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 vq_callback_t **callbacks; 968 const char **names; 969 struct virtqueue **vqs; 970 unsigned short num_vqs; 971 unsigned short num_poll_vqs; 972 struct virtio_device *vdev = vblk->vdev; 973 struct irq_affinity desc = { 0, }; 974 975 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 976 struct virtio_blk_config, num_queues, 977 &num_vqs); 978 if (err) 979 num_vqs = 1; 980 981 if (!err && !num_vqs) { 982 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 983 return -EINVAL; 984 } 985 986 num_vqs = min_t(unsigned int, 987 min_not_zero(num_request_queues, nr_cpu_ids), 988 num_vqs); 989 990 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 991 992 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 993 vblk->io_queues[HCTX_TYPE_READ] = 0; 994 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 995 996 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 997 vblk->io_queues[HCTX_TYPE_DEFAULT], 998 vblk->io_queues[HCTX_TYPE_READ], 999 vblk->io_queues[HCTX_TYPE_POLL]); 1000 1001 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 1002 if (!vblk->vqs) 1003 return -ENOMEM; 1004 1005 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); 1006 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); 1007 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1008 if (!names || !callbacks || !vqs) { 1009 err = -ENOMEM; 1010 goto out; 1011 } 1012 1013 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1014 callbacks[i] = virtblk_done; 1015 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1016 names[i] = vblk->vqs[i].name; 1017 } 1018 1019 for (; i < num_vqs; i++) { 1020 callbacks[i] = NULL; 1021 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1022 names[i] = vblk->vqs[i].name; 1023 } 1024 1025 /* Discover virtqueues and write information to configuration. */ 1026 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 1027 if (err) 1028 goto out; 1029 1030 for (i = 0; i < num_vqs; i++) { 1031 spin_lock_init(&vblk->vqs[i].lock); 1032 vblk->vqs[i].vq = vqs[i]; 1033 } 1034 vblk->num_vqs = num_vqs; 1035 1036 out: 1037 kfree(vqs); 1038 kfree(callbacks); 1039 kfree(names); 1040 if (err) 1041 kfree(vblk->vqs); 1042 return err; 1043 } 1044 1045 /* 1046 * Legacy naming scheme used for virtio devices. We are stuck with it for 1047 * virtio blk but don't ever use it for any new driver. 1048 */ 1049 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1050 { 1051 const int base = 'z' - 'a' + 1; 1052 char *begin = buf + strlen(prefix); 1053 char *end = buf + buflen; 1054 char *p; 1055 int unit; 1056 1057 p = end - 1; 1058 *p = '\0'; 1059 unit = base; 1060 do { 1061 if (p == begin) 1062 return -EINVAL; 1063 *--p = 'a' + (index % unit); 1064 index = (index / unit) - 1; 1065 } while (index >= 0); 1066 1067 memmove(begin, p, end - p); 1068 memcpy(buf, prefix, strlen(prefix)); 1069 1070 return 0; 1071 } 1072 1073 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1074 { 1075 u8 writeback; 1076 int err; 1077 1078 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1079 struct virtio_blk_config, wce, 1080 &writeback); 1081 1082 /* 1083 * If WCE is not configurable and flush is not available, 1084 * assume no writeback cache is in use. 1085 */ 1086 if (err) 1087 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1088 1089 return writeback; 1090 } 1091 1092 static const char *const virtblk_cache_types[] = { 1093 "write through", "write back" 1094 }; 1095 1096 static ssize_t 1097 cache_type_store(struct device *dev, struct device_attribute *attr, 1098 const char *buf, size_t count) 1099 { 1100 struct gendisk *disk = dev_to_disk(dev); 1101 struct virtio_blk *vblk = disk->private_data; 1102 struct virtio_device *vdev = vblk->vdev; 1103 struct queue_limits lim; 1104 int i; 1105 1106 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1107 i = sysfs_match_string(virtblk_cache_types, buf); 1108 if (i < 0) 1109 return i; 1110 1111 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1112 1113 lim = queue_limits_start_update(disk->queue); 1114 if (virtblk_get_cache_mode(vdev)) 1115 lim.features |= BLK_FEAT_WRITE_CACHE; 1116 else 1117 lim.features &= ~BLK_FEAT_WRITE_CACHE; 1118 blk_mq_freeze_queue(disk->queue); 1119 i = queue_limits_commit_update(disk->queue, &lim); 1120 blk_mq_unfreeze_queue(disk->queue); 1121 if (i) 1122 return i; 1123 return count; 1124 } 1125 1126 static ssize_t 1127 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1128 { 1129 struct gendisk *disk = dev_to_disk(dev); 1130 struct virtio_blk *vblk = disk->private_data; 1131 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1132 1133 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1134 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1135 } 1136 1137 static DEVICE_ATTR_RW(cache_type); 1138 1139 static struct attribute *virtblk_attrs[] = { 1140 &dev_attr_serial.attr, 1141 &dev_attr_cache_type.attr, 1142 NULL, 1143 }; 1144 1145 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1146 struct attribute *a, int n) 1147 { 1148 struct device *dev = kobj_to_dev(kobj); 1149 struct gendisk *disk = dev_to_disk(dev); 1150 struct virtio_blk *vblk = disk->private_data; 1151 struct virtio_device *vdev = vblk->vdev; 1152 1153 if (a == &dev_attr_cache_type.attr && 1154 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1155 return S_IRUGO; 1156 1157 return a->mode; 1158 } 1159 1160 static const struct attribute_group virtblk_attr_group = { 1161 .attrs = virtblk_attrs, 1162 .is_visible = virtblk_attrs_are_visible, 1163 }; 1164 1165 static const struct attribute_group *virtblk_attr_groups[] = { 1166 &virtblk_attr_group, 1167 NULL, 1168 }; 1169 1170 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1171 { 1172 struct virtio_blk *vblk = set->driver_data; 1173 int i, qoff; 1174 1175 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1176 struct blk_mq_queue_map *map = &set->map[i]; 1177 1178 map->nr_queues = vblk->io_queues[i]; 1179 map->queue_offset = qoff; 1180 qoff += map->nr_queues; 1181 1182 if (map->nr_queues == 0) 1183 continue; 1184 1185 /* 1186 * Regular queues have interrupts and hence CPU affinity is 1187 * defined by the core virtio code, but polling queues have 1188 * no interrupts so we let the block layer assign CPU affinity. 1189 */ 1190 if (i == HCTX_TYPE_POLL) 1191 blk_mq_map_queues(&set->map[i]); 1192 else 1193 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1194 } 1195 } 1196 1197 static void virtblk_complete_batch(struct io_comp_batch *iob) 1198 { 1199 struct request *req; 1200 1201 rq_list_for_each(&iob->req_list, req) { 1202 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1203 virtblk_cleanup_cmd(req); 1204 } 1205 blk_mq_end_request_batch(iob); 1206 } 1207 1208 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1209 { 1210 struct virtio_blk *vblk = hctx->queue->queuedata; 1211 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1212 struct virtblk_req *vbr; 1213 unsigned long flags; 1214 unsigned int len; 1215 int found = 0; 1216 1217 spin_lock_irqsave(&vq->lock, flags); 1218 1219 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1220 struct request *req = blk_mq_rq_from_pdu(vbr); 1221 1222 found++; 1223 if (!blk_mq_complete_request_remote(req) && 1224 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1225 virtblk_complete_batch)) 1226 virtblk_request_done(req); 1227 } 1228 1229 if (found) 1230 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1231 1232 spin_unlock_irqrestore(&vq->lock, flags); 1233 1234 return found; 1235 } 1236 1237 static const struct blk_mq_ops virtio_mq_ops = { 1238 .queue_rq = virtio_queue_rq, 1239 .queue_rqs = virtio_queue_rqs, 1240 .commit_rqs = virtio_commit_rqs, 1241 .complete = virtblk_request_done, 1242 .map_queues = virtblk_map_queues, 1243 .poll = virtblk_poll, 1244 }; 1245 1246 static unsigned int virtblk_queue_depth; 1247 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1248 1249 static int virtblk_read_limits(struct virtio_blk *vblk, 1250 struct queue_limits *lim) 1251 { 1252 struct virtio_device *vdev = vblk->vdev; 1253 u32 v, max_size, sg_elems, opt_io_size; 1254 u32 max_discard_segs = 0; 1255 