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_read_zoned_limits(struct virtio_blk *vblk, 724 struct queue_limits *lim) 725 { 726 struct virtio_device *vdev = vblk->vdev; 727 u32 v, wg; 728 729 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 730 731 lim->features |= BLK_FEAT_ZONED; 732 733 virtio_cread(vdev, struct virtio_blk_config, 734 zoned.max_open_zones, &v); 735 lim->max_open_zones = v; 736 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 737 738 virtio_cread(vdev, struct virtio_blk_config, 739 zoned.max_active_zones, &v); 740 lim->max_active_zones = v; 741 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 742 743 virtio_cread(vdev, struct virtio_blk_config, 744 zoned.write_granularity, &wg); 745 if (!wg) { 746 dev_warn(&vdev->dev, "zero write granularity reported\n"); 747 return -ENODEV; 748 } 749 lim->physical_block_size = wg; 750 lim->io_min = wg; 751 752 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 753 754 /* 755 * virtio ZBD specification doesn't require zones to be a power of 756 * two sectors in size, but the code in this driver expects that. 757 */ 758 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 759 &vblk->zone_sectors); 760 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 761 dev_err(&vdev->dev, 762 "zoned device with non power of two zone size %u\n", 763 vblk->zone_sectors); 764 return -ENODEV; 765 } 766 lim->chunk_sectors = vblk->zone_sectors; 767 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 768 769 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 770 dev_warn(&vblk->vdev->dev, 771 "ignoring negotiated F_DISCARD for zoned device\n"); 772 lim->max_hw_discard_sectors = 0; 773 } 774 775 virtio_cread(vdev, struct virtio_blk_config, 776 zoned.max_append_sectors, &v); 777 if (!v) { 778 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 779 return -ENODEV; 780 } 781 if ((v << SECTOR_SHIFT) < wg) { 782 dev_err(&vdev->dev, 783 "write granularity %u exceeds max_append_sectors %u limit\n", 784 wg, v); 785 return -ENODEV; 786 } 787 lim->max_zone_append_sectors = v; 788 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 789 790 return 0; 791 } 792 #else 793 /* 794 * Zoned block device support is not configured in this kernel, host-managed 795 * zoned devices can't be supported. 796 */ 797 #define virtblk_report_zones NULL 798 static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk, 799 struct queue_limits *lim) 800 { 801 dev_err(&vblk->vdev->dev, 802 "virtio_blk: zoned devices are not supported"); 803 return -EOPNOTSUPP; 804 } 805 #endif /* CONFIG_BLK_DEV_ZONED */ 806 807 /* return id (s/n) string for *disk to *id_str 808 */ 809 static int virtblk_get_id(struct gendisk *disk, char *id_str) 810 { 811 struct virtio_blk *vblk = disk->private_data; 812 struct request_queue *q = vblk->disk->queue; 813 struct request *req; 814 struct virtblk_req *vbr; 815 int err; 816 817 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 818 if (IS_ERR(req)) 819 return PTR_ERR(req); 820 821 vbr = blk_mq_rq_to_pdu(req); 822 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 823 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 824 vbr->out_hdr.sector = 0; 825 826 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 827 if (err) 828 goto out; 829 830 blk_execute_rq(req, false); 831 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 832 out: 833 blk_mq_free_request(req); 834 return err; 835 } 836 837 /* We provide getgeo only to please some old bootloader/partitioning tools */ 838 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 839 { 840 struct virtio_blk *vblk = bd->bd_disk->private_data; 841 int ret = 0; 842 843 mutex_lock(&vblk->vdev_mutex); 844 845 if (!vblk->vdev) { 846 ret = -ENXIO; 847 goto out; 848 } 849 850 /* see if the host passed in geometry config */ 851 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 852 