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 "hw/qdev-properties.h" 22 #include "sysemu/blockdev.h" 23 #include "hw/virtio/virtio-blk.h" 24 #include "dataplane/virtio-blk.h" 25 #include "scsi/constants.h" 26 #ifdef __linux__ 27 # include <scsi/sg.h> 28 #endif 29 #include "hw/virtio/virtio-bus.h" 30 #include "migration/qemu-file-types.h" 31 #include "hw/virtio/virtio-access.h" 32 33 /* Config size before the discard support (hide associated config fields) */ 34 #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \ 35 max_discard_sectors) 36 /* 37 * Starting from the discard feature, we can use this array to properly 38 * set the config size depending on the features enabled. 39 */ 40 static VirtIOFeature feature_sizes[] = { 41 {.flags = 1ULL << VIRTIO_BLK_F_DISCARD, 42 .end = virtio_endof(struct virtio_blk_config, discard_sector_alignment)}, 43 {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES, 44 .end = virtio_endof(struct virtio_blk_config, write_zeroes_may_unmap)}, 45 {} 46 }; 47 48 static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features) 49 { 50 s->config_size = MAX(VIRTIO_BLK_CFG_SIZE, 51 virtio_feature_get_config_size(feature_sizes, host_features)); 52 53 assert(s->config_size <= sizeof(struct virtio_blk_config)); 54 } 55 56 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, 57 VirtIOBlockReq *req) 58 { 59 req->dev = s; 60 req->vq = vq; 61 req->qiov.size = 0; 62 req->in_len = 0; 63 req->next = NULL; 64 req->mr_next = NULL; 65 } 66 67 static void virtio_blk_free_request(VirtIOBlockReq *req) 68 { 69 g_free(req); 70 } 71 72 static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status) 73 { 74 VirtIOBlock *s = req->dev; 75 VirtIODevice *vdev = VIRTIO_DEVICE(s); 76 77 trace_virtio_blk_req_complete(vdev, req, status); 78 79 stb_p(&req->in->status, status); 80 virtqueue_push(req->vq, &req->elem, req->in_len); 81 if (s->dataplane_started && !s->dataplane_disabled) { 82 virtio_blk_data_plane_notify(s->dataplane, req->vq); 83 } else { 84 virtio_notify(vdev, req->vq); 85 } 86 } 87 88 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, 89 bool is_read, bool acct_failed) 90 { 91 VirtIOBlock *s = req->dev; 92 BlockErrorAction action = blk_get_error_action(s->blk, is_read, error); 93 94 if (action == BLOCK_ERROR_ACTION_STOP) { 95 /* Break the link as the next request is going to be parsed from the 96 * ring again. Otherwise we may end up doing a double completion! */ 97 req->mr_next = NULL; 98 req->next = s->rq; 99 s->rq = req; 100 } else if (action == BLOCK_ERROR_ACTION_REPORT) { 101 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 102 if (acct_failed) { 103 block_acct_failed(blk_get_stats(s->blk), &req->acct); 104 } 105 virtio_blk_free_request(req); 106 } 107 108 blk_error_action(s->blk, action, is_read, error); 109 return action != BLOCK_ERROR_ACTION_IGNORE; 110 } 111 112 static void virtio_blk_rw_complete(void *opaque, int ret) 113 { 114 VirtIOBlockReq *next = opaque; 115 VirtIOBlock *s = next->dev; 116 VirtIODevice *vdev = VIRTIO_DEVICE(s); 117 118 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 119 while (next) { 120 VirtIOBlockReq *req = next; 121 next = req->mr_next; 122 trace_virtio_blk_rw_complete(vdev, req, ret); 123 124 if (req->qiov.nalloc != -1) { 125 /* If nalloc is != -1 req->qiov is a local copy of the original 126 * external iovec. It was allocated in submit_requests to be 127 * able to merge requests. */ 128 qemu_iovec_destroy(&req->qiov); 129 } 130 131 if (ret) { 132 int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type); 133 bool is_read = !(p & VIRTIO_BLK_T_OUT); 134 /* Note that memory may be dirtied on read failure. If the 135 * virtio request is not completed here, as is the case for 136 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied 137 * correctly during live migration. While this is ugly, 138 * it is acceptable because the device is free to write to 139 * the memory until the request is completed (which will 140 * happen on the other side of the migration). 141 */ 142 if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) { 143 continue; 144 } 145 } 146 147 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 148 block_acct_done(blk_get_stats(s->blk), &req->acct); 149 virtio_blk_free_request(req); 150 } 151 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 152 } 153 154 static void virtio_blk_flush_complete(void *opaque, int ret) 155 { 156 VirtIOBlockReq *req = opaque; 157 VirtIOBlock *s = req->dev; 158 159 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 160 if (ret) { 161 if (virtio_blk_handle_rw_error(req, -ret, 0, true)) { 162 goto out; 163 } 164 } 165 166 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 167 block_acct_done(blk_get_stats(s->blk), &req->acct); 168 virtio_blk_free_request(req); 169 170 out: 171 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 172 } 173 174 