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-common.h" 17 #include "qemu/iov.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(req->dev), &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(req->dev->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 VirtIODevice *vdev = VIRTIO_DEVICE(req->dev); 264 VirtQueueElement *elem = &req->elem; 265 VirtIOBlock *blk = req->dev; 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 block_acct_start(blk_get_stats(req->dev->blk), &req->acct, 0, 496 BLOCK_ACCT_FLUSH); 497 498 /* 499 * Make sure all outstanding writes are posted to the backing device. 500 */ 501 if (mrb->is_write && mrb->num_reqs > 0) { 502 virtio_blk_submit_multireq(req->dev->blk, mrb); 503 } 504 blk_aio_flush(req->dev->blk, virtio_blk_flush_complete, req); 505 } 506 507 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev, 508 uint64_t sector, size_t size) 509 { 510 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS; 511 uint64_t total_sectors; 512 513 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) { 514 return false; 515 } 516 if (sector & dev->sector_mask) { 517 return false; 518 } 519 if (size % dev->conf.conf.logical_block_size) { 520 return false; 521 } 522 blk_get_geometry(dev->blk, &total_sectors); 523 if (sector > total_sectors || nb_sectors > total_sectors - sector) { 524 return false; 525 } 526 return true; 527 } 528 529 static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req, 530 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes) 531 { 532 VirtIOBlock *s = req->dev; 533 VirtIODevice *vdev = VIRTIO_DEVICE(s); 534 uint64_t sector; 535 uint32_t num_sectors, flags, max_sectors; 536 uint8_t err_status; 537 int bytes; 538 539 sector = virtio_ldq_p(vdev, &dwz_hdr->sector); 540 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors); 541 flags = virtio_ldl_p(vdev, &dwz_hdr->flags); 542 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors : 543 s->conf.max_discard_sectors; 544 545 /* 546 * max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check 547 * make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in 548 * the integer variable. 549 */ 550 if (unlikely(num_sectors > max_sectors)) { 551 err_status = VIRTIO_BLK_S_IOERR; 552 goto err; 553 } 554 555 bytes = num_sectors << BDRV_SECTOR_BITS; 556 557 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) { 558 err_status = VIRTIO_BLK_S_IOERR; 559 goto err; 560 } 561 562 /* 563 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard 564 * and write zeroes commands if any unknown flag is set. 565 */ 566 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 567 err_status = VIRTIO_BLK_S_UNSUPP; 568 goto err; 569 } 570 571 if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */ 572 int blk_aio_flags = 0; 573 574 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { 575 blk_aio_flags |= BDRV_REQ_MAY_UNMAP; 576 } 577 578 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes, 579 BLOCK_ACCT_WRITE); 580 581 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS, 582 bytes, blk_aio_flags, 583 virtio_blk_discard_write_zeroes_complete, req); 584 } else { /* VIRTIO_BLK_T_DISCARD */ 585 /* 586 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for 587 * discard commands if the unmap flag is set. 588 */ 589 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 590 err_status = VIRTIO_BLK_S_UNSUPP; 591 goto err; 592 } 593 594 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes, 595 virtio_blk_discard_write_zeroes_complete, req); 596 } 597 598 return VIRTIO_BLK_S_OK; 599 600 err: 601 if (is_write_zeroes) { 602 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE); 603 } 604 return err_status; 605 } 606 607 static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) 608 { 609 uint32_t type; 610 struct iovec *in_iov = req->elem.in_sg; 611 struct iovec *out_iov = req->elem.out_sg; 612 unsigned in_num = req->elem.in_num; 613 unsigned out_num = req->elem.out_num; 614 VirtIOBlock *s = req->dev; 615 VirtIODevice *vdev = VIRTIO_DEVICE(s); 616 617 if (req->elem.out_num < 1 || req->elem.in_num < 1) { 618 virtio_error(vdev, "virtio-blk missing headers"); 619 return -1; 620 } 621 622 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out, 