virtio_cread(vblk->vdev, struct virtio_blk_config, 853 geometry.cylinders, &geo->cylinders); 854 virtio_cread(vblk->vdev, struct virtio_blk_config, 855 geometry.heads, &geo->heads); 856 virtio_cread(vblk->vdev, struct virtio_blk_config, 857 geometry.sectors, &geo->sectors); 858 } else { 859 /* some standard values, similar to sd */ 860 geo->heads = 1 << 6; 861 geo->sectors = 1 << 5; 862 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 863 } 864 out: 865 mutex_unlock(&vblk->vdev_mutex); 866 return ret; 867 } 868 869 static void virtblk_free_disk(struct gendisk *disk) 870 { 871 struct virtio_blk *vblk = disk->private_data; 872 873 ida_free(&vd_index_ida, vblk->index); 874 mutex_destroy(&vblk->vdev_mutex); 875 kfree(vblk); 876 } 877 878 static const struct block_device_operations virtblk_fops = { 879 .owner = THIS_MODULE, 880 .getgeo = virtblk_getgeo, 881 .free_disk = virtblk_free_disk, 882 .report_zones = virtblk_report_zones, 883 }; 884 885 static int index_to_minor(int index) 886 { 887 return index << PART_BITS; 888 } 889 890 static int minor_to_index(int minor) 891 { 892 return minor >> PART_BITS; 893 } 894 895 static ssize_t serial_show(struct device *dev, 896 struct device_attribute *attr, char *buf) 897 { 898 struct gendisk *disk = dev_to_disk(dev); 899 int err; 900 901 /* sysfs gives us a PAGE_SIZE buffer */ 902 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 903 904 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 905 err = virtblk_get_id(disk, buf); 906 if (!err) 907 return strlen(buf); 908 909 if (err == -EIO) /* Unsupported? Make it empty. */ 910 return 0; 911 912 return err; 913 } 914 915 static DEVICE_ATTR_RO(serial); 916 917 /* The queue's logical block size must be set before calling this */ 918 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 919 { 920 struct virtio_device *vdev = vblk->vdev; 921 struct request_queue *q = vblk->disk->queue; 922 char cap_str_2[10], cap_str_10[10]; 923 unsigned long long nblocks; 924 u64 capacity; 925 926 /* Host must always specify the capacity. */ 927 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 928 929 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 930 931 string_get_size(nblocks, queue_logical_block_size(q), 932 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 933 string_get_size(nblocks, queue_logical_block_size(q), 934 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 935 936 dev_notice(&vdev->dev, 937 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 938 vblk->disk->disk_name, 939 resize ? "new size: " : "", 940 nblocks, 941 queue_logical_block_size(q), 942 cap_str_10, 943 cap_str_2); 944 945 set_capacity_and_notify(vblk->disk, capacity); 946 } 947 948 static void virtblk_config_changed_work(struct work_struct *work) 949 { 950 struct virtio_blk *vblk = 951 container_of(work, struct virtio_blk, config_work); 952 953 virtblk_update_capacity(vblk, true); 954 } 955 956 static void virtblk_config_changed(struct virtio_device *vdev) 957 { 958 struct virtio_blk *vblk = vdev->priv; 959 960 queue_work(virtblk_wq, &vblk->config_work); 961 } 962 963 static int init_vq(struct virtio_blk *vblk) 964 { 965 int err; 966 unsigned short i; 967 struct virtqueue_info *vqs_info; 968 struct virtqueue **vqs; 969 unsigned short num_vqs; 970 unsigned short num_poll_vqs; 971 struct virtio_device *vdev = vblk->vdev; 972 struct irq_affinity desc = { 0, }; 973 974 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 975 struct virtio_blk_config, num_queues, 976 &num_vqs); 977 if (err) 978 num_vqs = 1; 979 980 if (!err && !num_vqs) { 981 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 982 return -EINVAL; 983 } 984 985 num_vqs = min_t(unsigned int, 986 min_not_zero(num_request_queues, nr_cpu_ids), 987 num_vqs); 988 989 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 990 991 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 