1 // SPDX-License-Identifier: GPL-2.0-only 2 //#define DEBUG 3 #include <linux/spinlock.h> 4 #include <linux/slab.h> 5 #include <linux/blkdev.h> 6 #include <linux/hdreg.h> 7 #include <linux/module.h> 8 #include <linux/mutex.h> 9 #include <linux/interrupt.h> 10 #include <linux/virtio.h> 11 #include <linux/virtio_blk.h> 12 #include <linux/scatterlist.h> 13 #include <linux/string_helpers.h> 14 #include <linux/idr.h> 15 #include <linux/blk-mq.h> 16 #include <linux/blk-mq-virtio.h> 17 #include <linux/numa.h> 18 #include <linux/vmalloc.h> 19 #include <uapi/linux/virtio_ring.h> 20 21 #define PART_BITS 4 22 #define VQ_NAME_LEN 16 23 #define MAX_DISCARD_SEGMENTS 256u 24 25 /* The maximum number of sg elements that fit into a virtqueue */ 26 #define VIRTIO_BLK_MAX_SG_ELEMS 32768 27 28 #ifdef CONFIG_ARCH_NO_SG_CHAIN 29 #define VIRTIO_BLK_INLINE_SG_CNT 0 30 #else 31 #define VIRTIO_BLK_INLINE_SG_CNT 2 32 #endif 33 34 static unsigned int num_request_queues; 35 module_param(num_request_queues, uint, 0644); 36 MODULE_PARM_DESC(num_request_queues, 37 "Limit the number of request queues to use for blk device. " 38 "0 for no limit. " 39 "Values > nr_cpu_ids truncated to nr_cpu_ids."); 40 41 static unsigned int poll_queues; 42 module_param(poll_queues, uint, 0644); 43 MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); 44 45 static int major; 46 static DEFINE_IDA(vd_index_ida); 47 48 static struct workqueue_struct *virtblk_wq; 49 50 struct virtio_blk_vq { 51 struct virtqueue *vq; 52 spinlock_t lock; 53 char name[VQ_NAME_LEN]; 54 } ____cacheline_aligned_in_smp; 55 56 struct virtio_blk { 57 /* 58 * This mutex must be held by anything that may run after 59 * virtblk_remove() sets vblk->vdev to NULL. 60 * 61 * blk-mq, virtqueue processing, and sysfs attribute code paths are 62 * shut down before vblk->vdev is set to NULL and therefore do not need 63 * to hold this mutex. 64 */ 65 struct mutex vdev_mutex; 66 struct virtio_device *vdev; 67 68 /* The disk structure for the kernel. */ 69 struct gendisk *disk; 70 71 /* Block layer tags. */ 72 struct blk_mq_tag_set tag_set; 73 74 /* Process context for config space updates */ 75 struct work_struct config_work; 76 77 /* Ida index - used to track minor number allocations. */ 78 int index; 79 80 /* num of vqs */ 81 int num_vqs; 82 int io_queues[HCTX_MAX_TYPES]; 83 struct virtio_blk_vq *vqs; 84 85 /* For zoned device */ 86 unsigned int zone_sectors; 87 }; 88 89 struct virtblk_req { 90 /* Out header */ 91 struct virtio_blk_outhdr out_hdr; 92 93 /* In header */ 94 union { 95 u8 status; 96 97 /* 98 * The zone append command has an extended in header. 99 * The status field in zone_append_in_hdr must always 100 * be the last byte. 101 */ 102 struct { 103 __virtio64 sector; 104 u8 status; 105 } zone_append; 106 } in_hdr; 107 108 size_t in_hdr_len; 109 110 struct sg_table sg_table; 111 struct scatterlist sg[]; 112 }; 113 114 static inline blk_status_t virtblk_result(u8 status) 115 { 116 switch (status) { 117 case VIRTIO_BLK_S_OK: 118 return BLK_STS_OK; 119 case VIRTIO_BLK_S_UNSUPP: 120 return BLK_STS_NOTSUPP; 121 case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE: 122 return BLK_STS_ZONE_OPEN_RESOURCE; 123 case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE: 124 return BLK_STS_ZONE_ACTIVE_RESOURCE; 125 case VIRTIO_BLK_S_IOERR: 126 case VIRTIO_BLK_S_ZONE_UNALIGNED_WP: 127 default: 128 return BLK_STS_IOERR; 129 } 130 } 131 132 static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) 133 { 134 struct virtio_blk *vblk = hctx->queue->queuedata; 135 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 136 137 return vq; 138 } 139 140 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) 141 { 142 struct scatterlist out_hdr, in_hdr, *sgs[3]; 143 unsigned int num_out = 0, num_in = 0; 144 145 sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); 146 sgs[num_out++] = &out_hdr; 147 148 if (vbr->sg_table.nents) { 149 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) 150 sgs[num_out++] = vbr->sg_table.sgl; 151 else 152 sgs[num_out + num_in++] = vbr->sg_table.sgl; 153 } 154 155 sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len); 156 sgs[num_out + num_in++] = &in_hdr; 157 158 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); 159 } 160 161 static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap) 162 { 163 unsigned short segments = blk_rq_nr_discard_segments(req); 164 unsigned short n = 0; 165 struct virtio_blk_discard_write_zeroes *range; 166 struct bio *bio; 167 u32 flags = 0; 168 169 if (unmap) 170 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; 171 172 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); 173 if (!range) 174 return -ENOMEM; 175 176 /* 177 * Single max discard segment means multi-range discard isn't 178 * supported, and block layer only runs contiguity merge like 179 * normal RW request. So we can't reply on bio for retrieving 180 * each range info. 181 */ 182 if (queue_max_discard_segments(req->q) == 1) { 183 range[0].flags = cpu_to_le32(flags); 184 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); 185 range[0].sector = cpu_to_le64(blk_rq_pos(req)); 186 n = 1; 187 } else { 188 __rq_for_each_bio(bio, req) { 189 u64 sector = bio->bi_iter.bi_sector; 190 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; 191 192 range[n].flags = cpu_to_le32(flags); 193 range[n].num_sectors = cpu_to_le32(num_sectors); 194 range[n].sector = cpu_to_le64(sector); 195 n++; 196 } 197 } 198 199 WARN_ON_ONCE(n != segments); 200 201 bvec_set_virt(&req->special_vec, range, sizeof(*range) * segments); 202 req->rq_flags |= RQF_SPECIAL_PAYLOAD; 203 204 return 0; 205 } 206 207 static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr) 208 { 209 if (blk_rq_nr_phys_segments(req)) 210 sg_free_table_chained(&vbr->sg_table, 211 VIRTIO_BLK_INLINE_SG_CNT); 212 } 213 214 static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req, 215 struct virtblk_req *vbr) 216 { 217 int err; 218 219 if (!blk_rq_nr_phys_segments(req)) 220 return 0; 221 222 vbr->sg_table.sgl = vbr->sg; 223 err = sg_alloc_table_chained(&vbr->sg_table, 224 blk_rq_nr_phys_segments(req), 225 vbr->sg_table.sgl, 226 VIRTIO_BLK_INLINE_SG_CNT); 227 if (unlikely(err)) 228 return -ENOMEM; 229 230 return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl); 231 } 232 233 static void virtblk_cleanup_cmd(struct request *req) 234 { 235 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) 236 kfree(bvec_virt(&req->special_vec)); 237 } 238 239 static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, 240 struct request *req, 241 struct virtblk_req *vbr) 242 { 243 size_t in_hdr_len = sizeof(vbr->in_hdr.status); 244 bool unmap = false; 245 u32 type; 246 u64 sector = 0; 247 248 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req))) 249 return BLK_STS_NOTSUPP; 250 251 /* Set fields for all request types */ 252 vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); 253 254 switch (req_op(req)) { 255 case REQ_OP_READ: 256 type = VIRTIO_BLK_T_IN; 257 sector = blk_rq_pos(req); 258 break; 259 case REQ_OP_WRITE: 260 type = VIRTIO_BLK_T_OUT; 261 sector = blk_rq_pos(req); 262 break; 263 case REQ_OP_FLUSH: 264 type = VIRTIO_BLK_T_FLUSH; 265 break; 266 case REQ_OP_DISCARD: 267 type = VIRTIO_BLK_T_DISCARD; 268 break; 269 case REQ_OP_WRITE_ZEROES: 270 type = VIRTIO_BLK_T_WRITE_ZEROES; 271 unmap = !(req->cmd_flags & REQ_NOUNMAP); 272 break; 273 case REQ_OP_SECURE_ERASE: 274 type = VIRTIO_BLK_T_SECURE_ERASE; 275 break; 276 case REQ_OP_ZONE_OPEN: 277 type = VIRTIO_BLK_T_ZONE_OPEN; 278 sector = blk_rq_pos(req); 279 break; 280 case REQ_OP_ZONE_CLOSE: 281 type = VIRTIO_BLK_T_ZONE_CLOSE; 282 sector = blk_rq_pos(req); 283 break; 284 case REQ_OP_ZONE_FINISH: 285 type = VIRTIO_BLK_T_ZONE_FINISH; 286 sector = blk_rq_pos(req); 287 break; 288 case REQ_OP_ZONE_APPEND: 289 type = VIRTIO_BLK_T_ZONE_APPEND; 290 sector = blk_rq_pos(req); 291 in_hdr_len = sizeof(vbr->in_hdr.zone_append); 292 break; 293 case REQ_OP_ZONE_RESET: 294 type = VIRTIO_BLK_T_ZONE_RESET; 295 sector = blk_rq_pos(req); 296 break; 297 case REQ_OP_ZONE_RESET_ALL: 298 type = VIRTIO_BLK_T_ZONE_RESET_ALL; 299 break; 300 case REQ_OP_DRV_IN: 301 /* 302 * Out header has already been prepared by the caller (virtblk_get_id() 303 * or virtblk_submit_zone_report()), nothing to do here. 304 */ 305 return 0; 306 default: 307 WARN_ON_ONCE(1); 308 return BLK_STS_IOERR; 309 } 310 311 /* Set fields for non-REQ_OP_DRV_IN request types */ 312 vbr->in_hdr_len = in_hdr_len; 313 vbr->out_hdr.type = cpu_to_virtio32(vdev, type); 314 vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector); 315 316 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES || 317 type == VIRTIO_BLK_T_SECURE_ERASE) { 318 if (virtblk_setup_discard_write_zeroes_erase(req, unmap)) 319 return BLK_STS_RESOURCE; 320 } 321 322 return 0; 323 } 324 325 /* 326 * The status byte is always the last byte of the virtblk request 327 * in-header. This helper fetches its value for all in-header formats 328 * that are currently defined. 329 */ 330 static inline u8 virtblk_vbr_status(struct virtblk_req *vbr) 331 { 332 return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1); 333 } 334 335 static inline void virtblk_request_done(struct request *req) 336 { 337 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 338 blk_status_t status = virtblk_result(virtblk_vbr_status(vbr)); 339 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 340 341 virtblk_unmap_data(req, vbr); 342 virtblk_cleanup_cmd(req); 343 344 if (req_op(req) == REQ_OP_ZONE_APPEND) 345 req->__sector = virtio64_to_cpu(vblk->vdev, 346 vbr->in_hdr.zone_append.sector); 347 348 blk_mq_end_request(req, status); 349 } 350 351 static void virtblk_done(struct virtqueue *vq) 352 { 353 struct virtio_blk *vblk = vq->vdev->priv; 354 bool req_done = false; 355 int qid = vq->index; 356 struct virtblk_req *vbr; 357 unsigned long flags; 358 unsigned int len; 359 360 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 361 do { 362 virtqueue_disable_cb(vq); 363 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { 364 struct request *req = blk_mq_rq_from_pdu(vbr); 365 366 if (likely(!blk_should_fake_timeout(req->q))) 367 blk_mq_complete_request(req); 368 req_done = true; 369 } 370 if (unlikely(virtqueue_is_broken(vq))) 371 break; 372 } while (!virtqueue_enable_cb(vq)); 373 374 /* In case queue is stopped waiting for more buffers. */ 375 if (req_done) 376 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 377 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 378 } 379 380 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) 381 { 382 struct virtio_blk *vblk = hctx->queue->queuedata; 383 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 384 bool kick; 385 386 spin_lock_irq(&vq->lock); 387 kick = virtqueue_kick_prepare(vq->vq); 388 spin_unlock_irq(&vq->lock); 389 390 if (kick) 391 virtqueue_notify(vq->vq); 392 } 393 394 static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) 395 { 396 virtblk_cleanup_cmd(req); 397 switch (rc) { 398 case -ENOSPC: 399 return BLK_STS_DEV_RESOURCE; 400 case -ENOMEM: 401 return BLK_STS_RESOURCE; 402 default: 403 return BLK_STS_IOERR; 404 } 405 } 406 407 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, 408 struct virtio_blk *vblk, 409 struct request *req, 410 struct virtblk_req *vbr) 411 { 412 blk_status_t status; 413 int num; 414 415 status = virtblk_setup_cmd(vblk->vdev, req, vbr); 416 if (unlikely(status)) 417 return status; 418 419 num = virtblk_map_data(hctx, req, vbr); 420 if (unlikely(num < 0)) 421 return virtblk_fail_to_queue(req, -ENOMEM); 422 vbr->sg_table.nents = num; 423 424 blk_mq_start_request(req); 425 426 return BLK_STS_OK; 427 } 428 429 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, 430 const struct blk_mq_queue_data *bd) 431 { 432 struct virtio_blk *vblk = hctx->queue->queuedata; 433 struct request *req = bd->rq; 434 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 435 unsigned long flags; 436 int qid = hctx->queue_num; 437 bool notify = false; 438 blk_status_t status; 439 int err; 440 441 status = virtblk_prep_rq(hctx, vblk, req, vbr); 442 if (unlikely(status)) 443 return status; 444 445 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 446 err = virtblk_add_req(vblk->vqs[qid].vq, vbr); 447 if (err) { 448 virtqueue_kick(vblk->vqs[qid].vq); 449 /* Don't stop the queue if -ENOMEM: we may have failed to 450 * bounce the buffer due to global resource outage. 