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 } while (!virtqueue_enable_cb(vq)); 371 372 /* In case queue is stopped waiting for more buffers. */ 373 if (req_done) 374 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 375 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 376 } 377 378 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) 379 { 380 struct virtio_blk *vblk = hctx->queue->queuedata; 381 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 382 bool kick; 383 384 spin_lock_irq(&vq->lock); 385 kick = virtqueue_kick_prepare(vq->vq); 386 spin_unlock_irq(&vq->lock); 387 388 if (kick) 389 virtqueue_notify(vq->vq); 390 } 391 392 static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) 393 { 394 virtblk_cleanup_cmd(req); 395 switch (rc) { 396 case -ENOSPC: 397 return BLK_STS_DEV_RESOURCE; 398 case -ENOMEM: 399 return BLK_STS_RESOURCE; 400 default: 401 return BLK_STS_IOERR; 402 } 403 } 404 405 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, 406 struct virtio_blk *vblk, 407 struct request *req, 408 struct virtblk_req *vbr) 409 { 410 blk_status_t status; 411 int num; 412 413 status = virtblk_setup_cmd(vblk->vdev, req, vbr); 414 if (unlikely(status)) 415 return status; 416 417 num = virtblk_map_data(hctx, req, vbr); 418 if (unlikely(num < 0)) 419 return virtblk_fail_to_queue(req, -ENOMEM); 420 vbr->sg_table.nents = num; 421 422 blk_mq_start_request(req); 423 424 return BLK_STS_OK; 425 } 426 427 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, 428 const struct blk_mq_queue_data *bd) 429 { 430 struct virtio_blk *vblk = hctx->queue->queuedata; 431 struct request *req = bd->rq; 432 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 433 unsigned long flags; 434 int qid = hctx->queue_num; 435 bool notify = false; 436 blk_status_t status; 437 int err; 438 439 status = virtblk_prep_rq(hctx, vblk, req, vbr); 440 if (unlikely(status)) 441 return status; 442 443 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 444 err = virtblk_add_req(vblk->vqs[qid].vq, vbr); 445 if (err) { 446 virtqueue_kick(vblk->vqs[qid].vq); 447 /* Don't stop the queue if -ENOMEM: we may have failed to 448 * bounce the buffer due to global resource outage. 449 */ 450 if (err == -ENOSPC) 451 blk_mq_stop_hw_queue(hctx); 452 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 453 virtblk_unmap_data(req, vbr); 454 return virtblk_fail_to_queue(req, err); 455 } 456 457 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) 458 notify = true; 459 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 460 461 if (notify) 462 virtqueue_notify(vblk->vqs[qid].vq); 463 return BLK_STS_OK; 464 } 465 466 static bool virtblk_prep_rq_batch(struct request *req) 467 { 468 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 469 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 470 471 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 472 } 473 474 static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, 475 struct request **rqlist) 476 { 477 unsigned long flags; 478 int err; 479 bool kick; 480 481 spin_lock_irqsave(&vq->lock, flags); 482 483 while (!rq_list_empty(*rqlist)) { 484 struct request *req = rq_list_pop(rqlist); 485 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 486 487 err = virtblk_add_req(vq->vq, vbr); 488 if (err) { 489 virtblk_unmap_data(req, vbr); 490 virtblk_cleanup_cmd(req); 491 blk_mq_requeue_request(req, true); 492 } 493 } 494 495 kick = virtqueue_kick_prepare(vq->vq); 496 spin_unlock_irqrestore(&vq->lock, flags); 497 498 return kick; 499 } 500 501 static void virtio_queue_rqs(struct request **rqlist) 502 { 503 struct request *req, *next, *prev = NULL; 504 struct request *requeue_list = NULL; 505 506 rq_list_for_each_safe(rqlist, req, next) { 507 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); 508 bool kick; 509 510 if (!virtblk_prep_rq_batch(req)) { 511 rq_list_move(rqlist, &requeue_list, req, prev); 512 req = prev; 513 if (!req) 514 continue; 515 } 516 517 if (!next || req->mq_hctx != next->mq_hctx) { 518 req->rq_next = NULL; 519 kick = virtblk_add_req_batch(vq, rqlist); 520 if (kick) 521 virtqueue_notify(vq->vq); 522 523 *rqlist = next; 524 prev = NULL; 525 } else 526 prev = req; 527 } 528 529 *rqlist = requeue_list; 530 } 531 532 #ifdef CONFIG_BLK_DEV_ZONED 533 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 534 unsigned int nr_zones, 535 size_t *buflen) 536 { 537 struct request_queue *q = vblk->disk->queue; 538 size_t bufsize; 539 void *buf; 540 541 nr_zones = min_t(unsigned int, nr_zones, 542 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); 543 544 bufsize = sizeof(struct virtio_blk_zone_report) + 545 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 546 bufsize = min_t(size_t, bufsize, 547 