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 req->mq_hctx->tags->rqs[req->tag] = req; 474 475 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 476 } 477 478 static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, 479 struct request **rqlist) 480 { 481 unsigned long flags; 482 int err; 483 bool kick; 484 485 spin_lock_irqsave(&vq->lock, flags); 486 487 while (!rq_list_empty(*rqlist)) { 488 struct request *req = rq_list_pop(rqlist); 489 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 490 491 err = virtblk_add_req(vq->vq, vbr); 492 if (err) { 493 virtblk_unmap_data(req, vbr); 494 virtblk_cleanup_cmd(req); 495 blk_mq_requeue_request(req, true); 496 } 497 } 498 499 kick = virtqueue_kick_prepare(vq->vq); 500 spin_unlock_irqrestore(&vq->lock, flags); 501 502 return kick; 503 } 504 505 static void virtio_queue_rqs(struct request **rqlist) 506 { 507 struct request *req, *next, *prev = NULL; 508 struct request *requeue_list = NULL; 509 510 rq_list_for_each_safe(rqlist, req, next) { 511 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); 512 bool kick; 513 514 if (!virtblk_prep_rq_batch(req)) { 515 rq_list_move(rqlist, &requeue_list, req, prev); 516 req = prev; 517 if (!req) 518 continue; 519 } 520 521 if (!next || req->mq_hctx != next->mq_hctx) { 522 req->rq_next = NULL; 523 kick = virtblk_add_req_batch(vq, rqlist); 524 if (kick) 525 virtqueue_notify(vq->vq); 526 527 *rqlist = next; 528 prev = NULL; 529 } else 530 prev = req; 531 } 532 533 *rqlist = requeue_list; 534 } 535 536 #ifdef CONFIG_BLK_DEV_ZONED 537 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 538 unsigned int nr_zones, 539 size_t *buflen) 540 { 541 struct request_queue *q = vblk->disk->queue; 542 size_t bufsize; 543 void *buf; 544 545 nr_zones = min_t(unsigned int, nr_zones, 546 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); 547 548 bufsize = sizeof(struct virtio_blk_zone_report) + 549 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 550 bufsize = min_t(size_t, bufsize, 551 queue_max_hw_sectors(q) << SECTOR_SHIFT); 552 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 553 554 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 555 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 556 if (buf) { 557 *buflen = bufsize; 558 return buf; 559 } 560 bufsize >>= 1; 561 } 562 563 return NULL; 564 } 565 566 static int virtblk_submit_zone_report(struct virtio_blk *vblk, 567 char *report_buf, size_t report_len, 568 sector_t sector) 569 { 570 struct request_queue *q = vblk->disk->queue; 571 struct request *req; 572 struct virtblk_req *vbr; 573 int err; 574 575 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 576 if (IS_ERR(req)) 577 return PTR_ERR(req); 578 579 vbr = blk_mq_rq_to_pdu(req); 580 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 581 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 582 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 583 584 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); 585 if (err) 586 goto out; 587 588 blk_execute_rq(req, false); 589 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 590 out: 591 blk_mq_free_request(req); 592 return err; 593 } 594 595 static int virtblk_parse_zone(struct virtio_blk *vblk, 596 struct virtio_blk_zone_descriptor *entry, 597 unsigned int idx, report_zones_cb cb, void *data) 598 { 599 struct blk_zone zone = { }; 600 601 zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start); 602 if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk)) 603 zone.len = vblk->zone_sectors; 604 else 605 zone.len = get_capacity(vblk->disk) - zone.start; 606 zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap); 607 zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp); 608 609 switch (entry->z_type) { 610 case VIRTIO_BLK_ZT_SWR: 611 zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ; 612 break; 613 case VIRTIO_BLK_ZT_SWP: 614 zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF; 615 break; 616 case VIRTIO_BLK_ZT_CONV: 617 zone.type = BLK_ZONE_TYPE_CONVENTIONAL; 618 break; 619 default: 620 dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n", 621 zone.start, entry->z_type); 622 return -EIO; 623 } 624 625 switch (entry->z_state) { 626 case VIRTIO_BLK_ZS_EMPTY: 627 zone.cond = BLK_ZONE_COND_EMPTY; 628 break; 629 case VIRTIO_BLK_ZS_CLOSED: 630 zone.cond = BLK_ZONE_COND_CLOSED; 631 break; 632 case VIRTIO_BLK_ZS_FULL: 633 zone.cond = BLK_ZONE_COND_FULL; 634 zone.wp = zone.start + zone.len; 635 break; 636 case VIRTIO_BLK_ZS_EOPEN: 