1 /* 2 * Virtio Block Device 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/iov.h" 17 #include "qemu/module.h" 18 #include "qemu/error-report.h" 19 #include "trace.h" 20 #include "hw/block/block.h" 21 #include "sysemu/blockdev.h" 22 #include "hw/virtio/virtio-blk.h" 23 #include "dataplane/virtio-blk.h" 24 #include "scsi/constants.h" 25 #ifdef __linux__ 26 # include <scsi/sg.h> 27 #endif 28 #include "hw/virtio/virtio-bus.h" 29 #include "hw/virtio/virtio-access.h" 30 31 /* Config size before the discard support (hide associated config fields) */ 32 #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \ 33 max_discard_sectors) 34 /* 35 * Starting from the discard feature, we can use this array to properly 36 * set the config size depending on the features enabled. 37 */ 38 static VirtIOFeature feature_sizes[] = { 39 {.flags = 1ULL << VIRTIO_BLK_F_DISCARD, 40 .end = virtio_endof(struct virtio_blk_config, discard_sector_alignment)}, 41 {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES, 42 .end = virtio_endof(struct virtio_blk_config, write_zeroes_may_unmap)}, 43 {} 44 }; 45 46 static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features) 47 { 48 s->config_size = MAX(VIRTIO_BLK_CFG_SIZE, 49 virtio_feature_get_config_size(feature_sizes, host_features)); 50 51 assert(s->config_size <= sizeof(struct virtio_blk_config)); 52 } 53 54 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, 55 VirtIOBlockReq *req) 56 { 57 req->dev = s; 58 req->vq = vq; 59 req->qiov.size = 0; 60 req->in_len = 0; 61 req->next = NULL; 62 req->mr_next = NULL; 63 } 64 65 static void virtio_blk_free_request(VirtIOBlockReq *req) 66 { 67 g_free(req); 68 } 69 70 static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status) 71 { 72 VirtIOBlock *s = req->dev; 73 VirtIODevice *vdev = VIRTIO_DEVICE(s); 74 75 trace_virtio_blk_req_complete(vdev, req, status); 76 77 stb_p(&req->in->status, status); 78 virtqueue_push(req->vq, &req->elem, req->in_len); 79 if (s->dataplane_started && !s->dataplane_disabled) { 80 virtio_blk_data_plane_notify(s->dataplane, req->vq); 81 } else { 82 virtio_notify(vdev, req->vq); 83 } 84 } 85 86 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, 87 bool is_read, bool acct_failed) 88 { 89 VirtIOBlock *s = req->dev; 90 BlockErrorAction action = blk_get_error_action(s->blk, is_read, error); 91 92 if (action == BLOCK_ERROR_ACTION_STOP) { 93 /* Break the link as the next request is going to be parsed from the 94 * ring again. Otherwise we may end up doing a double completion! */ 95 req->mr_next = NULL; 96 req->next = s->rq; 97 s->rq = req; 98 } else if (action == BLOCK_ERROR_ACTION_REPORT) { 99 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 100 if (acct_failed) { 101 block_acct_failed(blk_get_stats(s->blk), &req->acct); 102 } 103 virtio_blk_free_request(req); 104 } 105 106 blk_error_action(s->blk, action, is_read, error); 107 return action != BLOCK_ERROR_ACTION_IGNORE; 108 } 109 110 static void virtio_blk_rw_complete(void *opaque, int ret) 111 { 112 VirtIOBlockReq *next = opaque; 113 VirtIOBlock *s = next->dev; 114 VirtIODevice *vdev = VIRTIO_DEVICE(s); 115 116 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 117 while (next) { 118 VirtIOBlockReq *req = next; 119 next = req->mr_next; 120 trace_virtio_blk_rw_complete(vdev, req, ret); 121 122 if (req->qiov.nalloc != -1) { 123 /* If nalloc is != -1 req->qiov is a local copy of the original 124 * external iovec. It was allocated in submit_requests to be 125 * able to merge requests. */ 126 qemu_iovec_destroy(&req->qiov); 127 } 128 129 if (ret) { 130 int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type); 131 bool is_read = !(p & VIRTIO_BLK_T_OUT); 132 /* Note that memory may be dirtied on read failure. If the 133 * virtio request is not completed here, as is the case for 134 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied 135 * correctly during live migration. While this is ugly, 136 * it is acceptable because the device is free to write to 137 * the memory until the request is completed (which will 138 * happen on the other side of the migration). 139 */ 140 if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) { 141 continue; 142 } 143 } 144 145 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 146 block_acct_done(blk_get_stats(s->blk), &req->acct); 147 virtio_blk_free_request(req); 148 } 149 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 150 } 151 152 static void virtio_blk_flush_complete(void *opaque, int ret) 153 { 154 VirtIOBlockReq *req = opaque; 155 VirtIOBlock *s = req->dev; 156 157 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 158 if (ret) { 159 if (virtio_blk_handle_rw_error(req, -ret, 0, true)) { 160 goto out; 161 } 162 } 163 164 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 165 block_acct_done(blk_get_stats(s->blk), &req->acct); 166 virtio_blk_free_request(req); 167 168 out: 169 