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 "qemu/main-loop.h" 20 #include "trace.h" 21 #include "hw/block/block.h" 22 #include "hw/qdev-properties.h" 23 #include "sysemu/blockdev.h" 24 #include "sysemu/sysemu.h" 25 #include "sysemu/runstate.h" 26 #include "hw/virtio/virtio-blk.h" 27 #include "dataplane/virtio-blk.h" 28 #include "scsi/constants.h" 29 #ifdef __linux__ 30 # include <scsi/sg.h> 31 #endif 32 #include "hw/virtio/virtio-bus.h" 33 #include "migration/qemu-file-types.h" 34 #include "hw/virtio/virtio-access.h" 35 #include "qemu/coroutine.h" 36 37 /* Config size before the discard support (hide associated config fields) */ 38 #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \ 39 max_discard_sectors) 40 /* 41 * Starting from the discard feature, we can use this array to properly 42 * set the config size depending on the features enabled. 43 */ 44 static const VirtIOFeature feature_sizes[] = { 45 {.flags = 1ULL << VIRTIO_BLK_F_DISCARD, 46 .end = endof(struct virtio_blk_config, discard_sector_alignment)}, 47 {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES, 48 .end = endof(struct virtio_blk_config, write_zeroes_may_unmap)}, 49 {} 50 }; 51 52 static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features) 53 { 54 s->config_size = MAX(VIRTIO_BLK_CFG_SIZE, 55 virtio_feature_get_config_size(feature_sizes, host_features)); 56 57 assert(s->config_size <= sizeof(struct virtio_blk_config)); 58 } 59 60 static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, 61 VirtIOBlockReq *req) 62 { 63 req->dev = s; 64 req->vq = vq; 65 req->qiov.size = 0; 66 req->in_len = 0; 67 req->next = NULL; 68 req->mr_next = NULL; 69 } 70 71 static void virtio_blk_free_request(VirtIOBlockReq *req) 72 { 73 g_free(req); 74 } 75 76 static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status) 77 { 78 VirtIOBlock *s = req->dev; 79 VirtIODevice *vdev = VIRTIO_DEVICE(s); 80 81 trace_virtio_blk_req_complete(vdev, req, status); 82 83 stb_p(&req->in->status, status); 84 iov_discard_undo(&req->inhdr_undo); 85 iov_discard_undo(&req->outhdr_undo); 86 virtqueue_push(req->vq, &req->elem, req->in_len); 87 if (s->dataplane_started && !s->dataplane_disabled) { 88 virtio_blk_data_plane_notify(s->dataplane, req->vq); 89 } else { 90 virtio_notify(vdev, req->vq); 91 } 92 } 93 94 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, 95 bool is_read, bool acct_failed) 96 { 97 VirtIOBlock *s = req->dev; 98 BlockErrorAction action = blk_get_error_action(s->blk, is_read, error); 99 100 if (action == BLOCK_ERROR_ACTION_STOP) { 101 /* Break the link as the next request is going to be parsed from the 102 * ring again. Otherwise we may end up doing a double completion! */ 103 req->mr_next = NULL; 104 req->next = s->rq; 105 s->rq = req; 106 } else if (action == BLOCK_ERROR_ACTION_REPORT) { 107 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 108 if (acct_failed) { 109 block_acct_failed(blk_get_stats(s->blk), &req->acct); 110 } 111 virtio_blk_free_request(req); 112 } 113 114 blk_error_action(s->blk, action, is_read, error); 115 return action != BLOCK_ERROR_ACTION_IGNORE; 116 } 117 118 static void virtio_blk_rw_complete(void *opaque, int ret) 119 { 120 VirtIOBlockReq *next = opaque; 121 VirtIOBlock *s = next->dev; 122 VirtIODevice *vdev = VIRTIO_DEVICE(s); 123 124 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 125 while (next) { 126 VirtIOBlockReq *req = next; 127 next = req->mr_next; 128 trace_virtio_blk_rw_complete(vdev, req, ret); 129 130 if (req->qiov.nalloc != -1) { 131 /* If nalloc is != -1 req->qiov is a local copy of the original 132 * external iovec. It was allocated in submit_requests to be 133 * able to merge requests. */ 134 qemu_iovec_destroy(&req->qiov); 135 } 136 137 if (ret) { 138 int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type); 139 bool is_read = !(p & VIRTIO_BLK_T_OUT); 140 /* Note that memory may be dirtied on read failure. If the 141 * virtio request is not completed here, as is the case for 142 * BLOCK_ERROR_ACTION_STOP, the memory may not be copied 143 * correctly during live migration. While this is ugly, 144 * it is acceptable because the device is free to write to 145 * the memory until the request is completed (which will 146 * happen on the other side of the migration). 147 */ 148 if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) { 149 continue; 150 } 151 } 152 153 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 154 block_acct_done(blk_get_stats(s->blk), &req->acct); 155 virtio_blk_free_request(req); 156 } 157 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 158 } 159 160 static void virtio_blk_flush_complete(void *opaque, int ret) 161 { 162 VirtIOBlockReq *req = opaque; 163 VirtIOBlock *s = req->dev; 164 165 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 166 if (ret) { 167 if (virtio_blk_handle_rw_error(req, -ret, 0, true)) { 168 goto out; 169 } 170 } 171 172 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 173 block_acct_done(blk_get_stats(s->blk), &req->acct); 174 virtio_blk_free_request(req); 175 176 out: 177 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 178 } 179 180 static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret) 181 { 182 