637 zone.cond = BLK_ZONE_COND_EXP_OPEN; 638 break; 639 case VIRTIO_BLK_ZS_IOPEN: 640 zone.cond = BLK_ZONE_COND_IMP_OPEN; 641 break; 642 case VIRTIO_BLK_ZS_NOT_WP: 643 zone.cond = BLK_ZONE_COND_NOT_WP; 644 break; 645 case VIRTIO_BLK_ZS_RDONLY: 646 zone.cond = BLK_ZONE_COND_READONLY; 647 zone.wp = ULONG_MAX; 648 break; 649 case VIRTIO_BLK_ZS_OFFLINE: 650 zone.cond = BLK_ZONE_COND_OFFLINE; 651 zone.wp = ULONG_MAX; 652 break; 653 default: 654 dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n", 655 zone.start, entry->z_state); 656 return -EIO; 657 } 658 659 /* 660 * The callback below checks the validity of the reported 661 * entry data, no need to further validate it here. 662 */ 663 return cb(&zone, idx, data); 664 } 665 666 static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 667 unsigned int nr_zones, report_zones_cb cb, 668 void *data) 669 { 670 struct virtio_blk *vblk = disk->private_data; 671 struct virtio_blk_zone_report *report; 672 unsigned long long nz, i; 673 size_t buflen; 674 unsigned int zone_idx = 0; 675 int ret; 676 677 if (WARN_ON_ONCE(!vblk->zone_sectors)) 678 return -EOPNOTSUPP; 679 680 report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen); 681 if (!report) 682 return -ENOMEM; 683 684 mutex_lock(&vblk->vdev_mutex); 685 686 if (!vblk->vdev) { 687 ret = -ENXIO; 688 goto fail_report; 689 } 690 691 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { 692 memset(report, 0, buflen); 693 694 ret = virtblk_submit_zone_report(vblk, (char *)report, 695 buflen, sector); 696 if (ret) 697 goto fail_report; 698 699 nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones), 700 nr_zones); 701 if (!nz) 702 break; 703 704 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 705 ret = virtblk_parse_zone(vblk, &report->zones[i], 706 zone_idx, cb, data); 707 if (ret) 708 goto fail_report; 709 710 sector = virtio64_to_cpu(vblk->vdev, 711 report->zones[i].z_start) + 712 vblk->zone_sectors; 713 zone_idx++; 714 } 715 } 716 717 if (zone_idx > 0) 718 ret = zone_idx; 719 else 720 ret = -EINVAL; 721 fail_report: 722 mutex_unlock(&vblk->vdev_mutex); 723 kvfree(report); 724 return ret; 725 } 726 727 static void virtblk_revalidate_zones(struct virtio_blk *vblk) 728 { 729 u8 model; 730 731 virtio_cread(vblk->vdev, struct virtio_blk_config, 732 zoned.model, &model); 733 switch (model) { 734 default: 735 dev_err(&vblk->vdev->dev, "unknown zone model %d\n", model); 736 fallthrough; 737 case VIRTIO_BLK_Z_NONE: 738 case VIRTIO_BLK_Z_HA: 739 disk_set_zoned(vblk->disk, BLK_ZONED_NONE); 740 return; 741 case VIRTIO_BLK_Z_HM: 742 WARN_ON_ONCE(!vblk->zone_sectors); 743 if (!blk_revalidate_disk_zones(vblk->disk, NULL)) 744 set_capacity_and_notify(vblk->disk, 0); 745 } 746 } 747 748 static int virtblk_probe_zoned_device(struct virtio_device *vdev, 749 struct virtio_blk *vblk, 750 struct request_queue *q) 751 { 752 u32 v, wg; 753 u8 model; 754 int ret; 755 756 virtio_cread(vdev, struct virtio_blk_config, 757 zoned.model, &model); 758 759 switch (model) { 760 case VIRTIO_BLK_Z_NONE: 761 case VIRTIO_BLK_Z_HA: 762 /* Present the host-aware device as non-zoned */ 763 return 0; 764 case VIRTIO_BLK_Z_HM: 765 break; 766 default: 767 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 768 return -EINVAL; 769 } 770 771 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 772 773 disk_set_zoned(vblk->disk, BLK_ZONED_HM); 774 blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); 775 776 virtio_cread(vdev, struct virtio_blk_config, 777 zoned.max_open_zones, &v); 778 disk_set_max_open_zones(vblk->disk, v); 779 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 780 781 virtio_cread(vdev, struct virtio_blk_config, 782 zoned.max_active_zones, &v); 783 disk_set_max_active_zones(vblk->disk, v); 784 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 785 786 virtio_cread(vdev, struct virtio_blk_config, 787 zoned.write_granularity, &wg); 788 if (!wg) { 789 dev_warn(&vdev->dev, "zero write granularity reported\n"); 790 return -ENODEV; 791 } 792 blk_queue_physical_block_size(q, wg); 793 blk_queue_io_min(q, wg); 794 795 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 796 797 /* 798 * virtio ZBD specification doesn't require zones to be a power of 799 * two sectors in size, but the code in this driver expects that. 800 */ 801 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 802 &vblk->zone_sectors); 803 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 804 dev_err(&vdev->dev, 805 "zoned device with non power