static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret) 175 { 176 VirtIOBlockReq *req = opaque; 177 VirtIOBlock *s = req->dev; 178 bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) & 179 ~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES; 180 181 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 182 if (ret) { 183 if (virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) { 184 goto out; 185 } 186 } 187 188 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 189 if (is_write_zeroes) { 190 block_acct_done(blk_get_stats(s->blk), &req->acct); 191 } 192 virtio_blk_free_request(req); 193 194 out: 195 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 196 } 197 198 #ifdef __linux__ 199 200 typedef struct { 201 VirtIOBlockReq *req; 202 struct sg_io_hdr hdr; 203 } VirtIOBlockIoctlReq; 204 205 static void virtio_blk_ioctl_complete(void *opaque, int status) 206 { 207 VirtIOBlockIoctlReq *ioctl_req = opaque; 208 VirtIOBlockReq *req = ioctl_req->req; 209 VirtIOBlock *s = req->dev; 210 VirtIODevice *vdev = VIRTIO_DEVICE(s); 211 struct virtio_scsi_inhdr *scsi; 212 struct sg_io_hdr *hdr; 213 214 scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base; 215 216 if (status) { 217 status = VIRTIO_BLK_S_UNSUPP; 218 virtio_stl_p(vdev, &scsi->errors, 255); 219 goto out; 220 } 221 222 hdr = &ioctl_req->hdr; 223 /* 224 * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi) 225 * clear the masked_status field [hence status gets cleared too, see 226 * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED 227 * status has occurred. However they do set DRIVER_SENSE in driver_status 228 * field. Also a (sb_len_wr > 0) indicates there is a sense buffer. 229 */ 230 if (hdr->status == 0 && hdr->sb_len_wr > 0) { 231 hdr->status = CHECK_CONDITION; 232 } 233 234 virtio_stl_p(vdev, &scsi->errors, 235 hdr->status | (hdr->msg_status << 8) | 236 (hdr->host_status << 16) | (hdr->driver_status << 24)); 237 virtio_stl_p(vdev, &scsi->residual, hdr->resid); 238 virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr); 239 virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len); 240 241 out: 242 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 243 virtio_blk_req_complete(req, status); 244 virtio_blk_free_request(req); 245 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 246 g_free(ioctl_req); 247 } 248 249 #endif 250 251 static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq) 252 { 253 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq)); 254 255 if (req) { 256 virtio_blk_init_request(s, vq, req); 257 } 258 return req; 259 } 260 261 static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req) 262 { 263 int status = VIRTIO_BLK_S_OK; 264 struct virtio_scsi_inhdr *scsi = NULL; 265 VirtIOBlock *blk = req->dev; 266 VirtIODevice *vdev = VIRTIO_DEVICE(blk); 267 VirtQueueElement *elem = &req->elem; 268 269 #ifdef __linux__ 270 int i; 271 VirtIOBlockIoctlReq *ioctl_req; 272 BlockAIOCB *acb; 273 #endif 274 275 /* 276 * We require at least one output segment each for the virtio_blk_outhdr 277 * and the SCSI command block. 278 * 279 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr 280 * and the sense buffer pointer in the input segments. 281 */ 282 if (elem->out_num < 2 || elem->in_num < 3) { 283 status = VIRTIO_BLK_S_IOERR; 284 goto fail; 285 } 286 287 /* 288 * The scsi inhdr is placed in the second-to-last input segment, just 289 * before the regular inhdr. 290 */ 291 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base; 292 293 if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) { 294 status = VIRTIO_BLK_S_UNSUPP; 295 goto fail; 296 } 297 298 /* 299 * No support for bidirection commands yet. 300 */ 301 if (elem->out_num > 2 && elem->in_num > 3) { 302 status = VIRTIO_BLK_S_UNSUPP; 303 goto fail; 304 } 305 306 #ifdef __linux__ 307 ioctl_req = g_new0(VirtIOBlockIoctlReq, 1); 308 ioctl_req->req = req; 309 ioctl_req->hdr.interface_id = 'S'; 310 ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len; 311 ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base; 312 ioctl_req->hdr.dxfer_len = 0; 313 314 if (elem->out_num > 2) { 315 /* 316 * If there are more than the minimally required 2 output segments 317 * there is write payload starting from the third iovec. 