VirtIOBlockReq *req = opaque; 183 VirtIOBlock *s = req->dev; 184 bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) & 185 ~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES; 186 187 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 188 if (ret) { 189 if (virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) { 190 goto out; 191 } 192 } 193 194 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 195 if (is_write_zeroes) { 196 block_acct_done(blk_get_stats(s->blk), &req->acct); 197 } 198 virtio_blk_free_request(req); 199 200 out: 201 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 202 } 203 204 #ifdef __linux__ 205 206 typedef struct { 207 VirtIOBlockReq *req; 208 struct sg_io_hdr hdr; 209 } VirtIOBlockIoctlReq; 210 211 static void virtio_blk_ioctl_complete(void *opaque, int status) 212 { 213 VirtIOBlockIoctlReq *ioctl_req = opaque; 214 VirtIOBlockReq *req = ioctl_req->req; 215 VirtIOBlock *s = req->dev; 216 VirtIODevice *vdev = VIRTIO_DEVICE(s); 217 struct virtio_scsi_inhdr *scsi; 218 struct sg_io_hdr *hdr; 219 220 scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base; 221 222 if (status) { 223 status = VIRTIO_BLK_S_UNSUPP; 224 virtio_stl_p(vdev, &scsi->errors, 255); 225 goto out; 226 } 227 228 hdr = &ioctl_req->hdr; 229 /* 230 * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi) 231 * clear the masked_status field [hence status gets cleared too, see 232 * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED 233 * status has occurred. However they do set DRIVER_SENSE in driver_status 234 * field. Also a (sb_len_wr > 0) indicates there is a sense buffer. 235 */ 236 if (hdr->status == 0 && hdr->sb_len_wr > 0) { 237 hdr->status = CHECK_CONDITION; 238 } 239 240 virtio_stl_p(vdev, &scsi->errors, 241 hdr->status | (hdr->msg_status << 8) | 242 (hdr->host_status << 16) | (hdr->driver_status << 24)); 243 virtio_stl_p(vdev, &scsi->residual, hdr->resid); 244 virtio_stl_p(vdev, &scsi->sense_len, hdr->sb_len_wr); 245 virtio_stl_p(vdev, &scsi->data_len, hdr->dxfer_len); 246 247 out: 248 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 249 virtio_blk_req_complete(req, status); 250 virtio_blk_free_request(req); 251 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 252 g_free(ioctl_req); 253 } 254 255 #endif 256 257 static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq) 258 { 259 VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq)); 260 261 if (req) { 262 virtio_blk_init_request(s, vq, req); 263 } 264 return req; 265 } 266 267 static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req) 268 { 269 int status = VIRTIO_BLK_S_OK; 270 struct virtio_scsi_inhdr *scsi = NULL; 271 VirtIOBlock *blk = req->dev; 272 VirtIODevice *vdev = VIRTIO_DEVICE(blk); 273 VirtQueueElement *elem = &req->elem; 274 275 #ifdef __linux__ 276 int i; 277 VirtIOBlockIoctlReq *ioctl_req; 278 BlockAIOCB *acb; 279 #endif 280 281 /* 282 * We require at least one output segment each for the virtio_blk_outhdr 283 * and the SCSI command block. 284 * 285 * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr 286 * and the sense buffer pointer in the input segments. 287 */ 288 if (elem->out_num < 2 || elem->in_num < 3) { 289 status = VIRTIO_BLK_S_IOERR; 290 goto fail; 291 } 292 293 /* 294 * The scsi inhdr is placed in the second-to-last input segment, just 295 * before the regular inhdr. 296 */ 297 scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base; 298 299 if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) { 300 status = VIRTIO_BLK_S_UNSUPP; 301 goto fail; 302 } 303 304 /* 305 * No support for bidirection commands yet. 306 */ 307 if (elem->out_num > 2 && elem->in_num > 3) { 308 status = VIRTIO_BLK_S_UNSUPP; 309 goto fail; 310 } 311 312 #ifdef __linux__ 313 ioctl_req = g_new0(VirtIOBlockIoctlReq, 1); 314 ioctl_req->req = req; 315 ioctl_req->hdr.interface_id = 'S'; 316 ioctl_req->hdr.cmd_len = elem->out_sg[1].iov_len; 317 ioctl_req->hdr.cmdp = elem->out_sg[1].iov_base; 318 ioctl_req->hdr.dxfer_len = 0; 319 320 if (elem->out_num > 2) { 321 /* 322 * If there are more than the minimally required 2 output segments 323 * there is write payload starting from the third iovec. 324 */ 325 ioctl_req->hdr.dxfer_direction = SG_DXFER_TO_DEV; 326 ioctl_req->hdr.iovec_count = elem->out_num - 2; 327 328 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) { 329 ioctl_req->hdr.dxfer_len += elem->out_sg[i + 2].iov_len; 330 } 331 332 ioctl_req->hdr.dxferp = elem->out_sg + 2; 333 334 } else if (elem->in_num > 3) { 335 /* 336 * If we have more than 3 input segments the guest wants to actually 337 * read data. 338 */ 339 ioctl_req->hdr.dxfer_direction = SG_DXFER_FROM_DEV; 340 ioctl_req->hdr.iovec_count = elem->in_num - 3; 341 for (i = 0; i < ioctl_req->hdr.iovec_count; i++) { 342 ioctl_req->hdr.dxfer_len += elem->in_sg[i].iov_len; 343 } 344 345 ioctl_req->hdr.dxferp = elem->in_sg; 346 } else { 347 /* 348 * Some SCSI commands don't actually transfer any data. 349 */ 350 ioctl_req->hdr.dxfer_direction = SG_DXFER_NONE; 351 } 352 353 ioctl_req->hdr.sbp = elem->in_sg[elem->in_num - 3].iov_base; 354 ioctl_req->hdr.mx_sb_len = elem->in_sg[elem->in_num - 3].iov_len; 355 356 acb = blk_aio_ioctl(blk->blk, SG_IO, &ioctl_req->hdr, 357 