of two zone size %u\n", 806 vblk->zone_sectors); 807 return -ENODEV; 808 } 809 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 810 811 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 812 dev_warn(&vblk->vdev->dev, 813 "ignoring negotiated F_DISCARD for zoned device\n"); 814 blk_queue_max_discard_sectors(q, 0); 815 } 816 817 ret = blk_revalidate_disk_zones(vblk->disk, NULL); 818 if (!ret) { 819 virtio_cread(vdev, struct virtio_blk_config, 820 zoned.max_append_sectors, &v); 821 if (!v) { 822 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 823 return -ENODEV; 824 } 825 if ((v << SECTOR_SHIFT) < wg) { 826 dev_err(&vdev->dev, 827 "write granularity %u exceeds max_append_sectors %u limit\n", 828 wg, v); 829 return -ENODEV; 830 } 831 832 blk_queue_max_zone_append_sectors(q, v); 833 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 834 } 835 836 return ret; 837 } 838 839 #else 840 841 /* 842 * Zoned block device support is not configured in this kernel. 843 * Host-managed zoned devices can't be supported, but others are 844 * good to go as regular block devices. 845 */ 846 #define virtblk_report_zones NULL 847 848 static inline void virtblk_revalidate_zones(struct virtio_blk *vblk) 849 { 850 } 851 852 static inline int virtblk_probe_zoned_device(struct virtio_device *vdev, 853 struct virtio_blk *vblk, struct request_queue *q) 854 { 855 u8 model; 856 857 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); 858 if (model == VIRTIO_BLK_Z_HM) { 859 dev_err(&vdev->dev, 860 "virtio_blk: zoned devices are not supported"); 861 return -EOPNOTSUPP; 862 } 863 864 return 0; 865 } 866 #endif /* CONFIG_BLK_DEV_ZONED */ 867 868 /* return id (s/n) string for *disk to *id_str 869 */ 870 static int virtblk_get_id(struct gendisk *disk, char *id_str) 871 { 872 struct virtio_blk *vblk = disk->private_data; 873 struct request_queue *q = vblk->disk->queue; 874 struct request *req; 875 struct virtblk_req *vbr; 876 int err; 877 878 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 879 if (IS_ERR(req)) 880 return PTR_ERR(req); 881 882 vbr = blk_mq_rq_to_pdu(req); 883 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 884 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 885 vbr->out_hdr.sector = 0; 886 887 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 888 if (err) 889 goto out; 890 891 blk_execute_rq(req, false); 892 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 893 out: 894 blk_mq_free_request(req); 895 return err; 896 } 897 898 /* We provide getgeo only to please some old bootloader/partitioning tools */ 899 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 900 { 901 struct virtio_blk *vblk = bd->bd_disk->private_data; 902 int ret = 0; 903 904 mutex_lock(&vblk->vdev_mutex); 905 906 if (!vblk->vdev) { 907 ret = -ENXIO; 908 goto out; 909 } 910 911 /* see if the host passed in geometry config */ 912 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 913 virtio_cread(vblk->vdev, struct virtio_blk_config, 914 geometry.cylinders, &geo->cylinders); 915 virtio_cread(vblk->vdev, struct virtio_blk_config, 916 geometry.heads, &geo->heads); 917 virtio_cread(vblk->vdev, struct virtio_blk_config, 918 geometry.sectors, &geo->sectors); 919 } else { 920 /* some standard values, similar to sd */ 921 geo->heads = 1 << 6; 922 geo->sectors = 1 << 5; 923 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 924 } 925 out: 926 mutex_unlock(&vblk->vdev_mutex); 927 return ret; 928 } 929 930 static void virtblk_free_disk(struct gendisk *disk) 931 { 932 struct virtio_blk *vblk = disk->private_data; 933 934 ida_free(&vd_index_ida, vblk->index); 935 mutex_destroy(&vblk->vdev_mutex); 936 kfree(vblk); 937 } 938 939 static const struct block_device_operations virtblk_fops = { 940 .owner = THIS_MODULE, 941 .getgeo = virtblk_getgeo, 942 .free_disk = virtblk_free_disk, 943 .report_zones = virtblk_report_zones, 944 }; 945 946 static int index_to_minor(int index) 947 { 948 return index << PART_BITS; 949 } 950 951 static int minor_to_index(int minor) 952 { 953 return minor >> PART_BITS; 954 } 955 956 static ssize_t serial_show(struct device *dev, 957 struct device_attribute *attr, char *buf) 958 { 959 struct gendisk *disk = dev_to_disk(dev); 960 int err; 961 962 /* sysfs gives us a PAGE_SIZE buffer */ 963 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 964 965 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 966 err = virtblk_get_id(disk, buf); 967 if (!err) 968 return strlen(buf); 969 970 if (err == -EIO) /* Unsupported? Make it empty. */ 971 return 0; 972 973 return err; 974 } 975 976 static DEVICE_ATTR_RO(serial); 977 978 /* The queue's logical block size must be set before calling this */ 979 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 980 { 981 struct virtio_device *vdev = vblk->vdev; 982 struct request_queue *q = vblk->disk->queue; 983 char cap_str_2[10], cap_str_10[10]; 984 unsigned long long nblocks; 985 u64 capacity; 986 987 /* Host must always specify the capacity. */ 988 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 989 990 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 991 992 string_get_size(nblocks, queue_logical_block_size(q), 993 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 994 string_get_size(nblocks, queue_logical_block_size(q), 995 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 996 997 dev_notice(&vdev->dev, 998 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 999 vblk->disk->disk_name, 1000 resize ? "new size: " : "", 1001 nblocks, 1002 queue_logical_block_size(q), 1003 cap_str_10, 1004 cap_str_2); 1005 1006 set_capacity_and_notify(vblk->disk, capacity); 1007 } 1008 1009 static void virtblk_config_changed_work(struct work_struct *work) 1010 { 1011 struct virtio_blk *vblk = 1012 container_of(work, struct virtio_blk, config_work); 1013 1014 virtblk_revalidate_zones(vblk); 1015 virtblk_update_capacity(vblk, true); 1016 } 1017 1018 static void virtblk_config_changed(struct virtio_device *vdev) 1019 { 1020 struct virtio_blk *vblk = vdev->priv; 1021 1022 queue_work(virtblk_wq, &vblk->config_work); 1023 } 1024 1025 static int init_vq(struct virtio_blk *vblk) 1026 { 1027 int err; 1028 int i; 1029 vq_callback_t **callbacks; 1030 const char **names; 1031 struct virtqueue **vqs; 1032 unsigned short num_vqs; 1033 unsigned int num_poll_vqs; 1034 struct virtio_device *vdev = vblk->vdev; 1035 struct irq_affinity desc = { 0, }; 1036 1037 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 1038 struct virtio_blk_config, num_queues, 1039 &num_vqs); 1040 if (err) 1041 num_vqs = 1; 1042 1043 if (!err && !num_vqs) { 1044 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 1045 return -EINVAL; 1046 } 1047 1048 num_vqs = min_t(unsigned int, 1049 min_not_zero(num_request_queues, nr_cpu_ids), 1050 num_vqs); 1051 1052 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 1053 1054 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 1055 vblk->io_queues[HCTX_TYPE_READ] = 0; 1056 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 1057 1058 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 1059 vblk->io_queues[HCTX_TYPE_DEFAULT], 1060 vblk->io_queues[HCTX_TYPE_READ], 1061 vblk->io_queues[HCTX_TYPE_POLL]); 1062 1063 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 1064 if (!vblk->vqs) 1065 return -ENOMEM; 1066 1067 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); 1068 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); 1069 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1070 if (!names || !callbacks || !vqs) { 1071 err = -ENOMEM; 1072 goto out; 1073 } 1074 1075 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1076 callbacks[i] = virtblk_done; 1077 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); 1078 names[i] = vblk->vqs[i].name; 1079 } 1080 1081 for (; i < num_vqs; i++) { 1082 callbacks[i] = NULL; 1083 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i); 1084 names[i] = vblk->vqs[i].name; 1085 } 1086 1087 /* Discover virtqueues and write information to configuration. */ 1088 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 1089 if (err) 1090 goto out; 1091 1092 for (i = 0; i < num_vqs; i++) { 1093 spin_lock_init(&vblk->vqs[i].lock); 1094 vblk->vqs[i].vq = vqs[i]; 1095 } 1096 vblk->num_vqs = num_vqs; 1097 1098 out: 1099 kfree(vqs); 1100 kfree(callbacks); 1101 kfree(names); 1102 if (err) 1103 kfree(vblk->vqs); 1104 return err; 1105 } 1106 1107 /* 1108 * Legacy naming scheme used for virtio devices. We are stuck with it for 1109 * virtio blk but don't ever use it for any new driver. 