queue_max_hw_sectors(q) << SECTOR_SHIFT); 548 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 549 550 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 551 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 552 if (buf) { 553 *buflen = bufsize; 554 return buf; 555 } 556 bufsize >>= 1; 557 } 558 559 return NULL; 560 } 561 562 static int virtblk_submit_zone_report(struct virtio_blk *vblk, 563 char *report_buf, size_t report_len, 564 sector_t sector) 565 { 566 struct request_queue *q = vblk->disk->queue; 567 struct request *req; 568 struct virtblk_req *vbr; 569 int err; 570 571 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 572 if (IS_ERR(req)) 573 return PTR_ERR(req); 574 575 vbr = blk_mq_rq_to_pdu(req); 576 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 577 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 578 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 579 580 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); 581 if (err) 582 goto out; 583 584 blk_execute_rq(req, false); 585 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 586 out: 587 blk_mq_free_request(req); 588 return err; 589 } 590 591 static int virtblk_parse_zone(struct virtio_blk *vblk, 592 struct virtio_blk_zone_descriptor *entry, 593 unsigned int idx, report_zones_cb cb, void *data) 594 { 595 struct blk_zone zone = { }; 596 597 zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start); 598 if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk)) 599 zone.len = vblk->zone_sectors; 600 else 601 zone.len = get_capacity(vblk->disk) - zone.start; 602 zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap); 603 zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp); 604 605 switch (entry->z_type) { 606 case VIRTIO_BLK_ZT_SWR: 607 zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ; 608 break; 609 case VIRTIO_BLK_ZT_SWP: 610 zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF; 611 break; 612 case VIRTIO_BLK_ZT_CONV: 613 zone.type = BLK_ZONE_TYPE_CONVENTIONAL; 614 break; 615 default: 616 dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n", 617 zone.start, entry->z_type); 618 return -EIO; 619 } 620 621 switch (entry->z_state) { 622 case VIRTIO_BLK_ZS_EMPTY: 623 zone.cond = BLK_ZONE_COND_EMPTY; 624 break; 625 case VIRTIO_BLK_ZS_CLOSED: 626 zone.cond = BLK_ZONE_COND_CLOSED; 627 break; 628 case VIRTIO_BLK_ZS_FULL: 629 zone.cond = BLK_ZONE_COND_FULL; 630 zone.wp = zone.start + zone.len; 631 break; 632 case VIRTIO_BLK_ZS_EOPEN: 633 zone.cond = BLK_ZONE_COND_EXP_OPEN; 634 break; 635 case VIRTIO_BLK_ZS_IOPEN: 636 zone.cond = BLK_ZONE_COND_IMP_OPEN; 637 break; 638 case VIRTIO_BLK_ZS_NOT_WP: 639 zone.cond = BLK_ZONE_COND_NOT_WP; 640 break; 641 case VIRTIO_BLK_ZS_RDONLY: 642 zone.cond = BLK_ZONE_COND_READONLY; 643 zone.wp = ULONG_MAX; 644 break; 645 case VIRTIO_BLK_ZS_OFFLINE: 646 zone.cond = BLK_ZONE_COND_OFFLINE; 647 zone.wp = ULONG_MAX; 648 break; 649 default: 650 dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n", 651 zone.start, entry->z_state); 652 return -EIO; 653 } 654 655 /* 656 * The callback below checks the validity of the reported 657 * entry data, no need to further validate it here. 658 */ 659 return cb(&zone, idx, data); 660 } 661 662 static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 663 unsigned int nr_zones, report_zones_cb cb, 664 void *data) 665 { 666 struct virtio_blk *vblk = disk->private_data; 667 struct virtio_blk_zone_report *report; 668 unsigned long long nz, i; 669 size_t buflen; 670 unsigned int zone_idx = 0; 671 int ret; 672 673 if (WARN_ON_ONCE(!vblk->zone_sectors)) 674 return -EOPNOTSUPP; 675 676 report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen); 677 if (!report) 678 return -ENOMEM; 679 680 mutex_lock(&vblk->vdev_mutex); 681 682 if (!vblk->vdev) { 683 ret = -ENXIO; 684 goto fail_report; 685 } 686 687 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { 688 memset(report, 0, buflen); 689 690 ret = virtblk_submit_zone_report(vblk, (char *)report, 691 buflen, sector); 692 if (ret) 693 goto fail_report; 694 695 nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones), 696 nr_zones); 697 if (!nz) 698 break; 699 700 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 701 ret = virtblk_parse_zone(vblk, &report->zones[i], 702 zone_idx, cb, data); 703 if (ret) 704 goto fail_report; 705 706 sector = virtio64_to_cpu(vblk->vdev, 707 report->zones[i].z_start) + 708 vblk->zone_sectors; 709 zone_idx++; 710 } 711 } 712 713 if (zone_idx > 0) 714 ret = zone_idx; 715 else 716 ret = -EINVAL; 717 fail_report: 718 mutex_unlock(&vblk->vdev_mutex); 719 kvfree(report); 720 return ret; 721 } 722 723 static int virtblk_probe_zoned_device(struct virtio_device *vdev, 724 struct virtio_blk *vblk, 725 