virtio_blk_ioctl_complete, ioctl_req); 358 if (!acb) { 359 g_free(ioctl_req); 360 status = VIRTIO_BLK_S_UNSUPP; 361 goto fail; 362 } 363 return -EINPROGRESS; 364 #else 365 abort(); 366 #endif 367 368 fail: 369 /* Just put anything nonzero so that the ioctl fails in the guest. */ 370 if (scsi) { 371 virtio_stl_p(vdev, &scsi->errors, 255); 372 } 373 return status; 374 } 375 376 static void virtio_blk_handle_scsi(VirtIOBlockReq *req) 377 { 378 int status; 379 380 status = virtio_blk_handle_scsi_req(req); 381 if (status != -EINPROGRESS) { 382 virtio_blk_req_complete(req, status); 383 virtio_blk_free_request(req); 384 } 385 } 386 387 static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, 388 int start, int num_reqs, int niov) 389 { 390 QEMUIOVector *qiov = &mrb->reqs[start]->qiov; 391 int64_t sector_num = mrb->reqs[start]->sector_num; 392 bool is_write = mrb->is_write; 393 394 if (num_reqs > 1) { 395 int i; 396 struct iovec *tmp_iov = qiov->iov; 397 int tmp_niov = qiov->niov; 398 399 /* mrb->reqs[start]->qiov was initialized from external so we can't 400 * modify it here. We need to initialize it locally and then add the 401 * external iovecs. */ 402 qemu_iovec_init(qiov, niov); 403 404 for (i = 0; i < tmp_niov; i++) { 405 qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len); 406 } 407 408 for (i = start + 1; i < start + num_reqs; i++) { 409 qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0, 410 mrb->reqs[i]->qiov.size); 411 mrb->reqs[i - 1]->mr_next = mrb->reqs[i]; 412 } 413 414 trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev), 415 mrb, start, num_reqs, 416 sector_num << BDRV_SECTOR_BITS, 417 qiov->size, is_write); 418 block_acct_merge_done(blk_get_stats(blk), 419 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ, 420 num_reqs - 1); 421 } 422 423 if (is_write) { 424 blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, 425 virtio_blk_rw_complete, mrb->reqs[start]); 426 } else { 427 blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, 428 virtio_blk_rw_complete, mrb->reqs[start]); 429 } 430 } 431 432 static int multireq_compare(const void *a, const void *b) 433 { 434 const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a, 435 *req2 = *(VirtIOBlockReq **)b; 436 437 /* 438 * Note that we can't simply subtract sector_num1 from sector_num2 439 * here as that could overflow the return value. 440 */ 441 if (req1->sector_num > req2->sector_num) { 442 return 1; 443 } else if (req1->sector_num < req2->sector_num) { 444 return -1; 445 } else { 446 return 0; 447 } 448 } 449 450 static void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) 451 { 452 int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0; 453 uint32_t max_transfer; 454 int64_t sector_num = 0; 455 456 if (mrb->num_reqs == 1) { 457 submit_requests(blk, mrb, 0, 1, -1); 458 mrb->num_reqs = 0; 459 return; 460 } 461 462 max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk); 463 464 qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs), 465 &multireq_compare); 466 467 for (i = 0; i < mrb->num_reqs; i++) { 468 VirtIOBlockReq *req = mrb->reqs[i]; 469 if (num_reqs > 0) { 470 /* 471 * NOTE: We cannot merge the requests in below situations: 472 * 1. requests are not sequential 473 * 2. merge would exceed maximum number of IOVs 474 * 3. merge would exceed maximum transfer length of backend device 475 */ 476 if (sector_num + nb_sectors != req->sector_num || 477 niov > blk_get_max_iov(blk) - req->qiov.niov || 478 req->qiov.size > max_transfer || 479 nb_sectors > (max_transfer - 480 req->qiov.size) / BDRV_SECTOR_SIZE) { 481 submit_requests(blk, mrb, start, num_reqs, niov); 482 num_reqs = 0; 483 } 484 } 485 486 if (num_reqs == 0) { 487 sector_num = req->sector_num; 488 nb_sectors = niov = 0; 489 start = i; 490 } 491 492 nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE; 493 niov += req->qiov.niov; 494 num_reqs++; 495 } 496 497 submit_requests(blk, mrb, start, num_reqs, niov); 498 mrb->num_reqs = 0; 499 } 500 501 static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb) 502 { 503 VirtIOBlock *s = req->dev; 504 505 block_acct_start(blk_get_stats(s->blk), &req->acct, 0, 506 BLOCK_ACCT_FLUSH); 507 508 /* 509 * Make sure all outstanding writes are posted to the backing device. 510 */ 511 if (mrb->is_write && mrb->num_reqs > 0) { 512 virtio_blk_submit_multireq(s->blk, mrb); 513 } 514 blk_aio_flush(s->blk, virtio_blk_flush_complete, req); 515 } 516 517 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev, 518 uint64_t sector, size_t size) 519 { 520 uint64_t nb_sectors = size >> BDRV_SECTOR_BITS; 521 uint64_t total_sectors; 522 523 if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) { 524 return false; 525 } 526 if (sector & dev->sector_mask) { 527 return false; 528 } 529 if (size % dev->conf.conf.logical_block_size) { 530 return false; 531 } 532 blk_get_geometry(dev->blk, &total_sectors); 533 if (sector > total_sectors || nb_sectors > total_sectors - sector) { 534 return false; 535 } 536 return true; 537 } 538 539 static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req, 540 struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes) 541 { 542 VirtIOBlock *s = req->dev; 543 VirtIODevice *vdev = VIRTIO_DEVICE(s); 544 uint64_t sector; 545 uint32_t num_sectors, flags, max_sectors; 546 uint8_t err_status; 547 int bytes; 548 549 sector = virtio_ldq_p(vdev, &dwz_hdr->sector); 550 num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors); 551 flags = virtio_ldl_p(vdev, &dwz_hdr->flags); 552 max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors : 553 s->conf.max_discard_sectors; 554 555 /* 556 * max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check 557 * make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in 558 * the integer variable. 