740 741 /* Now copy what we have collected and mapped */ 742 elem = virtqueue_alloc_element(sz, out_num, in_num); 743 elem->index = head; 744 for (i = 0; i < out_num; i++) { 745 elem->out_addr[i] = addr[i]; 746 elem->out_sg[i] = iov[i]; 747 } 748 for (i = 0; i < in_num; i++) { 749 elem->in_addr[i] = addr[out_num + i]; 750 elem->in_sg[i] = iov[out_num + i]; 751 } 752 753 vq->inuse++; 754 755 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); 756 return elem; 757 758 err_undo_map: 759 virtqueue_undo_map_desc(out_num, in_num, iov); 760 return NULL; 761 } 762 763 /* virtqueue_drop_all: 764 * @vq: The #VirtQueue 765 * Drops all queued buffers and indicates them to the guest 766 * as if they are done. Useful when buffers can not be 767 * processed but must be returned to the guest. 768 */ 769 unsigned int virtqueue_drop_all(VirtQueue *vq) 770 { 771 unsigned int dropped = 0; 772 VirtQueueElement elem = {}; 773 VirtIODevice *vdev = vq->vdev; 774 bool fEventIdx = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); 775 776 if (unlikely(vdev->broken)) { 777 return 0; 778 } 779 780 while (!virtio_queue_empty(vq) && vq->inuse < vq->vring.num) { 781 /* works similar to virtqueue_pop but does not map buffers 782 * and does not allocate any memory */ 783 smp_rmb(); 784 if (!virtqueue_get_head(vq, vq->last_avail_idx, &elem.index)) { 785 break; 786 } 787 vq->inuse++; 788 vq->last_avail_idx++; 789 if (fEventIdx) { 790 vring_set_avail_event(vq, vq->last_avail_idx); 791 } 792 /* immediately push the element, nothing to unmap 793 * as both in_num and out_num are set to 0 */ 794 virtqueue_push(vq, &elem, 0); 795 dropped++; 796 } 797 798 return dropped; 799 } 800 801 /* Reading and writing a structure directly to QEMUFile is *awful*, but 802 * it is what QEMU has always done by mistake. We can change it sooner 803 * or later by bumping the version number of the affected vm states. 804 * In the meanwhile, since the in-memory layout of VirtQueueElement 805 * has changed, we need to marshal to and from the layout that was 806 * used before the change. 807 */ 808 typedef struct VirtQueueElementOld { 809 unsigned int index; 810 unsigned int out_num; 811 unsigned int in_num; 812 hwaddr in_addr[VIRTQUEUE_MAX_SIZE]; 813 hwaddr out_addr[VIRTQUEUE_MAX_SIZE]; 814 struct iovec in_sg[VIRTQUEUE_MAX_SIZE]; 815 struct iovec out_sg[VIRTQUEUE_MAX_SIZE]; 816 } VirtQueueElementOld; 817 818 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz) 819 { 820 VirtQueueElement *elem; 821 VirtQueueElementOld data; 822 int i; 823 824 qemu_get_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 825 826 /* TODO: teach all callers that this can fail, and return failure instead 827 * of asserting here. 828 * When we do, we might be able to re-enable NDEBUG below. 829 */ 830 #ifdef NDEBUG 831 #error building with NDEBUG is not supported 832 #endif 833 assert(ARRAY_SIZE(data.in_addr) >= data.in_num); 834 assert(ARRAY_SIZE(data.out_addr) >= data.out_num); 835 836 elem = virtqueue_alloc_element(sz, data.out_num, data.in_num); 837 elem->index = data.index; 838 839 for (i = 0; i < elem->in_num; i++) { 840 elem->in_addr[i] = data.in_addr[i]; 841 } 842 843 for (i = 0; i < elem->out_num; i++) { 844 elem->out_addr[i] = data.out_addr[i]; 845 } 846 847 for (i = 0; i < elem->in_num; i++) { 848 /* Base is overwritten by virtqueue_map. */ 849 elem->in_sg[i].iov_base = 0; 850 elem->in_sg[i].iov_len = data.in_sg[i].iov_len; 851 } 852 853 for (i = 0; i < elem->out_num; i++) { 854 /* Base is overwritten by virtqueue_map. */ 855 elem->out_sg[i].iov_base = 0; 856 elem->out_sg[i].iov_len = data.out_sg[i].iov_len; 857 } 858 859 virtqueue_map(vdev, elem); 860 return elem; 861 } 862 863 void qemu_put_virtqueue_element(QEMUFile *f, VirtQueueElement *elem) 864 { 865 VirtQueueElementOld data; 866 int i; 867 868 memset(&data, 0, sizeof(data)); 869 data.index = elem->index; 870 data.in_num = elem->in_num; 871 data.out_num = elem->out_num; 872 873 for (i = 0; i < elem->in_num; i++) { 874 data.in_addr[i] = elem->in_addr[i]; 875 } 876 877 for (i = 0; i < elem->out_num; i++) { 878 data.out_addr[i] = elem->out_addr[i]; 879 } 880 881 for (i = 0; i < elem->in_num; i++) { 882 /* Base is overwritten by virtqueue_map when loading. Do not 883 * save it, as it would leak the QEMU address space layout. */ 884 data.in_sg[i].iov_len = elem->in_sg[i].iov_len; 885 } 886 887 for (i = 0; i < elem->out_num; i++) { 888 /* Do not save iov_base as above. */ 889 data.out_sg[i].iov_len = elem->out_sg[i].iov_len; 890 } 891 qemu_put_buffer(f, (uint8_t *)&data, sizeof(VirtQueueElementOld)); 892 } 893 894 /* virtio device */ 895 static void virtio_notify_vector(VirtIODevice *vdev, uint16_t vector) 896 { 897 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 898 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 899 900 if (unlikely(vdev->broken)) { 901 return; 902 } 903 904 if (k->notify) { 905 k->notify(qbus->parent, vector); 906 } 907 } 908 909 void virtio_update_irq(VirtIODevice *vdev) 910 { 911 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 912 } 913 914 static int virtio_validate_features(VirtIODevice *vdev) 915 { 916 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 917 918 if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM) && 919 !virtio_vdev_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) { 920 return -EFAULT; 921 } 922 923 if (k->validate_features) { 924 return k->validate_features(vdev); 925 } else { 926 return 0; 927 } 928 } 929 930 int virtio_set_status(VirtIODevice *vdev, uint8_t val) 931 { 932 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 933 trace_virtio_set_status(vdev, val); 934 935 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 936 if (!(vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) && 937 val & VIRTIO_CONFIG_S_FEATURES_OK) { 938 int ret = virtio_validate_features(vdev); 939 940 if (ret) { 941 return ret; 942 } 943 } 944 } 945 if (k->set_status) { 946 k->set_status(vdev, val); 947 } 948 vdev->status = val; 949 return 0; 950 } 951 952 bool target_words_bigendian(void); 953 static enum virtio_device_endian virtio_default_endian(void) 954 { 955 if (target_words_bigendian()) { 956 return VIRTIO_DEVICE_ENDIAN_BIG; 957 } else { 958 return VIRTIO_DEVICE_ENDIAN_LITTLE; 959 } 960 } 961 962 static enum virtio_device_endian virtio_current_cpu_endian(void) 963 { 964 CPUClass *cc = CPU_GET_CLASS(current_cpu); 965 966 if (cc->virtio_is_big_endian(current_cpu)) { 967 return VIRTIO_DEVICE_ENDIAN_BIG; 968 } else { 969 return VIRTIO_DEVICE_ENDIAN_LITTLE; 970 } 971 } 972 973 void virtio_reset(void *opaque) 974 { 975 VirtIODevice *vdev = opaque; 976 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 977 int i; 978 979 virtio_set_status(vdev, 0); 980 if (current_cpu) { 981 /* Guest initiated reset */ 982 vdev->device_endian = virtio_current_cpu_endian(); 983 } else { 984 /* System reset */ 985 vdev->device_endian = virtio_default_endian(); 986 } 987 988 if (k->reset) { 989 k->reset(vdev); 990 } 991 992 vdev->broken = false; 993 vdev->guest_features = 0; 994 vdev->queue_sel = 0; 995 vdev->status = 0; 996 atomic_set(&vdev->isr, 0); 997 vdev->config_vector = VIRTIO_NO_VECTOR; 998 virtio_notify_vector(vdev, vdev->config_vector); 999 1000 for(i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1001 vdev->vq[i].vring.desc = 0; 1002 vdev->vq[i].vring.avail = 0; 1003 vdev->vq[i].vring.used = 0; 1004 vdev->vq[i].last_avail_idx = 0; 1005 vdev->vq[i].shadow_avail_idx = 0; 1006 vdev->vq[i].used_idx = 0; 1007 virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR); 1008 vdev->vq[i].signalled_used = 0; 1009 vdev->vq[i].signalled_used_valid = false; 1010 vdev->vq[i].notification = true; 1011 vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; 1012 vdev->vq[i].inuse = 0; 1013 } 1014 } 1015 1016 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr) 1017 { 1018 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1019 uint8_t val; 1020 1021 if (addr + sizeof(val) > vdev->config_len) { 1022 return (uint32_t)-1; 1023 } 1024 1025 k->get_config(vdev, vdev->config); 1026 1027 val = ldub_p(vdev->config + addr); 1028 return val; 1029 } 1030 1031 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) 1032 { 1033 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1034 uint16_t val; 1035 1036 if (addr + sizeof(val) > vdev->config_len) { 1037 return (uint32_t)-1; 1038 } 1039 1040 k->get_config(vdev, vdev->config); 1041 1042 val = lduw_p(vdev->config + addr); 1043 return val; 1044 } 1045 1046 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr) 1047 { 1048 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1049 uint32_t val; 1050 1051 if (addr + sizeof(val) > vdev->config_len) { 1052 return (uint32_t)-1; 1053 } 1054 1055 k->get_config(vdev, vdev->config); 1056 1057 val = ldl_p(vdev->config + addr); 1058 return val; 1059 } 1060 1061 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1062 { 1063 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1064 uint8_t val = data; 1065 1066 if (addr + sizeof(val) > vdev->config_len) { 1067 return; 1068 } 1069 1070 stb_p(vdev->config + addr, val); 1071 1072 if (k->set_config) { 1073 k->set_config(vdev, vdev->config); 1074 } 1075 } 1076 1077 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1078 { 1079 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1080 uint16_t val = data; 1081 1082 if (addr + sizeof(val) > vdev->config_len) { 1083 return; 1084 } 1085 1086 stw_p(vdev->config + addr, val); 1087 1088 if (k->set_config) { 1089 k->set_config(vdev, vdev->config); 1090 } 1091 } 1092 1093 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data) 1094 { 1095 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1096 uint32_t val = data; 1097 1098 if (addr + sizeof(val) > vdev->config_len) { 1099 return; 1100 } 1101 1102 stl_p(vdev->config + addr, val); 1103 1104 if (k->set_config) { 1105 k->set_config(vdev, vdev->config); 1106 } 1107 } 1108 1109 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr) 1110 { 1111 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1112 uint8_t val; 1113 1114 if (addr + sizeof(val) > vdev->config_len) { 1115 return (uint32_t)-1; 1116 } 1117 1118 k->get_config(vdev, vdev->config); 1119 1120 val = ldub_p(vdev->config + addr); 1121 return val; 1122 } 1123 1124 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr) 1125 { 1126 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1127 uint16_t val; 1128 1129 if (addr + sizeof(val) > vdev->config_len) { 1130 return (uint32_t)-1; 1131 } 1132 1133 k->get_config(vdev, vdev->config); 1134 1135 val = lduw_le_p(vdev->config + addr); 1136 return val; 1137 } 1138 1139 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr) 1140 { 1141 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1142 uint32_t val; 1143 1144 if (addr + sizeof(val) > vdev->config_len) { 1145 return (uint32_t)-1; 1146 } 1147 1148 k->get_config(vdev, vdev->config); 1149 1150 val = ldl_le_p(vdev->config + addr); 1151 return val; 1152 } 1153 1154 void virtio_config_modern_writeb(VirtIODevice *vdev, 1155 uint32_t addr, uint32_t data) 1156 { 1157 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1158 uint8_t val = data; 1159 1160 if (addr + sizeof(val) > vdev->config_len) { 1161 return; 1162 } 1163 1164 stb_p(vdev->config + addr, val); 1165 1166 if (k->set_config) { 1167 k->set_config(vdev, vdev->config); 1168 } 1169 } 1170 1171 void virtio_config_modern_writew(VirtIODevice *vdev, 1172 uint32_t addr, uint32_t data) 1173 { 1174 