u32 discard_granularity = 0; 1256 u16 min_io_size; 1257 u8 physical_block_exp, alignment_offset; 1258 size_t max_dma_size; 1259 int err; 1260 1261 /* We need to know how many segments before we allocate. */ 1262 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1263 struct virtio_blk_config, seg_max, 1264 &sg_elems); 1265 1266 /* We need at least one SG element, whatever they say. */ 1267 if (err || !sg_elems) 1268 sg_elems = 1; 1269 1270 /* Prevent integer overflows and honor max vq size */ 1271 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1272 1273 /* We can handle whatever the host told us to handle. */ 1274 lim->max_segments = sg_elems; 1275 1276 /* No real sector limit. */ 1277 lim->max_hw_sectors = UINT_MAX; 1278 1279 max_dma_size = virtio_max_dma_size(vdev); 1280 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1281 1282 /* Host can optionally specify maximum segment size and number of 1283 * segments. */ 1284 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1285 struct virtio_blk_config, size_max, &v); 1286 if (!err) 1287 max_size = min(max_size, v); 1288 1289 lim->max_segment_size = max_size; 1290 1291 /* Host can optionally specify the block size of the device */ 1292 virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1293 struct virtio_blk_config, blk_size, 1294 &lim->logical_block_size); 1295 1296 /* Use topology information if available */ 1297 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1298 struct virtio_blk_config, physical_block_exp, 1299 &physical_block_exp); 1300 if (!err && physical_block_exp) 1301 lim->physical_block_size = 1302 lim->logical_block_size * (1 << physical_block_exp); 1303 1304 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1305 struct virtio_blk_config, alignment_offset, 1306 &alignment_offset); 1307 if (!err && alignment_offset) 1308 lim->alignment_offset = 1309 lim->logical_block_size * alignment_offset; 1310 1311 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1312 struct virtio_blk_config, min_io_size, 1313 &min_io_size); 1314 if (!err && min_io_size) 1315 lim->io_min = lim->logical_block_size * min_io_size; 1316 1317 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1318 struct virtio_blk_config, opt_io_size, 1319 &opt_io_size); 1320 if (!err && opt_io_size) 1321 lim->io_opt = lim->logical_block_size * opt_io_size; 1322 1323 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1324 virtio_cread(vdev, struct virtio_blk_config, 1325 discard_sector_alignment, &discard_granularity); 1326 1327 virtio_cread(vdev, struct virtio_blk_config, 1328 max_discard_sectors, &v); 1329 lim->max_hw_discard_sectors = v ? v : UINT_MAX; 1330 1331 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1332 &max_discard_segs); 1333 } 1334 1335 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1336 virtio_cread(vdev, struct virtio_blk_config, 1337 max_write_zeroes_sectors, &v); 1338 lim->max_write_zeroes_sectors = v ? v : UINT_MAX; 1339 } 1340 1341 /* The discard and secure erase limits are combined since the Linux 1342 * block layer uses the same limit for both commands. 1343 * 1344 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1345 * are negotiated, we will use the minimum between the limits. 1346 * 1347 * discard sector alignment is set to the minimum between discard_sector_alignment 1348 * and secure_erase_sector_alignment. 1349 * 1350 * max discard sectors is set to the minimum between max_discard_seg and 1351 * max_secure_erase_seg. 1352 */ 1353 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1354 1355 virtio_cread(vdev, struct virtio_blk_config, 1356 secure_erase_sector_alignment, &v); 1357 1358 /* secure_erase_sector_alignment should not be zero, the device should set a 1359 * valid number of sectors. 1360 */ 1361 if (!v) { 1362 dev_err(&vdev->dev, 1363 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1364 return -EINVAL; 1365 } 1366 1367 discard_granularity = min_not_zero(discard_granularity, v); 1368 1369 virtio_cread(vdev, struct virtio_blk_config, 1370 max_secure_erase_sectors, &v); 1371 1372 /* max_secure_erase_sectors should not be zero, the device should set a 1373 * valid number of sectors. 