318 */ 319 ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV; 320 ioctl_req->hdr.iovec_count = elem->out_num - 2; 321 322 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) { 323 ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len; 324 } 325 326 ioctl_req->hdr.dxferp = elem->out_sg + 2; 327 328 } else if (elem->in_num > 3) { 329 /* 330 * If we have more than 3 input segments the guest wants to actually 331 * read data. 332 */ 333 ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV; 334 ioctl_req->hdr.iovec_count = elem->in_num - 3; 335 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) { 336 ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len; 337 } 338 339 ioctl_req->hdr.dxferp = elem->in_sg; 340 } else { 341 /* 342 * Some SCSI commands don't actually transfer any data. 343 */ 344 ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE; 345 } 346 347 ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base; 348 ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len; 349 350 acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr, 351 virtio_blk_ioctl_complete, ioctl_req); 352 if (!acb) { 353 g_free(ioctl_req); 354 status = VIRTIO_BLK_S_UNSUPP; 355 goto fail; 356 } 357 return -EINPROGRESS; 358 #else 359 abort(); 360 #endif 361 362 fail: 363 /* Just put anything nonzero so that the ioctl fails in the guest. */ 364 if (scsi) { 365 virtio_stl_p(vdev, &scsi->errors, 255); 366 } 367 return status; 368 } 369 370 static void virtio_blk_handle_scsi(VirtIOBlockReq *req) 371 { 372 int status; 373 374 status = virtio_blk_handle_scsi_req(req); 375 if (status != -EINPROGRESS) { 376 virtio_blk_req_complete(req, status); 377 virtio_blk_free_request(req); 378 } 379 } 380 381 static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, 382 int start, int num_reqs, int niov) 383 { 384 QEMUIOVector *qiov = &mrb->reqs[start]->qiov; 385 int64_t sector_num = mrb->reqs[start]->sector_num; 386 bool is_write = mrb->is_write; 387 388 if (num_reqs > 1) { 389 int i; 390 struct iovec *tmp_iov = qiov->iov; 391 int tmp_niov = qiov->niov; 392 393 /* mrb->reqs[start]->qiov was initialized from external so we can't 394 * modify it here. We need to initialize it locally and then add the 395 * external iovecs. */ 396 qemu_iovec_init(qiov, niov); 397 398 for (i = 0; i < tmp_niov; i++) { 399 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len); 400 } 401 402 for (i = start + 1; i < start + num_reqs; i++) { 403 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0, 404 mrb->reqs[i]->qiov.size); 405 mrb->reqs[i - 1]->mr_next = mrb->reqs[i]; 406 } 407 408 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev), 409 mrb, start, num_reqs, 410 sector_num << BDRV_SECTOR_BITS, 411 qiov->size, is_write); 412 block_acct_merge_done(blk_get_stats(blk), 413 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ, 414 num_reqs - 1); 415 } 416 417 if (is_write) { 418 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, 419 virtio_blk_rw_complete, mrb->reqs[start]); 420 } else { 421 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, 422 virtio_blk_rw_complete, mrb->reqs[start]); 423 } 424 } 425 426 static int multireq_compare(const void *a, const void *b) 427 { 428 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a, 429 *req2 = *(VirtIOBlockReq **)b; 430 431 /* 432 * Note that we can't simply subtract sector_num1 from sector_num2 433 * here as that could overflow the return value. 434 */ 435 if (req1->sector_num > req2->sector_num) { 436 return 1; 437 } else if (req1->sector_num < req2->sector_num) { 438 return -1; 439 } else { 440 return 0; 441 } 442 } 443 444 static void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) 445 { 446 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0; 447 uint32_t max_transfer; 448 int64_t sector_num = 0; 449 450 if (mrb->num_reqs == 1) { 451 submit_requests(blk, mrb, 0, 1, -1); 452 mrb->num_reqs = 0; 453 return; 454 } 455 456 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk); 457 458 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs), 459 &multireq_compare); 460 461 for (i = 0; i < mrb->num_reqs; i++) { 462 VirtIOBlockReq *req = mrb->reqs[i]; 463 if (num_reqs > 0) { 464 /* 465 * NOTE: We cannot merge the requests in below situations: 466 * 1. requests are not sequential 467 * 2. merge would exceed maximum number of IOVs 468 * 3. merge would exceed maximum transfer length of backend device 469 */ 470 if (sector_num + nb_sectors != req->sector_num || 471 niov > blk_get_max_iov(blk) - req->qiov.niov || 472 req->qiov.size > max_transfer || 473 nb_sectors > (max_transfer - 474 req->qiov.size) / BDRV_SECTOR_SIZE) { 475 submit_requests(blk, mrb, start, num_reqs, niov); 476 num_reqs = 0; 477 } 478 } 479 480 if (num_reqs == 0) { 481 sector_num = req->sector_num; 482 nb_sectors = niov = 0; 483 start = i; 484 } 485 486 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE; 487 niov += req->qiov.niov; 488 num_reqs++; 489 } 490 491 submit_requests(blk, mrb, start, num_reqs, niov); 492 mrb->num_reqs = 0; 493 } 494 495 static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb) 496 { 497 VirtIOBlock *s = req->dev; 498 499 block_acct_start(blk_get_stats(s->blk), &req->acct, 0, 500 BLOCK_ACCT_FLUSH); 501 502 /* 503 * Make sure all outstanding writes are posted to the backing device. 