559 */ 560 if (unlikely(num_sectors > max_sectors)) { 561 err_status = VIRTIO_BLK_S_IOERR; 562 goto err; 563 } 564 565 bytes = num_sectors << BDRV_SECTOR_BITS; 566 567 if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) { 568 err_status = VIRTIO_BLK_S_IOERR; 569 goto err; 570 } 571 572 /* 573 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard 574 * and write zeroes commands if any unknown flag is set. 575 */ 576 if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 577 err_status = VIRTIO_BLK_S_UNSUPP; 578 goto err; 579 } 580 581 if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */ 582 int blk_aio_flags = 0; 583 584 if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { 585 blk_aio_flags |= BDRV_REQ_MAY_UNMAP; 586 } 587 588 block_acct_start(blk_get_stats(s->blk), &req->acct, bytes, 589 BLOCK_ACCT_WRITE); 590 591 blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS, 592 bytes, blk_aio_flags, 593 virtio_blk_discard_write_zeroes_complete, req); 594 } else { /* VIRTIO_BLK_T_DISCARD */ 595 /* 596 * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for 597 * discard commands if the unmap flag is set. 598 */ 599 if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { 600 err_status = VIRTIO_BLK_S_UNSUPP; 601 goto err; 602 } 603 604 blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes, 605 virtio_blk_discard_write_zeroes_complete, req); 606 } 607 608 return VIRTIO_BLK_S_OK; 609 610 err: 611 if (is_write_zeroes) { 612 block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE); 613 } 614 return err_status; 615 } 616 617 static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) 618 { 619 uint32_t type; 620 struct iovec *in_iov = req->elem.in_sg; 621 struct iovec *out_iov = req->elem.out_sg; 622 unsigned in_num = req->elem.in_num; 623 unsigned out_num = req->elem.out_num; 624 VirtIOBlock *s = req->dev; 625 VirtIODevice *vdev = VIRTIO_DEVICE(s); 626 627 if (req->elem.out_num < 1 || req->elem.in_num < 1) { 628 virtio_error(vdev, "virtio-blk missing headers"); 629 return -1; 630 } 631 632 if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out, 633 sizeof(req->out)) != sizeof(req->out))) { 634 virtio_error(vdev, "virtio-blk request outhdr too short"); 635 return -1; 636 } 637 638 iov_discard_front_undoable(&out_iov, &out_num, sizeof(req->out), 639 &req->outhdr_undo); 640 641 if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { 642 virtio_error(vdev, "virtio-blk request inhdr too short"); 643 iov_discard_undo(&req->outhdr_undo); 644 return -1; 645 } 646 647 /* We always touch the last byte, so just see how big in_iov is. */ 648 req->in_len = iov_size(in_iov, in_num); 649 req->in = (void *)in_iov[in_num - 1].iov_base 650 + in_iov[in_num - 1].iov_len 651 - sizeof(struct virtio_blk_inhdr); 652 iov_discard_back_undoable(in_iov, &in_num, sizeof(struct virtio_blk_inhdr), 653 &req->inhdr_undo); 654 655 type = virtio_ldl_p(vdev, &req->out.type); 656 657 /* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER 658 * is an optional flag. Although a guest should not send this flag if 659 * not negotiated we ignored it in the past. So keep ignoring it. */ 660 switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) { 661 case VIRTIO_BLK_T_IN: 662 { 663 bool is_write = type & VIRTIO_BLK_T_OUT; 664 req->sector_num = virtio_ldq_p(vdev, &req->out.sector); 665 666 if (is_write) { 667 qemu_iovec_init_external(&req->qiov, out_iov, out_num); 668 trace_virtio_blk_handle_write(vdev, req, req->sector_num, 669 req->qiov.size / BDRV_SECTOR_SIZE); 670 } else { 671 qemu_iovec_init_external(&req->qiov, in_iov, in_num); 672 trace_virtio_blk_handle_read(vdev, req, req->sector_num, 673 req->qiov.size / BDRV_SECTOR_SIZE); 674 } 675 676 if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) { 677 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); 678 block_acct_invalid(blk_get_stats(s->blk), 679 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 680 virtio_blk_free_request(req); 681 return 0; 682 } 683 684 block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size, 685 is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ); 686 687 /* merge would exceed maximum number of requests or IO direction 688 * changes */ 689 if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS || 690 is_write != mrb->is_write || 691 !s->conf.request_merging)) { 692 virtio_blk_submit_multireq(s->blk, mrb); 693 } 694 695 assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS); 696 mrb->reqs[mrb->num_reqs++] = req; 697 mrb->is_write = is_write; 698 break; 699 } 700 case VIRTIO_BLK_T_FLUSH: 701 virtio_blk_handle_flush(req, mrb); 702 break; 703 case VIRTIO_BLK_T_SCSI_CMD: 704 virtio_blk_handle_scsi(req); 705 break; 706 case VIRTIO_BLK_T_GET_ID: 707 { 708 /* 709 * NB: per existing s/n string convention the string is 710 * terminated by '\0' only when shorter than buffer. 