struct request_queue *q) 726 { 727 u32 v, wg; 728 729 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 730 731 disk_set_zoned(vblk->disk); 732 blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); 733 734 virtio_cread(vdev, struct virtio_blk_config, 735 zoned.max_open_zones, &v); 736 disk_set_max_open_zones(vblk->disk, v); 737 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 738 739 virtio_cread(vdev, struct virtio_blk_config, 740 zoned.max_active_zones, &v); 741 disk_set_max_active_zones(vblk->disk, v); 742 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 743 744 virtio_cread(vdev, struct virtio_blk_config, 745 zoned.write_granularity, &wg); 746 if (!wg) { 747 dev_warn(&vdev->dev, "zero write granularity reported\n"); 748 return -ENODEV; 749 } 750 blk_queue_physical_block_size(q, wg); 751 blk_queue_io_min(q, wg); 752 753 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 754 755 /* 756 * virtio ZBD specification doesn't require zones to be a power of 757 * two sectors in size, but the code in this driver expects that. 758 */ 759 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 760 &vblk->zone_sectors); 761 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 762 dev_err(&vdev->dev, 763 "zoned device with non power of two zone size %u\n", 764 vblk->zone_sectors); 765 return -ENODEV; 766 } 767 blk_queue_chunk_sectors(q, vblk->zone_sectors); 768 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 769 770 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 771 dev_warn(&vblk->vdev->dev, 772 "ignoring negotiated F_DISCARD for zoned device\n"); 773 blk_queue_max_discard_sectors(q, 0); 774 } 775 776 virtio_cread(vdev, struct virtio_blk_config, 777 zoned.max_append_sectors, &v); 778 if (!v) { 779 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 780 return -ENODEV; 781 } 782 if ((v << SECTOR_SHIFT) < wg) { 783 dev_err(&vdev->dev, 784 "write granularity %u exceeds max_append_sectors %u limit\n", 785 wg, v); 786 return -ENODEV; 787 } 788 blk_queue_max_zone_append_sectors(q, v); 789 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 790 791 return blk_revalidate_disk_zones(vblk->disk, NULL); 792 } 793 794 #else 795 796 /* 797 * Zoned block device support is not configured in this kernel. 798 * Host-managed zoned devices can't be supported, but others are 799 * good to go as regular block devices. 800 */ 801 #define virtblk_report_zones NULL 802 803 static inline int virtblk_probe_zoned_device(struct virtio_device *vdev, 804 struct virtio_blk *vblk, struct request_queue *q) 805 { 806 dev_err(&vdev->dev, 807 "virtio_blk: zoned devices are not supported"); 808 return -EOPNOTSUPP; 809 } 810 #endif /* CONFIG_BLK_DEV_ZONED */ 811 812 /* return id (s/n) string for *disk to *id_str 813 */ 814 static int virtblk_get_id(struct gendisk *disk, char *id_str) 815 { 816 struct virtio_blk *vblk = disk->private_data; 817 struct request_queue *q = vblk->disk->queue; 818 struct request *req; 819 struct virtblk_req *vbr; 820 int err; 821 822 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 823 if (IS_ERR(req)) 824 return PTR_ERR(req); 825 826 vbr = blk_mq_rq_to_pdu(req); 827 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 828 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 829 vbr->out_hdr.sector = 0; 830 831 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 832 if (err) 833 goto out; 834 835 blk_execute_rq(req, false); 836 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 837 out: 838 blk_mq_free_request(req); 839 return err; 840 } 841 842 /* We provide getgeo only to please some old bootloader/partitioning tools */ 843 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 844 { 845 struct virtio_blk *vblk = bd->bd_disk->private_data; 846 int ret = 0; 847 848 mutex_lock(&vblk->vdev_mutex); 849 850 if (!vblk->vdev) { 851 ret = -ENXIO; 852 goto out; 853 } 854 855 /* see if the host passed in geometry config */ 856 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 857 virtio_cread(vblk->vdev, struct virtio_blk_config, 858 geometry.cylinders, &geo->cylinders); 859 virtio_cread(vblk->vdev, struct virtio_blk_config, 860 geometry.heads, &geo->heads); 861 virtio_cread(vblk->vdev, struct virtio_blk_config, 862 geometry.sectors, &geo->sectors); 863 } else { 864 /* some standard values, similar to sd */ 865 geo->heads = 1 << 6; 866 geo->sectors = 1 << 5; 867 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 868 } 869 out: 870 mutex_unlock(&vblk->vdev_mutex); 871 return ret; 872 } 873 874 static void virtblk_free_disk(struct gendisk *disk) 875 { 876 struct virtio_blk *vblk = disk->private_data; 877 878 ida_free(&vd_index_ida, vblk->index); 879 mutex_destroy(&vblk->vdev_mutex); 880 kfree(vblk); 881 } 882 883 static const