504 */ 505 if (mrb->is_write && mrb->num_reqs > 0) { 506 virtio_blk_submit_multireq(s->blk, mrb); 507 } 508 blk_aio_flush(s->blk, virtio_blk_flush_complete, req); 509 } 510 511 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev, 512 uint64_t sector, size_t size) 513 { 514 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS; 515 uint64_t total_sectors; 516 517 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) { 518 return false; 519 } 520 if (sector & dev->sector_mask) { 521 return false; 522 } 523 if (size % dev->conf.conf.logical_block_size) { 524 return false; 525 } 526 blk_get_geometry(dev->blk, &total_sectors); 527 if (sector > total_sectors || nb_sectors > total_sectors - sector) { 528 return false; 529 } 530 return true; 531 } 532 533 static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req, 534 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes) 535 { 536 VirtIOBlock *s = req->dev; 537 VirtIODevice *vdev = VIRTIO_DEVICE(s); 538 uint64_t sector; 539 uint32_t num_sectors, flags, max_sectors; 540 uint8_t err_status; 541 int bytes; 542 543 sector = virtio_ldq_p(vdev, &dwz_hdr->sector); 544 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors); 545 flags = virtio_ldl_p(vdev, &dwz_hdr->flags); 546 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors : 547 s->conf.max_discard_sectors; 548 549 /* 550 * max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check 551 * make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in 552 * the integer variable. 553 */ 554 if (unlikely(num_sectors > max_sectors)) { 555 err_status = VIRTIO_BLK_S_IOERR; 556 goto err; 557 } 558 559 bytes = num_sectors << BDRV_SECTOR_BITS; 560 561 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) { 562 err_status = VIRTIO_BLK_S_IOERR; 563 goto err; 564 } 565 566 /* 567 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard 568 * and write zeroes commands if any unknown flag is set. 569 */ 570 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 571 err_status = VIRTIO_BLK_S_UNSUPP; 572 goto err; 573 } 574 575 if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */ 576 int blk_aio_flags = 0; 577 578 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { 579 blk_aio_flags |= BDRV_REQ_MAY_UNMAP; 580 } 581 582 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes, 583 BLOCK_ACCT_WRITE); 584 585 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS, 586 bytes, blk_aio_flags, 587 virtio_blk_discard_write_zeroes_complete, req); 588 } else { /* VIRTIO_BLK_T_DISCARD */ 589 /* 590 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for 591 * discard commands if the unmap flag is set. 592 */ 593 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 594 err_status = VIRTIO_BLK_S_UNSUPP; 595 goto err; 596 } 597 598 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes, 599 virtio_blk_discard_write_zeroes_complete, req); 600 } 601 602 return VIRTIO_BLK_S_OK; 603 604 err: 605 if (is_write_zeroes) { 606 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE); 607 } 608 return err_status; 609 } 610 611 static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) 612 { 613 uint32_t type; 614 struct iovec *in_iov = req->elem.in_sg; 615 struct iovec *out_iov = req->elem.out_sg; 616 unsigned in_num = req->elem.in_num; 617 unsigned out_num = req->elem.out_num; 618 VirtIOBlock *s = req->dev; 619 VirtIODevice *vdev = VIRTIO_DEVICE(s); 620 621 if (req->elem.out_num < 1 || req->elem.in_num < 1) { 622 virtio_error(vdev, "virtio-blk missing headers"); 623 return -1; 624 } 625 626 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out, 627 sizeof(req->out)) != sizeof(req->out))) { 628 virtio_error(vdev, "virtio-blk request outhdr too short"); 629 return -1; 630 } 631 632 iov_discard_front(&out_iov, &out_num, sizeof(req->out)); 633 634 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { 635 virtio_error(vdev, "virtio-blk request inhdr too short"); 636 return -1; 637 } 638 639 /* We always touch the last byte, so just see how big in_iov is. */ 640 req->in_len = iov_size(in_iov, in_num); 641 req->in = (void *)in_iov[in_num - 1].iov_base 642 + in_iov[in_num - 1].iov_len 643 - sizeof(struct virtio_blk_inhdr); 644 iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr)); 645 646 type = virtio_ldl_p(vdev, &req->out.type); 647 648 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER 649 * is an optional flag. Although a guest should not send this flag if 650 * not negotiated we ignored it in the past. So keep ignoring it. */ 651 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) { 652 case VIRTIO_BLK_T_IN: 653 { 654 bool is_write = type & VIRTIO_BLK_T_OUT; 655 req->sector_num = virtio_ldq_p(vdev, &req->out.sector); 656 657 if (is_write) { 658 qemu_iovec_init_external(&req->qiov, out_iov, out_num); 659 trace_virtio_blk_handle_write(vdev, req, req->sector_num, 660 req->qiov.size / BDRV_SECTOR_SIZE); 661 } else { 662 qemu_iovec_init_external(&req->qiov, in_iov, in_num); 663 trace_virtio_blk_handle_read(vdev, req, req->sector_num, 664 req->qiov.size / BDRV_SECTOR_SIZE); 665 } 666 667 