623 sizeof(req->out)) != sizeof(req->out))) { 624 virtio_error(vdev, "virtio-blk request outhdr too short"); 625 return -1; 626 } 627 628 iov_discard_front(&out_iov, &out_num, sizeof(req->out)); 629 630 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { 631 virtio_error(vdev, "virtio-blk request inhdr too short"); 632 return -1; 633 } 634 635 /* We always touch the last byte, so just see how big in_iov is. */ 636 req->in_len = iov_size(in_iov, in_num); 637 req->in = (void *)in_iov[in_num - 1].iov_base 638 + in_iov[in_num - 1].iov_len 639 - sizeof(struct virtio_blk_inhdr); 640 iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr)); 641 642 type = virtio_ldl_p(vdev, &req->out.type); 643 644 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER 645 * is an optional flag. Although a guest should not send this flag if 646 * not negotiated we ignored it in the past. So keep ignoring it. */ 647 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) { 648 case VIRTIO_BLK_T_IN: 649 { 650 bool is_write = type & VIRTIO_BLK_T_OUT; 651 req->sector_num = virtio_ldq_p(vdev, &req->out.sector); 652 653 if (is_write) { 654 qemu_iovec_init_external(&req->qiov, out_iov, out_num); 655 trace_virtio_blk_handle_write(vdev, req, req->sector_num, 656 req->qiov.size / BDRV_SECTOR_SIZE); 657 } else { 658 qemu_iovec_init_external(&req->qiov, in_iov, in_num); 659 trace_virtio_blk_handle_read(vdev, req, req->sector_num, 660 req->qiov.size / BDRV_SECTOR_SIZE); 661 } 662 663 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) { 664 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 665 block_acct_invalid(blk_get_stats(s->blk), 666 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 667 virtio_blk_free_request(req); 668 return 0; 669 } 670 671 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size, 672 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 673 674 /* merge would exceed maximum number of requests or IO direction 675 * changes */ 676 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS || 677 is_write != mrb->is_write || 678 !s->conf.request_merging)) { 679 virtio_blk_submit_multireq(s->blk, mrb); 680 } 681 682 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS); 683 mrb->reqs[mrb->num_reqs++] = req; 684 mrb->is_write = is_write; 685 break; 686 } 687 case VIRTIO_BLK_T_FLUSH: 688 virtio_blk_handle_flush(req, mrb); 689 break; 690 case VIRTIO_BLK_T_SCSI_CMD: 691 virtio_blk_handle_scsi(req); 692 break; 693 case VIRTIO_BLK_T_GET_ID: 694 { 695 /* 696 * NB: per existing s/n string convention the string is 697 * terminated by '\0' only when shorter than buffer. 698 */ 699 const char *serial = s->conf.serial ? s->conf.serial : ""; 700 size_t size = MIN(strlen(serial) + 1, 701 MIN(iov_size(in_iov, in_num), 702 VIRTIO_BLK_ID_BYTES)); 703 iov_from_buf(in_iov, in_num, 0, serial, size); 704 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 705 virtio_blk_free_request(req); 706 break; 707 } 708 /* 709 * VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with 710 * VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement, 711 * so we must mask it for these requests, then we will check if it is set. 712 */ 713 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT: 714 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT: 715 { 716 struct virtio_blk_discard_write_zeroes dwz_hdr; 717 size_t out_len = iov_size(out_iov, out_num); 718 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) == 719 VIRTIO_BLK_T_WRITE_ZEROES; 720 uint8_t err_status; 721 722 /* 723 * Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains 724 * more than one segment. 725 */ 726 if (unlikely(!