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 170 } 171 172 static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret) 173 { 174 VirtIOBlockReq *req = opaque; 175 VirtIOBlock *s = req->dev; 176 bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) & 177 ~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES; 178 179 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 180 if (ret) { 181 if (virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) { 182 goto out; 183 } 184 } 185 186 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 187 if (is_write_zeroes) { 188 block_acct_done(blk_get_stats(s->blk), &req->acct); 189 } 190 virtio_blk_free_request(req); 191 192 out: 193 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 194 } 195 196 #ifdef __linux__ 197 198 typedef struct { 199 VirtIOBlockReq *req; 200 struct sg_io_hdr hdr; 201 } VirtIOBlockIoctlReq; 202 203 static void virtio_blk_ioctl_complete(void *opaque, int status) 204 { 205 VirtIOBlockIoctlReq *ioctl_req = opaque; 206 VirtIOBlockReq *req = ioctl_req->req; 207 VirtIOBlock *s = req->dev; 208 VirtIODevice *vdev = VIRTIO_DEVICE(s); 209 struct virtio_scsi_inhdr *scsi; 210 struct sg_io_hdr *hdr; 211 212 scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base; 213 214 if (status) { 215 status = VIRTIO_BLK_S_UNSUPP; 216 virtio_stl_p(vdev, &scsi->errors, 255); 217 goto out; 218 } 219 220 hdr = &ioctl_req->hdr; 221 /* 222 * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi) 223 * clear the masked_status field [hence status gets cleared too, see 224 * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED 225 * status has occurred. However they do set DRIVER_SENSE in driver_status 226 * field. Also a (sb_len_wr > 0) indicates there is a sense buffer. 227 */ 228 if (hdr->status == 0 && hdr->sb_len_wr > 0) { 229 hdr->status = CHECK_CONDITION; 230 } 231 232 virtio_stl_p(vdev, &scsi->errors, 233 hdr->status | (hdr->msg_status << 8) | 234 (hdr->host_status << 16) | (hdr->driver_status << 24)); 235 virtio_stl_p(vdev, &scsi->residual, hdr->resid); 236 virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr); 237 virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len); 238 239 out: 240 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 241 virtio_blk_req_complete(req, status); 242 virtio_blk_free_request(req); 243 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 244 g_free(ioctl_req); 245 } 246 247 #endif 248 249 static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq) 250 { 251 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq)); 252 253 if (req) { 254 virtio_blk_init_request(s, vq, req); 255 } 256 return req; 257 } 258 259 static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req) 260 { 261 int status = VIRTIO_BLK_S_OK; 262 struct virtio_scsi_inhdr *scsi = NULL; 263 VirtIOBlock *blk = req->dev; 264 VirtIODevice *vdev = VIRTIO_DEVICE(blk); 265 VirtQueueElement *elem = &req->elem; 266 267 #ifdef __linux__ 268 int i; 269 VirtIOBlockIoctlReq *ioctl_req; 270 BlockAIOCB *acb; 271 #endif 272 273 /* 274 * We require at least one output segment each for the virtio_blk_outhdr 275 * and the SCSI command block. 276 * 277 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr 278 * and the sense buffer pointer in the input segments. 279 */ 280 if (elem->out_num < 2 || elem->in_num < 3) { 281 status = VIRTIO_BLK_S_IOERR; 282 goto fail; 283 } 284 285 /* 286 * The scsi inhdr is placed in the second-to-last input segment, just 287 * before the regular inhdr. 288 */ 289 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base; 290 291 if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) { 292 status = VIRTIO_BLK_S_UNSUPP; 293 goto fail; 294 } 295 296 /* 297 * No support for bidirection commands yet. 298 */ 299 if (elem->out_num > 2 && elem->in_num > 3) { 300 status = VIRTIO_BLK_S_UNSUPP; 301 goto fail; 302 } 303 304 #ifdef __linux__ 305 ioctl_req = g_new0(VirtIOBlockIoctlReq, 1); 306 ioctl_req->req = req; 307 ioctl_req->hdr.interface_id = 'S'; 308 ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len; 309 ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base; 310 ioctl_req->hdr.dxfer_len = 0; 311 312 if (elem->out_num > 2) { 313 /* 314 * If there are more than the minimally required 2 output segments 315 * there is write payload starting from the third iovec. 