struct block_device_operations virtblk_fops = { 884 .owner = THIS_MODULE, 885 .getgeo = virtblk_getgeo, 886 .free_disk = virtblk_free_disk, 887 .report_zones = virtblk_report_zones, 888 }; 889 890 static int index_to_minor(int index) 891 { 892 return index << PART_BITS; 893 } 894 895 static int minor_to_index(int minor) 896 { 897 return minor >> PART_BITS; 898 } 899 900 static ssize_t serial_show(struct device *dev, 901 struct device_attribute *attr, char *buf) 902 { 903 struct gendisk *disk = dev_to_disk(dev); 904 int err; 905 906 /* sysfs gives us a PAGE_SIZE buffer */ 907 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 908 909 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 910 err = virtblk_get_id(disk, buf); 911 if (!err) 912 return strlen(buf); 913 914 if (err == -EIO) /* Unsupported? Make it empty. */ 915 return 0; 916 917 return err; 918 } 919 920 static DEVICE_ATTR_RO(serial); 921 922 /* The queue's logical block size must be set before calling this */ 923 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 924 { 925 struct virtio_device *vdev = vblk->vdev; 926 struct request_queue *q = vblk->disk->queue; 927 char cap_str_2[10], cap_str_10[10]; 928 unsigned long long nblocks; 929 u64 capacity; 930 931 /* Host must always specify the capacity. */ 932 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 933 934 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 935 936 string_get_size(nblocks, queue_logical_block_size(q), 937 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 938 string_get_size(nblocks, queue_logical_block_size(q), 939 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 940 941 dev_notice(&vdev->dev, 942 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 943 vblk->disk->disk_name, 944 resize ? "new size: " : "", 945 nblocks, 946 queue_logical_block_size(q), 947 cap_str_10, 948 cap_str_2); 949 950 set_capacity_and_notify(vblk->disk, capacity); 951 } 952 953 static void virtblk_config_changed_work(struct work_struct *work) 954 { 955 struct virtio_blk *vblk = 956 container_of(work, struct virtio_blk, config_work); 957 958 virtblk_update_capacity(vblk, true); 959 } 960 961 static void virtblk_config_changed(struct virtio_device *vdev) 962 { 963 struct virtio_blk *vblk = vdev->priv; 964 965 queue_work(virtblk_wq, &vblk->config_work); 966 } 967 968 static int init_vq(struct virtio_blk *vblk) 969 { 970 int err; 971 unsigned short i; 972 vq_callback_t **callbacks; 973 const char **names; 974 struct virtqueue **vqs; 975 unsigned short num_vqs; 976 unsigned short num_poll_vqs; 977 struct virtio_device *vdev = vblk->vdev; 978 struct irq_affinity desc = { 0, }; 979 980 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 981 struct virtio_blk_config, num_queues, 982 &num_vqs); 983 if (err) 984 num_vqs = 1; 985 986 if (!err && !num_vqs) { 987 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 988 return -EINVAL; 989 } 990 991 num_vqs = min_t(unsigned int, 992 min_not_zero(num_request_queues, nr_cpu_ids), 993 num_vqs); 994 995 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 996 997 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 998 vblk->io_queues[HCTX_TYPE_READ] = 0; 999 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 1000 1001 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 1002 vblk->io_queues[HCTX_TYPE_DEFAULT], 1003 vblk->io_queues[HCTX_TYPE_READ], 1004 vblk->io_queues[HCTX_TYPE_POLL]); 1005 1006 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 1007 if (!vblk->vqs) 1008 return -ENOMEM; 1009 1010 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); 1011 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); 1012 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1013 if (!names || !callbacks || !vqs) { 1014 err = -ENOMEM; 1015 goto out; 1016 } 1017 1018 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1019 callbacks[i] = virtblk_done; 1020 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1021 names[i] = vblk->vqs[i].name; 1022 } 1023 1024 for (; i < num_vqs; i++) { 1025 callbacks[i] = NULL; 1026 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1027 names[i] = vblk->vqs[i].name; 1028 } 1029 1030 /* Discover virtqueues and write information to configuration. */ 1031 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 1032 if (err) 1033 goto out; 1034 1035 for (i = 0; i < num_vqs; i++) { 1036 spin_lock_init(&vblk->vqs[i].lock); 1037 vblk->vqs[i].vq = vqs[i]; 1038 } 1039 vblk->num_vqs = num_vqs; 1040 1041 out: 1042 kfree(vqs); 1043 kfree(callbacks); 1044 kfree(names); 1045 if (err) 1046 kfree(vblk->vqs); 1047 return err; 1048 } 1049 1050 /* 1051 * Legacy naming scheme used for virtio devices. We are stuck with it for 1052 * virtio blk but don't ever use it for any new driver. 