(type & VIRTIO_BLK_T_OUT) || 727 out_len > sizeof(dwz_hdr))) { 728 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 729 virtio_blk_free_request(req); 730 return 0; 731 } 732 733 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr, 734 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) { 735 virtio_error(vdev, "virtio-blk discard/write_zeroes header" 736 " too short"); 737 return -1; 738 } 739 740 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr, 741 is_write_zeroes); 742 if (err_status != VIRTIO_BLK_S_OK) { 743 virtio_blk_req_complete(req, err_status); 744 virtio_blk_free_request(req); 745 } 746 747 break; 748 } 749 default: 750 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 751 virtio_blk_free_request(req); 752 } 753 return 0; 754 } 755 756 bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) 757 { 758 VirtIOBlockReq *req; 759 MultiReqBuffer mrb = {}; 760 bool progress = false; 761 762 aio_context_acquire(blk_get_aio_context(s->blk)); 763 blk_io_plug(s->blk); 764 765 do { 766 virtio_queue_set_notification(vq, 0); 767 768 while ((req = virtio_blk_get_request(s, vq))) { 769 progress = true; 770 if (virtio_blk_handle_request(req, &mrb)) { 771 virtqueue_detach_element(req->vq, &req->elem, 0); 772 virtio_blk_free_request(req); 773 break; 774 } 775 } 776 777 virtio_queue_set_notification(vq, 1); 778 } while (!virtio_queue_empty(vq)); 779 780 if (mrb.num_reqs) { 781 virtio_blk_submit_multireq(s->blk, &mrb); 782 } 783 784 blk_io_unplug(s->blk); 785 aio_context_release(blk_get_aio_context(s->blk)); 786 return progress; 787 } 788 789 static void virtio_blk_handle_output_do(VirtIOBlock *s, VirtQueue *vq) 790 { 791 virtio_blk_handle_vq(s, vq); 792 } 793 794 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 795 { 796 VirtIOBlock *s = (VirtIOBlock *)vdev; 797 798 if (s->dataplane) { 799 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 800 * dataplane here instead of waiting for .set_status(). 801 */ 802 virtio_device_start_ioeventfd(vdev); 803 if (!s->dataplane_disabled) { 804 return; 805 } 806 } 807 virtio_blk_handle_output_do(s, vq); 808 } 809 810 static void virtio_blk_dma_restart_bh(void *opaque) 811 { 812 VirtIOBlock *s = opaque; 813 VirtIOBlockReq *req = s->rq; 814 MultiReqBuffer mrb = {}; 815 816 qemu_bh_delete(s->bh); 817 s->bh = NULL; 818 819 s->rq = NULL; 820 821 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 822 while (req) { 823 VirtIOBlockReq *next = req->next; 824 if (virtio_blk_handle_request(req, &mrb)) { 825 /* Device is now broken and won't do any processing until it gets 826 * reset. Already queued requests will be lost: let's purge them. 827 */ 828 while (req) { 829 next = req->next; 830 virtqueue_detach_element(req->vq, &req->elem, 0); 831 virtio_blk_free_request(req); 832 req = next; 833 } 834 break; 835 } 836 req = next; 837 } 838 839 if (mrb.num_reqs) { 840 virtio_blk_submit_multireq(s->blk, &mrb); 841 } 842 blk_dec_in_flight(s->conf.conf.blk); 843 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 844 } 845 846 static void virtio_blk_dma_restart_cb(void *opaque, int running, 847 RunState state) 848 { 849 VirtIOBlock *s = opaque; 850 851 if (!running) { 852 return; 853 } 854 855 if (!s->bh) { 856 /* FIXME The data plane is not started yet, so these requests are 857 * processed in the main thread. */ 858 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk), 859 virtio_blk_dma_restart_bh, s); 860 blk_inc_in_flight(s->conf.conf.blk); 861 qemu_bh_schedule(s->bh); 862 } 863 } 864 865 static void virtio_blk_reset(VirtIODevice *vdev) 866 { 867 VirtIOBlock *s = VIRTIO_BLK(vdev); 868 AioContext *ctx; 869 VirtIOBlockReq *req; 870 871 ctx = blk_get_aio_context(s->blk); 872 aio_context_acquire(ctx); 873 blk_drain(s->blk); 874 875 /* We drop queued requests after blk_drain() because blk_drain() itself can 876 * produce them. */ 877 while (s->rq) { 878 req = s->rq; 879 s->rq = req->next; 880 virtqueue_detach_element(req->vq, &req->elem, 0); 881 virtio_blk_free_request(req); 882 } 883 884 aio_context_release(ctx); 885 886 assert(!s->dataplane_started); 887 blk_set_enable_write_cache(s->blk, s->original_wce); 888 } 889 890 /* coalesce internal state, copy to pci i/o region 0 891 */ 892 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) 893 { 894 VirtIOBlock *s = VIRTIO_BLK(vdev); 895 BlockConf *conf = &s->conf.conf; 896 struct virtio_blk_config blkcfg; 897 uint64_t capacity; 898 int64_t length; 899 int blk_size = conf->logical_block_size; 900 901 blk_get_geometry(s->blk, &capacity); 902 memset(&blkcfg, 0, sizeof(blkcfg)); 903 virtio_stq_p(vdev, &blkcfg.capacity, capacity); 904 virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2); 905 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls); 906 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size); 907 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size); 908 virtio_stw_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size); 909 blkcfg.geometry.heads = conf->heads; 910 /* 911 * We must ensure that the block device capacity is a multiple of 912 * the logical block size. If that is not the case, let's use 913 * sector_mask to adopt the geometry to have a correct picture. 