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1175 uint16_t val = data; 1176 1177 if (addr + sizeof(val) > vdev->config_len) { 1178 return; 1179 } 1180 1181 stw_le_p(vdev->config + addr, val); 1182 1183 if (k->set_config) { 1184 k->set_config(vdev, vdev->config); 1185 } 1186 } 1187 1188 void virtio_config_modern_writel(VirtIODevice *vdev, 1189 uint32_t addr, uint32_t data) 1190 { 1191 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1192 uint32_t val = data; 1193 1194 if (addr + sizeof(val) > vdev->config_len) { 1195 return; 1196 } 1197 1198 stl_le_p(vdev->config + addr, val); 1199 1200 if (k->set_config) { 1201 k->set_config(vdev, vdev->config); 1202 } 1203 } 1204 1205 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) 1206 { 1207 vdev->vq[n].vring.desc = addr; 1208 virtio_queue_update_rings(vdev, n); 1209 } 1210 1211 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 1212 { 1213 return vdev->vq[n].vring.desc; 1214 } 1215 1216 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 1217 hwaddr avail, hwaddr used) 1218 { 1219 vdev->vq[n].vring.desc = desc; 1220 vdev->vq[n].vring.avail = avail; 1221 vdev->vq[n].vring.used = used; 1222 } 1223 1224 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) 1225 { 1226 /* Don't allow guest to flip queue between existent and 1227 * nonexistent states, or to set it to an invalid size. 1228 */ 1229 if (!!num != !!vdev->vq[n].vring.num || 1230 num > VIRTQUEUE_MAX_SIZE || 1231 num < 0) { 1232 return; 1233 } 1234 vdev->vq[n].vring.num = num; 1235 } 1236 1237 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector) 1238 { 1239 return QLIST_FIRST(&vdev->vector_queues[vector]); 1240 } 1241 1242 VirtQueue *virtio_vector_next_queue(VirtQueue *vq) 1243 { 1244 return QLIST_NEXT(vq, node); 1245 } 1246 1247 int virtio_queue_get_num(VirtIODevice *vdev, int n) 1248 { 1249 return vdev->vq[n].vring.num; 1250 } 1251 1252 int virtio_queue_get_max_num(VirtIODevice *vdev, int n) 1253 { 1254 return vdev->vq[n].vring.num_default; 1255 } 1256 1257 int virtio_get_num_queues(VirtIODevice *vdev) 1258 { 1259 int i; 1260 1261 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1262 if (!virtio_queue_get_num(vdev, i)) { 1263 break; 1264 } 1265 } 1266 1267 return i; 1268 } 1269 1270 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 1271 { 1272 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1273 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1274 1275 /* virtio-1 compliant devices cannot change the alignment */ 1276 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1277 error_report("tried to modify queue alignment for virtio-1 device"); 1278 return; 1279 } 1280 /* Check that the transport told us it was going to do this 1281 * (so a buggy transport will immediately assert rather than 1282 * silently failing to migrate this state) 1283 */ 1284 assert(k->has_variable_vring_alignment); 1285 1286 vdev->vq[n].vring.align = align; 1287 virtio_queue_update_rings(vdev, n); 1288 } 1289 1290 static void virtio_queue_notify_aio_vq(VirtQueue *vq) 1291 { 1292 if (vq->vring.desc && vq->handle_aio_output) { 1293 VirtIODevice *vdev = vq->vdev; 1294 1295 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1296 vq->handle_aio_output(vdev, vq); 1297 } 1298 } 1299 1300 static void virtio_queue_notify_vq(VirtQueue *vq) 1301 { 1302 if (vq->vring.desc && vq->handle_output) { 1303 VirtIODevice *vdev = vq->vdev; 1304 1305 if (unlikely(vdev->broken)) { 1306 return; 1307 } 1308 1309 trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); 1310 vq->handle_output(vdev, vq); 1311 } 1312 } 1313 1314 void virtio_queue_notify(VirtIODevice *vdev, int n) 1315 { 1316 virtio_queue_notify_vq(&vdev->vq[n]); 1317 } 1318 1319 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) 1320 { 1321 return n < VIRTIO_QUEUE_MAX ? vdev->vq[n].vector : 1322 VIRTIO_NO_VECTOR; 1323 } 1324 1325 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector) 1326 { 1327 VirtQueue *vq = &vdev->vq[n]; 1328 1329 if (n < VIRTIO_QUEUE_MAX) { 1330 if (vdev->vector_queues && 1331 vdev->vq[n].vector != VIRTIO_NO_VECTOR) { 1332 QLIST_REMOVE(vq, node); 1333 } 1334 vdev->vq[n].vector = vector; 1335 if (vdev->vector_queues && 1336 vector != VIRTIO_NO_VECTOR) { 1337 QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node); 1338 } 1339 } 1340 } 1341 1342 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 1343 VirtIOHandleOutput handle_output) 1344 { 1345 int i; 1346 1347 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1348 if (vdev->vq[i].vring.num == 0) 1349 break; 1350 } 1351 1352 if (i == VIRTIO_QUEUE_MAX || queue_size > VIRTQUEUE_MAX_SIZE) 1353 abort(); 1354 1355 vdev->vq[i].vring.num = queue_size; 1356 vdev->vq[i].vring.num_default = queue_size; 1357 vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; 1358 vdev->vq[i].handle_output = handle_output; 1359 vdev->vq[i].handle_aio_output = NULL; 1360 1361 return &vdev->vq[i]; 1362 } 1363 1364 void virtio_del_queue(VirtIODevice *vdev, int n) 1365 { 1366 if (n < 0 || n >= VIRTIO_QUEUE_MAX) { 1367 abort(); 1368 } 1369 1370 vdev->vq[n].vring.num = 0; 1371 vdev->vq[n].vring.num_default = 0; 1372 } 1373 1374 static void virtio_set_isr(VirtIODevice *vdev, int value) 1375 { 1376 uint8_t old = atomic_read(&vdev->isr); 1377 1378 /* Do not write ISR if it does not change, so that its cacheline remains 1379 * shared in the common case where the guest does not read it. 1380 */ 1381 if ((old & value) != value) { 1382 atomic_or(&vdev->isr, value); 1383 } 1384 } 1385 1386 bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 1387 { 1388 uint16_t old, new; 1389 bool v; 1390 /* We need to expose used array entries before checking used event. */ 1391 smp_mb(); 1392 /* Always notify when queue is empty (when