992 vblk->io_queues[HCTX_TYPE_READ] = 0; 993 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 994 995 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 996 vblk->io_queues[HCTX_TYPE_DEFAULT], 997 vblk->io_queues[HCTX_TYPE_READ], 998 vblk->io_queues[HCTX_TYPE_POLL]); 999 1000 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 1001 if (!vblk->vqs) 1002 return -ENOMEM; 1003 1004 vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL); 1005 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1006 if (!vqs_info || !vqs) { 1007 err = -ENOMEM; 1008 goto out; 1009 } 1010 1011 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1012 vqs_info[i].callback = virtblk_done; 1013 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1014 vqs_info[i].name = vblk->vqs[i].name; 1015 } 1016 1017 for (; i < num_vqs; i++) { 1018 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1019 vqs_info[i].name = vblk->vqs[i].name; 1020 } 1021 1022 /* Discover virtqueues and write information to configuration. */ 1023 err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc); 1024 if (err) 1025 goto out; 1026 1027 for (i = 0; i < num_vqs; i++) { 1028 spin_lock_init(&vblk->vqs[i].lock); 1029 vblk->vqs[i].vq = vqs[i]; 1030 } 1031 vblk->num_vqs = num_vqs; 1032 1033 out: 1034 kfree(vqs); 1035 kfree(vqs_info); 1036 if (err) 1037 kfree(vblk->vqs); 1038 return err; 1039 } 1040 1041 /* 1042 * Legacy naming scheme used for virtio devices. We are stuck with it for 1043 * virtio blk but don't ever use it for any new driver. 1044 */ 1045 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1046 { 1047 const int base = 'z' - 'a' + 1; 1048 char *begin = buf + strlen(prefix); 1049 char *end = buf + buflen; 1050 char *p; 1051 int unit; 1052 1053 p = end - 1; 1054 *p = '\0'; 1055 unit = base; 1056 do { 1057 if (p == begin) 1058 return -EINVAL; 1059 *--p = 'a' + (index % unit); 1060 index = (index / unit) - 1; 1061 } while (index >= 0); 1062 1063 memmove(begin, p, end - p); 1064 memcpy(buf, prefix, strlen(prefix)); 1065 1066 return 0; 1067 } 1068 1069 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1070 { 1071 u8 writeback; 1072 int err; 1073 1074 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1075 struct virtio_blk_config, wce, 1076 &writeback); 1077 1078 /* 1079 * If WCE is not configurable and flush is not available, 1080 * assume no writeback cache is in use. 1081 */ 1082 if (err) 1083 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1084 1085 return writeback; 1086 } 1087 1088 static const char *const virtblk_cache_types[] = { 1089 "write through", "write back" 1090 }; 1091 1092 static ssize_t 1093 cache_type_store(struct device *dev, struct device_attribute *attr, 1094 const char *buf, size_t count) 1095 { 1096 struct gendisk *disk = dev_to_disk(dev); 1097 struct virtio_blk *vblk = disk->private_data; 1098 struct virtio_device *vdev = vblk->vdev; 1099 struct queue_limits lim; 1100 int i; 1101 1102 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1103 i = sysfs_match_string(virtblk_cache_types, buf); 1104 if (i < 0) 1105 return i; 1106 1107 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1108 1109 lim = queue_limits_start_update(disk->queue); 1110 if (virtblk_get_cache_mode(vdev)) 1111 lim.features |= BLK_FEAT_WRITE_CACHE; 1112 else 1113 lim.features &= ~BLK_FEAT_WRITE_CACHE; 1114 blk_mq_freeze_queue(disk->queue); 1115 i = queue_limits_commit_update(disk->queue, &lim); 1116 blk_mq_unfreeze_queue(disk->queue); 1117 if (i) 1118 return i; 1119 return count; 1120 } 1121 1122 static ssize_t 1123 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1124 { 1125 struct gendisk *disk = dev_to_disk(dev); 1126 struct virtio_blk *vblk = disk->private_data; 1127 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1128 1129 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1130 