1053 */ 1054 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1055 { 1056 const int base = 'z' - 'a' + 1; 1057 char *begin = buf + strlen(prefix); 1058 char *end = buf + buflen; 1059 char *p; 1060 int unit; 1061 1062 p = end - 1; 1063 *p = '\0'; 1064 unit = base; 1065 do { 1066 if (p == begin) 1067 return -EINVAL; 1068 *--p = 'a' + (index % unit); 1069 index = (index / unit) - 1; 1070 } while (index >= 0); 1071 1072 memmove(begin, p, end - p); 1073 memcpy(buf, prefix, strlen(prefix)); 1074 1075 return 0; 1076 } 1077 1078 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1079 { 1080 u8 writeback; 1081 int err; 1082 1083 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1084 struct virtio_blk_config, wce, 1085 &writeback); 1086 1087 /* 1088 * If WCE is not configurable and flush is not available, 1089 * assume no writeback cache is in use. 1090 */ 1091 if (err) 1092 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1093 1094 return writeback; 1095 } 1096 1097 static void virtblk_update_cache_mode(struct virtio_device *vdev) 1098 { 1099 u8 writeback = virtblk_get_cache_mode(vdev); 1100 struct virtio_blk *vblk = vdev->priv; 1101 1102 blk_queue_write_cache(vblk->disk->queue, writeback, false); 1103 } 1104 1105 static const char *const virtblk_cache_types[] = { 1106 "write through", "write back" 1107 }; 1108 1109 static ssize_t 1110 cache_type_store(struct device *dev, struct device_attribute *attr, 1111 const char *buf, size_t count) 1112 { 1113 struct gendisk *disk = dev_to_disk(dev); 1114 struct virtio_blk *vblk = disk->private_data; 1115 struct virtio_device *vdev = vblk->vdev; 1116 int i; 1117 1118 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1119 i = sysfs_match_string(virtblk_cache_types, buf); 1120 if (i < 0) 1121 return i; 1122 1123 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1124 virtblk_update_cache_mode(vdev); 1125 return count; 1126 } 1127 1128 static ssize_t 1129 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1130 { 1131 struct gendisk *disk = dev_to_disk(dev); 1132 struct virtio_blk *vblk = disk->private_data; 1133 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1134 1135 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1136 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1137 } 1138 1139 static DEVICE_ATTR_RW(cache_type); 1140 1141 static struct attribute *virtblk_attrs[] = { 1142 &dev_attr_serial.attr, 1143 &dev_attr_cache_type.attr, 1144 NULL, 1145 }; 1146 1147 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1148 struct attribute *a, int n) 1149 { 1150 struct device *dev = kobj_to_dev(kobj); 1151 struct gendisk *disk = dev_to_disk(dev); 1152 struct virtio_blk *vblk = disk->private_data; 1153 struct virtio_device *vdev = vblk->vdev; 1154 1155 if (a == &dev_attr_cache_type.attr && 1156 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1157 return S_IRUGO; 1158 1159 return a->mode; 1160 } 1161 1162 static const struct attribute_group virtblk_attr_group = { 1163 .attrs = virtblk_attrs, 1164 .is_visible = virtblk_attrs_are_visible, 1165 }; 1166 1167 static const struct attribute_group *virtblk_attr_groups[] = { 1168 &virtblk_attr_group, 1169 NULL, 1170 }; 1171 1172 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1173 { 1174 struct virtio_blk *vblk = set->driver_data; 1175 int i, qoff; 1176 1177 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1178 struct blk_mq_queue_map *map = &set->map[i]; 1179 1180 map->nr_queues = vblk->io_queues[i]; 1181 map->queue_offset = qoff; 1182 qoff += map->nr_queues; 1183 1184 if (map->nr_queues == 0) 1185 continue; 1186 1187 /* 1188 * Regular queues have interrupts and hence CPU affinity is 1189 * defined by the core virtio code, but polling queues have 1190 * no interrupts so we let the block layer assign CPU affinity. 1191 */ 1192 if (i == HCTX_TYPE_POLL) 1193 blk_mq_map_queues(&set->map[i]); 1194 else 1195 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1196 } 1197 } 1198 1199 static void virtblk_complete_batch(struct io_comp_batch *iob) 1200 { 1201 struct request *req; 1202 1203 rq_list_for_each(&iob->req_list, req) { 1204 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1205 virtblk_cleanup_cmd(req); 1206 } 1207 blk_mq_end_request_batch(iob); 1208 } 1209 1210 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1211 { 1212 struct virtio_blk *vblk = hctx->queue->queuedata; 1213 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1214 struct virtblk_req *vbr; 1215 unsigned long flags; 1216 unsigned int len; 1217 int found = 0; 1218 1219 spin_lock_irqsave(&vq->lock, flags); 1220 1221 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1222 struct request *req = blk_mq_rq_from_pdu(vbr); 1223 1224 found++; 1225 if (!blk_mq_complete_request_remote(req) && 1226 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1227 virtblk_complete_batch)) 1228 virtblk_request_done(req); 1229 } 1230 1231 if (found) 1232 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1233 1234 spin_unlock_irqrestore(&vq->lock, flags); 1235 1236 return found; 1237 } 1238 1239 static const struct blk_mq_ops virtio_mq_ops = { 1240 .queue_rq = virtio_queue_rq, 1241 .queue_rqs = virtio_queue_rqs, 1242 .commit_rqs = virtio_commit_rqs, 1243 .complete = virtblk_request_done, 1244 .map_queues = virtblk_map_queues, 1245 .poll = virtblk_poll, 1246 }; 1247 1248 static unsigned int virtblk_queue_depth; 1249 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1250 1251 static int virtblk_probe(struct virtio_device *vdev) 1252 { 1253 struct virtio_blk *vblk; 1254 struct request_queue *q; 1255 int err, index; 1256 1257 u32 v, blk_size, max_size, sg_elems, opt_io_size; 1258 u32 max_discard_segs = 0; 1259 u32 discard_granularity = 0; 1260 u16 min_io_size; 1261 u8 physical_block_exp, alignment_offset; 1262 unsigned int queue_depth; 1263 size_t max_dma_size; 1264 1265 if (!vdev->config->get) { 1266 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1267 __func__); 1268 return -EINVAL; 1269 } 1270 1271 err = ida_alloc_range(&vd_index_ida, 0, 1272 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1273 if (err < 0) 1274 goto out; 1275 index = err; 1276 1277 /* We need to know how many segments before we allocate. */ 1278 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1279 struct virtio_blk_config, seg_max, 1280 &sg_elems); 1281 1282 /* We need at least one SG element, whatever they say. */ 1283 if (err || !sg_elems) 1284 sg_elems = 1; 1285 1286 /* Prevent integer overflows and honor max vq size */ 1287 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1288 1289 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1290 if (!vblk) { 1291 err = -ENOMEM; 1292 goto out_free_index; 1293 } 1294 1295 mutex_init(&vblk->vdev_mutex); 1296 1297 vblk->vdev = vdev; 1298 1299 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1300 1301 err = init_vq(vblk); 1302 if (err) 1303 goto out_free_vblk; 1304 1305 /* Default queue sizing is to fill the ring. */ 1306 if (!virtblk_queue_depth) { 1307 queue_depth = vblk->vqs[0].vq->num_free; 1308 /* ... but without indirect descs, we use 2 descs per req */ 1309 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1310 queue_depth /= 2; 1311 } else { 1312 queue_depth = virtblk_queue_depth; 1313 } 1314 1315 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1316 vblk->tag_set.ops = &virtio_mq_ops; 1317 vblk->tag_set.queue_depth = queue_depth; 1318 vblk->tag_set.numa_node = NUMA_NO_NODE; 1319 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1320 vblk->tag_set.cmd_size = 1321 sizeof(struct virtblk_req) + 1322 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1323 vblk->tag_set.driver_data = vblk; 1324 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1325 vblk->tag_set.nr_maps = 1; 1326 if (vblk->io_queues[HCTX_TYPE_POLL]) 1327 vblk->tag_set.nr_maps = 3; 1328 1329 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1330 if (err) 1331 goto out_free_vq; 1332 1333 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); 1334 if (IS_ERR(vblk->disk)) { 1335 err = PTR_ERR(vblk->disk); 1336 goto out_free_tags; 1337 } 1338 q = vblk->disk->queue; 1339 1340 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1341 1342 vblk->disk->major = major; 1343 vblk->disk->first_minor = index_to_minor(index); 1344 vblk->disk->minors = 1 << PART_BITS; 1345 vblk->disk->private_data = vblk; 1346 vblk->disk->fops = &virtblk_fops; 1347 vblk->index = index; 1348 1349 /* configure queue flush support */ 1350 virtblk_update_cache_mode(vdev); 1351 1352 /* If disk is read-only in the host, the guest should obey */ 1353 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1354 set_disk_ro(vblk->disk, 1); 1355 1356 /* We can handle whatever the host told us to handle. */ 1357 blk_queue_max_segments(q, sg_elems); 1358 1359 /* No real sector limit. */ 1360 blk_queue_max_hw_sectors(q, UINT_MAX); 1361 1362 max_dma_size = virtio_max_dma_size(vdev); 1363 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1364 1365 /* Host can optionally specify maximum segment size and number of 1366 * segments. */ 1367 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1368 struct virtio_blk_config, size_max, &v); 1369 if (!err) 1370 max_size = min(max_size, v); 1371 1372 blk_queue_max_segment_size(q, max_size); 1373 1374 /* Host can optionally specify the block size of the device */ 1375 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1376 struct virtio_blk_config, blk_size, 1377 &blk_size); 1378 if (!err) { 1379 