711 */ 712 const char *serial = s->conf.serial ? s->conf.serial : ""; 713 size_t size = MIN(strlen(serial) + 1, 714 MIN(iov_size(in_iov, in_num), 715 VIRTIO_BLK_ID_BYTES)); 716 iov_from_buf(in_iov, in_num, 0, serial, size); 717 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); 718 virtio_blk_free_request(req); 719 break; 720 } 721 /* 722 * VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with 723 * VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement, 724 * so we must mask it for these requests, then we will check if it is set. 725 */ 726 case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT: 727 case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT: 728 { 729 struct virtio_blk_discard_write_zeroes dwz_hdr; 730 size_t out_len = iov_size(out_iov, out_num); 731 bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) == 732 VIRTIO_BLK_T_WRITE_ZEROES; 733 uint8_t err_status; 734 735 /* 736 * Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains 737 * more than one segment. 738 */ 739 if (unlikely(!(type & VIRTIO_BLK_T_OUT) || 740 out_len > sizeof(dwz_hdr))) { 741 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 742 virtio_blk_free_request(req); 743 return 0; 744 } 745 746 if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr, 747 sizeof(dwz_hdr)) != sizeof(dwz_hdr))) { 748 iov_discard_undo(&req->inhdr_undo); 749 iov_discard_undo(&req->outhdr_undo); 750 virtio_error(vdev, "virtio-blk discard/write_zeroes header" 751 " too short"); 752 return -1; 753 } 754 755 err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr, 756 is_write_zeroes); 757 if (err_status != VIRTIO_BLK_S_OK) { 758 virtio_blk_req_complete(req, err_status); 759 virtio_blk_free_request(req); 760 } 761 762 break; 763 } 764 default: 765 virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); 766 virtio_blk_free_request(req); 767 } 768 return 0; 769 } 770 771 void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq) 772 { 773 VirtIOBlockReq *req; 774 MultiReqBuffer mrb = {}; 775 bool suppress_notifications = virtio_queue_get_notification(vq); 776 777 aio_context_acquire(blk_get_aio_context(s->blk)); 778 blk_io_plug(s->blk); 779 780 do { 781 if (suppress_notifications) { 782 virtio_queue_set_notification(vq, 0); 783 } 784 785 while ((req = virtio_blk_get_request(s, vq))) { 786 if (virtio_blk_handle_request(req, &mrb)) { 787 virtqueue_detach_element(req->vq, &req->elem, 0); 788 virtio_blk_free_request(req); 789 break; 790 } 791 } 792 793 if (suppress_notifications) { 794 virtio_queue_set_notification(vq, 1); 795 } 796 } while (!virtio_queue_empty(vq)); 797 798 if (mrb.num_reqs) { 799 virtio_blk_submit_multireq(s->blk, &mrb); 800 } 801 802 blk_io_unplug(s->blk); 803 aio_context_release(blk_get_aio_context(s->blk)); 804 } 805 806 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 807 { 808 VirtIOBlock *s = (VirtIOBlock *)vdev; 809 810 if (s->dataplane && !s->dataplane_started) { 811 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 812 * dataplane here instead of waiting for .set_status(). 813 */ 814 virtio_device_start_ioeventfd(vdev); 815 if (!s->dataplane_disabled) { 816 return; 817 } 818 } 819 virtio_blk_handle_vq(s, vq); 820 } 821 822 void virtio_blk_process_queued_requests(VirtIOBlock *s, bool is_bh) 823 { 824 VirtIOBlockReq *req = s->rq; 825 MultiReqBuffer mrb = {}; 826 827 s->rq = NULL; 828 829 aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); 830 while (req) { 831 VirtIOBlockReq *next = req->next; 832 if (virtio_blk_handle_request(req, &mrb)) { 833 /* Device is now broken and won't do any processing until it gets 834 * reset. Already queued requests will be lost: let's purge them. 835 */ 836 while (req) { 837 next = req->next; 838 virtqueue_detach_element(req->vq, &req->elem, 0); 839 virtio_blk_free_request(req); 840 req = next; 841 } 842 break; 843 } 844 req = next; 845 } 846 847 if (mrb.num_reqs) { 848 virtio_blk_submit_multireq(s->blk, &mrb); 849 } 850 if (is_bh) { 851 blk_dec_in_flight(s->conf.conf.blk); 852 } 853 aio_context_release(blk_get_aio_context(s->conf.conf.blk)); 854 } 855 856 static void virtio_blk_dma_restart_bh(void *opaque) 857 { 858 VirtIOBlock *s = opaque; 859 860 qemu_bh_delete(s->bh); 861 s->bh = NULL; 862 863 virtio_blk_process_queued_requests(s, true); 864 } 865 866 static void virtio_blk_dma_restart_cb(void *opaque, bool running, 867 RunState state) 868 { 869 VirtIOBlock *s = opaque; 870 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); 871 VirtioBusState *bus = VIRTIO_BUS(qbus); 872 873 if (!running) { 874 return; 875 } 876 877 /* 878 * If ioeventfd is enabled, don't schedule the BH here as queued 879 * requests will be processed while starting the data plane. 