1110 */ 1111 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1112 { 1113 const int base = 'z' - 'a' + 1; 1114 char *begin = buf + strlen(prefix); 1115 char *end = buf + buflen; 1116 char *p; 1117 int unit; 1118 1119 p = end - 1; 1120 *p = '\0'; 1121 unit = base; 1122 do { 1123 if (p == begin) 1124 return -EINVAL; 1125 *--p = 'a' + (index % unit); 1126 index = (index / unit) - 1; 1127 } while (index >= 0); 1128 1129 memmove(begin, p, end - p); 1130 memcpy(buf, prefix, strlen(prefix)); 1131 1132 return 0; 1133 } 1134 1135 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1136 { 1137 u8 writeback; 1138 int err; 1139 1140 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1141 struct virtio_blk_config, wce, 1142 &writeback); 1143 1144 /* 1145 * If WCE is not configurable and flush is not available, 1146 * assume no writeback cache is in use. 1147 */ 1148 if (err) 1149 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1150 1151 return writeback; 1152 } 1153 1154 static void virtblk_update_cache_mode(struct virtio_device *vdev) 1155 { 1156 u8 writeback = virtblk_get_cache_mode(vdev); 1157 struct virtio_blk *vblk = vdev->priv; 1158 1159 blk_queue_write_cache(vblk->disk->queue, writeback, false); 1160 } 1161 1162 static const char *const virtblk_cache_types[] = { 1163 "write through", "write back" 1164 }; 1165 1166 static ssize_t 1167 cache_type_store(struct device *dev, struct device_attribute *attr, 1168 const char *buf, size_t count) 1169 { 1170 struct gendisk *disk = dev_to_disk(dev); 1171 struct virtio_blk *vblk = disk->private_data; 1172 struct virtio_device *vdev = vblk->vdev; 1173 int i; 1174 1175 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1176 i = sysfs_match_string(virtblk_cache_types, buf); 1177 if (i < 0) 1178 return i; 1179 1180 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1181 virtblk_update_cache_mode(vdev); 1182 return count; 1183 } 1184 1185 static ssize_t 1186 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1187 { 1188 struct gendisk *disk = dev_to_disk(dev); 1189 struct virtio_blk *vblk = disk->private_data; 1190 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1191 1192 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1193 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1194 } 1195 1196 static DEVICE_ATTR_RW(cache_type); 1197 1198 static struct attribute *virtblk_attrs[] = { 1199 &dev_attr_serial.attr, 1200 &dev_attr_cache_type.attr, 1201 NULL, 1202 }; 1203 1204 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1205 struct attribute *a, int n) 1206 { 1207 struct device *dev = kobj_to_dev(kobj); 1208 struct gendisk *disk = dev_to_disk(dev); 1209 struct virtio_blk *vblk = disk->private_data; 1210 struct virtio_device *vdev = vblk->vdev; 1211 1212 if (a == &dev_attr_cache_type.attr && 1213 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1214 return S_IRUGO; 1215 1216 return a->mode; 1217 } 1218 1219 static const struct attribute_group virtblk_attr_group = { 1220 .attrs = virtblk_attrs, 1221 .is_visible = virtblk_attrs_are_visible, 1222 }; 1223 1224 static const struct attribute_group *virtblk_attr_groups[] = { 1225 &virtblk_attr_group, 1226 NULL, 1227 }; 1228 1229 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1230 { 1231 struct virtio_blk *vblk = set->driver_data; 1232 int i, qoff; 1233 1234 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1235 struct blk_mq_queue_map *map = &set->map[i]; 1236 1237 map->nr_queues = vblk->io_queues[i]; 1238 map->queue_offset = qoff; 1239 qoff += map->nr_queues; 1240 1241 if (map->nr_queues == 0) 1242 continue; 1243 1244 /* 1245 * Regular queues have interrupts and hence CPU affinity is 1246 * defined by the core virtio code, but polling queues have 1247 * no interrupts so we let the block layer assign CPU affinity. 1248 */ 1249 if (i == HCTX_TYPE_POLL) 1250 blk_mq_map_queues(&set->map[i]); 1251 else 1252 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1253 } 1254 } 1255 1256 static void virtblk_complete_batch(struct io_comp_batch *iob) 1257 { 1258 struct request *req; 1259 1260 rq_list_for_each(&iob->req_list, req) { 1261 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1262 virtblk_cleanup_cmd(req); 1263 } 1264 blk_mq_end_request_batch(iob); 1265 } 1266 1267 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1268 { 1269 struct virtio_blk *vblk = hctx->queue->queuedata; 1270 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1271 struct virtblk_req *vbr; 1272 unsigned long flags; 1273 unsigned int len; 1274 int found = 0; 1275 1276 spin_lock_irqsave(&vq->lock, flags); 1277 1278 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1279 struct request *req = blk_mq_rq_from_pdu(vbr); 1280 1281 found++; 1282 if (!blk_mq_complete_request_remote(req) && 1283 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1284 virtblk_complete_batch)) 1285 virtblk_request_done(req); 1286 } 1287 1288 if (found) 1289 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1290 