914 * For those devices where the capacity is ok for the given geometry 915 * we don't touch the sector value of the geometry, since some devices 916 * (like s390 dasd) need a specific value. Here the capacity is already 917 * cyls*heads*secs*blk_size and the sector value is not block size 918 * divided by 512 - instead it is the amount of blk_size blocks 919 * per track (cylinder). 920 */ 921 length = blk_getlength(s->blk); 922 if (length > 0 && length / conf->heads / conf->secs % blk_size) { 923 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask; 924 } else { 925 blkcfg.geometry.sectors = conf->secs; 926 } 927 blkcfg.size_max = 0; 928 blkcfg.physical_block_exp = get_physical_block_exp(conf); 929 blkcfg.alignment_offset = 0; 930 blkcfg.wce = blk_enable_write_cache(s->blk); 931 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); 932 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) { 933 virtio_stl_p(vdev, &blkcfg.max_discard_sectors, 934 s->conf.max_discard_sectors); 935 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment, 936 blk_size >> BDRV_SECTOR_BITS); 937 /* 938 * We support only one segment per request since multiple segments 939 * are not widely used and there are no userspace APIs that allow 940 * applications to submit multiple segments in a single call. 941 */ 942 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1); 943 } 944 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) { 945 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors, 946 s->conf.max_write_zeroes_sectors); 947 blkcfg.write_zeroes_may_unmap = 1; 948 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1); 949 } 950 memcpy(config, &blkcfg, s->config_size); 951 } 952 953 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) 954 { 955 VirtIOBlock *s = VIRTIO_BLK(vdev); 956 struct virtio_blk_config blkcfg; 957 958 memcpy(&blkcfg, config, s->config_size); 959 960 aio_context_acquire(blk_get_aio_context(s->blk)); 961 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); 962 aio_context_release(blk_get_aio_context(s->blk)); 963 } 964 965 static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, 966 Error **errp) 967 { 968 VirtIOBlock *s = VIRTIO_BLK(vdev); 969 970 /* Firstly sync all virtio-blk possible supported features */ 971 features |= s->host_features; 972 973 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 974 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 975 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 976 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 977 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) { 978 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) { 979 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0"); 980 return 0; 981 } 982 } else { 983 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT); 984 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); 985 } 986 987 if (blk_enable_write_cache(s->blk)) { 988 virtio_add_feature(&features, VIRTIO_BLK_F_WCE); 989 } 990 if (blk_is_read_only(s->blk)) { 991 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 992 } 993 if (s->conf.num_queues > 1) { 994 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 995 } 996 997 return features; 998 } 999 1000 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) 1001 { 1002 VirtIOBlock *s = VIRTIO_BLK(vdev); 1003 1004 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) { 1005 assert(!s->dataplane_started); 1006 } 1007 1008 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { 1009 return; 1010 } 1011 1012 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send 1013 * cache flushes. Thus, the "auto writethrough" behavior is never 1014 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature. 