316 */ 317 ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV; 318 ioctl_req->hdr.iovec_count = elem->out_num - 2; 319 320 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) { 321 ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len; 322 } 323 324 ioctl_req->hdr.dxferp = elem->out_sg + 2; 325 326 } else if (elem->in_num > 3) { 327 /* 328 * If we have more than 3 input segments the guest wants to actually 329 * read data. 330 */ 331 ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV; 332 ioctl_req->hdr.iovec_count = elem->in_num - 3; 333 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) { 334 ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len; 335 } 336 337 ioctl_req->hdr.dxferp = elem->in_sg; 338 } else { 339 /* 340 * Some SCSI commands don't actually transfer any data. 341 */ 342 ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE; 343 } 344 345 ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base; 346 ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len; 347 348 acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr, 349 virtio_blk_ioctl_complete, ioctl_req); 350 if (!acb) { 351 g_free(ioctl_req); 352 status = VIRTIO_BLK_S_UNSUPP; 353 goto fail; 354 } 355 return -EINPROGRESS; 356 #else 357 abort(); 358 #endif 359 360 fail: 361 /* Just put anything nonzero so that the ioctl fails in the guest. */ 362 if (scsi) { 363 virtio_stl_p(vdev, &scsi->errors, 255); 364 } 365 return status; 366 } 367 368 static void virtio_blk_handle_scsi(VirtIOBlockReq *req) 369 { 370 int status; 371 372 status = virtio_blk_handle_scsi_req(req); 373 if (status != -EINPROGRESS) { 374 virtio_blk_req_complete(req, status); 375 virtio_blk_free_request(req); 376 } 377 } 378 379 static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, 380 int start, int num_reqs, int niov) 381 { 382 QEMUIOVector *qiov = &mrb->reqs[start]->qiov; 383 int64_t sector_num = mrb->reqs[start]->sector_num; 384 bool is_write = mrb->is_write; 385 386 if (num_reqs > 1) { 387 int i; 388 struct iovec *tmp_iov = qiov->iov; 389 int tmp_niov = qiov->niov; 390 391 /* mrb->reqs[start]->qiov was initialized from external so we can't 392 * modify it here. We need to initialize it locally and then add the 393 * external iovecs. */ 394 qemu_iovec_init(qiov, niov); 395 396 for (i = 0; i < tmp_niov; i++) { 397 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len); 398 } 399 400 for (i = start + 1; i < start + num_reqs; i++) { 401 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0, 402 mrb->reqs[i]->qiov.size); 403 mrb->reqs[i - 1]->mr_next = mrb->reqs[i]; 404 } 405 406 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev), 407 mrb, start, num_reqs, 408 sector_num << BDRV_SECTOR_BITS, 409 qiov->size, is_write); 410 block_acct_merge_done(blk_get_stats(blk), 411 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ, 412 num_reqs - 1); 413 } 414 415 if (is_write) { 416 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, 417 virtio_blk_rw_complete, mrb->reqs[start]); 418 } else { 419 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, 420 virtio_blk_rw_complete, mrb->reqs[start]); 421 } 422 } 423 424 static int multireq_compare(const void *a, const void *b) 425 { 426 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a, 427 *req2 = *(VirtIOBlockReq **)b; 428 429 /* 430 * Note that we can't simply subtract sector_num1 from sector_num2 431 * here as that could overflow the return value. 432 */ 433 if (req1->sector_num > req2->sector_num) { 434 return 1; 435 } else if (req1->sector_num < req2->sector_num) { 436 return -1; 437 } else { 438 return 0; 439 } 440 } 441 442 static void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) 443 { 444 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0; 445 uint32_t max_transfer; 446 int64_t sector_num = 0; 447 448 if (mrb->num_reqs == 1) { 449 submit_requests(blk, mrb, 0, 1, -1); 450 mrb->num_reqs = 0; 451 return; 452 } 453 454 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk); 455 456 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs), 457 &multireq_compare); 458 459 for (i = 0; i < mrb->num_reqs; i++) { 460 VirtIOBlockReq *req = mrb->reqs[i]; 461 if (num_reqs > 0) { 462 /* 463 * NOTE: We cannot merge the requests in below situations: 464 * 1. requests are not sequential 465 * 2. merge would exceed maximum number of IOVs 466 * 3. merge would exceed maximum transfer length of backend device 467 */ 468 if (sector_num + nb_sectors != req->sector_num || 469 niov > blk_get_max_iov(blk) - req->qiov.niov || 470 req->qiov.size > max_transfer || 471 nb_sectors > (max_transfer - 472 req->qiov.size) / BDRV_SECTOR_SIZE) { 473 submit_requests(blk, mrb, start, num_reqs, niov); 474 num_reqs = 0; 475 } 476 } 477 478 if (num_reqs == 0) { 479 sector_num = req->sector_num; 480 nb_sectors = niov = 0; 481 start = i; 482 } 483 484 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE; 485 niov += req->qiov.niov; 486 num_reqs++; 487 } 488 489 submit_requests(blk, mrb, start, num_reqs, niov); 490 mrb->num_reqs = 0; 491 } 492 493 static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb) 494 { 495 VirtIOBlock *s = req->dev; 496 497 block_acct_start(blk_get_stats(s->blk), &req->acct, 0, 498 BLOCK_ACCT_FLUSH); 499 500 /* 501 * Make sure all outstanding writes are posted to the backing device. 