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) { 668 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 669 block_acct_invalid(blk_get_stats(s->blk), 670 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 671 virtio_blk_free_request(req); 672 return 0; 673 } 674 675 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size, 676 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 677 678 /* merge would exceed maximum number of requests or IO direction 679 * changes */ 680 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS || 681 is_write != mrb->is_write || 682 !s->conf.request_merging)) { 683 virtio_blk_submit_multireq(s->blk, mrb); 684 } 685 686 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS); 687 mrb->reqs[mrb->num_reqs++] = req; 688 mrb->is_write = is_write; 689 break; 690 } 691 case VIRTIO_BLK_T_FLUSH: 692 virtio_blk_handle_flush(req, mrb); 693 break; 694 case VIRTIO_BLK_T_SCSI_CMD: 695 virtio_blk_handle_scsi(req); 696 break; 697 case VIRTIO_BLK_T_GET_ID: 698 { 699 /* 700 * NB: per existing s/n string convention the string is 701 * terminated by '\0' only when shorter than buffer. 702 */ 703 const char *serial = s->conf.serial ? s->conf.serial : ""; 704 size_t size = MIN(strlen(serial) + 1, 705 MIN(iov_size(in_iov, in_num), 706 VIRTIO_BLK_ID_BYTES)); 707 iov_from_buf(in_iov, in_num, 0, serial, size); 708 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 709 virtio_blk_free_request(req); 710 break; 711 } 712 /* 713 * VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with 714 * VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement, 715 * so we must mask it for these requests, then we will check if it is set. 716 */ 717 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT: 718 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT: 719 { 720 struct virtio_blk_discard_write_zeroes dwz_hdr; 721 size_t out_len = iov_size(out_iov, out_num); 722 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) == 723 VIRTIO_BLK_T_WRITE_ZEROES; 724 uint8_t err_status; 725 726 /* 727 * Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains 728 * more than one segment. 729 */ 730 if (unlikely(!(type & VIRTIO_BLK_T_OUT) || 731 out_len > sizeof(dwz_hdr))) { 732 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 733 virtio_blk_free_request(req); 734 return 0; 735 } 736 737 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr, 738 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) { 739 virtio_error(vdev, "virtio-blk discard/write_zeroes header" 740 " too short"); 741 return -1; 742 } 743 744 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr, 745 is_write_zeroes); 746 if (err_status != VIRTIO_BLK_S_OK) { 747 virtio_blk_req_complete(req, err_status); 748 virtio_blk_free_request(req); 749 } 750 751 break; 752 } 753 default: 754 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 755 virtio_blk_free_request(req); 756 } 757 return 0; 758 } 759 760 bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) 761 { 762 VirtIOBlockReq *req; 763 MultiReqBuffer mrb = {}; 764 bool progress = false; 765 766 aio_context_acquire(blk_get_aio_context(s->blk)); 767 blk_io_plug(s->blk); 768 769 do { 770 virtio_queue_set_notification(vq, 0); 771 772 while ((req = virtio_blk_get_request(s, vq))) { 773 progress = true; 774 if (virtio_blk_handle_request(req, &mrb)) { 775 virtqueue_detach_element(req->vq, &req->elem, 0); 776 virtio_blk_free_request(req); 777 break; 778 } 779 } 780 781 virtio_queue_set_notification(vq, 1); 782 } while (!virtio_queue_empty(vq)); 783 784 if (mrb.num_reqs) { 785 virtio_blk_submit_multireq(s->blk, &mrb); 786 } 787 788 blk_io_unplug(s->blk); 789 aio_context_release(blk_get_aio_context(s->blk)); 790 return progress; 791 } 792 793 static void virtio_blk_handle_output_do(VirtIOBlock *s, VirtQueue *vq) 794 { 795 virtio_blk_handle_vq(s, vq); 796 } 797 798 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 799 { 800 VirtIOBlock *s = (VirtIOBlock *)vdev; 801 802 if (s->dataplane) { 803 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 804 * dataplane here instead of waiting for .set_status(). 805 */ 806 virtio_device_start_ioeventfd(vdev); 807 if (!s->dataplane_disabled) { 808 return; 809 } 810 } 811 virtio_blk_handle_output_do(s, vq); 812 } 813 814 static void virtio_blk_dma_restart_bh(void *opaque) 815 { 816 VirtIOBlock *s = opaque; 817 VirtIOBlockReq *req = s->rq; 818 MultiReqBuffer mrb = {}; 819 820 qemu_bh_delete(s->bh); 821 s->bh = NULL; 822 823 s->rq = NULL; 824 825 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 826 while (req) { 827 VirtIOBlockReq *next = req->next; 828 if (virtio_blk_handle_request(req, &mrb)) { 829 /* Device is now broken and won't do any processing until it gets 830 * reset. Already queued requests will be lost: let's purge them. 831 */ 832 while (req) { 833 next = req->next; 834 virtqueue_detach_element(req->vq, &req->elem, 0); 835 