451 */ 452 if (err == -ENOSPC) 453 blk_mq_stop_hw_queue(hctx); 454 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 455 virtblk_unmap_data(req, vbr); 456 return virtblk_fail_to_queue(req, err); 457 } 458 459 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) 460 notify = true; 461 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 462 463 if (notify) 464 virtqueue_notify(vblk->vqs[qid].vq); 465 return BLK_STS_OK; 466 } 467 468 static bool virtblk_prep_rq_batch(struct request *req) 469 { 470 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 471 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 472 473 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 474 } 475 476 static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, 477 struct request **rqlist) 478 { 479 unsigned long flags; 480 int err; 481 bool kick; 482 483 spin_lock_irqsave(&vq->lock, flags); 484 485 while (!rq_list_empty(*rqlist)) { 486 struct request *req = rq_list_pop(rqlist); 487 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 488 489 err = virtblk_add_req(vq->vq, vbr); 490 if (err) { 491 virtblk_unmap_data(req, vbr); 492 virtblk_cleanup_cmd(req); 493 blk_mq_requeue_request(req, true); 494 } 495 } 496 497 kick = virtqueue_kick_prepare(vq->vq); 498 spin_unlock_irqrestore(&vq->lock, flags); 499 500 return kick; 501 } 502 503 static void virtio_queue_rqs(struct request **rqlist) 504 { 505 struct request *req, *next, *prev = NULL; 506 struct request *requeue_list = NULL; 507 508 rq_list_for_each_safe(rqlist, req, next) { 509 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); 510 bool kick; 511 512 if (!virtblk_prep_rq_batch(req)) { 513 rq_list_move(rqlist, &requeue_list, req, prev); 514 req = prev; 515 if (!req) 516 continue; 517 } 518 519 if (!next || req->mq_hctx != next->mq_hctx) { 520 req->rq_next = NULL; 521 kick = virtblk_add_req_batch(vq, rqlist); 522 if (kick) 523 virtqueue_notify(vq->vq); 524 525 *rqlist = next; 526 prev = NULL; 527 } else 528 prev = req; 529 } 530 531 *rqlist = requeue_list; 532 } 533 534 #ifdef CONFIG_BLK_DEV_ZONED 535 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 536 unsigned int nr_zones, 537 size_t *buflen) 538 { 539 struct request_queue *q = vblk->disk->queue; 540 size_t bufsize; 541 void *buf; 542 543 nr_zones = min_t(unsigned int, nr_zones, 544 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); 545 546 bufsize = sizeof(struct virtio_blk_zone_report) + 547 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 548 bufsize = min_t(size_t, bufsize, 549 queue_max_hw_sectors(q) << SECTOR_SHIFT); 550 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 551 552 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 553 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 554 if (buf) { 555 *buflen = bufsize; 556 return buf; 557 } 558 bufsize >>= 1; 559 } 560 561 return NULL; 562 } 563 564 static int virtblk_submit_zone_report(struct virtio_blk *vblk, 565 char *report_buf, size_t report_len, 566 sector_t sector) 567 { 568 struct request_queue *q = vblk->disk->queue; 569 struct request *req; 570 struct virtblk_req *vbr; 571 int err; 572 573 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 574 if (IS_ERR(req)) 575 return PTR_ERR(req); 576 577 vbr = blk_mq_rq_to_pdu(req); 578 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 579 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 580 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 581 582 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); 583 if (err) 584 goto out; 585 586 blk_execute_rq(req, false); 587 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 588 out: 589 blk_mq_free_request(req); 590 return err; 591 } 592 593 static int virtblk_parse_zone(struct virtio_blk *vblk, 594 struct virtio_blk_zone_descriptor *entry, 595 unsigned int idx, report_zones_cb cb, void *data) 596 { 597 struct blk_zone zone = { }; 598 599 zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start); 600 if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk)) 601 zone.len = vblk->zone_sectors; 602 else 603 zone.len = get_capacity(vblk->disk) - zone.start; 604 zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap); 605 zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp); 606 607 switch (entry->z_type) { 608 case VIRTIO_BLK_ZT_SWR: 609 zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ; 610 break; 611 case VIRTIO_BLK_ZT_SWP: 612 zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF; 613 break; 614 case VIRTIO_BLK_ZT_CONV: 615 zone.type = BLK_ZONE_TYPE_CONVENTIONAL; 616 break; 617 default: 618 dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n", 619 zone.start, entry->z_type); 620 return -EIO; 621 } 622 623 switch (entry->z_state) { 624 case VIRTIO_BLK_ZS_EMPTY: 625 zone.cond = BLK_ZONE_COND_EMPTY; 626 break; 627 case VIRTIO_BLK_ZS_CLOSED: 628 zone.cond = BLK_ZONE_COND_CLOSED; 629 break; 630 case VIRTIO_BLK_ZS_FULL: 631 zone.cond = BLK_ZONE_COND_FULL; 632 zone.wp = zone.start + zone.len; 633 break; 634 case VIRTIO_BLK_ZS_EOPEN: 635 zone.cond = BLK_ZONE_COND_EXP_OPEN; 636 break; 637 case VIRTIO_BLK_ZS_IOPEN: 638 zone.cond = BLK_ZONE_COND_IMP_OPEN; 639 break; 640 case VIRTIO_BLK_ZS_NOT_WP: 641 zone.cond = BLK_ZONE_COND_NOT_WP; 642 break; 643 case VIRTIO_BLK_ZS_RDONLY: 644 zone.cond = BLK_ZONE_COND_READONLY; 645 zone.wp = ULONG_MAX; 646 break; 647 case VIRTIO_BLK_ZS_OFFLINE: 648 zone.cond = BLK_ZONE_COND_OFFLINE; 649 zone.wp = ULONG_MAX; 650 break; 651 default: 652 dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n", 653 zone.start, entry->z_state); 654 return -EIO; 655 } 656 657 /* 658 * The callback below checks