feature acknowledge) */ 1393 if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) && 1394 !vq->inuse && virtio_queue_empty(vq)) { 1395 return true; 1396 } 1397 1398 if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { 1399 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 1400 } 1401 1402 v = vq->signalled_used_valid; 1403 vq->signalled_used_valid = true; 1404 old = vq->signalled_used; 1405 new = vq->signalled_used = vq->used_idx; 1406 return !v || vring_need_event(vring_get_used_event(vq), new, old); 1407 } 1408 1409 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq) 1410 { 1411 if (!virtio_should_notify(vdev, vq)) { 1412 return; 1413 } 1414 1415 trace_virtio_notify_irqfd(vdev, vq); 1416 1417 /* 1418 * virtio spec 1.0 says ISR bit 0 should be ignored with MSI, but 1419 * windows drivers included in virtio-win 1.8.0 (circa 2015) are 1420 * incorrectly polling this bit during crashdump and hibernation 1421 * in MSI mode, causing a hang if this bit is never updated. 1422 * Recent releases of Windows do not really shut down, but rather 1423 * log out and hibernate to make the next startup faster. Hence, 1424 * this manifested as a more serious hang during shutdown with 1425 * 1426 * Next driver release from 2016 fixed this problem, so working around it 1427 * is not a must, but it's easy to do so let's do it here. 1428 * 1429 * Note: it's safe to update ISR from any thread as it was switched 1430 * to an atomic operation. 1431 */ 1432 virtio_set_isr(vq->vdev, 0x1); 1433 event_notifier_set(&vq->guest_notifier); 1434 } 1435 1436 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) 1437 { 1438 if (!virtio_should_notify(vdev, vq)) { 1439 return; 1440 } 1441 1442 trace_virtio_notify(vdev, vq); 1443 virtio_set_isr(vq->vdev, 0x1); 1444 virtio_notify_vector(vdev, vq->vector); 1445 } 1446 1447 void virtio_notify_config(VirtIODevice *vdev) 1448 { 1449 if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) 1450 return; 1451 1452 virtio_set_isr(vdev, 0x3); 1453 vdev->generation++; 1454 virtio_notify_vector(vdev, vdev->config_vector); 1455 } 1456 1457 static bool virtio_device_endian_needed(void *opaque) 1458 { 1459 VirtIODevice *vdev = opaque; 1460 1461 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 1462 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 1463 return vdev->device_endian != virtio_default_endian(); 1464 } 1465 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 1466 return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; 1467 } 1468 1469 static bool virtio_64bit_features_needed(void *opaque) 1470 { 1471 VirtIODevice *vdev = opaque; 1472 1473 return (vdev->host_features >> 32) != 0; 1474 } 1475 1476 static bool virtio_virtqueue_needed(void *opaque) 1477 { 1478 VirtIODevice *vdev = opaque; 1479 1480 return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); 1481 } 1482 1483 static bool virtio_ringsize_needed(void *opaque) 1484 { 1485 VirtIODevice *vdev = opaque; 1486 int i; 1487 1488 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1489 if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { 1490 return true; 1491 } 1492 } 1493 return false; 1494 } 1495 1496 static bool virtio_extra_state_needed(void *opaque) 1497 { 1498 VirtIODevice *vdev = opaque; 1499 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1500 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1501 1502 return k->has_extra_state && 1503 k->has_extra_state(qbus->parent); 1504 } 1505 1506 static bool virtio_broken_needed(void *opaque) 1507 { 1508 VirtIODevice *vdev = opaque; 1509 1510 return vdev->broken; 1511 } 1512 1513 static const VMStateDescription vmstate_virtqueue = { 1514 .name = "virtqueue_state", 1515 .version_id = 1, 1516 .minimum_version_id = 1, 1517 .fields = (VMStateField[]) { 1518 VMSTATE_UINT64(vring.avail, struct VirtQueue), 1519 VMSTATE_UINT64(vring.used, struct VirtQueue), 1520 VMSTATE_END_OF_LIST() 1521 } 1522 }; 1523 1524 static const VMStateDescription vmstate_virtio_virtqueues = { 1525 .name = "virtio/virtqueues", 1526 .version_id = 1, 1527 .minimum_version_id = 1, 1528 .needed = &virtio_virtqueue_needed, 1529 .fields = (VMStateField[]) { 1530 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1531 VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), 1532 VMSTATE_END_OF_LIST() 1533 } 1534 }; 1535 1536 static const VMStateDescription vmstate_ringsize = { 1537 .name = "ringsize_state", 1538 .version_id = 1, 1539 .minimum_version_id = 1, 1540 .fields = (VMStateField[]) { 1541 VMSTATE_UINT32(vring.num_default, struct VirtQueue), 1542 VMSTATE_END_OF_LIST() 1543 } 1544 }; 1545 1546 static const VMStateDescription vmstate_virtio_ringsize = { 1547 .name = "virtio/ringsize", 1548 .version_id = 1, 1549 .minimum_version_id = 1, 1550 .needed = &virtio_ringsize_needed, 1551 .fields = (VMStateField[]) { 1552 VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, 1553 VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), 1554 VMSTATE_END_OF_LIST() 1555 } 1556 }; 1557 1558 static int get_extra_state(QEMUFile *f, void *pv, size_t size, 1559 VMStateField *field) 1560 { 1561 VirtIODevice *vdev = pv; 1562 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1563 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1564 1565 if (!k->load_extra_state) { 1566 return -1; 1567 } else { 1568 return k->load_extra_state(qbus->parent, f); 1569 } 1570 } 1571 1572 static int put_extra_state(QEMUFile *f, void *pv, size_t size, 1573 VMStateField *field, QJSON *vmdesc) 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 return 0; 1581 } 1582 1583 static const VMStateInfo vmstate_info_extra_state = { 1584 .name = "virtqueue_extra_state", 1585 .get = get_extra_state, 1586 .put = put_extra_state, 1587 }; 1588 1589 static