virtio_blk_free_request(req); 836 req = next; 837 } 838 break; 839 } 840 req = next; 841 } 842 843 if (mrb.num_reqs) { 844 virtio_blk_submit_multireq(s->blk, &mrb); 845 } 846 blk_dec_in_flight(s->conf.conf.blk); 847 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 848 } 849 850 static void virtio_blk_dma_restart_cb(void *opaque, int running, 851 RunState state) 852 { 853 VirtIOBlock *s = opaque; 854 855 if (!running) { 856 return; 857 } 858 859 if (!s->bh) { 860 /* FIXME The data plane is not started yet, so these requests are 861 * processed in the main thread. */ 862 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk), 863 virtio_blk_dma_restart_bh, s); 864 blk_inc_in_flight(s->conf.conf.blk); 865 qemu_bh_schedule(s->bh); 866 } 867 } 868 869 static void virtio_blk_reset(VirtIODevice *vdev) 870 { 871 VirtIOBlock *s = VIRTIO_BLK(vdev); 872 AioContext *ctx; 873 VirtIOBlockReq *req; 874 875 ctx = blk_get_aio_context(s->blk); 876 aio_context_acquire(ctx); 877 blk_drain(s->blk); 878 879 /* We drop queued requests after blk_drain() because blk_drain() itself can 880 * produce them. */ 881 while (s->rq) { 882 req = s->rq; 883 s->rq = req->next; 884 virtqueue_detach_element(req->vq, &req->elem, 0); 885 virtio_blk_free_request(req); 886 } 887 888 aio_context_release(ctx); 889 890 assert(!s->dataplane_started); 891 blk_set_enable_write_cache(s->blk, s->original_wce); 892 } 893 894 /* coalesce internal state, copy to pci i/o region 0 895 */ 896 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) 897 { 898 VirtIOBlock *s = VIRTIO_BLK(vdev); 899 BlockConf *conf = &s->conf.conf; 900 struct virtio_blk_config blkcfg; 901 uint64_t capacity; 902 int64_t length; 903 int blk_size = conf->logical_block_size; 904 905 blk_get_geometry(s->blk, &capacity); 906 memset(&blkcfg, 0, sizeof(blkcfg)); 907 virtio_stq_p(vdev, &blkcfg.capacity, capacity); 908 virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2); 909 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls); 910 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size); 911 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size); 912 virtio_stw_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size); 913 blkcfg.geometry.heads = conf->heads; 914 /* 915 * We must ensure that the block device capacity is a multiple of 916 * the logical block size. If that is not the case, let's use 917 * sector_mask to adopt the geometry to have a correct picture. 918 * For those devices where the capacity is ok for the given geometry 919 * we don't touch the sector value of the geometry, since some devices 920 * (like s390 dasd) need a specific value. Here the capacity is already 921 * cyls*heads*secs*blk_size and the sector value is not block size 922 * divided by 512 - instead it is the amount of blk_size blocks 923 * per track (cylinder). 924 */ 925 length = blk_getlength(s->blk); 926 if (length > 0 && length / conf->heads / conf->secs % blk_size) { 927 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask; 928 } else { 929 blkcfg.geometry.sectors = conf->secs; 930 } 931 blkcfg.size_max = 0; 932 blkcfg.physical_block_exp = get_physical_block_exp(conf); 933 blkcfg.alignment_offset = 0; 934 blkcfg.wce = blk_enable_write_cache(s->blk); 935 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); 936 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) { 937 virtio_stl_p(vdev, &blkcfg.max_discard_sectors, 938 s->conf.max_discard_sectors); 939 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment, 940 blk_size >> BDRV_SECTOR_BITS); 941 /* 942 * We support only one segment per request since multiple segments 943 * are not widely used and there are no userspace APIs that allow 944 * applications to submit multiple segments in a single call. 945 */ 946 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1); 947 } 948 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) { 949 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors, 950 s->conf.max_write_zeroes_sectors); 951 blkcfg.write_zeroes_may_unmap = 1; 952 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1); 953 } 954 memcpy(config, &blkcfg, s->config_size); 955 } 956 957 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) 958 { 959 VirtIOBlock *s = VIRTIO_BLK(vdev); 960 struct virtio_blk_config blkcfg; 961 962 memcpy(&blkcfg, config, s->config_size); 963 964 aio_context_acquire(blk_get_aio_context(s->blk)); 965 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); 966 aio_context_release(blk_get_aio_context(s->blk)); 967 } 968 969 static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, 970 Error **errp) 971 { 972 VirtIOBlock *s = VIRTIO_BLK(vdev); 973 974 /* Firstly sync all virtio-blk possible supported features */ 975 features |= s->host_features; 976 977 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 978 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 979 