502 */ 503 if (mrb->is_write && mrb->num_reqs > 0) { 504 virtio_blk_submit_multireq(s->blk, mrb); 505 } 506 blk_aio_flush(s->blk, virtio_blk_flush_complete, req); 507 } 508 509 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev, 510 uint64_t sector, size_t size) 511 { 512 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS; 513 uint64_t total_sectors; 514 515 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) { 516 return false; 517 } 518 if (sector & dev->sector_mask) { 519 return false; 520 } 521 if (size % dev->conf.conf.logical_block_size) { 522 return false; 523 } 524 blk_get_geometry(dev->blk, &total_sectors); 525 if (sector > total_sectors || nb_sectors > total_sectors - sector) { 526 return false; 527 } 528 return true; 529 } 530 531 static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req, 532 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes) 533 { 534 VirtIOBlock *s = req->dev; 535 VirtIODevice *vdev = VIRTIO_DEVICE(s); 536 uint64_t sector; 537 uint32_t num_sectors, flags, max_sectors; 538 uint8_t err_status; 539 int bytes; 540 541 sector = virtio_ldq_p(vdev, &dwz_hdr->sector); 542 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors); 543 flags = virtio_ldl_p(vdev, &dwz_hdr->flags); 544 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors : 545 s->conf.max_discard_sectors; 546 547 /* 548 * max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check 549 * make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in 550 * the integer variable. 551 */ 552 if (unlikely(num_sectors > max_sectors)) { 553 err_status = VIRTIO_BLK_S_IOERR; 554 goto err; 555 } 556 557 bytes = num_sectors << BDRV_SECTOR_BITS; 558 559 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) { 560 err_status = VIRTIO_BLK_S_IOERR; 561 goto err; 562 } 563 564 /* 565 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard 566 * and write zeroes commands if any unknown flag is set. 567 */ 568 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 569 err_status = VIRTIO_BLK_S_UNSUPP; 570 goto err; 571 } 572 573 if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */ 574 int blk_aio_flags = 0; 575 576 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { 577 blk_aio_flags |= BDRV_REQ_MAY_UNMAP; 578 } 579 580 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes, 581 BLOCK_ACCT_WRITE); 582 583 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS, 584 bytes, blk_aio_flags, 585 virtio_blk_discard_write_zeroes_complete, req); 586 } else { /* VIRTIO_BLK_T_DISCARD */ 587 /* 588 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for 589 * discard commands if the unmap flag is set. 590 */ 591 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 592 err_status = VIRTIO_BLK_S_UNSUPP; 593 goto err; 594 } 595 596 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes, 597 virtio_blk_discard_write_zeroes_complete, req); 598 } 599 600 return VIRTIO_BLK_S_OK; 601 602 err: 603 if (is_write_zeroes) { 604 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE); 605 } 606 return err_status; 607 } 608 609 static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) 610 { 611 uint32_t type; 612 struct iovec *in_iov = req->elem.in_sg; 613 struct iovec *out_iov = req->elem.out_sg; 614 unsigned in_num = req->elem.in_num; 615 unsigned out_num = req->elem.out_num; 616 VirtIOBlock *s = req->dev; 617 VirtIODevice *vdev = VIRTIO_DEVICE(s); 618 619 if (req->elem.out_num < 1 || req->elem.in_num < 1) { 620 virtio_error(vdev, "virtio-blk missing headers"); 621 return -1; 622 } 623 624 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out, 625 sizeof(req->out)) != sizeof(req->out))) { 626 virtio_error(vdev, "virtio-blk request outhdr too short"); 627 return -1; 628 } 629 630 iov_discard_front(&out_iov, &out_num, sizeof(req->out)); 631 632 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { 633 virtio_error(vdev, "virtio-blk request inhdr too short"); 634 return -1; 635 } 636 637 /* We always touch the last byte, so just see how big in_iov is. */ 638 req->in_len = iov_size(in_iov, in_num); 639 req->in = (void *)in_iov[in_num - 1].iov_base 640 + in_iov[in_num - 1].iov_len 641 - sizeof(struct virtio_blk_inhdr); 642 iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr)); 643 644 type = virtio_ldl_p(vdev, &req->out.type); 645 646 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER 647 * is an optional flag. Although a guest should not send this flag if 648 * not negotiated we ignored it in the past. So keep ignoring it. */ 649 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) { 650 case VIRTIO_BLK_T_IN: 651 { 652 bool is_write = type & VIRTIO_BLK_T_OUT; 653 req->sector_num = virtio_ldq_p(vdev, &req->out.sector); 654 655 if (is_write) { 656 qemu_iovec_init_external(&req->qiov, out_iov, out_num); 657 trace_virtio_blk_handle_write(vdev, req, req->sector_num, 658 req->qiov.size / BDRV_SECTOR_SIZE); 659 } else { 660 qemu_iovec_init_external(&req->qiov, in_iov, in_num); 661 trace_virtio_blk_handle_read(vdev, req, req->sector_num, 662 req->qiov.size / BDRV_SECTOR_SIZE); 