the validity of the reported 659 * entry data, no need to further validate it here. 660 */ 661 return cb(&zone, idx, data); 662 } 663 664 static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 665 unsigned int nr_zones, report_zones_cb cb, 666 void *data) 667 { 668 struct virtio_blk *vblk = disk->private_data; 669 struct virtio_blk_zone_report *report; 670 unsigned long long nz, i; 671 size_t buflen; 672 unsigned int zone_idx = 0; 673 int ret; 674 675 if (WARN_ON_ONCE(!vblk->zone_sectors)) 676 return -EOPNOTSUPP; 677 678 report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen); 679 if (!report) 680 return -ENOMEM; 681 682 mutex_lock(&vblk->vdev_mutex); 683 684 if (!vblk->vdev) { 685 ret = -ENXIO; 686 goto fail_report; 687 } 688 689 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { 690 memset(report, 0, buflen); 691 692 ret = virtblk_submit_zone_report(vblk, (char *)report, 693 buflen, sector); 694 if (ret) 695 goto fail_report; 696 697 nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones), 698 nr_zones); 699 if (!nz) 700 break; 701 702 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 703 ret = virtblk_parse_zone(vblk, &report->zones[i], 704 zone_idx, cb, data); 705 if (ret) 706 goto fail_report; 707 708 sector = virtio64_to_cpu(vblk->vdev, 709 report->zones[i].z_start) + 710 vblk->zone_sectors; 711 zone_idx++; 712 } 713 } 714 715 if (zone_idx > 0) 716 ret = zone_idx; 717 else 718 ret = -EINVAL; 719 fail_report: 720 mutex_unlock(&vblk->vdev_mutex); 721 kvfree(report); 722 return ret; 723 } 724 725 static int virtblk_probe_zoned_device(struct virtio_device *vdev, 726 struct virtio_blk *vblk, 727 struct request_queue *q) 728 { 729 u32 v, wg; 730 731 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 732 733 disk_set_zoned(vblk->disk); 734 blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); 735 736 virtio_cread(vdev, struct virtio_blk_config, 737 zoned.max_open_zones, &v); 738 disk_set_max_open_zones(vblk->disk, v); 739 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 740 741 virtio_cread(vdev, struct virtio_blk_config, 742 zoned.max_active_zones, &v); 743 disk_set_max_active_zones(vblk->disk, v); 744 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 745 746 virtio_cread(vdev, struct virtio_blk_config, 747 zoned.write_granularity, &wg); 748 if (!wg) { 749 dev_warn(&vdev->dev, "zero write granularity reported\n"); 750 return -ENODEV; 751 } 752 blk_queue_physical_block_size(q, wg); 753 blk_queue_io_min(q, wg); 754 755 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 756 757 /* 758 * virtio ZBD specification doesn't require zones to be a power of 759 * two sectors in size, but the code in this driver expects that. 760 */ 761 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 762 &vblk->zone_sectors); 763 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 764 dev_err(&vdev->dev, 765 "zoned device with non power of two zone size %u\n", 766 vblk->zone_sectors); 767 return -ENODEV; 768 } 769 blk_queue_chunk_sectors(q, vblk->zone_sectors); 770 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 771 772 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 773 dev_warn(&vblk->vdev->dev, 774 "ignoring negotiated F_DISCARD for zoned device\n"); 775 blk_queue_max_discard_sectors(q, 0); 776 } 777 778 virtio_cread(vdev, struct virtio_blk_config, 779 zoned.max_append_sectors, &v); 780 if (!v) { 781 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 782 return -ENODEV; 783 } 784 if ((v << SECTOR_SHIFT) < wg) { 785 dev_err(&vdev->dev, 786 "write granularity %u exceeds max_append_sectors %u limit\n", 787 wg, v); 788 return -ENODEV; 789 } 790 blk_queue_max_zone_append_sectors(q, v); 791 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 792 793 return blk_revalidate_disk_zones(vblk->disk, NULL); 794 } 795 796 #else 797 798 /* 799 * Zoned block device support is not configured in this kernel. 800 * Host-managed zoned devices can't be supported, but others are 801 * good to go as regular block devices. 802 */ 803 #define virtblk_report_zones NULL 804 805 static inline int virtblk_probe_zoned_device(struct virtio_device *vdev, 806 struct virtio_blk *vblk, struct request_queue *q) 807 { 808 dev_err(&vdev->dev, 809 "virtio_blk: zoned devices are not supported"); 810 return -EOPNOTSUPP; 811 } 812 #endif /* CONFIG_BLK_DEV_ZONED */ 813 814 /* return id (s/n) string for *disk to *id_str 815 */ 816 static int virtblk_get_id(struct gendisk *disk, char *id_str) 817 { 818 struct virtio_blk *vblk = disk->private_data; 819 struct request_queue *q = vblk->disk->queue; 820 struct request *req; 821 struct virtblk_req *vbr; 822 int err; 823 824 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 825 if (IS_ERR(req)) 826 return PTR_ERR(req); 827 828 vbr = blk_mq_rq_to_pdu(req); 829 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 830 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 831 vbr->out_hdr.sector = 0; 832 833 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 834 if (err) 835 goto out; 836 837 blk_execute_rq(req, false); 838 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 839 out: 840 blk_mq_free_request(req); 841 return err; 842 } 843 844 /* We provide getgeo only to please some old bootloader/partitioning tools */ 845 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 846 { 847 struct virtio_blk *vblk = bd->bd_disk->private_data; 848 int ret = 0; 849 850 mutex_lock(&vblk->vdev_mutex); 851 852 if (!vblk->vdev) { 853 ret = -ENXIO; 854 goto out; 855 } 856 857 /* see if the host passed in geometry config */ 858 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 859 virtio_cread(vblk->vdev, struct virtio_blk_config, 860 geometry.cylinders, &geo->cylinders); 861 virtio_cread(vblk->vdev, struct virtio_blk_config, 862 geometry.heads, &geo->heads); 863 virtio_cread(vblk->vdev, struct virtio_blk_config, 864 geometry.sectors, &geo->sectors); 865 } else { 866 /* some standard values, similar to sd */ 867 geo->heads = 1 << 6; 868 geo->sectors = 1 << 5; 869 