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 980 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 981 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) { 982 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) { 983 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0"); 984 return 0; 985 } 986 } else { 987 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT); 988 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); 989 } 990 991 if (blk_enable_write_cache(s->blk)) { 992 virtio_add_feature(&features, VIRTIO_BLK_F_WCE); 993 } 994 if (blk_is_read_only(s->blk)) { 995 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 996 } 997 if (s->conf.num_queues > 1) { 998 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 999 } 1000 1001 return features; 1002 } 1003 1004 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) 1005 { 1006 VirtIOBlock *s = VIRTIO_BLK(vdev); 1007 1008 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) { 1009 assert(!s->dataplane_started); 1010 } 1011 1012 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { 1013 return; 1014 } 1015 1016 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send 1017 * cache flushes. Thus, the "auto writethrough" behavior is never 1018 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature. 1019 * Leaving it enabled would break the following sequence: 1020 * 1021 * Guest started with "-drive cache=writethrough" 1022 * Guest sets status to 0 1023 * Guest sets DRIVER bit in status field 1024 * Guest reads host features (WCE=0, CONFIG_WCE=1) 1025 * Guest writes guest features (WCE=0, CONFIG_WCE=1) 1026 * Guest writes 1 to the WCE configuration field (writeback mode) 1027 * Guest sets DRIVER_OK bit in status field 1028 * 1029 * s->blk would erroneously be placed in writethrough mode. 1030 */ 1031 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) { 1032 aio_context_acquire(blk_get_aio_context(s->blk)); 1033 blk_set_enable_write_cache(s->blk, 1034 virtio_vdev_has_feature(vdev, 1035 VIRTIO_BLK_F_WCE)); 1036 aio_context_release(blk_get_aio_context(s->blk)); 1037 } 1038 } 1039 1040 static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f) 1041 { 1042 VirtIOBlock *s = VIRTIO_BLK(vdev); 1043 VirtIOBlockReq *req = s->rq; 1044 1045 while (req) { 1046 qemu_put_sbyte(f, 1); 1047 1048 if (s->conf.num_queues > 1) { 1049 qemu_put_be32(f, virtio_get_queue_index(req->vq)); 1050 } 1051 1052 qemu_put_virtqueue_element(f, &req->elem); 1053 req = req->next; 1054 } 1055 qemu_put_sbyte(f, 0); 1056 } 1057 1058 static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, 1059 int version_id) 1060 { 1061 VirtIOBlock *s = VIRTIO_BLK(vdev); 1062 1063 while (qemu_get_sbyte(f)) { 1064 unsigned nvqs = s->conf.num_queues; 1065 unsigned vq_idx = 0; 1066 VirtIOBlockReq *req; 1067 1068 if (nvqs > 1) { 1069 vq_idx = qemu_get_be32(f); 1070 1071 if (vq_idx >= nvqs) { 1072 error_report("Invalid virtqueue index in request list: %#x", 1073 vq_idx); 1074 return -EINVAL; 1075 } 1076 } 1077 1078 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq)); 1079 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req); 1080 req->next = s->rq; 1081 s->rq = req; 1082 } 1083 1084 return 0; 1085 } 1086 1087 static void virtio_blk_resize(void *opaque) 1088 { 1089 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1090 1091 virtio_notify_config(vdev); 1092 } 1093 1094 static const BlockDevOps virtio_block_ops = { 1095 .resize_cb = virtio_blk_resize, 1096 }; 1097 1098 static void virtio_blk_device_realize(DeviceState *dev, Error **errp) 1099 { 1100 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1101 VirtIOBlock *s = VIRTIO_BLK(dev); 1102 VirtIOBlkConf *conf = &s->conf; 1103 Error *err = NULL; 1104 unsigned i; 1105 1106 if (!conf->conf.blk) { 1107 error_setg(errp, "drive property not set"); 1108 return; 1109 } 1110 if (!blk_is_inserted(conf->conf.blk)) { 1111 error_setg(errp, "Device needs media, but drive is empty"); 1112 return; 1113 } 1114 if (!conf->num_queues) { 1115 error_setg(errp, "num-queues property must be larger than 0"); 1116 return; 1117 } 1118 if (!is_power_of_2(conf->queue_size) || 1119 conf->queue_size > VIRTQUEUE_MAX_SIZE) { 1120 error_setg(errp, "invalid queue-size property (%" PRIu16 "), " 1121 "must be a power of 2 (max %d)", 1122 conf->queue_size, VIRTQUEUE_MAX_SIZE); 1123 return; 1124 } 1125 1126 if (!blkconf_apply_backend_options(&conf->conf, 1127 blk_is_read_only(conf->conf.blk), true, 1128 errp)) { 1129 return; 1130 } 1131 s->original_wce = blk_enable_write_cache(conf->conf.blk); 1132 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) { 1133 return; 1134 } 1135 1136 blkconf_blocksizes(&conf->conf); 1137 1138 if (conf->conf.logical_block_size > 1139 conf->conf.physical_block_size) { 1140 error_setg(errp, 1141 "logical_block_size > physical_block_size not supported"); 1142 return; 1143 } 1144 1145 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) && 