1291 spin_unlock_irqrestore(&vq->lock, flags); 1292 1293 return found; 1294 } 1295 1296 static const struct blk_mq_ops virtio_mq_ops = { 1297 .queue_rq = virtio_queue_rq, 1298 .queue_rqs = virtio_queue_rqs, 1299 .commit_rqs = virtio_commit_rqs, 1300 .complete = virtblk_request_done, 1301 .map_queues = virtblk_map_queues, 1302 .poll = virtblk_poll, 1303 }; 1304 1305 static unsigned int virtblk_queue_depth; 1306 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1307 1308 static int virtblk_probe(struct virtio_device *vdev) 1309 { 1310 struct virtio_blk *vblk; 1311 struct request_queue *q; 1312 int err, index; 1313 1314 u32 v, blk_size, max_size, sg_elems, opt_io_size; 1315 u32 max_discard_segs = 0; 1316 u32 discard_granularity = 0; 1317 u16 min_io_size; 1318 u8 physical_block_exp, alignment_offset; 1319 unsigned int queue_depth; 1320 1321 if (!vdev->config->get) { 1322 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1323 __func__); 1324 return -EINVAL; 1325 } 1326 1327 err = ida_alloc_range(&vd_index_ida, 0, 1328 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1329 if (err < 0) 1330 goto out; 1331 index = err; 1332 1333 /* We need to know how many segments before we allocate. */ 1334 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1335 struct virtio_blk_config, seg_max, 1336 &sg_elems); 1337 1338 /* We need at least one SG element, whatever they say. */ 1339 if (err || !sg_elems) 1340 sg_elems = 1; 1341 1342 /* Prevent integer overflows and honor max vq size */ 1343 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1344 1345 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1346 if (!vblk) { 1347 err = -ENOMEM; 1348 goto out_free_index; 1349 } 1350 1351 mutex_init(&vblk->vdev_mutex); 1352 1353 vblk->vdev = vdev; 1354 1355 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1356 1357 err = init_vq(vblk); 1358 if (err) 1359 goto out_free_vblk; 1360 1361 /* Default queue sizing is to fill the ring. */ 1362 if (!virtblk_queue_depth) { 1363 queue_depth = vblk->vqs[0].vq->num_free; 1364 /* ... but without indirect descs, we use 2 descs per req */ 1365 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1366 queue_depth /= 2; 1367 } else { 1368 queue_depth = virtblk_queue_depth; 1369 } 1370 1371 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1372 vblk->tag_set.ops = &virtio_mq_ops; 1373 vblk->tag_set.queue_depth = queue_depth; 1374 vblk->tag_set.numa_node = NUMA_NO_NODE; 1375 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1376 vblk->tag_set.cmd_size = 1377 sizeof(struct virtblk_req) + 1378 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1379 vblk->tag_set.driver_data = vblk; 1380 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1381 vblk->tag_set.nr_maps = 1; 1382 if (vblk->io_queues[HCTX_TYPE_POLL]) 1383 vblk->tag_set.nr_maps = 3; 1384 1385 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1386 if (err) 1387 goto out_free_vq; 1388 1389 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); 1390 if (IS_ERR(vblk->disk)) { 1391 err = PTR_ERR(vblk->disk); 1392 goto out_free_tags; 1393 } 1394 q = vblk->disk->queue; 1395 1396 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1397 1398 vblk->disk->major = major; 1399 vblk->disk->first_minor = index_to_minor(index); 1400 vblk->disk->minors = 1 << PART_BITS; 1401 vblk->disk->private_data = vblk; 1402 vblk->disk->fops = &virtblk_fops; 1403 vblk->index = index; 1404 1405 /* configure queue flush support */ 1406 virtblk_update_cache_mode(vdev); 1407 1408 /* If disk is read-only in the host, the guest should obey */ 1409 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1410 set_disk_ro(vblk->disk, 1); 1411 1412 /* We can handle whatever the host told us to handle. */ 1413 blk_queue_max_segments(q, sg_elems); 1414 1415 /* No real sector limit. */ 1416 blk_queue_max_hw_sectors(q, UINT_MAX); 1417 1418 max_size = virtio_max_dma_size(vdev); 1419 1420 /* Host can optionally specify maximum segment size and number of 1421 * segments. */ 1422 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1423 struct virtio_blk_config, size_max, &v); 1424 if (!err) 1425 max_size = min(max_size, v); 1426 1427 blk_queue_max_segment_size(q, max_size); 1428 1429 /* Host can optionally specify the block size of the device */ 1430 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1431 struct virtio_blk_config, blk_size, 1432 &blk_size); 1433 if (!err) { 1434 err = blk_validate_block_size(blk_size); 1435 if (err) { 1436 