const VMStateDescription vmstate_virtio_extra_state = { 1590 .name = "virtio/extra_state", 1591 .version_id = 1, 1592 .minimum_version_id = 1, 1593 .needed = &virtio_extra_state_needed, 1594 .fields = (VMStateField[]) { 1595 { 1596 .name = "extra_state", 1597 .version_id = 0, 1598 .field_exists = NULL, 1599 .size = 0, 1600 .info = &vmstate_info_extra_state, 1601 .flags = VMS_SINGLE, 1602 .offset = 0, 1603 }, 1604 VMSTATE_END_OF_LIST() 1605 } 1606 }; 1607 1608 static const VMStateDescription vmstate_virtio_device_endian = { 1609 .name = "virtio/device_endian", 1610 .version_id = 1, 1611 .minimum_version_id = 1, 1612 .needed = &virtio_device_endian_needed, 1613 .fields = (VMStateField[]) { 1614 VMSTATE_UINT8(device_endian, VirtIODevice), 1615 VMSTATE_END_OF_LIST() 1616 } 1617 }; 1618 1619 static const VMStateDescription vmstate_virtio_64bit_features = { 1620 .name = "virtio/64bit_features", 1621 .version_id = 1, 1622 .minimum_version_id = 1, 1623 .needed = &virtio_64bit_features_needed, 1624 .fields = (VMStateField[]) { 1625 VMSTATE_UINT64(guest_features, VirtIODevice), 1626 VMSTATE_END_OF_LIST() 1627 } 1628 }; 1629 1630 static const VMStateDescription vmstate_virtio_broken = { 1631 .name = "virtio/broken", 1632 .version_id = 1, 1633 .minimum_version_id = 1, 1634 .needed = &virtio_broken_needed, 1635 .fields = (VMStateField[]) { 1636 VMSTATE_BOOL(broken, VirtIODevice), 1637 VMSTATE_END_OF_LIST() 1638 } 1639 }; 1640 1641 static const VMStateDescription vmstate_virtio = { 1642 .name = "virtio", 1643 .version_id = 1, 1644 .minimum_version_id = 1, 1645 .minimum_version_id_old = 1, 1646 .fields = (VMStateField[]) { 1647 VMSTATE_END_OF_LIST() 1648 }, 1649 .subsections = (const VMStateDescription*[]) { 1650 &vmstate_virtio_device_endian, 1651 &vmstate_virtio_64bit_features, 1652 &vmstate_virtio_virtqueues, 1653 &vmstate_virtio_ringsize, 1654 &vmstate_virtio_broken, 1655 &vmstate_virtio_extra_state, 1656 NULL 1657 } 1658 }; 1659 1660 void virtio_save(VirtIODevice *vdev, QEMUFile *f) 1661 { 1662 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1663 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1664 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1665 uint32_t guest_features_lo = (vdev->guest_features & 0xffffffff); 1666 int i; 1667 1668 if (k->save_config) { 1669 k->save_config(qbus->parent, f); 1670 } 1671 1672 qemu_put_8s(f, &vdev->status); 1673 qemu_put_8s(f, &vdev->isr); 1674 qemu_put_be16s(f, &vdev->queue_sel); 1675 qemu_put_be32s(f, &guest_features_lo); 1676 qemu_put_be32(f, vdev->config_len); 1677 qemu_put_buffer(f, vdev->config, vdev->config_len); 1678 1679 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1680 if (vdev->vq[i].vring.num == 0) 1681 break; 1682 } 1683 1684 qemu_put_be32(f, i); 1685 1686 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1687 if (vdev->vq[i].vring.num == 0) 1688 break; 1689 1690 qemu_put_be32(f, vdev->vq[i].vring.num); 1691 if (k->has_variable_vring_alignment) { 1692 qemu_put_be32(f, vdev->vq[i].vring.align); 1693 } 1694 /* XXX virtio-1 devices */ 1695 qemu_put_be64(f, vdev->vq[i].vring.desc); 1696 qemu_put_be16s(f, &vdev->vq[i].last_avail_idx); 1697 if (k->save_queue) { 1698 k->save_queue(qbus->parent, i, f); 1699 } 1700 } 1701 1702 if (vdc->save != NULL) { 1703 vdc->save(vdev, f); 1704 } 1705 1706 if (vdc->vmsd) { 1707 vmstate_save_state(f, vdc->vmsd, vdev, NULL); 1708 } 1709 1710 /* Subsections */ 1711 vmstate_save_state(f, &vmstate_virtio, vdev, NULL); 1712 } 1713 1714 /* A wrapper for use as a VMState .put function */ 1715 static int virtio_device_put(QEMUFile *f, void *opaque, size_t size, 1716 VMStateField *field, QJSON *vmdesc) 1717 { 1718 virtio_save(VIRTIO_DEVICE(opaque), f); 1719 1720 return 0; 1721 } 1722 1723 /* A wrapper for use as a VMState .get function */ 1724 static int virtio_device_get(QEMUFile *f, void *opaque, size_t size, 1725 VMStateField *field) 1726 { 1727 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1728 DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); 1729 1730 return virtio_load(vdev, f, dc->vmsd->version_id); 1731 } 1732 1733 const VMStateInfo virtio_vmstate_info = { 1734 .name = "virtio", 1735 .get = virtio_device_get, 1736 .put = virtio_device_put, 1737 }; 1738 1739 static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) 1740 { 1741 VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); 1742 bool bad = (val & ~(vdev->host_features)) != 0; 1743 1744 val &= vdev->host_features; 1745 if (k->set_features) { 1746 k->set_features(vdev, val); 1747 } 1748 vdev->guest_features = val; 1749 return bad ? -1 : 0; 1750 } 1751 1752 int virtio_set_features(VirtIODevice *vdev, uint64_t val) 1753 { 1754 /* 1755 * The driver must not attempt to set features after feature negotiation 1756 * has finished. 1757 */ 1758 if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) { 1759 return -EINVAL; 1760 } 1761 return virtio_set_features_nocheck(vdev, val); 1762 } 1763 1764 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 1765 { 1766 int i, ret; 1767 int32_t config_len; 1768 uint32_t num; 1769 uint32_t features; 1770 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1771 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1772 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); 1773 1774 /* 1775 * We poison the endianness to ensure it does not get used before 1776 * subsections have been loaded. 1777 */ 1778 vdev->device_endian = VIRTIO_DEVICE_ENDIAN_UNKNOWN; 1779 1780 if (k->load_config) { 1781 ret = k->load_config(qbus->parent, f); 1782 if (ret) 1783 return ret; 1784 } 1785 1786 qemu_get_8s(f, &vdev->status); 1787 qemu_get_8s(f, &vdev->isr); 1788 qemu_get_be16s(f, &vdev->queue_sel); 1789 if (vdev->queue_sel >= VIRTIO_QUEUE_MAX) { 1790 return -1; 1791 } 1792 qemu_get_be32s(f, &features); 1793 1794 /* 1795 * Temporarily set guest_features low bits - needed by 1796 * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 1797 * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. 