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1131 } 1132 1133 static DEVICE_ATTR_RW(cache_type); 1134 1135 static struct attribute *virtblk_attrs[] = { 1136 &dev_attr_serial.attr, 1137 &dev_attr_cache_type.attr, 1138 NULL, 1139 }; 1140 1141 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1142 struct attribute *a, int n) 1143 { 1144 struct device *dev = kobj_to_dev(kobj); 1145 struct gendisk *disk = dev_to_disk(dev); 1146 struct virtio_blk *vblk = disk->private_data; 1147 struct virtio_device *vdev = vblk->vdev; 1148 1149 if (a == &dev_attr_cache_type.attr && 1150 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1151 return S_IRUGO; 1152 1153 return a->mode; 1154 } 1155 1156 static const struct attribute_group virtblk_attr_group = { 1157 .attrs = virtblk_attrs, 1158 .is_visible = virtblk_attrs_are_visible, 1159 }; 1160 1161 static const struct attribute_group *virtblk_attr_groups[] = { 1162 &virtblk_attr_group, 1163 NULL, 1164 }; 1165 1166 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1167 { 1168 struct virtio_blk *vblk = set->driver_data; 1169 int i, qoff; 1170 1171 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1172 struct blk_mq_queue_map *map = &set->map[i]; 1173 1174 map->nr_queues = vblk->io_queues[i]; 1175 map->queue_offset = qoff; 1176 qoff += map->nr_queues; 1177 1178 if (map->nr_queues == 0) 1179 continue; 1180 1181 /* 1182 * Regular queues have interrupts and hence CPU affinity is 1183 * defined by the core virtio code, but polling queues have 1184 * no interrupts so we let the block layer assign CPU affinity. 1185 */ 1186 if (i == HCTX_TYPE_POLL) 1187 blk_mq_map_queues(&set->map[i]); 1188 else 1189 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1190 } 1191 } 1192 1193 static void virtblk_complete_batch(struct io_comp_batch *iob) 1194 { 1195 struct request *req; 1196 1197 rq_list_for_each(&iob->req_list, req) { 1198 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1199 virtblk_cleanup_cmd(req); 1200 } 1201 blk_mq_end_request_batch(iob); 1202 } 1203 1204 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1205 { 1206 struct virtio_blk *vblk = hctx->queue->queuedata; 1207 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1208 struct virtblk_req *vbr; 1209 unsigned long flags; 1210 unsigned int len; 1211 int found = 0; 1212 1213 spin_lock_irqsave(&vq->lock, flags); 1214 1215 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1216 struct request *req = blk_mq_rq_from_pdu(vbr); 1217 1218 found++; 1219 if (!blk_mq_complete_request_remote(req) && 1220 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1221 virtblk_complete_batch)) 1222 virtblk_request_done(req); 1223 } 1224 1225 if (found) 1226 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1227 1228 spin_unlock_irqrestore(&vq->lock, flags); 1229 1230 return found; 1231 } 1232 1233 static const struct blk_mq_ops virtio_mq_ops = { 1234 .queue_rq = virtio_queue_rq, 1235 .queue_rqs = virtio_queue_rqs, 1236 .commit_rqs = virtio_commit_rqs, 1237 .complete = virtblk_request_done, 1238 .map_queues = virtblk_map_queues, 1239 .poll = virtblk_poll, 1240 }; 1241 1242 static unsigned int virtblk_queue_depth; 1243 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1244 1245 static int virtblk_read_limits(struct virtio_blk *vblk, 1246 struct queue_limits *lim) 1247 { 1248 struct virtio_device *vdev = vblk->vdev; 1249 u32 v, max_size, sg_elems, opt_io_size; 1250 u32 max_discard_segs = 0; 1251 u32 discard_granularity = 0; 1252 u16 min_io_size; 1253 u8 physical_block_exp, alignment_offset; 1254 size_t max_dma_size; 1255 int err; 1256 1257 /* We need to know how many segments before we allocate. */ 1258 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1259 struct virtio_blk_config, seg_max, 1260 &sg_elems); 1261 1262 /* We need at least one SG element, whatever they say. */ 1263 if (err || !sg_elems) 1264 sg_elems = 1; 1265 1266 /* Prevent integer overflows and honor max vq size */ 1267 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1268 1269 /* We can handle whatever the host told us to handle. */ 1270 lim->max_segments = sg_elems; 1271 1272 /* No real sector limit. */ 1273 lim->max_hw_sectors = UINT_MAX; 1274 1275 max_dma_size = virtio_max_dma_size(vdev); 1276 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1277 1278 /* Host can optionally specify maximum segment size and number of 1279 * segments. */ 1280 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1281 struct virtio_blk_config, size_max, &v); 1282 if (!err) 1283 max_size = min(max_size, v); 1284 1285 lim->max_segment_size = max_size; 1286 1287 /* Host can optionally specify the block size of the device */ 1288 virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1289 struct virtio_blk_config, blk_size, 1290 &lim->logical_block_size); 1291 1292 /* Use topology information if available */ 1293 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1294 struct virtio_blk_config, physical_block_exp, 1295 &physical_block_exp); 1296 if (!err && physical_block_exp) 1297 lim->physical_block_size = 1298 lim->logical_block_size * (1 << physical_block_exp); 1299 1300 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1301 struct virtio_blk_config, alignment_offset, 1302 &alignment_offset); 1303 if (!err && alignment_offset) 1304 lim->alignment_offset = 1305 lim->logical_block_size * alignment_offset; 1306 1307 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1308 struct virtio_blk_config, min_io_size, 1309 &min_io_size); 1310 if (!err && min_io_size) 1311 lim->io_min = lim->logical_block_size * min_io_size; 1312 1313 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1314 struct virtio_blk_config, opt_io_size, 1315 &opt_io_size); 1316 if (!err && opt_io_size) 1317 lim->io_opt = lim->logical_block_size * opt_io_size; 1318 1319 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1320 virtio_cread(vdev, struct virtio_blk_config, 1321 discard_sector_alignment, &discard_granularity); 1322 1323 virtio_cread(vdev, struct virtio_blk_config, 1324 max_discard_sectors, &v); 1325 lim->max_hw_discard_sectors = v ? v : UINT_MAX; 1326 1327 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1328 &max_discard_segs); 1329 } 1330 1331 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1332 virtio_cread(vdev, struct virtio_blk_config, 1333 max_write_zeroes_sectors, &v); 1334 lim->max_write_zeroes_sectors = v ? v : UINT_MAX; 1335 } 1336 1337 /* The discard and secure erase limits are combined since the Linux 1338 * block layer uses the same limit for both commands. 1339 * 1340 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1341 * are negotiated, we will use the minimum between the limits. 1342 * 1343 * discard sector alignment is set to the minimum between discard_sector_alignment 1344 * and secure_erase_sector_alignment. 1345 * 1346 * max discard sectors is set to the minimum between max_discard_seg and 1347 * max_secure_erase_seg. 1348 */ 1349 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1350 1351 virtio_cread(vdev, struct virtio_blk_config, 1352 secure_erase_sector_alignment, &v); 1353 1354 /* secure_erase_sector_alignment should not be zero, the device should set a 1355 * valid number of sectors. 1356 */ 1357 if (!v) { 1358 dev_err(&vdev->dev, 1359 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1360 return -EINVAL; 1361 } 1362 1363 discard_granularity = min_not_zero(discard_granularity, v); 1364 1365 virtio_cread(vdev, struct virtio_blk_config, 1366 max_secure_erase_sectors, &v); 1367 1368 /* max_secure_erase_sectors should not be zero, the device should set a 1369 * valid number of sectors. 