663 } 664 665 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) { 666 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 667 block_acct_invalid(blk_get_stats(s->blk), 668 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 669 virtio_blk_free_request(req); 670 return 0; 671 } 672 673 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size, 674 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 675 676 /* merge would exceed maximum number of requests or IO direction 677 * changes */ 678 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS || 679 is_write != mrb->is_write || 680 !s->conf.request_merging)) { 681 virtio_blk_submit_multireq(s->blk, mrb); 682 } 683 684 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS); 685 mrb->reqs[mrb->num_reqs++] = req; 686 mrb->is_write = is_write; 687 break; 688 } 689 case VIRTIO_BLK_T_FLUSH: 690 virtio_blk_handle_flush(req, mrb); 691 break; 692 case VIRTIO_BLK_T_SCSI_CMD: 693 virtio_blk_handle_scsi(req); 694 break; 695 case VIRTIO_BLK_T_GET_ID: 696 { 697 /* 698 * NB: per existing s/n string convention the string is 699 * terminated by '\0' only when shorter than buffer. 700 */ 701 const char *serial = s->conf.serial ? s->conf.serial : ""; 702 size_t size = MIN(strlen(serial) + 1, 703 MIN(iov_size(in_iov, in_num), 704 VIRTIO_BLK_ID_BYTES)); 705 iov_from_buf(in_iov, in_num, 0, serial, size); 706 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 707 virtio_blk_free_request(req); 708 break; 709 } 710 /* 711 * VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with 712 * VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement, 713 * so we must mask it for these requests, then we will check if it is set. 714 */ 715 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT: 716 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT: 717 { 718 struct virtio_blk_discard_write_zeroes dwz_hdr; 719 size_t out_len = iov_size(out_iov, out_num); 720 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) == 721 VIRTIO_BLK_T_WRITE_ZEROES; 722 uint8_t err_status; 723 724 /* 725 * Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains 726 * more than one segment. 727 */ 728 if (unlikely(!(type & VIRTIO_BLK_T_OUT) || 729 out_len > sizeof(dwz_hdr))) { 730 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 731 virtio_blk_free_request(req); 732 return 0; 733 } 734 735 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr, 736 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) { 737 virtio_error(vdev, "virtio-blk discard/write_zeroes header" 738 " too short"); 739 return -1; 740 } 741 742 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr, 743 is_write_zeroes); 744 if (err_status != VIRTIO_BLK_S_OK) { 745 virtio_blk_req_complete(req, err_status); 746 virtio_blk_free_request(req); 747 } 748 749 break; 750 } 751 default: 752 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 753 virtio_blk_free_request(req); 754 } 755 return 0; 756 } 757 758 bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) 759 { 760 VirtIOBlockReq *req; 761 MultiReqBuffer mrb = {}; 762 bool progress = false; 763 764 aio_context_acquire(blk_get_aio_context(s->blk)); 765 blk_io_plug(s->blk); 766 767 do { 768 virtio_queue_set_notification(vq, 0); 769 770 while ((req = virtio_blk_get_request(s, vq))) { 771 progress = true; 772 if (virtio_blk_handle_request(req, &mrb)) { 773 virtqueue_detach_element(req->vq, &req->elem, 0); 774 virtio_blk_free_request(req); 775 break; 776 } 777 } 778 779 virtio_queue_set_notification(vq, 1); 780 } while (!virtio_queue_empty(vq)); 781 782 if (mrb.num_reqs) { 783 virtio_blk_submit_multireq(s->blk, &mrb); 784 } 785 786 blk_io_unplug(s->blk); 787 aio_context_release(blk_get_aio_context(s->blk)); 788 return progress; 789 } 790 791 static void virtio_blk_handle_output_do(VirtIOBlock *s, VirtQueue *vq) 792 { 793 virtio_blk_handle_vq(s, vq); 794 } 795 796 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 797 { 798 VirtIOBlock *s = (VirtIOBlock *)vdev; 799 800 if (s->dataplane) { 801 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 802 * dataplane here instead of waiting for .set_status(). 803 */ 804 virtio_device_start_ioeventfd(vdev); 805 if (!s->dataplane_disabled) { 806 return; 807 } 808 } 809 virtio_blk_handle_output_do(s, vq); 810 } 811 812 static void virtio_blk_dma_restart_bh(void *opaque) 813 { 814 VirtIOBlock *s = opaque; 815 VirtIOBlockReq *req = s->rq; 816 MultiReqBuffer mrb = {}; 817 818 qemu_bh_delete(s->bh); 819 s->bh = NULL; 820 821 s->rq = NULL; 822 823 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 824 while (req) { 825 VirtIOBlockReq *next = req->next; 826 if (virtio_blk_handle_request(req, &mrb)) { 827 /* Device is now broken and won't do any processing until it gets 828 * reset. Already queued requests will be lost: let's purge them. 829 */ 830 while (req) { 831 next = req->next; 832 virtqueue_detach_element(req->vq, &req->elem, 