1015 * Leaving it enabled would break the following sequence: 1016 * 1017 * Guest started with "-drive cache=writethrough" 1018 * Guest sets status to 0 1019 * Guest sets DRIVER bit in status field 1020 * Guest reads host features (WCE=0, CONFIG_WCE=1) 1021 * Guest writes guest features (WCE=0, CONFIG_WCE=1) 1022 * Guest writes 1 to the WCE configuration field (writeback mode) 1023 * Guest sets DRIVER_OK bit in status field 1024 * 1025 * s->blk would erroneously be placed in writethrough mode. 1026 */ 1027 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) { 1028 aio_context_acquire(blk_get_aio_context(s->blk)); 1029 blk_set_enable_write_cache(s->blk, 1030 virtio_vdev_has_feature(vdev, 1031 VIRTIO_BLK_F_WCE)); 1032 aio_context_release(blk_get_aio_context(s->blk)); 1033 } 1034 } 1035 1036 static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f) 1037 { 1038 VirtIOBlock *s = VIRTIO_BLK(vdev); 1039 VirtIOBlockReq *req = s->rq; 1040 1041 while (req) { 1042 qemu_put_sbyte(f, 1); 1043 1044 if (s->conf.num_queues > 1) { 1045 qemu_put_be32(f, virtio_get_queue_index(req->vq)); 1046 } 1047 1048 qemu_put_virtqueue_element(f, &req->elem); 1049 req = req->next; 1050 } 1051 qemu_put_sbyte(f, 0); 1052 } 1053 1054 static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, 1055 int version_id) 1056 { 1057 VirtIOBlock *s = VIRTIO_BLK(vdev); 1058 1059 while (qemu_get_sbyte(f)) { 1060 unsigned nvqs = s->conf.num_queues; 1061 unsigned vq_idx = 0; 1062 VirtIOBlockReq *req; 1063 1064 if (nvqs > 1) { 1065 vq_idx = qemu_get_be32(f); 1066 1067 if (vq_idx >= nvqs) { 1068 error_report("Invalid virtqueue index in request list: %#x", 1069 vq_idx); 1070 return -EINVAL; 1071 } 1072 } 1073 1074 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq)); 1075 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req); 1076 req->next = s->rq; 1077 s->rq = req; 1078 } 1079 1080 return 0; 1081 } 1082 1083 static void virtio_blk_resize(void *opaque) 1084 { 1085 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1086 1087 virtio_notify_config(vdev); 1088 } 1089 1090 static const BlockDevOps virtio_block_ops = { 1091 .resize_cb = virtio_blk_resize, 1092 }; 1093 1094 static void virtio_blk_device_realize(DeviceState *dev, Error **errp) 1095 { 1096 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1097 VirtIOBlock *s = VIRTIO_BLK(dev); 1098 VirtIOBlkConf *conf = &s->conf; 1099 Error *err = NULL; 1100 unsigned i; 1101 1102 if (!conf->conf.blk) { 1103 error_setg(errp, "drive property not set"); 1104 return; 1105 } 1106 if (!blk_is_inserted(conf->conf.blk)) { 1107 error_setg(errp, "Device needs media, but drive is empty"); 1108 return; 1109 } 1110 if (!conf->num_queues) { 1111 error_setg(errp, "num-queues property must be larger than 0"); 1112 return; 1113 } 1114 if (!is_power_of_2(conf->queue_size) || 1115 conf->queue_size > VIRTQUEUE_MAX_SIZE) { 1116 error_setg(errp, "invalid queue-size property (%" PRIu16 "), " 1117 "must be a power of 2 (max %d)", 1118 conf->queue_size, VIRTQUEUE_MAX_SIZE); 1119 return; 1120 } 1121 1122 if (!blkconf_apply_backend_options(&conf->conf, 1123 blk_is_read_only(conf->conf.blk), true, 1124 errp)) { 1125 return; 1126 } 1127 s->original_wce = blk_enable_write_cache(conf->conf.blk); 1128 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) { 1129 return; 1130 } 1131 1132 blkconf_blocksizes(&conf->conf); 1133 1134 if (conf->conf.logical_block_size > 1135 conf->conf.physical_block_size) { 1136 error_setg(errp, 1137 "logical_block_size > physical_block_size not supported"); 1138 return; 1139 } 1140 1141 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) && 1142 (!conf->max_discard_sectors || 1143 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1144 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")" 1145 ", must be between 1 and %d", 1146 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS); 1147 return; 1148 } 1149 1150 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) && 1151 (!conf->max_write_zeroes_sectors || 1152 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1153 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32 1154 "), must be between 1 and %d", 1155 conf->max_write_zeroes_sectors, 1156 (int)BDRV_REQUEST_MAX_SECTORS); 1157 return; 1158 } 1159 1160 