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 870 } 871 out: 872 mutex_unlock(&vblk->vdev_mutex); 873 return ret; 874 } 875 876 static void virtblk_free_disk(struct gendisk *disk) 877 { 878 struct virtio_blk *vblk = disk->private_data; 879 880 ida_free(&vd_index_ida, vblk->index); 881 mutex_destroy(&vblk->vdev_mutex); 882 kfree(vblk); 883 } 884 885 static const struct block_device_operations virtblk_fops = { 886 .owner = THIS_MODULE, 887 .getgeo = virtblk_getgeo, 888 .free_disk = virtblk_free_disk, 889 .report_zones = virtblk_report_zones, 890 }; 891 892 static int index_to_minor(int index) 893 { 894 return index << PART_BITS; 895 } 896 897 static int minor_to_index(int minor) 898 { 899 return minor >> PART_BITS; 900 } 901 902 static ssize_t serial_show(struct device *dev, 903 struct device_attribute *attr, char *buf) 904 { 905 struct gendisk *disk = dev_to_disk(dev); 906 int err; 907 908 /* sysfs gives us a PAGE_SIZE buffer */ 909 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 910 911 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 912 err = virtblk_get_id(disk, buf); 913 if (!err) 914 return strlen(buf); 915 916 if (err == -EIO) /* Unsupported? Make it empty. */ 917 return 0; 918 919 return err; 920 } 921 922 static DEVICE_ATTR_RO(serial); 923 924 /* The queue's logical block size must be set before calling this */ 925 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 926 { 927 struct virtio_device *vdev = vblk->vdev; 928 struct request_queue *q = vblk->disk->queue; 929 char cap_str_2[10], cap_str_10[10]; 930 unsigned long long nblocks; 931 u64 capacity; 932 933 /* Host must always specify the capacity. */ 934 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 935 936 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 937 938 string_get_size(nblocks, queue_logical_block_size(q), 939 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 940 string_get_size(nblocks, queue_logical_block_size(q), 941 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 942 943 dev_notice(&vdev->dev, 944 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 945 vblk->disk->disk_name, 946 resize ? "new size: " : "", 947 nblocks, 948 queue_logical_block_size(q), 949 cap_str_10, 950 cap_str_2); 951 952 set_capacity_and_notify(vblk->disk, capacity); 953 } 954 955 static void virtblk_config_changed_work(struct work_struct *work) 956 { 957 struct virtio_blk *vblk = 958 container_of(work, struct virtio_blk, config_work); 959 960 virtblk_update_capacity(vblk, true); 961 } 962 963 static void virtblk_config_changed(struct virtio_device *vdev) 964 { 965 struct virtio_blk *vblk = vdev->priv; 966 967 queue_work(virtblk_wq, &vblk->config_work); 968 } 969 970 static int init_vq(struct virtio_blk *vblk) 971 { 972 int err; 973 unsigned short i; 974 vq_callback_t **callbacks; 975 const char **names; 976 struct virtqueue **vqs; 977 unsigned short num_vqs; 978 unsigned short num_poll_vqs; 979 struct virtio_device *vdev = vblk->vdev; 980 struct irq_affinity desc = { 0, }; 981 982 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 983 struct virtio_blk_config, num_queues, 984 &num_vqs); 985 if (err) 986 num_vqs = 1; 987 988 if (!err && !num_vqs) { 989 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 990 return -EINVAL; 991 } 992 993 num_vqs = min_t(unsigned int, 994 min_not_zero(num_request_queues, nr_cpu_ids), 995 num_vqs); 996 997 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 998 999 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 1000 vblk->io_queues[HCTX_TYPE_READ] = 0; 1001 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 1002 1003 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 1004 vblk->io_queues[HCTX_TYPE_DEFAULT], 1005 vblk->io_queues[HCTX_TYPE_READ], 1006 vblk->io_queues[HCTX_TYPE_POLL]); 1007 1008 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 1009 if (!vblk->vqs) 1010 return -ENOMEM; 1011 1012 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); 1013 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); 1014 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1015 if (!names || !callbacks || !vqs) { 1016 err = -ENOMEM; 1017 goto out; 1018 } 1019 1020 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1021 callbacks[i] = virtblk_done; 1022 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1023 names[i] = vblk->vqs[i].name; 1024 } 1025 1026 for (; i < num_vqs; i++) { 1027 callbacks[i] = NULL; 1028 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1029 names[i] = vblk->vqs[i].name; 1030 } 1031 1032 /* Discover virtqueues and write information to configuration. */ 1033 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 1034 if (err) 1035 goto out; 1036 1037 for (i = 0; i < num_vqs; i++) { 1038 spin_lock_init(&vblk->vqs[i].lock); 1039 vblk->vqs[i].vq = vqs[i]; 1040 } 1041 vblk->num_vqs = num_vqs; 1042 1043 out: 1044 kfree(vqs); 1045 kfree(callbacks); 1046 kfree(names); 1047 if (err) 1048 kfree(vblk->vqs); 1049 return err; 1050 } 1051 1052 /* 1053 * Legacy naming scheme used for virtio devices. We are stuck with it for 1054 * virtio blk but don't ever use it for any new driver. 