0); 833 virtio_blk_free_request(req); 834 req = next; 835 } 836 break; 837 } 838 req = next; 839 } 840 841 if (mrb.num_reqs) { 842 virtio_blk_submit_multireq(s->blk, &mrb); 843 } 844 blk_dec_in_flight(s->conf.conf.blk); 845 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 846 } 847 848 static void virtio_blk_dma_restart_cb(void *opaque, int running, 849 RunState state) 850 { 851 VirtIOBlock *s = opaque; 852 853 if (!running) { 854 return; 855 } 856 857 if (!s->bh) { 858 /* FIXME The data plane is not started yet, so these requests are 859 * processed in the main thread. */ 860 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk), 861 virtio_blk_dma_restart_bh, s); 862 blk_inc_in_flight(s->conf.conf.blk); 863 qemu_bh_schedule(s->bh); 864 } 865 } 866 867 static void virtio_blk_reset(VirtIODevice *vdev) 868 { 869 VirtIOBlock *s = VIRTIO_BLK(vdev); 870 AioContext *ctx; 871 VirtIOBlockReq *req; 872 873 ctx = blk_get_aio_context(s->blk); 874 aio_context_acquire(ctx); 875 blk_drain(s->blk); 876 877 /* We drop queued requests after blk_drain() because blk_drain() itself can 878 * produce them. */ 879 while (s->rq) { 880 req = s->rq; 881 s->rq = req->next; 882 virtqueue_detach_element(req->vq, &req->elem, 0); 883 virtio_blk_free_request(req); 884 } 885 886 aio_context_release(ctx); 887 888 assert(!s->dataplane_started); 889 blk_set_enable_write_cache(s->blk, s->original_wce); 890 } 891 892 /* coalesce internal state, copy to pci i/o region 0 893 */ 894 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) 895 { 896 VirtIOBlock *s = VIRTIO_BLK(vdev); 897 BlockConf *conf = &s->conf.conf; 898 struct virtio_blk_config blkcfg; 899 uint64_t capacity; 900 int64_t length; 901 int blk_size = conf->logical_block_size; 902 903 blk_get_geometry(s->blk, &capacity); 904 memset(&blkcfg, 0, sizeof(blkcfg)); 905 virtio_stq_p(vdev, &blkcfg.capacity, capacity); 906 virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2); 907 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls); 908 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size); 909 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size); 910 virtio_stw_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size); 911 blkcfg.geometry.heads = conf->heads; 912 /* 913 * We must ensure that the block device capacity is a multiple of 914 * the logical block size. If that is not the case, let's use 915 * sector_mask to adopt the geometry to have a correct picture. 916 * For those devices where the capacity is ok for the given geometry 917 * we don't touch the sector value of the geometry, since some devices 918 * (like s390 dasd) need a specific value. Here the capacity is already 919 * cyls*heads*secs*blk_size and the sector value is not block size 920 * divided by 512 - instead it is the amount of blk_size blocks 921 * per track (cylinder). 922 */ 923 length = blk_getlength(s->blk); 924 if (length > 0 && length / conf->heads / conf->secs % blk_size) { 925 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask; 926 } else { 927 blkcfg.geometry.sectors = conf->secs; 928 } 929 blkcfg.size_max = 0; 930 blkcfg.physical_block_exp = get_physical_block_exp(conf); 931 blkcfg.alignment_offset = 0; 932 blkcfg.wce = blk_enable_write_cache(s->blk); 933 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); 934 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) { 935 virtio_stl_p(vdev, &blkcfg.max_discard_sectors, 936 s->conf.max_discard_sectors); 937 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment, 938 blk_size >> BDRV_SECTOR_BITS); 939 /* 940 * We support only one segment per request since multiple segments 941 * are not widely used and there are no userspace APIs that allow 942 * applications to submit multiple segments in a single call. 943 */ 944 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1); 945 } 946 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) { 947 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors, 948 s->conf.max_write_zeroes_sectors); 949 blkcfg.write_zeroes_may_unmap = 1; 950 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1); 951 } 952 memcpy(config, &blkcfg, s->config_size); 953 } 954 955 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) 956 { 957 VirtIOBlock *s = VIRTIO_BLK(vdev); 958 struct virtio_blk_config blkcfg; 959 960 memcpy(&blkcfg, config, s->config_size); 961 962 aio_context_acquire(blk_get_aio_context(s->blk)); 963 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); 964 aio_context_release(blk_get_aio_context(s->blk)); 965 } 966 967 static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, 968 Error **errp) 969 { 970 VirtIOBlock *s = VIRTIO_BLK(vdev); 971 972 /* Firstly sync all virtio-blk possible supported features */ 973 features |= s->host_features; 974 975 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 976 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 