virtio_blk_set_config_size(s, s->host_features); 1161 1162 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, s->config_size); 1163 1164 s->blk = conf->conf.blk; 1165 s->rq = NULL; 1166 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1; 1167 1168 for (i = 0; i < conf->num_queues; i++) { 1169 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output); 1170 } 1171 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err); 1172 if (err != NULL) { 1173 error_propagate(errp, err); 1174 virtio_cleanup(vdev); 1175 return; 1176 } 1177 1178 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); 1179 blk_set_dev_ops(s->blk, &virtio_block_ops, s); 1180 blk_set_guest_block_size(s->blk, s->conf.conf.logical_block_size); 1181 1182 blk_iostatus_enable(s->blk); 1183 } 1184 1185 static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp) 1186 { 1187 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1188 VirtIOBlock *s = VIRTIO_BLK(dev); 1189 1190 virtio_blk_data_plane_destroy(s->dataplane); 1191 s->dataplane = NULL; 1192 qemu_del_vm_change_state_handler(s->change); 1193 blockdev_mark_auto_del(s->blk); 1194 virtio_cleanup(vdev); 1195 } 1196 1197 static void virtio_blk_instance_init(Object *obj) 1198 { 1199 VirtIOBlock *s = VIRTIO_BLK(obj); 1200 1201 device_add_bootindex_property(obj, &s->conf.conf.bootindex, 1202 "bootindex", "/disk@0,0", 1203 DEVICE(obj), NULL); 1204 } 1205 1206 static const VMStateDescription vmstate_virtio_blk = { 1207 .name = "virtio-blk", 1208 .minimum_version_id = 2, 1209 .version_id = 2, 1210 .fields = (VMStateField[]) { 1211 VMSTATE_VIRTIO_DEVICE, 1212 VMSTATE_END_OF_LIST() 1213 }, 1214 }; 1215 1216 static Property virtio_blk_properties[] = { 1217 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf), 1218 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf), 1219 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf), 1220 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial), 1221 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features, 1222 VIRTIO_BLK_F_CONFIG_WCE, true), 1223 #ifdef __linux__ 1224 DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features, 1225 VIRTIO_BLK_F_SCSI, false), 1226 #endif 1227 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0, 1228 true), 1229 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1), 1230 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128), 1231 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, 1232 IOThread *), 1233 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, 1234 VIRTIO_BLK_F_DISCARD, true), 1235 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features, 1236 VIRTIO_BLK_F_WRITE_ZEROES, true), 1237 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock, 1238 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS), 1239 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock, 1240 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS), 1241 DEFINE_PROP_END_OF_LIST(), 1242 }; 1243 1244 static void virtio_blk_class_init(ObjectClass *klass, void *data) 1245 { 1246 DeviceClass *dc = DEVICE_CLASS(klass); 1247 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 1248 1249 dc->props = virtio_blk_properties; 1250 dc->vmsd = &vmstate_virtio_blk; 1251 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 1252 vdc->realize = virtio_blk_device_realize; 1253 vdc->unrealize = virtio_blk_device_unrealize; 1254 vdc->get_config = virtio_blk_update_config; 1255 vdc->set_config = virtio_blk_set_config; 1256 vdc->get_features = virtio_blk_get_features; 1257 vdc->set_status = virtio_blk_set_status; 1258 vdc->reset = virtio_blk_reset; 1259 vdc->save = virtio_blk_save_device; 1260 vdc->load = virtio_blk_load_device; 1261 vdc->start_ioeventfd = virtio_blk_data_plane_start; 1262 vdc->stop_ioeventfd = virtio_blk_data_plane_stop; 1263 } 1264 1265 static const TypeInfo virtio_blk_info = { 1266 .name = TYPE_VIRTIO_BLK, 1267 .parent = TYPE_VIRTIO_DEVICE, 1268 .instance_size = sizeof(VirtIOBlock), 1269 .instance_init = virtio_blk_instance_init, 1270 .class_init = virtio_blk_class_init, 1271 }; 1272 1273 static void virtio_register_types(void) 1274 { 1275 type_register_static(&virtio_blk_info); 1276 } 1277 1278 type_init(virtio_register_types) 1279