880 */ 881 if (!s->bh && !virtio_bus_ioeventfd_enabled(bus)) { 882 s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk), 883 virtio_blk_dma_restart_bh, s); 884 blk_inc_in_flight(s->conf.conf.blk); 885 qemu_bh_schedule(s->bh); 886 } 887 } 888 889 static void virtio_blk_reset(VirtIODevice *vdev) 890 { 891 VirtIOBlock *s = VIRTIO_BLK(vdev); 892 AioContext *ctx; 893 VirtIOBlockReq *req; 894 895 ctx = blk_get_aio_context(s->blk); 896 aio_context_acquire(ctx); 897 blk_drain(s->blk); 898 899 /* We drop queued requests after blk_drain() because blk_drain() itself can 900 * produce them. */ 901 while (s->rq) { 902 req = s->rq; 903 s->rq = req->next; 904 virtqueue_detach_element(req->vq, &req->elem, 0); 905 virtio_blk_free_request(req); 906 } 907 908 aio_context_release(ctx); 909 910 assert(!s->dataplane_started); 911 blk_set_enable_write_cache(s->blk, s->original_wce); 912 } 913 914 /* coalesce internal state, copy to pci i/o region 0 915 */ 916 static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) 917 { 918 VirtIOBlock *s = VIRTIO_BLK(vdev); 919 BlockConf *conf = &s->conf.conf; 920 struct virtio_blk_config blkcfg; 921 uint64_t capacity; 922 int64_t length; 923 int blk_size = conf->logical_block_size; 924 925 blk_get_geometry(s->blk, &capacity); 926 memset(&blkcfg, 0, sizeof(blkcfg)); 927 virtio_stq_p(vdev, &blkcfg.capacity, capacity); 928 virtio_stl_p(vdev, &blkcfg.seg_max, 929 s->conf.seg_max_adjust ? s->conf.queue_size - 2 : 128 - 2); 930 virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls); 931 virtio_stl_p(vdev, &blkcfg.blk_size, blk_size); 932 virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size); 933 virtio_stl_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size); 934 blkcfg.geometry.heads = conf->heads; 935 /* 936 * We must ensure that the block device capacity is a multiple of 937 * the logical block size. If that is not the case, let's use 938 * sector_mask to adopt the geometry to have a correct picture. 939 * For those devices where the capacity is ok for the given geometry 940 * we don't touch the sector value of the geometry, since some devices 941 * (like s390 dasd) need a specific value. Here the capacity is already 942 * cyls*heads*secs*blk_size and the sector value is not block size 943 * divided by 512 - instead it is the amount of blk_size blocks 944 * per track (cylinder). 945 */ 946 length = blk_getlength(s->blk); 947 if (length > 0 && length / conf->heads / conf->secs % blk_size) { 948 blkcfg.geometry.sectors = conf->secs & ~s->sector_mask; 949 } else { 950 blkcfg.geometry.sectors = conf->secs; 951 } 952 blkcfg.size_max = 0; 953 blkcfg.physical_block_exp = get_physical_block_exp(conf); 954 blkcfg.alignment_offset = 0; 955 blkcfg.wce = blk_enable_write_cache(s->blk); 956 virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); 957 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) { 958 uint32_t discard_granularity = conf->discard_granularity; 959 if (discard_granularity == -1 || !s->conf.report_discard_granularity) { 960 discard_granularity = blk_size; 961 } 962 virtio_stl_p(vdev, &blkcfg.max_discard_sectors, 963 s->conf.max_discard_sectors); 964 virtio_stl_p(vdev, &blkcfg.discard_sector_alignment, 965 discard_granularity >> BDRV_SECTOR_BITS); 966 /* 967 * We support only one segment per request since multiple segments 968 * are not widely used and there are no userspace APIs that allow 969 * applications to submit multiple segments in a single call. 970 */ 971 virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1); 972 } 973 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) { 974 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors, 975 s->conf.max_write_zeroes_sectors); 976 blkcfg.write_zeroes_may_unmap = 1; 977 virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1); 978 } 979 memcpy(config, &blkcfg, s->config_size); 980 } 981 982 static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) 983 { 984 VirtIOBlock *s = VIRTIO_BLK(vdev); 985 struct virtio_blk_config blkcfg; 986 987 memcpy(&blkcfg, config, s->config_size); 988 989 aio_context_acquire(blk_get_aio_context(s->blk)); 990 blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); 991 aio_context_release(blk_get_aio_context(s->blk)); 992 } 993 994 static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, 995 Error **errp) 996 { 997 VirtIOBlock *s = VIRTIO_BLK(vdev); 998 999 /* Firstly sync all virtio-blk possible supported features */ 1000 features |= s->host_features; 1001 1002 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 1003 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 1004 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 1005 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 1006 if (virtio_has_feature(features, VIRTIO_F_VERSION_1)) { 1007 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) { 1008 error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0"); 1009 return 0; 1010 } 1011 } else { 1012 virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT); 1013 virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); 1014 } 1015 1016 if (blk_enable_write_cache(s->blk) || 1017 (s->conf.x_enable_wce_if_config_wce && 1018 virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) { 1019 virtio_add_feature(&features, VIRTIO_BLK_F_WCE); 1020 } 1021 if (!blk_is_writable(s->blk)) { 1022 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 1023 } 1024 if (s->conf.num_queues > 1) { 1025 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 1026 } 1027 1028 return features; 1029 } 1030 1031 static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) 1032 { 1033 VirtIOBlock *s = VIRTIO_BLK(vdev); 1034 1035 if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) { 1036 assert(!s->dataplane_started); 1037 } 1038 1039 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { 1040 return; 1041 } 1042 1043 /* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send 1044 * cache flushes. Thus, the "auto writethrough" behavior is never 1045 * necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature. 