977 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 978 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 979 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) { 980 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) { 981 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0"); 982 return 0; 983 } 984 } else { 985 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT); 986 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); 987 } 988 989 if (blk_enable_write_cache(s->blk)) { 990 virtio_add_feature(&features, VIRTIO_BLK_F_WCE); 991 } 992 if (blk_is_read_only(s->blk)) { 993 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 994 } 995 if (s->conf.num_queues > 1) { 996 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 997 } 998 999 return features; 1000 } 1001 1002 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) 1003 { 1004 VirtIOBlock *s = VIRTIO_BLK(vdev); 1005 1006 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) { 1007 assert(!s->dataplane_started); 1008 } 1009 1010 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { 1011 return; 1012 } 1013 1014 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send 1015 * cache flushes. Thus, the "auto writethrough" behavior is never 1016 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature. 1017 * Leaving it enabled would break the following sequence: 1018 * 1019 * Guest started with "-drive cache=writethrough" 1020 * Guest sets status to 0 1021 * Guest sets DRIVER bit in status field 1022 * Guest reads host features (WCE=0, CONFIG_WCE=1) 1023 * Guest writes guest features (WCE=0, CONFIG_WCE=1) 1024 * Guest writes 1 to the WCE configuration field (writeback mode) 1025 * Guest sets DRIVER_OK bit in status field 1026 * 1027 * s->blk would erroneously be placed in writethrough mode. 1028 */ 1029 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) { 1030 aio_context_acquire(blk_get_aio_context(s->blk)); 1031 blk_set_enable_write_cache(s->blk, 1032 virtio_vdev_has_feature(vdev, 1033 VIRTIO_BLK_F_WCE)); 1034 aio_context_release(blk_get_aio_context(s->blk)); 1035 } 1036 } 1037 1038 static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f) 1039 { 1040 VirtIOBlock *s = VIRTIO_BLK(vdev); 1041 VirtIOBlockReq *req = s->rq; 1042 1043 while (req) { 1044 qemu_put_sbyte(f, 1); 1045 1046 if (s->conf.num_queues > 1) { 1047 qemu_put_be32(f, virtio_get_queue_index(req->vq)); 1048 } 1049 1050 qemu_put_virtqueue_element(f, &req->elem); 1051 req = req->next; 1052 } 1053 qemu_put_sbyte(f, 0); 1054 } 1055 1056 static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, 1057 int version_id) 1058 { 1059 VirtIOBlock *s = VIRTIO_BLK(vdev); 1060 1061 while (qemu_get_sbyte(f)) { 1062 unsigned nvqs = s->conf.num_queues; 1063 unsigned vq_idx = 0; 1064 VirtIOBlockReq *req; 1065 1066 if (nvqs > 1) { 1067 vq_idx = qemu_get_be32(f); 1068 1069 if (vq_idx >= nvqs) { 1070 error_report("Invalid virtqueue index in request list: %#x", 1071 vq_idx); 1072 return -EINVAL; 1073 } 1074 } 1075 1076 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq)); 1077 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req); 1078 req->next = s->rq; 1079 s->rq = req; 1080 } 1081 1082 return 0; 1083 } 1084 1085 static void virtio_blk_resize(void *opaque) 1086 { 1087 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1088 1089 virtio_notify_config(vdev); 1090 } 1091 1092 static const BlockDevOps virtio_block_ops = { 1093 .resize_cb = virtio_blk_resize, 1094 }; 1095 1096 static void virtio_blk_device_realize(DeviceState *dev, Error **errp) 1097 { 1098 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1099 VirtIOBlock *s = VIRTIO_BLK(dev); 1100 VirtIOBlkConf *conf = &s->conf; 1101 Error *err = NULL; 1102 unsigned i; 1103 1104 if (!conf->conf.blk) { 1105 error_setg(errp, "drive property not set"); 1106 return; 1107 } 1108 if (!blk_is_inserted(conf->conf.blk)) { 1109 error_setg(errp, "Device needs media, but drive is empty"); 1110 return; 1111 } 1112 if (!conf->num_queues) { 1113 error_setg(errp, "num-queues property must be larger than 0"); 1114 return; 1115 } 1116 if (!is_power_of_2(conf->queue_size) || 1117 conf->queue_size > VIRTQUEUE_MAX_SIZE) { 1118 error_setg(errp, "invalid queue-size property (%" PRIu16 "), " 1119 "must be a power of 2 (max %d)", 1120 conf->queue_size, VIRTQUEUE_MAX_SIZE); 1121 return; 1122 } 1123 1124 if (!blkconf_apply_backend_options(&conf->conf, 1125 blk_is_read_only(conf->conf.blk), true, 1126 errp)) { 1127 return; 1128 } 1129 s->original_wce = blk_enable_write_cache(conf->conf.blk); 1130 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) { 1131 return; 1132 } 1133 1134 blkconf_blocksizes(&conf->conf); 1135 1136 if (conf->conf.logical_block_size > 1137 conf->conf.physical_block_size) { 1138 error_setg(errp, 1139 "logical_block_size > physical_block_size not supported"); 1140 return; 1141 } 1142 1143 