1798 * 1799 * Note: devices should always test host features in future - don't create 1800 * new dependencies like this. 1801 */ 1802 vdev->guest_features = features; 1803 1804 config_len = qemu_get_be32(f); 1805 1806 /* 1807 * There are cases where the incoming config can be bigger or smaller 1808 * than what we have; so load what we have space for, and skip 1809 * any excess that's in the stream. 1810 */ 1811 qemu_get_buffer(f, vdev->config, MIN(config_len, vdev->config_len)); 1812 1813 while (config_len > vdev->config_len) { 1814 qemu_get_byte(f); 1815 config_len--; 1816 } 1817 1818 num = qemu_get_be32(f); 1819 1820 if (num > VIRTIO_QUEUE_MAX) { 1821 error_report("Invalid number of virtqueues: 0x%x", num); 1822 return -1; 1823 } 1824 1825 for (i = 0; i < num; i++) { 1826 vdev->vq[i].vring.num = qemu_get_be32(f); 1827 if (k->has_variable_vring_alignment) { 1828 vdev->vq[i].vring.align = qemu_get_be32(f); 1829 } 1830 vdev->vq[i].vring.desc = qemu_get_be64(f); 1831 qemu_get_be16s(f, &vdev->vq[i].last_avail_idx); 1832 vdev->vq[i].signalled_used_valid = false; 1833 vdev->vq[i].notification = true; 1834 1835 if (vdev->vq[i].vring.desc) { 1836 /* XXX virtio-1 devices */ 1837 virtio_queue_update_rings(vdev, i); 1838 } else if (vdev->vq[i].last_avail_idx) { 1839 error_report("VQ %d address 0x0 " 1840 "inconsistent with Host index 0x%x", 1841 i, vdev->vq[i].last_avail_idx); 1842 return -1; 1843 } 1844 if (k->load_queue) { 1845 ret = k->load_queue(qbus->parent, i, f); 1846 if (ret) 1847 return ret; 1848 } 1849 } 1850 1851 virtio_notify_vector(vdev, VIRTIO_NO_VECTOR); 1852 1853 if (vdc->load != NULL) { 1854 ret = vdc->load(vdev, f, version_id); 1855 if (ret) { 1856 return ret; 1857 } 1858 } 1859 1860 if (vdc->vmsd) { 1861 ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); 1862 if (ret) { 1863 return ret; 1864 } 1865 } 1866 1867 /* Subsections */ 1868 ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); 1869 if (ret) { 1870 return ret; 1871 } 1872 1873 if (vdev->device_endian == VIRTIO_DEVICE_ENDIAN_UNKNOWN) { 1874 vdev->device_endian = virtio_default_endian(); 1875 } 1876 1877 if (virtio_64bit_features_needed(vdev)) { 1878 /* 1879 * Subsection load filled vdev->guest_features. Run them 1880 * through virtio_set_features to sanity-check them against 1881 * host_features. 1882 */ 1883 uint64_t features64 = vdev->guest_features; 1884 if (virtio_set_features_nocheck(vdev, features64) < 0) { 1885 error_report("Features 0x%" PRIx64 " unsupported. " 1886 "Allowed features: 0x%" PRIx64, 1887 features64, vdev->host_features); 1888 return -1; 1889 } 1890 } else { 1891 if (virtio_set_features_nocheck(vdev, features) < 0) { 1892 error_report("Features 0x%x unsupported. " 1893 "Allowed features: 0x%" PRIx64, 1894 features, vdev->host_features); 1895 return -1; 1896 } 1897 } 1898 1899 for (i = 0; i < num; i++) { 1900 if (vdev->vq[i].vring.desc) { 1901 uint16_t nheads; 1902 nheads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx; 1903 /* Check it isn't doing strange things with descriptor numbers. */ 1904 if (nheads > vdev->vq[i].vring.num) { 1905 error_report("VQ %d size 0x%x Guest index 0x%x " 1906 "inconsistent with Host index 0x%x: delta 0x%x", 1907 i, vdev->vq[i].vring.num, 1908 vring_avail_idx(&vdev->vq[i]), 1909 vdev->vq[i].last_avail_idx, nheads); 1910 return -1; 1911 } 1912 vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); 1913 vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); 1914 1915 /* 1916 * Some devices migrate VirtQueueElements that have been popped 1917 * from the avail ring but not yet returned to the used ring. 1918 * Since max ring size < UINT16_MAX it's safe to use modulo 1919 * UINT16_MAX + 1 subtraction. 1920 */ 1921 vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - 1922 vdev->vq[i].used_idx); 1923 if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { 1924 error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " 1925 "used_idx 0x%x", 1926 i, vdev->vq[i].vring.num, 1927 vdev->vq[i].last_avail_idx, 1928 vdev->vq[i].used_idx); 1929 return -1; 1930 } 1931 } 1932 } 1933 1934 return 0; 1935 } 1936 1937 void virtio_cleanup(VirtIODevice *vdev) 1938 { 1939 qemu_del_vm_change_state_handler(vdev->vmstate); 1940 g_free(vdev->config); 1941 g_free(vdev->vq); 1942 g_free(vdev->vector_queues); 1943 } 1944 1945 static void virtio_vmstate_change(void *opaque, int running, RunState state) 1946 { 1947 VirtIODevice *vdev = opaque; 1948 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1949 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1950 bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK); 1951 vdev->vm_running = running; 1952 1953 if (backend_run) { 1954 virtio_set_status(vdev, vdev->status); 1955 } 1956 1957 if (k->vmstate_change) { 1958 k->vmstate_change(qbus->parent, backend_run); 1959 } 1960 1961 if (!backend_run) { 1962 virtio_set_status(vdev, vdev->status); 1963 } 1964 } 1965 1966 void virtio_instance_init_common(Object *proxy_obj, void *data, 1967 size_t vdev_size, const char *vdev_name) 1968 { 1969 DeviceState *vdev = data; 1970 1971 object_initialize(vdev, vdev_size, vdev_name); 1972 object_property_add_child(proxy_obj, "virtio-backend", OBJECT(vdev), NULL); 1973 object_unref(OBJECT(vdev)); 1974 qdev_alias_all_properties(vdev, proxy_obj); 1975 } 1976 1977 void virtio_init(VirtIODevice *vdev, const char *name, 1978 uint16_t device_id, size_t config_size) 1979 { 1980 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 1981 