1046 * Leaving it enabled would break the following sequence: 1047 * 1048 * Guest started with "-drive cache=writethrough" 1049 * Guest sets status to 0 1050 * Guest sets DRIVER bit in status field 1051 * Guest reads host features (WCE=0, CONFIG_WCE=1) 1052 * Guest writes guest features (WCE=0, CONFIG_WCE=1) 1053 * Guest writes 1 to the WCE configuration field (writeback mode) 1054 * Guest sets DRIVER_OK bit in status field 1055 * 1056 * s->blk would erroneously be placed in writethrough mode. 1057 */ 1058 if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) { 1059 aio_context_acquire(blk_get_aio_context(s->blk)); 1060 blk_set_enable_write_cache(s->blk, 1061 virtio_vdev_has_feature(vdev, 1062 VIRTIO_BLK_F_WCE)); 1063 aio_context_release(blk_get_aio_context(s->blk)); 1064 } 1065 } 1066 1067 static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f) 1068 { 1069 VirtIOBlock *s = VIRTIO_BLK(vdev); 1070 VirtIOBlockReq *req = s->rq; 1071 1072 while (req) { 1073 qemu_put_sbyte(f, 1); 1074 1075 if (s->conf.num_queues > 1) { 1076 qemu_put_be32(f, virtio_get_queue_index(req->vq)); 1077 } 1078 1079 qemu_put_virtqueue_element(vdev, f, &req->elem); 1080 req = req->next; 1081 } 1082 qemu_put_sbyte(f, 0); 1083 } 1084 1085 static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, 1086 int version_id) 1087 { 1088 VirtIOBlock *s = VIRTIO_BLK(vdev); 1089 1090 while (qemu_get_sbyte(f)) { 1091 unsigned nvqs = s->conf.num_queues; 1092 unsigned vq_idx = 0; 1093 VirtIOBlockReq *req; 1094 1095 if (nvqs > 1) { 1096 vq_idx = qemu_get_be32(f); 1097 1098 if (vq_idx >= nvqs) { 1099 error_report("Invalid virtqueue index in request list: %#x", 1100 vq_idx); 1101 return -EINVAL; 1102 } 1103 } 1104 1105 req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq)); 1106 virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req); 1107 req->next = s->rq; 1108 s->rq = req; 1109 } 1110 1111 return 0; 1112 } 1113 1114 static void virtio_resize_cb(void *opaque) 1115 { 1116 VirtIODevice *vdev = opaque; 1117 1118 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1119 virtio_notify_config(vdev); 1120 } 1121 1122 static void virtio_blk_resize(void *opaque) 1123 { 1124 VirtIODevice *vdev = VIRTIO_DEVICE(opaque); 1125 1126 /* 1127 * virtio_notify_config() needs to acquire the global mutex, 1128 * so it can't be called from an iothread. Instead, schedule 1129 * it to be run in the main context BH. 1130 */ 1131 aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); 1132 } 1133 1134 static const BlockDevOps virtio_block_ops = { 1135 .resize_cb = virtio_blk_resize, 1136 }; 1137 1138 static void virtio_blk_device_realize(DeviceState *dev, Error **errp) 1139 { 1140 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1141 VirtIOBlock *s = VIRTIO_BLK(dev); 1142 VirtIOBlkConf *conf = &s->conf; 1143 Error *err = NULL; 1144 unsigned i; 1145 1146 if (!conf->conf.blk) { 1147 error_setg(errp, "drive property not set"); 1148 return; 1149 } 1150 if (!blk_is_inserted(conf->conf.blk)) { 1151 error_setg(errp, "Device needs media, but drive is empty"); 1152 return; 1153 } 1154 if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) { 1155 conf->num_queues = 1; 1156 } 1157 if (!conf->num_queues) { 1158 error_setg(errp, "num-queues property must be larger than 0"); 1159 return; 1160 } 1161 if (conf->queue_size <= 2) { 1162 error_setg(errp, "invalid queue-size property (%" PRIu16 "), " 1163 "must be > 2", conf->queue_size); 1164 return; 1165 } 1166 if (!is_power_of_2(conf->queue_size) || 1167 conf->queue_size > VIRTQUEUE_MAX_SIZE) { 1168 error_setg(errp, "invalid queue-size property (%" PRIu16 "), " 1169 "must be a power of 2 (max %d)", 1170 conf->queue_size, VIRTQUEUE_MAX_SIZE); 1171 return; 1172 } 1173 1174 if (!blkconf_apply_backend_options(&conf->conf, 1175 !blk_supports_write_perm(conf->conf.blk), 1176 true, errp)) { 1177 return; 1178 } 1179 s->original_wce = blk_enable_write_cache(conf->conf.blk); 1180 if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) { 1181 return; 1182 } 1183 1184 if (!blkconf_blocksizes(&conf->conf, errp)) { 1185 return; 1186 } 1187 1188 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) && 1189 (!conf->max_discard_sectors || 1190 conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1191 error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")" 1192 ", must be between 1 and %d", 1193 conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS); 1194 return; 1195 } 1196 1197 if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) && 1198 (!conf->max_write_zeroes_sectors || 1199 conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) { 1200 error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32 