1055 */ 1056 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1057 { 1058 const int base = 'z' - 'a' + 1; 1059 char *begin = buf + strlen(prefix); 1060 char *end = buf + buflen; 1061 char *p; 1062 int unit; 1063 1064 p = end - 1; 1065 *p = '\0'; 1066 unit = base; 1067 do { 1068 if (p == begin) 1069 return -EINVAL; 1070 *--p = 'a' + (index % unit); 1071 index = (index / unit) - 1; 1072 } while (index >= 0); 1073 1074 memmove(begin, p, end - p); 1075 memcpy(buf, prefix, strlen(prefix)); 1076 1077 return 0; 1078 } 1079 1080 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1081 { 1082 u8 writeback; 1083 int err; 1084 1085 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1086 struct virtio_blk_config, wce, 1087 &writeback); 1088 1089 /* 1090 * If WCE is not configurable and flush is not available, 1091 * assume no writeback cache is in use. 1092 */ 1093 if (err) 1094 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1095 1096 return writeback; 1097 } 1098 1099 static void virtblk_update_cache_mode(struct virtio_device *vdev) 1100 { 1101 u8 writeback = virtblk_get_cache_mode(vdev); 1102 struct virtio_blk *vblk = vdev->priv; 1103 1104 blk_queue_write_cache(vblk->disk->queue, writeback, false); 1105 } 1106 1107 static const char *const virtblk_cache_types[] = { 1108 "write through", "write back" 1109 }; 1110 1111 static ssize_t 1112 cache_type_store(struct device *dev, struct device_attribute *attr, 1113 const char *buf, size_t count) 1114 { 1115 struct gendisk *disk = dev_to_disk(dev); 1116 struct virtio_blk *vblk = disk->private_data; 1117 struct virtio_device *vdev = vblk->vdev; 1118 int i; 1119 1120 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1121 i = sysfs_match_string(virtblk_cache_types, buf); 1122 if (i < 0) 1123 return i; 1124 1125 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1126 virtblk_update_cache_mode(vdev); 1127 return count; 1128 } 1129 1130 static ssize_t 1131 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1132 { 1133 struct gendisk *disk = dev_to_disk(dev); 1134 struct virtio_blk *vblk = disk->private_data; 1135 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1136 1137 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1138 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1139 } 1140 1141 static DEVICE_ATTR_RW(cache_type); 1142 1143 static struct attribute *virtblk_attrs[] = { 1144 &dev_attr_serial.attr, 1145 &dev_attr_cache_type.attr, 1146 NULL, 1147 }; 1148 1149 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1150 struct attribute *a, int n) 1151 { 1152 struct device *dev = kobj_to_dev(kobj); 1153 struct gendisk *disk = dev_to_disk(dev); 1154 struct virtio_blk *vblk = disk->private_data; 1155 struct virtio_device *vdev = vblk->vdev; 1156 1157 if (a == &dev_attr_cache_type.attr && 1158 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1159 return S_IRUGO; 1160 1161 return a->mode; 1162 } 1163 1164 static const struct attribute_group virtblk_attr_group = { 1165 .attrs = virtblk_attrs, 1166 .is_visible = virtblk_attrs_are_visible, 1167 }; 1168 1169 static const struct attribute_group *virtblk_attr_groups[] = { 1170 &virtblk_attr_group, 1171 NULL, 1172 }; 1173 1174 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1175 { 1176 struct virtio_blk *vblk = set->driver_data; 1177 int i, qoff; 1178 1179 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1180 struct blk_mq_queue_map *map = &set->map[i]; 1181 1182 map->nr_queues = vblk->io_queues[i]; 1183 map->queue_offset = qoff; 1184 qoff += map->nr_queues; 1185 1186 if (map->nr_queues == 0) 1187 continue; 1188 1189 /* 1190 * Regular queues have interrupts and hence CPU affinity is 1191 * defined by the core virtio code, but polling queues have 1192 * no interrupts so we let the block layer assign CPU affinity. 1193 */ 1194 if (i == HCTX_TYPE_POLL) 1195 blk_mq_map_queues(&set->map[i]); 1196 else 1197 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1198 } 1199 } 1200 1201 static void virtblk_complete_batch(struct io_comp_batch *iob) 1202 { 1203 struct request *req; 1204 1205 rq_list_for_each(&iob->req_list, req) { 1206 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1207 virtblk_cleanup_cmd(req); 1208 } 1209 blk_mq_end_request_batch(iob); 1210 } 1211 1212 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1213 { 1214 struct virtio_blk *vblk = hctx->queue->queuedata; 1215 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1216 struct virtblk_req *vbr; 1217 unsigned long flags; 1218 unsigned int len; 1219 int found = 0; 1220 1221 spin_lock_irqsave(&vq->lock, flags); 1222 1223 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1224 struct request *req = blk_mq_rq_from_pdu(vbr); 1225 1226 found++; 1227 if (!blk_mq_complete_request_remote(req) && 1228 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1229 virtblk_complete_batch)) 1230 virtblk_request_done(req); 1231 } 1232 1233 if (found) 1234 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1235 1236 spin_unlock_irqrestore(&vq->lock, flags); 1237 1238 return found; 1239 } 1240 1241 static const struct blk_mq_ops virtio_mq_ops = { 1242 .queue_rq = virtio_queue_rq, 1243 .queue_rqs = virtio_queue_rqs, 1244 .commit_rqs = virtio_commit_rqs, 1245 .complete = virtblk_request_done, 1246 .map_queues = virtblk_map_queues, 1247 .poll = virtblk_poll, 1248 }; 1249 1250 static unsigned int virtblk_queue_depth; 1251 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1252 1253 static int virtblk_probe(struct virtio_device *vdev) 1254 { 1255 struct virtio_blk *vblk; 1256 struct request_queue *q; 1257 int err, index; 1258 1259 u32 v, blk_size, max_size, sg_elems, opt_io_size; 1260 u32 max_discard_segs = 0; 1261 u32 discard_granularity = 0; 1262 u16 min_io_size; 1263 u8 physical_block_exp, alignment_offset; 1264 unsigned int queue_depth; 1265 size_t max_dma_size; 1266 1267 if (!vdev->config->get) { 1268 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1269 __func__); 1270 return -EINVAL; 1271 } 1272 1273 err = ida_alloc_range(&vd_index_ida, 0, 1274 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1275 if (err < 0) 1276 goto out; 1277 index = err; 1278 1279 /* We need to know how many segments before we allocate. */ 1280 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1281 struct virtio_blk_config, seg_max, 1282 &sg_elems); 1283 1284 /* We need at least one SG element, whatever they say. */ 1285 if (err || !sg_elems) 1286 sg_elems = 1; 1287 1288 /* Prevent integer overflows and honor max vq size */ 1289 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1290 1291 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1292 if (!vblk) { 1293 err = -ENOMEM; 1294 goto out_free_index; 1295 } 1296 1297 mutex_init(&vblk->vdev_mutex); 1298 1299 vblk->vdev = vdev; 1300 1301 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1302 1303 err = init_vq(vblk); 1304 if (err) 1305 goto out_free_vblk; 1306 1307 /* Default queue sizing is to fill the ring. */ 1308 if (!virtblk_queue_depth) { 1309 queue_depth = vblk->vqs[0].vq->num_free; 1310 /* ... but without indirect descs, we use 2 descs per req */ 1311 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1312 queue_depth /= 2; 1313 } else { 1314 queue_depth = virtblk_queue_depth; 1315 } 1316 1317 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1318 vblk->tag_set.ops = &virtio_mq_ops; 1319 vblk->tag_set.queue_depth = queue_depth; 1320 vblk->tag_set.numa_node = NUMA_NO_NODE; 1321 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1322 vblk->tag_set.cmd_size = 1323 sizeof(struct virtblk_req) + 1324 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1325 vblk->tag_set.driver_data = vblk; 1326 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1327 vblk->tag_set.nr_maps = 1; 1328 if (vblk->io_queues[HCTX_TYPE_POLL]) 1329 vblk->tag_set.nr_maps = 3; 1330 1331 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1332 if (err) 1333 goto out_free_vq; 1334 1335 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); 1336 if (IS_ERR(vblk->disk)) { 1337 err = PTR_ERR(vblk->disk); 1338 goto out_free_tags; 1339 } 1340 q = vblk->disk->queue; 1341 1342 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1343 1344 vblk->disk->major = major; 1345 vblk->disk->first_minor = index_to_minor(index); 1346 vblk->disk->minors = 1 << PART_BITS; 1347 vblk->disk->private_data = vblk; 1348 vblk->disk->fops = &virtblk_fops; 1349 vblk->index = index; 1350 1351 /* configure queue flush support */ 1352 virtblk_update_cache_mode(vdev); 1353 1354 /* If disk is read-only in the host, the guest should obey */ 1355 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1356 set_disk_ro(vblk->disk, 1); 1357 1358 /* We can handle whatever the host told us to handle. */ 1359 blk_queue_max_segments(q, sg_elems); 1360 1361 /* No real sector limit. */ 1362 blk_queue_max_hw_sectors(q, UINT_MAX); 1363 1364 max_dma_size = virtio_max_dma_size(vdev); 1365 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1366 1367 /* Host can optionally specify maximum segment size and number of 1368 * segments. */ 1369 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1370 struct virtio_blk_config, size_max, &v); 1371 if (!err) 1372 max_size = min(max_size, v); 1373 1374 blk_queue_max_segment_size(q, max_size); 1375 1376 /* Host can optionally specify the block size of the device */ 1377 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1378 struct virtio_blk_config, blk_size, 1379 &blk_size); 1380 if (!err) { 1381 err = blk_validate_block_size(blk_size); 1382 if (err) { 1383 dev_err(&vdev->dev, 1384 "virtio_blk: invalid block size: 0x%x\n", 1385 blk_size); 1386 goto out_cleanup_disk; 1387 } 1388 1389 blk_queue_logical_block_size(q, blk_size); 1390 } else 1391 blk_size = queue_logical_block_size(q); 1392 1393 /* Use topology information if available */ 1394 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1395 struct virtio_blk_config, physical_block_exp, 1396 &physical_block_exp); 1397 if (!err && physical_block_exp) 1398 blk_queue_physical_block_size(q, 1399 blk_size * (1 << physical_block_exp)); 1400 1401 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1402 struct virtio_blk_config, alignment_offset, 1403 &alignment_offset); 1404 if (!err && alignment_offset) 1405 blk_queue_alignment_offset(q, blk_size * alignment_offset); 1406 1407 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1408 struct virtio_blk_config, min_io_size, 1409 &min_io_size); 1410 if (!err && min_io_size) 1411 blk_queue_io_min(q, blk_size * min_io_size); 1412 1413 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1414 struct virtio_blk_config, opt_io_size, 1415 &opt_io_size); 1416 if (!err && opt_io_size) 1417 blk_queue_io_opt(q, blk_size * opt_io_size); 1418 1419 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1420 virtio_cread(vdev, struct virtio_blk_config, 1421 discard_sector_alignment, &discard_granularity); 1422 1423 virtio_cread(vdev, struct virtio_blk_config, 1424 max_discard_sectors, &v); 1425 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); 1426 1427 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1428 &max_discard_segs); 1429 } 1430 1431 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1432 virtio_cread(vdev, struct virtio_blk_config, 1433 max_write_zeroes_sectors, &v); 1434 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); 1435 } 1436 1437 /* The discard and secure erase limits are combined since the Linux 1438 * block layer uses the same limit for both commands. 1439 * 1440 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1441 * are negotiated, we will use the minimum between the limits. 1442 * 1443 * discard sector alignment is set to the minimum between discard_sector_alignment 1444 * and secure_erase_sector_alignment. 1445 * 1446 * max discard sectors is set to the minimum between max_discard_seg and 1447 * max_secure_erase_seg. 1448 */ 1449 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1450 1451 virtio_cread(vdev, struct virtio_blk_config, 1452 secure_erase_sector_alignment, &v); 1453 1454 /* secure_erase_sector_alignment should not be zero, the device should set a 1455 * valid number of sectors. 1456 */ 1457 if (!v) { 1458 dev_err(&vdev->dev, 1459 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1460 err = -EINVAL; 1461 goto out_cleanup_disk; 1462 } 1463 1464 discard_granularity = min_not_zero(discard_granularity, v); 1465 1466 virtio_cread(vdev, struct virtio_blk_config, 1467 max_secure_erase_sectors, &v); 1468 1469 /* max_secure_erase_sectors should not be zero, the device should set a 1470 * valid number of sectors. 