dev_err(&vdev->dev, 1437 "virtio_blk: invalid block size: 0x%x\n", 1438 blk_size); 1439 goto out_cleanup_disk; 1440 } 1441 1442 blk_queue_logical_block_size(q, blk_size); 1443 } else 1444 blk_size = queue_logical_block_size(q); 1445 1446 /* Use topology information if available */ 1447 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1448 struct virtio_blk_config, physical_block_exp, 1449 &physical_block_exp); 1450 if (!err && physical_block_exp) 1451 blk_queue_physical_block_size(q, 1452 blk_size * (1 << physical_block_exp)); 1453 1454 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1455 struct virtio_blk_config, alignment_offset, 1456 &alignment_offset); 1457 if (!err && alignment_offset) 1458 blk_queue_alignment_offset(q, blk_size * alignment_offset); 1459 1460 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1461 struct virtio_blk_config, min_io_size, 1462 &min_io_size); 1463 if (!err && min_io_size) 1464 blk_queue_io_min(q, blk_size * min_io_size); 1465 1466 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1467 struct virtio_blk_config, opt_io_size, 1468 &opt_io_size); 1469 if (!err && opt_io_size) 1470 blk_queue_io_opt(q, blk_size * opt_io_size); 1471 1472 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1473 virtio_cread(vdev, struct virtio_blk_config, 1474 discard_sector_alignment, &discard_granularity); 1475 1476 virtio_cread(vdev, struct virtio_blk_config, 1477 max_discard_sectors, &v); 1478 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); 1479 1480 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1481 &max_discard_segs); 1482 } 1483 1484 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1485 virtio_cread(vdev, struct virtio_blk_config, 1486 max_write_zeroes_sectors, &v); 1487 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); 1488 } 1489 1490 /* The discard and secure erase limits are combined since the Linux 1491 * block layer uses the same limit for both commands. 1492 * 1493 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1494 * are negotiated, we will use the minimum between the limits. 1495 * 1496 * discard sector alignment is set to the minimum between discard_sector_alignment 1497 * and secure_erase_sector_alignment. 1498 * 1499 * max discard sectors is set to the minimum between max_discard_seg and 1500 * max_secure_erase_seg. 1501 */ 1502 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1503 1504 virtio_cread(vdev, struct virtio_blk_config, 1505 secure_erase_sector_alignment, &v); 1506 1507 /* secure_erase_sector_alignment should not be zero, the device should set a 1508 * valid number of sectors. 1509 */ 1510 if (!v) { 1511 dev_err(&vdev->dev, 1512 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1513 err = -EINVAL; 1514 goto out_cleanup_disk; 1515 } 1516 1517 discard_granularity = min_not_zero(discard_granularity, v); 1518 1519 virtio_cread(vdev, struct virtio_blk_config, 1520 max_secure_erase_sectors, &v); 1521 1522 /* max_secure_erase_sectors should not be zero, the device should set a 1523 * valid number of sectors. 1524 */ 1525 if (!v) { 1526 dev_err(&vdev->dev, 1527 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1528 err = -EINVAL; 1529 goto out_cleanup_disk; 1530 } 1531 1532 blk_queue_max_secure_erase_sectors(q, v); 1533 1534 virtio_cread(vdev, struct virtio_blk_config, 1535 max_secure_erase_seg, &v); 1536 1537 /* max_secure_erase_seg should not be zero, the device should set a 1538 * valid number of segments 1539 */ 1540 if (!v) { 1541 dev_err(&vdev->dev, 1542 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1543 err = -EINVAL; 1544 goto out_cleanup_disk; 1545 } 1546 1547 max_discard_segs = min_not_zero(max_discard_segs, v); 1548 } 1549 1550 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1551 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1552 /* max_discard_seg and discard_granularity will be 0 only 1553 * if max_discard_seg and discard_sector_alignment fields in the virtio 1554 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1555 * In this case, we use default values. 1556 */ 1557 if (!max_discard_segs) 1558 max_discard_segs = sg_elems; 1559 1560 blk_queue_max_discard_segments(q, 1561 min(max_discard_segs, MAX_DISCARD_SEGMENTS)); 1562 1563 if (discard_granularity) 1564 q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT; 1565 else 1566 q->limits.discard_granularity = blk_size; 1567 } 1568 1569 virtblk_update_capacity(vblk, false); 1570 virtio_device_ready(vdev); 1571 1572 /* 1573 * All steps that follow use the VQs therefore they need to be 1574 * placed after the virtio_device_ready() call above. 