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 1982 int i; 1983 int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0; 1984 1985 if (nvectors) { 1986 vdev->vector_queues = 1987 g_malloc0(sizeof(*vdev->vector_queues) * nvectors); 1988 } 1989 1990 vdev->device_id = device_id; 1991 vdev->status = 0; 1992 atomic_set(&vdev->isr, 0); 1993 vdev->queue_sel = 0; 1994 vdev->config_vector = VIRTIO_NO_VECTOR; 1995 vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_QUEUE_MAX); 1996 vdev->vm_running = runstate_is_running(); 1997 vdev->broken = false; 1998 for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { 1999 vdev->vq[i].vector = VIRTIO_NO_VECTOR; 2000 vdev->vq[i].vdev = vdev; 2001 vdev->vq[i].queue_index = i; 2002 } 2003 2004 vdev->name = name; 2005 vdev->config_len = config_size; 2006 if (vdev->config_len) { 2007 vdev->config = g_malloc0(config_size); 2008 } else { 2009 vdev->config = NULL; 2010 } 2011 vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, 2012 vdev); 2013 vdev->device_endian = virtio_default_endian(); 2014 vdev->use_guest_notifier_mask = true; 2015 } 2016 2017 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) 2018 { 2019 return vdev->vq[n].vring.desc; 2020 } 2021 2022 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n) 2023 { 2024 return vdev->vq[n].vring.avail; 2025 } 2026 2027 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n) 2028 { 2029 return vdev->vq[n].vring.used; 2030 } 2031 2032 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n) 2033 { 2034 return sizeof(VRingDesc) * vdev->vq[n].vring.num; 2035 } 2036 2037 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n) 2038 { 2039 return offsetof(VRingAvail, ring) + 2040 sizeof(uint16_t) * vdev->vq[n].vring.num; 2041 } 2042 2043 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) 2044 { 2045 return offsetof(VRingUsed, ring) + 2046 sizeof(VRingUsedElem) * vdev->vq[n].vring.num; 2047 } 2048 2049 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) 2050 { 2051 return vdev->vq[n].last_avail_idx; 2052 } 2053 2054 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) 2055 { 2056 vdev->vq[n].last_avail_idx = idx; 2057 vdev->vq[n].shadow_avail_idx = idx; 2058 } 2059 2060 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) 2061 { 2062 vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); 2063 } 2064 2065 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n) 2066 { 2067 vdev->vq[n].signalled_used_valid = false; 2068 } 2069 2070 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n) 2071 { 2072 return vdev->vq + n; 2073 } 2074 2075 uint16_t virtio_get_queue_index(VirtQueue *vq) 2076 { 2077 return vq->queue_index; 2078 } 2079 2080 static void virtio_queue_guest_notifier_read(EventNotifier *n) 2081 { 2082 VirtQueue *vq = container_of(n, VirtQueue, guest_notifier); 2083 if (event_notifier_test_and_clear(n)) { 2084 virtio_notify_vector(vq->vdev, vq->vector); 2085 } 2086 } 2087 2088 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 2089 bool with_irqfd) 2090 { 2091 if (assign && !with_irqfd) { 2092 event_notifier_set_handler(&vq->guest_notifier, 2093 virtio_queue_guest_notifier_read); 2094 } else { 2095 event_notifier_set_handler(&vq->guest_notifier, NULL); 2096 } 2097 if (!assign) { 2098 /* Test and clear notifier before closing it, 2099 * in case poll callback didn't have time to run. */ 2100 virtio_queue_guest_notifier_read(&vq->guest_notifier); 2101 } 2102 } 2103 2104 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq) 2105 { 2106 return &vq->guest_notifier; 2107 } 2108 2109 static void virtio_queue_host_notifier_aio_read(EventNotifier *n) 2110 { 2111 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2112 if (event_notifier_test_and_clear(n)) { 2113 virtio_queue_notify_aio_vq(vq); 2114 } 2115 } 2116 2117 static void virtio_queue_host_notifier_aio_poll_begin(EventNotifier *n) 2118 { 2119 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2120 2121 virtio_queue_set_notification(vq, 0); 2122 } 2123 2124 static bool virtio_queue_host_notifier_aio_poll(void *opaque) 2125 { 2126 EventNotifier *n = opaque; 2127 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2128 2129 if (virtio_queue_empty(vq)) { 2130 return false; 2131 } 2132 2133 virtio_queue_notify_aio_vq(vq); 2134 2135 /* In case the handler function re-enabled notifications */ 2136 virtio_queue_set_notification(vq, 0); 2137 return true; 2138 } 2139 2140 static void virtio_queue_host_notifier_aio_poll_end(EventNotifier *n) 2141 { 2142 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2143 2144 /* Caller polls once more after this to catch requests that race with us */ 2145 virtio_queue_set_notification(vq, 1); 2146 } 2147 2148 void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx, 2149 VirtIOHandleOutput handle_output) 2150 { 2151 if (handle_output) { 2152 vq->handle_aio_output = handle_output; 2153 aio_set_event_notifier(ctx, &vq->host_notifier, true, 2154 virtio_queue_host_notifier_aio_read, 2155 virtio_queue_host_notifier_aio_poll); 2156 aio_set_event_notifier_poll(ctx, &vq->host_notifier, 2157 virtio_queue_host_notifier_aio_poll_begin, 2158 virtio_queue_host_notifier_aio_poll_end); 2159 } else { 2160 aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL, NULL); 2161 /* Test and clear notifier before after disabling event, 2162 * in case poll callback didn't have time to run. */ 2163 virtio_queue_host_notifier_aio_read(&vq->host_notifier); 2164 vq->handle_aio_output = NULL; 2165 } 2166 } 2167 2168 void virtio_queue_host_notifier_read(EventNotifier *n) 2169 { 2170 VirtQueue *vq = container_of(n, VirtQueue, host_notifier); 2171 if (event_notifier_test_and_clear(n)) { 2172 virtio_queue_notify_vq(vq); 2173 } 2174 } 2175 2176 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq) 2177 { 2178 return &vq->host_notifier; 2179 } 2180 2181 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name) 2182 { 2183 g_free(vdev->bus_name); 2184 vdev->bus_name = g_strdup(bus_name); 2185 } 2186 2187 void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...) 