1374 */ 1375 if (!v) { 1376 dev_err(&vdev->dev, 1377 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1378 return -EINVAL; 1379 } 1380 1381 lim->max_secure_erase_sectors = v; 1382 1383 virtio_cread(vdev, struct virtio_blk_config, 1384 max_secure_erase_seg, &v); 1385 1386 /* max_secure_erase_seg should not be zero, the device should set a 1387 * valid number of segments 1388 */ 1389 if (!v) { 1390 dev_err(&vdev->dev, 1391 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1392 return -EINVAL; 1393 } 1394 1395 max_discard_segs = min_not_zero(max_discard_segs, v); 1396 } 1397 1398 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1399 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1400 /* max_discard_seg and discard_granularity will be 0 only 1401 * if max_discard_seg and discard_sector_alignment fields in the virtio 1402 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1403 * In this case, we use default values. 1404 */ 1405 if (!max_discard_segs) 1406 max_discard_segs = sg_elems; 1407 1408 lim->max_discard_segments = 1409 min(max_discard_segs, MAX_DISCARD_SEGMENTS); 1410 1411 if (discard_granularity) 1412 lim->discard_granularity = 1413 discard_granularity << SECTOR_SHIFT; 1414 else 1415 lim->discard_granularity = lim->logical_block_size; 1416 } 1417 1418 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1419 u8 model; 1420 1421 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); 1422 switch (model) { 1423 case VIRTIO_BLK_Z_NONE: 1424 case VIRTIO_BLK_Z_HA: 1425 /* treat host-aware devices as non-zoned */ 1426 return 0; 1427 case VIRTIO_BLK_Z_HM: 1428 err = virtblk_read_zoned_limits(vblk, lim); 1429 if (err) 1430 return err; 1431 break; 1432 default: 1433 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 1434 return -EINVAL; 1435 } 1436 } 1437 1438 return 0; 1439 } 1440 1441 static int virtblk_probe(struct virtio_device *vdev) 1442 { 1443 struct virtio_blk *vblk; 1444 struct queue_limits lim = { 1445 .features = BLK_FEAT_ROTATIONAL, 1446 .logical_block_size = SECTOR_SIZE, 1447 }; 1448 int err, index; 1449 unsigned int queue_depth; 1450 1451 if (!vdev->config->get) { 1452 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1453 __func__); 1454 return -EINVAL; 1455 } 1456 1457 err = ida_alloc_range(&vd_index_ida, 0, 1458 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1459 if (err < 0) 1460 goto out; 1461 index = err; 1462 1463 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1464 if (!vblk) { 1465 err = -ENOMEM; 1466 goto out_free_index; 1467 } 1468 1469 mutex_init(&vblk->vdev_mutex); 1470 1471 vblk->vdev = vdev; 1472 1473 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1474 1475 err = init_vq(vblk); 1476 if (err) 1477 goto out_free_vblk; 1478 1479 /* Default queue sizing is to fill the ring. */ 1480 if (!virtblk_queue_depth) { 1481 queue_depth = vblk->vqs[0].vq->num_free; 1482 /* ... but without indirect descs, we use 2 descs per req */ 1483 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1484 queue_depth /= 2; 1485 } else { 1486 queue_depth = virtblk_queue_depth; 1487 } 1488 1489 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1490 vblk->tag_set.ops = &virtio_mq_ops; 1491 vblk->tag_set.queue_depth = queue_depth; 1492 vblk->tag_set.numa_node = NUMA_NO_NODE; 1493 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1494 vblk->tag_set.cmd_size = 1495 sizeof(struct virtblk_req) + 1496 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1497 vblk->tag_set.driver_data = vblk; 1498 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1499 vblk->tag_set.nr_maps = 1; 1500 if (vblk->io_queues[HCTX_TYPE_POLL]) 1501 vblk->tag_set.nr_maps = 3; 1502 1503 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1504 if (err) 1505 goto out_free_vq; 1506 1507 err = virtblk_read_limits(vblk, &lim); 1508 if (err) 1509 goto out_free_tags; 1510 1511 if (virtblk_get_cache_mode(vdev)) 1512 lim.features |= BLK_FEAT_WRITE_CACHE; 1513 1514 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk); 