1575 */ 1576 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1577 err = virtblk_probe_zoned_device(vdev, vblk, q); 1578 if (err) 1579 goto out_cleanup_disk; 1580 } 1581 1582 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1583 if (err) 1584 goto out_cleanup_disk; 1585 1586 return 0; 1587 1588 out_cleanup_disk: 1589 put_disk(vblk->disk); 1590 out_free_tags: 1591 blk_mq_free_tag_set(&vblk->tag_set); 1592 out_free_vq: 1593 vdev->config->del_vqs(vdev); 1594 kfree(vblk->vqs); 1595 out_free_vblk: 1596 kfree(vblk); 1597 out_free_index: 1598 ida_free(&vd_index_ida, index); 1599 out: 1600 return err; 1601 } 1602 1603 static void virtblk_remove(struct virtio_device *vdev) 1604 { 1605 struct virtio_blk *vblk = vdev->priv; 1606 1607 /* Make sure no work handler is accessing the device. */ 1608 flush_work(&vblk->config_work); 1609 1610 del_gendisk(vblk->disk); 1611 blk_mq_free_tag_set(&vblk->tag_set); 1612 1613 mutex_lock(&vblk->vdev_mutex); 1614 1615 /* Stop all the virtqueues. */ 1616 virtio_reset_device(vdev); 1617 1618 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1619 vblk->vdev = NULL; 1620 1621 vdev->config->del_vqs(vdev); 1622 kfree(vblk->vqs); 1623 1624 mutex_unlock(&vblk->vdev_mutex); 1625 1626 put_disk(vblk->disk); 1627 } 1628 1629 #ifdef CONFIG_PM_SLEEP 1630 static int virtblk_freeze(struct virtio_device *vdev) 1631 { 1632 struct virtio_blk *vblk = vdev->priv; 1633 1634 /* Ensure we don't receive any more interrupts */ 1635 virtio_reset_device(vdev); 1636 1637 /* Make sure no work handler is accessing the device. */ 1638 flush_work(&vblk->config_work); 1639 1640 blk_mq_quiesce_queue(vblk->disk->queue); 1641 1642 vdev->config->del_vqs(vdev); 1643 kfree(vblk->vqs); 1644 1645 return 0; 1646 } 1647 1648 static int virtblk_restore(struct virtio_device *vdev) 1649 { 1650 struct virtio_blk *vblk = vdev->priv; 1651 int ret; 1652 1653 ret = init_vq(vdev->priv); 1654 if (ret) 1655 return ret; 1656 1657 virtio_device_ready(vdev); 1658 1659 blk_mq_unquiesce_queue(vblk->disk->queue); 1660 return 0; 1661 } 1662 #endif 1663 1664 static const struct virtio_device_id id_table[] = { 1665 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1666 { 0 }, 1667 }; 1668 1669 static unsigned int features_legacy[] = { 1670 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1671 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1672 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1673 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1674 VIRTIO_BLK_F_SECURE_ERASE, 1675 } 1676 ; 1677 static unsigned int features[] = { 1678 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1679 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1680 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1681 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1682 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1683 }; 1684 1685 static struct virtio_driver virtio_blk = { 1686 .feature_table = features, 1687 .feature_table_size = ARRAY_SIZE(features), 1688 .feature_table_legacy = features_legacy, 1689 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1690 .driver.name = KBUILD_MODNAME, 1691 .driver.owner = THIS_MODULE, 1692 .id_table = id_table, 1693 .probe = virtblk_probe, 1694 .remove = virtblk_remove, 1695 .config_changed = virtblk_config_changed, 1696 #ifdef CONFIG_PM_SLEEP 1697 .freeze = virtblk_freeze, 1698 .restore = virtblk_restore, 1699 #endif 1700 }; 1701 1702 static int __init virtio_blk_init(void) 1703 { 1704 int error; 1705 1706 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1707 if (!virtblk_wq) 1708 return -ENOMEM; 1709 1710 major = register_blkdev(0, "virtblk"); 1711 if (major < 0) { 1712 error = major; 1713 goto out_destroy_workqueue; 1714 } 1715 1716 error = register_virtio_driver(&virtio_blk); 1717 if (error) 1718 goto out_unregister_blkdev; 1719 return 0; 1720 1721 out_unregister_blkdev: 1722 unregister_blkdev(major, "virtblk"); 1723 out_destroy_workqueue: 1724 destroy_workqueue(virtblk_wq); 1725 return error; 1726 } 1727 1728 static void __exit virtio_blk_fini(void) 1729 { 1730 unregister_virtio_driver(&virtio_blk); 1731 unregister_blkdev(major, "virtblk"); 1732 destroy_workqueue(virtblk_wq); 1733 } 1734 module_init(virtio_blk_init); 1735 module_exit(virtio_blk_fini); 1736 1737 MODULE_DEVICE_TABLE(virtio, id_table); 1738 MODULE_DESCRIPTION("Virtio block driver"); 1739 MODULE_LICENSE("GPL"); 1740