1146 (!conf->max_discard_sectors || 1147 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1148 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")" 1149 ", must be between 1 and %d", 1150 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS); 1151 return; 1152 } 1153 1154 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) && 1155 (!conf->max_write_zeroes_sectors || 1156 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1157 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32 1158 "), must be between 1 and %d", 1159 conf->max_write_zeroes_sectors, 1160 (int)BDRV_REQUEST_MAX_SECTORS); 1161 return; 1162 } 1163 1164 virtio_blk_set_config_size(s, s->host_features); 1165 1166 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, s->config_size); 1167 1168 s->blk = conf->conf.blk; 1169 s->rq = NULL; 1170 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1; 1171 1172 for (i = 0; i < conf->num_queues; i++) { 1173 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output); 1174 } 1175 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err); 1176 if (err != NULL) { 1177 error_propagate(errp, err); 1178 virtio_cleanup(vdev); 1179 return; 1180 } 1181 1182 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); 1183 blk_set_dev_ops(s->blk, &virtio_block_ops, s); 1184 blk_set_guest_block_size(s->blk, s->conf.conf.logical_block_size); 1185 1186 blk_iostatus_enable(s->blk); 1187 } 1188 1189 static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp) 1190 { 1191 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1192 VirtIOBlock *s = VIRTIO_BLK(dev); 1193 1194 virtio_blk_data_plane_destroy(s->dataplane); 1195 s->dataplane = NULL; 1196 qemu_del_vm_change_state_handler(s->change); 1197 blockdev_mark_auto_del(s->blk); 1198 virtio_cleanup(vdev); 1199 } 1200 1201 static void virtio_blk_instance_init(Object *obj) 1202 { 1203 VirtIOBlock *s = VIRTIO_BLK(obj); 1204 1205 device_add_bootindex_property(obj, &s->conf.conf.bootindex, 1206 "bootindex", "/disk@0,0", 1207 DEVICE(obj), NULL); 1208 } 1209 1210 static const VMStateDescription vmstate_virtio_blk = { 1211 .name = "virtio-blk", 1212 .minimum_version_id = 2, 1213 .version_id = 2, 1214 .fields = (VMStateField[]) { 1215 VMSTATE_VIRTIO_DEVICE, 1216 VMSTATE_END_OF_LIST() 1217 }, 1218 }; 1219 1220 static Property virtio_blk_properties[] = { 1221 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf), 1222 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf), 1223 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf), 1224 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial), 1225 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features, 1226 VIRTIO_BLK_F_CONFIG_WCE, true), 1227 #ifdef __linux__ 1228 DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features, 1229 VIRTIO_BLK_F_SCSI, false), 1230 #endif 1231 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0, 1232 true), 1233 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1), 1234 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128), 1235 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, 1236 IOThread *), 1237 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, 1238 VIRTIO_BLK_F_DISCARD, true), 1239 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features, 1240 VIRTIO_BLK_F_WRITE_ZEROES, true), 1241 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock, 1242 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS), 1243 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock, 1244 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS), 1245 DEFINE_PROP_END_OF_LIST(), 1246 }; 1247 1248 static void virtio_blk_class_init(ObjectClass *klass, void *data) 1249 { 1250 DeviceClass *dc = DEVICE_CLASS(klass); 1251 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 1252 1253 dc->props = virtio_blk_properties; 1254 dc->vmsd = &vmstate_virtio_blk; 1255 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 1256 vdc->realize = virtio_blk_device_realize; 1257 vdc->unrealize = virtio_blk_device_unrealize; 1258 vdc->get_config = virtio_blk_update_config; 1259 vdc->set_config = virtio_blk_set_config; 1260 vdc->get_features = virtio_blk_get_features; 1261 vdc->set_status = virtio_blk_set_status; 1262 vdc->reset = virtio_blk_reset; 1263 vdc->save = virtio_blk_save_device; 1264 vdc->load = virtio_blk_load_device; 1265 vdc->start_ioeventfd = virtio_blk_data_plane_start; 1266 vdc->stop_ioeventfd = virtio_blk_data_plane_stop; 1267 } 1268 1269 static const TypeInfo virtio_blk_info = { 1270 .name = TYPE_VIRTIO_BLK, 1271 .parent = TYPE_VIRTIO_DEVICE, 1272 .instance_size = sizeof(VirtIOBlock), 1273 .instance_init = virtio_blk_instance_init, 1274 .class_init = virtio_blk_class_init, 1275 }; 1276 1277 static void virtio_register_types(void) 1278 { 1279 type_register_static(&virtio_blk_info); 1280 } 1281 1282 type_init(virtio_register_types) 1283