1370 */ 1371 if (!v) { 1372 dev_err(&vdev->dev, 1373 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1374 return -EINVAL; 1375 } 1376 1377 lim->max_secure_erase_sectors = v; 1378 1379 virtio_cread(vdev, struct virtio_blk_config, 1380 max_secure_erase_seg, &v); 1381 1382 /* max_secure_erase_seg should not be zero, the device should set a 1383 * valid number of segments 1384 */ 1385 if (!v) { 1386 dev_err(&vdev->dev, 1387 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1388 return -EINVAL; 1389 } 1390 1391 max_discard_segs = min_not_zero(max_discard_segs, v); 1392 } 1393 1394 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1395 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1396 /* max_discard_seg and discard_granularity will be 0 only 1397 * if max_discard_seg and discard_sector_alignment fields in the virtio 1398 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1399 * In this case, we use default values. 1400 */ 1401 if (!max_discard_segs) 1402 max_discard_segs = sg_elems; 1403 1404 lim->max_discard_segments = 1405 min(max_discard_segs, MAX_DISCARD_SEGMENTS); 1406 1407 if (discard_granularity) 1408 lim->discard_granularity = 1409 discard_granularity << SECTOR_SHIFT; 1410 else 1411 lim->discard_granularity = lim->logical_block_size; 1412 } 1413 1414 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1415 u8 model; 1416 1417 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); 1418 switch (model) { 1419 case VIRTIO_BLK_Z_NONE: 1420 case VIRTIO_BLK_Z_HA: 1421 /* treat host-aware devices as non-zoned */ 1422 return 0; 1423 case VIRTIO_BLK_Z_HM: 1424 err = virtblk_read_zoned_limits(vblk, lim); 1425 if (err) 1426 return err; 1427 break; 1428 default: 1429 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 1430 return -EINVAL; 1431 } 1432 } 1433 1434 return 0; 1435 } 1436 1437 static int virtblk_probe(struct virtio_device *vdev) 1438 { 1439 struct virtio_blk *vblk; 1440 struct queue_limits lim = { 1441 .features = BLK_FEAT_ROTATIONAL, 1442 .logical_block_size = SECTOR_SIZE, 1443 }; 1444 int err, index; 1445 unsigned int queue_depth; 1446 1447 if (!vdev->config->get) { 1448 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1449 __func__); 1450 return -EINVAL; 1451 } 1452 1453 err = ida_alloc_range(&vd_index_ida, 0, 1454 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1455 if (err < 0) 1456 goto out; 1457 index = err; 1458 1459 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1460 if (!vblk) { 1461 err = -ENOMEM; 1462 goto out_free_index; 1463 } 1464 1465 mutex_init(&vblk->vdev_mutex); 1466 1467 vblk->vdev = vdev; 1468 1469 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1470 1471 err = init_vq(vblk); 1472 if (err) 1473 goto out_free_vblk; 1474 1475 /* Default queue sizing is to fill the ring. */ 1476 if (!virtblk_queue_depth) { 1477 queue_depth = vblk->vqs[0].vq->num_free; 1478 /* ... but without indirect descs, we use 2 descs per req */ 1479 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1480 queue_depth /= 2; 1481 } else { 1482 queue_depth = virtblk_queue_depth; 1483 } 1484 1485 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1486 vblk->tag_set.ops = &virtio_mq_ops; 1487 vblk->tag_set.queue_depth = queue_depth; 1488 vblk->tag_set.numa_node = NUMA_NO_NODE; 1489 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1490 vblk->tag_set.cmd_size = 1491 sizeof(struct virtblk_req) + 1492 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1493 vblk->tag_set.driver_data = vblk; 1494 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1495 vblk->tag_set.nr_maps = 1; 1496 if (vblk->io_queues[HCTX_TYPE_POLL]) 1497 vblk->tag_set.nr_maps = 3; 1498 1499 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1500 if (err) 1501 goto out_free_vq; 1502 1503 err = virtblk_read_limits(vblk, &lim); 1504 if (err) 1505 goto out_free_tags; 1506 1507 if (virtblk_get_cache_mode(vdev)) 1508 lim.features |= BLK_FEAT_WRITE_CACHE; 1509 1510 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk); 1511 if (IS_ERR(vblk->disk)) { 1512 err = PTR_ERR(vblk->disk); 1513 goto out_free_tags; 1514 } 1515 1516 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1517 1518 vblk->disk->major = major; 1519 vblk->disk->first_minor = index_to_minor(index); 1520 vblk->disk->minors = 1 << PART_BITS; 1521 vblk->disk->private_data = vblk; 1522 vblk->disk->fops = &virtblk_fops; 1523 vblk->index = index; 1524 1525 /* If disk is read-only in the host, the guest should obey */ 1526 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1527 set_disk_ro(vblk->disk, 1); 1528 1529 virtblk_update_capacity(vblk, false); 1530 virtio_device_ready(vdev); 1531 1532 /* 1533 * All steps that follow use the VQs therefore they need to be 1534 * placed after the virtio_device_ready() call above. 1535 */ 1536 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && 1537 (lim.features & BLK_FEAT_ZONED)) { 1538 err = blk_revalidate_disk_zones(vblk->disk); 1539 if (err) 1540 goto out_cleanup_disk; 1541 } 1542 1543 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1544 if (err) 1545 goto out_cleanup_disk; 1546 1547 return 0; 1548 1549 out_cleanup_disk: 1550 put_disk(vblk->disk); 1551 out_free_tags: 1552 blk_mq_free_tag_set(&vblk->tag_set); 1553 out_free_vq: 1554 vdev->config->del_vqs(vdev); 1555 kfree(vblk->vqs); 1556 out_free_vblk: 1557 kfree(vblk); 1558 out_free_index: 1559 ida_free(&vd_index_ida, index); 1560 out: 1561 return err; 1562 } 1563 1564 static void virtblk_remove(struct virtio_device *vdev) 1565 { 1566 struct virtio_blk *vblk = vdev->priv; 1567 1568 /* Make sure no work handler is accessing the device. */ 1569 flush_work(&vblk->config_work); 1570 1571 del_gendisk(vblk->disk); 1572 blk_mq_free_tag_set(&vblk->tag_set); 1573 1574 mutex_lock(&vblk->vdev_mutex); 1575 1576 /* Stop all the virtqueues. */ 1577 virtio_reset_device(vdev); 1578 1579 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1580 vblk->vdev = NULL; 1581 1582 vdev->config->del_vqs(vdev); 1583 kfree(vblk->vqs); 1584 1585 mutex_unlock(&vblk->vdev_mutex); 1586 1587 put_disk(vblk->disk); 1588 } 1589 1590 #ifdef CONFIG_PM_SLEEP 1591 static int virtblk_freeze(struct virtio_device *vdev) 1592 { 1593 struct virtio_blk *vblk = vdev->priv; 1594 1595 /* Ensure no requests in virtqueues before deleting vqs. */ 1596 blk_mq_freeze_queue(vblk->disk->queue); 1597 1598 /* Ensure we don't receive any more interrupts */ 1599 virtio_reset_device(vdev); 1600 1601 /* Make sure no work handler is accessing the device. */ 1602 flush_work(&vblk->config_work); 1603 1604 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_unfreeze_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 .id_table = id_table, 1654 .probe = virtblk_probe, 1655 .remove = virtblk_remove, 1656 .config_changed = virtblk_config_changed, 1657 #ifdef CONFIG_PM_SLEEP 1658 .freeze = virtblk_freeze, 1659 .restore = virtblk_restore, 1660 #endif 1661 }; 1662 1663 static int __init virtio_blk_init(void) 1664 { 1665 int error; 1666 1667 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1668 if (!virtblk_wq) 1669 return -ENOMEM; 1670 1671 major = register_blkdev(0, "virtblk"); 1672 if (major < 0) { 1673 error = major; 1674 goto out_destroy_workqueue; 1675 } 1676 1677 error = register_virtio_driver(&virtio_blk); 1678 if (error) 1679 goto out_unregister_blkdev; 1680 return 0; 1681 1682 out_unregister_blkdev: 1683 unregister_blkdev(major, "virtblk"); 1684 out_destroy_workqueue: 1685 destroy_workqueue(virtblk_wq); 1686 return error; 1687 } 1688 1689 static void __exit virtio_blk_fini(void) 1690 { 1691 unregister_virtio_driver(&virtio_blk); 1692 unregister_blkdev(major, "virtblk"); 1693 destroy_workqueue(virtblk_wq); 1694 } 1695 module_init(virtio_blk_init); 1696 module_exit(virtio_blk_fini); 1697 1698 MODULE_DEVICE_TABLE(virtio, id_table); 1699 MODULE_DESCRIPTION("Virtio block driver"); 1700 MODULE_LICENSE("GPL"); 1701