err = blk_validate_block_size(blk_size); 1380 if (err) { 1381 dev_err(&vdev->dev, 1382 "virtio_blk: invalid block size: 0x%x\n", 1383 blk_size); 1384 goto out_cleanup_disk; 1385 } 1386 1387 blk_queue_logical_block_size(q, blk_size); 1388 } else 1389 blk_size = queue_logical_block_size(q); 1390 1391 /* Use topology information if available */ 1392 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1393 struct virtio_blk_config, physical_block_exp, 1394 &physical_block_exp); 1395 if (!err && physical_block_exp) 1396 blk_queue_physical_block_size(q, 1397 blk_size * (1 << physical_block_exp)); 1398 1399 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1400 struct virtio_blk_config, alignment_offset, 1401 &alignment_offset); 1402 if (!err && alignment_offset) 1403 blk_queue_alignment_offset(q, blk_size * alignment_offset); 1404 1405 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1406 struct virtio_blk_config, min_io_size, 1407 &min_io_size); 1408 if (!err && min_io_size) 1409 blk_queue_io_min(q, blk_size * min_io_size); 1410 1411 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1412 struct virtio_blk_config, opt_io_size, 1413 &opt_io_size); 1414 if (!err && opt_io_size) 1415 blk_queue_io_opt(q, blk_size * opt_io_size); 1416 1417 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1418 virtio_cread(vdev, struct virtio_blk_config, 1419 discard_sector_alignment, &discard_granularity); 1420 1421 virtio_cread(vdev, struct virtio_blk_config, 1422 max_discard_sectors, &v); 1423 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); 1424 1425 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1426 &max_discard_segs); 1427 } 1428 1429 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1430 virtio_cread(vdev, struct virtio_blk_config, 1431 max_write_zeroes_sectors, &v); 1432 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); 1433 } 1434 1435 /* The discard and secure erase limits are combined since the Linux 1436 * block layer uses the same limit for both commands. 1437 * 1438 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1439 * are negotiated, we will use the minimum between the limits. 1440 * 1441 * discard sector alignment is set to the minimum between discard_sector_alignment 1442 * and secure_erase_sector_alignment. 1443 * 1444 * max discard sectors is set to the minimum between max_discard_seg and 1445 * max_secure_erase_seg. 1446 */ 1447 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1448 1449 virtio_cread(vdev, struct virtio_blk_config, 1450 secure_erase_sector_alignment, &v); 1451 1452 /* secure_erase_sector_alignment should not be zero, the device should set a 1453 * valid number of sectors. 1454 */ 1455 if (!v) { 1456 dev_err(&vdev->dev, 1457 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1458 err = -EINVAL; 1459 goto out_cleanup_disk; 1460 } 1461 1462 discard_granularity = min_not_zero(discard_granularity, v); 1463 1464 virtio_cread(vdev, struct virtio_blk_config, 1465 max_secure_erase_sectors, &v); 1466 1467 /* max_secure_erase_sectors should not be zero, the device should set a 1468 * valid number of sectors. 1469 */ 1470 if (!v) { 1471 dev_err(&vdev->dev, 1472 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1473 err = -EINVAL; 1474 goto out_cleanup_disk; 1475 } 1476 1477 blk_queue_max_secure_erase_sectors(q, v); 1478 1479 virtio_cread(vdev, struct virtio_blk_config, 1480 max_secure_erase_seg, &v); 1481 1482 /* max_secure_erase_seg should not be zero, the device should set a 1483 * valid number of segments 1484 */ 1485 if (!v) { 1486 dev_err(&vdev->dev, 1487 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1488 err = -EINVAL; 1489 goto out_cleanup_disk; 1490 } 1491 1492 max_discard_segs = min_not_zero(max_discard_segs, v); 1493 } 1494 1495 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1496 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1497 /* max_discard_seg and discard_granularity will be 0 only 1498 * if max_discard_seg and discard_sector_alignment fields in the virtio 1499 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1500 * In this case, we use default values. 1501 */ 1502 if (!max_discard_segs) 1503 max_discard_segs = sg_elems; 1504 1505 blk_queue_max_discard_segments(q, 1506 min(max_discard_segs, MAX_DISCARD_SEGMENTS)); 1507 1508 if (discard_granularity) 1509 q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT; 1510 else 1511 q->limits.discard_granularity = blk_size; 1512 } 1513 1514 virtblk_update_capacity(vblk, false); 1515 virtio_device_ready(vdev); 1516 1517 /* 1518 * All steps that follow use the VQs therefore they need to be 1519 * placed after the virtio_device_ready() call above. 