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) && 1144 (!conf->max_discard_sectors || 1145 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1146 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")" 1147 ", must be between 1 and %d", 1148 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS); 1149 return; 1150 } 1151 1152 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) && 1153 (!conf->max_write_zeroes_sectors || 1154 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1155 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32 1156 "), must be between 1 and %d", 1157 conf->max_write_zeroes_sectors, 1158 (int)BDRV_REQUEST_MAX_SECTORS); 1159 return; 1160 } 1161 1162 virtio_blk_set_config_size(s, s->host_features); 1163 1164 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, s->config_size); 1165 1166 s->blk = conf->conf.blk; 1167 s->rq = NULL; 1168 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1; 1169 1170 for (i = 0; i < conf->num_queues; i++) { 1171 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output); 1172 } 1173 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err); 1174 if (err != NULL) { 1175 error_propagate(errp, err); 1176 virtio_cleanup(vdev); 1177 return; 1178 } 1179 1180 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); 1181 blk_set_dev_ops(s->blk, &virtio_block_ops, s); 1182 blk_set_guest_block_size(s->blk, s->conf.conf.logical_block_size); 1183 1184 blk_iostatus_enable(s->blk); 1185 } 1186 1187 static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp) 1188 { 1189 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1190 VirtIOBlock *s = VIRTIO_BLK(dev); 1191 1192 virtio_blk_data_plane_destroy(s->dataplane); 1193 s->dataplane = NULL; 1194 qemu_del_vm_change_state_handler(s->change); 1195 blockdev_mark_auto_del(s->blk); 1196 virtio_cleanup(vdev); 1197 } 1198 1199 static void virtio_blk_instance_init(Object *obj) 1200 { 1201 VirtIOBlock *s = VIRTIO_BLK(obj); 1202 1203 device_add_bootindex_property(obj, &s->conf.conf.bootindex, 1204 "bootindex", "/disk@0,0", 1205 DEVICE(obj), NULL); 1206 } 1207 1208 static const VMStateDescription vmstate_virtio_blk = { 1209 .name = "virtio-blk", 1210 .minimum_version_id = 2, 1211 .version_id = 2, 1212 .fields = (VMStateField[]) { 1213 VMSTATE_VIRTIO_DEVICE, 1214 VMSTATE_END_OF_LIST() 1215 }, 1216 }; 1217 1218 static Property virtio_blk_properties[] = { 1219 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf), 1220 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf), 1221 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf), 1222 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial), 1223 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features, 1224 VIRTIO_BLK_F_CONFIG_WCE, true), 1225 #ifdef __linux__ 1226 DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features, 1227 VIRTIO_BLK_F_SCSI, false), 1228 #endif 1229 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0, 1230 true), 1231 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1), 1232 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128), 1233 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, 1234 IOThread *), 1235 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, 1236 VIRTIO_BLK_F_DISCARD, true), 1237 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features, 1238 VIRTIO_BLK_F_WRITE_ZEROES, true), 1239 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock, 1240 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS), 1241 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock, 1242 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS), 1243 DEFINE_PROP_END_OF_LIST(), 1244 }; 1245 1246 static void virtio_blk_class_init(ObjectClass *klass, void *data) 1247 { 1248 DeviceClass *dc = DEVICE_CLASS(klass); 1249 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 1250 1251 dc->props = virtio_blk_properties; 1252 dc->vmsd = &vmstate_virtio_blk; 1253 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 1254 vdc->realize = virtio_blk_device_realize; 1255 vdc->unrealize = virtio_blk_device_unrealize; 1256 vdc->get_config = virtio_blk_update_config; 1257 vdc->set_config = virtio_blk_set_config; 1258 vdc->get_features = virtio_blk_get_features; 1259 vdc->set_status = virtio_blk_set_status; 1260 vdc->reset = virtio_blk_reset; 1261 vdc->save = virtio_blk_save_device; 1262 vdc->load = virtio_blk_load_device; 1263 vdc->start_ioeventfd = virtio_blk_data_plane_start; 1264 vdc->stop_ioeventfd = virtio_blk_data_plane_stop; 1265 } 1266 1267 static const TypeInfo virtio_blk_info = { 1268 .name = TYPE_VIRTIO_BLK, 1269 .parent = TYPE_VIRTIO_DEVICE, 1270 .instance_size = sizeof(VirtIOBlock), 1271 .instance_init = virtio_blk_instance_init, 1272 .class_init = virtio_blk_class_init, 1273 }; 1274 1275 static void virtio_register_types(void) 1276 { 1277 type_register_static(&virtio_blk_info); 1278 } 1279 1280 type_init(virtio_register_types) 1281