1201 "), must be between 1 and %d", 1202 conf->max_write_zeroes_sectors, 1203 (int)BDRV_REQUEST_MAX_SECTORS); 1204 return; 1205 } 1206 1207 virtio_blk_set_config_size(s, s->host_features); 1208 1209 virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size); 1210 1211 s->blk = conf->conf.blk; 1212 s->rq = NULL; 1213 s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1; 1214 1215 for (i = 0; i < conf->num_queues; i++) { 1216 virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output); 1217 } 1218 qemu_coroutine_inc_pool_size(conf->num_queues * conf->queue_size / 2); 1219 virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err); 1220 if (err != NULL) { 1221 error_propagate(errp, err); 1222 for (i = 0; i < conf->num_queues; i++) { 1223 virtio_del_queue(vdev, i); 1224 } 1225 virtio_cleanup(vdev); 1226 return; 1227 } 1228 1229 s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); 1230 blk_set_dev_ops(s->blk, &virtio_block_ops, s); 1231 1232 blk_iostatus_enable(s->blk); 1233 1234 add_boot_device_lchs(dev, "/disk@0,0", 1235 conf->conf.lcyls, 1236 conf->conf.lheads, 1237 conf->conf.lsecs); 1238 } 1239 1240 static void virtio_blk_device_unrealize(DeviceState *dev) 1241 { 1242 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 1243 VirtIOBlock *s = VIRTIO_BLK(dev); 1244 VirtIOBlkConf *conf = &s->conf; 1245 unsigned i; 1246 1247 blk_drain(s->blk); 1248 del_boot_device_lchs(dev, "/disk@0,0"); 1249 virtio_blk_data_plane_destroy(s->dataplane); 1250 s->dataplane = NULL; 1251 for (i = 0; i < conf->num_queues; i++) { 1252 virtio_del_queue(vdev, i); 1253 } 1254 qemu_coroutine_dec_pool_size(conf->num_queues * conf->queue_size / 2); 1255 qemu_del_vm_change_state_handler(s->change); 1256 blockdev_mark_auto_del(s->blk); 1257 virtio_cleanup(vdev); 1258 } 1259 1260 static void virtio_blk_instance_init(Object *obj) 1261 { 1262 VirtIOBlock *s = VIRTIO_BLK(obj); 1263 1264 device_add_bootindex_property(obj, &s->conf.conf.bootindex, 1265 "bootindex", "/disk@0,0", 1266 DEVICE(obj)); 1267 } 1268 1269 static const VMStateDescription vmstate_virtio_blk = { 1270 .name = "virtio-blk", 1271 .minimum_version_id = 2, 1272 .version_id = 2, 1273 .fields = (VMStateField[]) { 1274 VMSTATE_VIRTIO_DEVICE, 1275 VMSTATE_END_OF_LIST() 1276 }, 1277 }; 1278 1279 static Property virtio_blk_properties[] = { 1280 DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf), 1281 DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf), 1282 DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf), 1283 DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial), 1284 DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features, 1285 VIRTIO_BLK_F_CONFIG_WCE, true), 1286 #ifdef __linux__ 1287 DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features, 1288 VIRTIO_BLK_F_SCSI, false), 1289 #endif 1290 DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0, 1291 true), 1292 DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1293 VIRTIO_BLK_AUTO_NUM_QUEUES), 1294 DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 256), 1295 DEFINE_PROP_BOOL("seg-max-adjust", VirtIOBlock, conf.seg_max_adjust, true), 1296 DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, 1297 IOThread *), 1298 DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, 1299 VIRTIO_BLK_F_DISCARD, true), 1300 DEFINE_PROP_BOOL("report-discard-granularity", VirtIOBlock, 1301 conf.report_discard_granularity, true), 1302 DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features, 1303 VIRTIO_BLK_F_WRITE_ZEROES, true), 1304 DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock, 1305 conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS), 1306 DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock, 1307 conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS), 1308 DEFINE_PROP_BOOL("x-enable-wce-if-config-wce", VirtIOBlock, 1309 conf.x_enable_wce_if_config_wce, true), 1310 DEFINE_PROP_END_OF_LIST(), 1311 }; 1312 1313 static void virtio_blk_class_init(ObjectClass *klass, void *data) 1314 { 1315 DeviceClass *dc = DEVICE_CLASS(klass); 1316 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 1317 1318 device_class_set_props(dc, virtio_blk_properties); 1319 dc->vmsd = &vmstate_virtio_blk; 1320 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 1321 vdc->realize = virtio_blk_device_realize; 1322 vdc->unrealize = virtio_blk_device_unrealize; 1323 vdc->get_config = virtio_blk_update_config; 1324 vdc->set_config = virtio_blk_set_config; 1325 vdc->get_features = virtio_blk_get_features; 1326 vdc->set_status = virtio_blk_set_status; 1327 vdc->reset = virtio_blk_reset; 1328 vdc->save = virtio_blk_save_device; 1329 vdc->load = virtio_blk_load_device; 1330 vdc->start_ioeventfd = virtio_blk_data_plane_start; 1331 vdc->stop_ioeventfd = virtio_blk_data_plane_stop; 1332 } 1333 1334 static const TypeInfo virtio_blk_info = { 1335 .name = TYPE_VIRTIO_BLK, 1336 .parent = TYPE_VIRTIO_DEVICE, 1337 .instance_size = sizeof(VirtIOBlock), 1338 .instance_init = virtio_blk_instance_init, 1339 .class_init = virtio_blk_class_init, 1340 }; 1341 1342 static void virtio_register_types(void) 1343 { 1344 type_register_static(&virtio_blk_info); 1345 } 1346 1347 type_init(virtio_register_types) 1348