1520 */ 1521 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1522 u8 model; 1523 1524 virtio_cread(vdev, struct virtio_blk_config, zoned.model, 1525 &model); 1526 switch (model) { 1527 case VIRTIO_BLK_Z_NONE: 1528 case VIRTIO_BLK_Z_HA: 1529 /* Present the host-aware device as non-zoned */ 1530 break; 1531 case VIRTIO_BLK_Z_HM: 1532 err = virtblk_probe_zoned_device(vdev, vblk, q); 1533 if (err) 1534 goto out_cleanup_disk; 1535 break; 1536 default: 1537 dev_err(&vdev->dev, "unsupported zone model %d\n", 1538 model); 1539 err = -EINVAL; 1540 goto out_cleanup_disk; 1541 } 1542 } 1543 1544 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1545 if (err) 1546 goto out_cleanup_disk; 1547 1548 return 0; 1549 1550 out_cleanup_disk: 1551 put_disk(vblk->disk); 1552 out_free_tags: 1553 blk_mq_free_tag_set(&vblk->tag_set); 1554 out_free_vq: 1555 vdev->config->del_vqs(vdev); 1556 kfree(vblk->vqs); 1557 out_free_vblk: 1558 kfree(vblk); 1559 out_free_index: 1560 ida_free(&vd_index_ida, index); 1561 out: 1562 return err; 1563 } 1564 1565 static void virtblk_remove(struct virtio_device *vdev) 1566 { 1567 struct virtio_blk *vblk = vdev->priv; 1568 1569 /* Make sure no work handler is accessing the device. */ 1570 flush_work(&vblk->config_work); 1571 1572 del_gendisk(vblk->disk); 1573 blk_mq_free_tag_set(&vblk->tag_set); 1574 1575 mutex_lock(&vblk->vdev_mutex); 1576 1577 /* Stop all the virtqueues. */ 1578 virtio_reset_device(vdev); 1579 1580 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1581 vblk->vdev = NULL; 1582 1583 vdev->config->del_vqs(vdev); 1584 kfree(vblk->vqs); 1585 1586 mutex_unlock(&vblk->vdev_mutex); 1587 1588 put_disk(vblk->disk); 1589 } 1590 1591 #ifdef CONFIG_PM_SLEEP 1592 static int virtblk_freeze(struct virtio_device *vdev) 1593 { 1594 struct virtio_blk *vblk = vdev->priv; 1595 1596 /* Ensure we don't receive any more interrupts */ 1597 virtio_reset_device(vdev); 1598 1599 /* Make sure no work handler is accessing the device. */ 1600 flush_work(&vblk->config_work); 1601 1602 blk_mq_quiesce_queue(vblk->disk->queue); 1603 1604 vdev->config->del_vqs(vdev); 1605 kfree(vblk->vqs); 1606 1607 return 0; 1608 } 1609 1610 static int virtblk_restore(struct virtio_device *vdev) 1611 { 1612 struct virtio_blk *vblk = vdev->priv; 1613 int ret; 1614 1615 ret = init_vq(vdev->priv); 1616 if (ret) 1617 return ret; 1618 1619 virtio_device_ready(vdev); 1620 1621 blk_mq_unquiesce_queue(vblk->disk->queue); 1622 return 0; 1623 } 1624 #endif 1625 1626 static const struct virtio_device_id id_table[] = { 1627 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1628 { 0 }, 1629 }; 1630 1631 static unsigned int features_legacy[] = { 1632 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1633 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1634 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1635 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1636 VIRTIO_BLK_F_SECURE_ERASE, 1637 } 1638 ; 1639 static unsigned int features[] = { 1640 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1641 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1642 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1643 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1644 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1645 }; 1646 1647 static struct virtio_driver virtio_blk = { 1648 .feature_table = features, 1649 .feature_table_size = ARRAY_SIZE(features), 1650 .feature_table_legacy = features_legacy, 1651 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1652 .driver.name = KBUILD_MODNAME, 1653 .driver.owner = THIS_MODULE, 1654 .id_table = id_table, 1655 .probe = virtblk_probe, 1656 .remove = virtblk_remove, 1657 .config_changed = virtblk_config_changed, 1658 #ifdef CONFIG_PM_SLEEP 1659 .freeze = virtblk_freeze, 1660 .restore = virtblk_restore, 1661 #endif 1662 }; 1663 1664 static int __init virtio_blk_init(void) 1665 { 1666 int error; 1667 1668 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1669 if (!virtblk_wq) 1670 return -ENOMEM; 1671 1672 major = register_blkdev(0, "virtblk"); 1673 if (major < 0) { 1674 error = major; 1675 goto out_destroy_workqueue; 1676 } 1677 1678 error = register_virtio_driver(&virtio_blk); 1679 if (error) 1680 goto out_unregister_blkdev; 1681 return 0; 1682 1683 out_unregister_blkdev: 1684 unregister_blkdev(major, "virtblk"); 1685 out_destroy_workqueue: 1686 destroy_workqueue(virtblk_wq); 1687 return error; 1688 } 1689 1690 static void __exit virtio_blk_fini(void) 1691 { 1692 unregister_virtio_driver(&virtio_blk); 1693 unregister_blkdev(major, "virtblk"); 1694 destroy_workqueue(virtblk_wq); 1695 } 1696 module_init(virtio_blk_init); 1697 module_exit(virtio_blk_fini); 1698 1699 MODULE_DEVICE_TABLE(virtio, id_table); 1700 MODULE_DESCRIPTION("Virtio block driver"); 1701 MODULE_LICENSE("GPL"); 1702