2188 { 2189 va_list ap; 2190 2191 va_start(ap, fmt); 2192 error_vreport(fmt, ap); 2193 va_end(ap); 2194 2195 vdev->broken = true; 2196 2197 if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 2198 virtio_set_status(vdev, vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET); 2199 virtio_notify_config(vdev); 2200 } 2201 } 2202 2203 static void virtio_device_realize(DeviceState *dev, Error **errp) 2204 { 2205 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2206 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2207 Error *err = NULL; 2208 2209 /* Devices should either use vmsd or the load/save methods */ 2210 assert(!vdc->vmsd || !vdc->load); 2211 2212 if (vdc->realize != NULL) { 2213 vdc->realize(dev, &err); 2214 if (err != NULL) { 2215 error_propagate(errp, err); 2216 return; 2217 } 2218 } 2219 2220 virtio_bus_device_plugged(vdev, &err); 2221 if (err != NULL) { 2222 error_propagate(errp, err); 2223 return; 2224 } 2225 } 2226 2227 static void virtio_device_unrealize(DeviceState *dev, Error **errp) 2228 { 2229 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 2230 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev); 2231 Error *err = NULL; 2232 2233 virtio_bus_device_unplugged(vdev); 2234 2235 if (vdc->unrealize != NULL) { 2236 vdc->unrealize(dev, &err); 2237 if (err != NULL) { 2238 error_propagate(errp, err); 2239 return; 2240 } 2241 } 2242 2243 g_free(vdev->bus_name); 2244 vdev->bus_name = NULL; 2245 } 2246 2247 static Property virtio_properties[] = { 2248 DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features), 2249 DEFINE_PROP_END_OF_LIST(), 2250 }; 2251 2252 static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev) 2253 { 2254 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2255 int n, r, err; 2256 2257 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2258 VirtQueue *vq = &vdev->vq[n]; 2259 if (!virtio_queue_get_num(vdev, n)) { 2260 continue; 2261 } 2262 r = virtio_bus_set_host_notifier(qbus, n, true); 2263 if (r < 0) { 2264 err = r; 2265 goto assign_error; 2266 } 2267 event_notifier_set_handler(&vq->host_notifier, 2268 virtio_queue_host_notifier_read); 2269 } 2270 2271 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2272 /* Kick right away to begin processing requests already in vring */ 2273 VirtQueue *vq = &vdev->vq[n]; 2274 if (!vq->vring.num) { 2275 continue; 2276 } 2277 event_notifier_set(&vq->host_notifier); 2278 } 2279 return 0; 2280 2281 assign_error: 2282 while (--n >= 0) { 2283 VirtQueue *vq = &vdev->vq[n]; 2284 if (!virtio_queue_get_num(vdev, n)) { 2285 continue; 2286 } 2287 2288 event_notifier_set_handler(&vq->host_notifier, NULL); 2289 r = virtio_bus_set_host_notifier(qbus, n, false); 2290 assert(r >= 0); 2291 } 2292 return err; 2293 } 2294 2295 int virtio_device_start_ioeventfd(VirtIODevice *vdev) 2296 { 2297 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2298 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2299 2300 return virtio_bus_start_ioeventfd(vbus); 2301 } 2302 2303 static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev) 2304 { 2305 VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev))); 2306 int n, r; 2307 2308 for (n = 0; n < VIRTIO_QUEUE_MAX; n++) { 2309 VirtQueue *vq = &vdev->vq[n]; 2310 2311 if (!virtio_queue_get_num(vdev, n)) { 2312 continue; 2313 } 2314 event_notifier_set_handler(&vq->host_notifier, NULL); 2315 r = virtio_bus_set_host_notifier(qbus, n, false); 2316 assert(r >= 0); 2317 } 2318 } 2319 2320 void virtio_device_stop_ioeventfd(VirtIODevice *vdev) 2321 { 2322 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2323 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2324 2325 virtio_bus_stop_ioeventfd(vbus); 2326 } 2327 2328 int virtio_device_grab_ioeventfd(VirtIODevice *vdev) 2329 { 2330 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2331 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2332 2333 return virtio_bus_grab_ioeventfd(vbus); 2334 } 2335 2336 void virtio_device_release_ioeventfd(VirtIODevice *vdev) 2337 { 2338 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2339 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2340 2341 virtio_bus_release_ioeventfd(vbus); 2342 } 2343 2344 static void virtio_device_class_init(ObjectClass *klass, void *data) 2345 { 2346 /* Set the default value here. */ 2347 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 2348 DeviceClass *dc = DEVICE_CLASS(klass); 2349 2350 dc->realize = virtio_device_realize; 2351 dc->unrealize = virtio_device_unrealize; 2352 dc->bus_type = TYPE_VIRTIO_BUS; 2353 dc->props = virtio_properties; 2354 vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl; 2355 vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl; 2356 2357 vdc->legacy_features |= VIRTIO_LEGACY_FEATURES; 2358 } 2359 2360 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev) 2361 { 2362 BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); 2363 VirtioBusState *vbus = VIRTIO_BUS(qbus); 2364 2365 return virtio_bus_ioeventfd_enabled(vbus); 2366 } 2367 2368 static const TypeInfo virtio_device_info = { 2369 .name = TYPE_VIRTIO_DEVICE, 2370 .parent = TYPE_DEVICE, 2371 .instance_size = sizeof(VirtIODevice), 2372 .class_init = virtio_device_class_init, 2373 .abstract = true, 2374 .class_size = sizeof(VirtioDeviceClass), 2375 }; 2376 2377 static void virtio_register_types(void) 2378 { 2379 type_register_static(&virtio_device_info); 2380 } 2381 2382 type_init(virtio_register_types) 2383