1471 */ 1472 if (!v) { 1473 dev_err(&vdev->dev, 1474 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1475 err = -EINVAL; 1476 goto out_cleanup_disk; 1477 } 1478 1479 blk_queue_max_secure_erase_sectors(q, v); 1480 1481 virtio_cread(vdev, struct virtio_blk_config, 1482 max_secure_erase_seg, &v); 1483 1484 /* max_secure_erase_seg should not be zero, the device should set a 1485 * valid number of segments 1486 */ 1487 if (!v) { 1488 dev_err(&vdev->dev, 1489 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1490 err = -EINVAL; 1491 goto out_cleanup_disk; 1492 } 1493 1494 max_discard_segs = min_not_zero(max_discard_segs, v); 1495 } 1496 1497 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1498 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1499 /* max_discard_seg and discard_granularity will be 0 only 1500 * if max_discard_seg and discard_sector_alignment fields in the virtio 1501 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1502 * In this case, we use default values. 1503 */ 1504 if (!max_discard_segs) 1505 max_discard_segs = sg_elems; 1506 1507 blk_queue_max_discard_segments(q, 1508 min(max_discard_segs, MAX_DISCARD_SEGMENTS)); 1509 1510 if (discard_granularity) 1511 q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT; 1512 else 1513 q->limits.discard_granularity = blk_size; 1514 } 1515 1516 virtblk_update_capacity(vblk, false); 1517 virtio_device_ready(vdev); 1518 1519 /* 1520 * All steps that follow use the VQs therefore they need to be 1521 * placed after the virtio_device_ready() call above. 1522 */ 1523 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1524 u8 model; 1525 1526 virtio_cread(vdev, struct virtio_blk_config, zoned.model, 1527 &model); 1528 switch (model) { 1529 case VIRTIO_BLK_Z_NONE: 1530 case VIRTIO_BLK_Z_HA: 1531 /* Present the host-aware device as non-zoned */ 1532 break; 1533 case VIRTIO_BLK_Z_HM: 1534 err = virtblk_probe_zoned_device(vdev, vblk, q); 1535 if (err) 1536 goto out_cleanup_disk; 1537 break; 1538 default: 1539 dev_err(&vdev->dev, "unsupported zone model %d\n", 1540 model); 1541 err = -EINVAL; 1542 goto out_cleanup_disk; 1543 } 1544 } 1545 1546 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1547 if (err) 1548 goto out_cleanup_disk; 1549 1550 return 0; 1551 1552 out_cleanup_disk: 1553 put_disk(vblk->disk); 1554 out_free_tags: 1555 blk_mq_free_tag_set(&vblk->tag_set); 1556 out_free_vq: 1557 vdev->config->del_vqs(vdev); 1558 kfree(vblk->vqs); 1559 out_free_vblk: 1560 kfree(vblk); 1561 out_free_index: 1562 ida_free(&vd_index_ida, index); 1563 out: 1564 return err; 1565 } 1566 1567 static void virtblk_remove(struct virtio_device *vdev) 1568 { 1569 struct virtio_blk *vblk = vdev->priv; 1570 1571 /* Make sure no work handler is accessing the device. */ 1572 flush_work(&vblk->config_work); 1573 1574 del_gendisk(vblk->disk); 1575 blk_mq_free_tag_set(&vblk->tag_set); 1576 1577 mutex_lock(&vblk->vdev_mutex); 1578 1579 /* Stop all the virtqueues. */ 1580 virtio_reset_device(vdev); 1581 1582 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1583 vblk->vdev = NULL; 1584 1585 vdev->config->del_vqs(vdev); 1586 kfree(vblk->vqs); 1587 1588 mutex_unlock(&vblk->vdev_mutex); 1589 1590 put_disk(vblk->disk); 1591 } 1592 1593 #ifdef CONFIG_PM_SLEEP 1594 static int virtblk_freeze(struct virtio_device *vdev) 1595 { 1596 struct virtio_blk *vblk = vdev->priv; 1597 1598 /* Ensure we don't receive any more interrupts */ 1599 virtio_reset_device(vdev); 1600 1601 /* Make sure no work handler is accessing the device. */ 1602 flush_work(&vblk->config_work); 1603 1604 blk_mq_quiesce_queue(vblk->disk->queue); 1605 1606 vdev->config->del_vqs(vdev); 1607 kfree(vblk->vqs); 1608 1609 return 0; 1610 } 1611 1612 static int virtblk_restore(struct virtio_device *vdev) 1613 { 1614 struct virtio_blk *vblk = vdev->priv; 1615 int ret; 1616 1617 ret = init_vq(vdev->priv); 1618 if (ret) 1619 return ret; 1620 1621 virtio_device_ready(vdev); 1622 1623 blk_mq_unquiesce_queue(vblk->disk->queue); 1624 return 0; 1625 } 1626 #endif 1627 1628 static const struct virtio_device_id id_table[] = { 1629 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1630 { 0 }, 1631 }; 1632 1633 static unsigned int features_legacy[] = { 1634 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1635 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1636 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1637 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1638 VIRTIO_BLK_F_SECURE_ERASE, 1639 } 1640 ; 1641 static unsigned int features[] = { 1642 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1643 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1644 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1645 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1646 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1647 }; 1648 1649 static struct virtio_driver virtio_blk = { 1650 .feature_table = features, 1651 .feature_table_size = ARRAY_SIZE(features), 1652 .feature_table_legacy = features_legacy, 1653 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1654 .driver.name = KBUILD_MODNAME, 1655 .driver.owner = THIS_MODULE, 1656 .id_table = id_table, 1657 .probe = virtblk_probe, 1658 .remove = virtblk_remove, 1659 .config_changed = virtblk_config_changed, 1660 #ifdef CONFIG_PM_SLEEP 1661 .freeze = virtblk_freeze, 1662 .restore = virtblk_restore, 1663 #endif 1664 }; 1665 1666 static int __init virtio_blk_init(void) 1667 { 1668 int error; 1669 1670 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1671 if (!virtblk_wq) 1672 return -ENOMEM; 1673 1674 major = register_blkdev(0, "virtblk"); 1675 if (major < 0) { 1676 error = major; 1677 goto out_destroy_workqueue; 1678 } 1679 1680 error = register_virtio_driver(&virtio_blk); 1681 if (error) 1682 goto out_unregister_blkdev; 1683 return 0; 1684 1685 out_unregister_blkdev: 1686 unregister_blkdev(major, "virtblk"); 1687 out_destroy_workqueue: 1688 destroy_workqueue(virtblk_wq); 1689 return error; 1690 } 1691 1692 static void __exit virtio_blk_fini(void) 1693 { 1694 unregister_virtio_driver(&virtio_blk); 1695 unregister_blkdev(major, "virtblk"); 1696 destroy_workqueue(virtblk_wq); 1697 } 1698 module_init(virtio_blk_init); 1699 module_exit(virtio_blk_fini); 1700 1701 MODULE_DEVICE_TABLE(virtio, id_table); 1702 MODULE_DESCRIPTION("Virtio block driver"); 1703 MODULE_LICENSE("GPL"); 1704