1515 if (IS_ERR(vblk->disk)) { 1516 err = PTR_ERR(vblk->disk); 1517 goto out_free_tags; 1518 } 1519 1520 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1521 1522 vblk->disk->major = major; 1523 vblk->disk->first_minor = index_to_minor(index); 1524 vblk->disk->minors = 1 << PART_BITS; 1525 vblk->disk->private_data = vblk; 1526 vblk->disk->fops = &virtblk_fops; 1527 vblk->index = index; 1528 1529 /* If disk is read-only in the host, the guest should obey */ 1530 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1531 set_disk_ro(vblk->disk, 1); 1532 1533 virtblk_update_capacity(vblk, false); 1534 virtio_device_ready(vdev); 1535 1536 /* 1537 * All steps that follow use the VQs therefore they need to be 1538 * placed after the virtio_device_ready() call above. 1539 */ 1540 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && 1541 (lim.features & BLK_FEAT_ZONED)) { 1542 err = blk_revalidate_disk_zones(vblk->disk); 1543 if (err) 1544 goto out_cleanup_disk; 1545 } 1546 1547 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1548 if (err) 1549 goto out_cleanup_disk; 1550 1551 return 0; 1552 1553 out_cleanup_disk: 1554 put_disk(vblk->disk); 1555 out_free_tags: 1556 blk_mq_free_tag_set(&vblk->tag_set); 1557 out_free_vq: 1558 vdev->config->del_vqs(vdev); 1559 kfree(vblk->vqs); 1560 out_free_vblk: 1561 kfree(vblk); 1562 out_free_index: 1563 ida_free(&vd_index_ida, index); 1564 out: 1565 return err; 1566 } 1567 1568 static void virtblk_remove(struct virtio_device *vdev) 1569 { 1570 struct virtio_blk *vblk = vdev->priv; 1571 1572 /* Make sure no work handler is accessing the device. */ 1573 flush_work(&vblk->config_work); 1574 1575 del_gendisk(vblk->disk); 1576 blk_mq_free_tag_set(&vblk->tag_set); 1577 1578 mutex_lock(&vblk->vdev_mutex); 1579 1580 /* Stop all the virtqueues. */ 1581 virtio_reset_device(vdev); 1582 1583 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1584 vblk->vdev = NULL; 1585 1586 vdev->config->del_vqs(vdev); 1587 kfree(vblk->vqs); 1588 1589 mutex_unlock(&vblk->vdev_mutex); 1590 1591 put_disk(vblk->disk); 1592 } 1593 1594 #ifdef CONFIG_PM_SLEEP 1595 static int virtblk_freeze(struct virtio_device *vdev) 1596 { 1597 struct virtio_blk *vblk = vdev->priv; 1598 1599 /* Ensure no requests in virtqueues before deleting vqs. */ 1600 blk_mq_freeze_queue(vblk->disk->queue); 1601 1602 /* Ensure we don't receive any more interrupts */ 1603 virtio_reset_device(vdev); 1604 1605 /* Make sure no work handler is accessing the device. */ 1606 flush_work(&vblk->config_work); 1607 1608 vdev->config->del_vqs(vdev); 1609 kfree(vblk->vqs); 1610 1611 return 0; 1612 } 1613 1614 static int virtblk_restore(struct virtio_device *vdev) 1615 { 1616 struct virtio_blk *vblk = vdev->priv; 1617 int ret; 1618 1619 ret = init_vq(vdev->priv); 1620 if (ret) 1621 return ret; 1622 1623 virtio_device_ready(vdev); 1624 1625 blk_mq_unfreeze_queue(vblk->disk->queue); 1626 return 0; 1627 } 1628 #endif 1629 1630 static const struct virtio_device_id id_table[] = { 1631 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1632 { 0 }, 1633 }; 1634 1635 static unsigned int features_legacy[] = { 1636 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1637 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1638 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1639 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1640 VIRTIO_BLK_F_SECURE_ERASE, 1641 } 1642 ; 1643 static unsigned int features[] = { 1644 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1645 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1646 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1647 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1648 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1649 }; 1650 1651 static struct virtio_driver virtio_blk = { 1652 .feature_table = features, 1653 .feature_table_size = ARRAY_SIZE(features), 1654 .feature_table_legacy = features_legacy, 1655 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1656 .driver.name = KBUILD_MODNAME, 1657 .id_table = id_table, 1658 .probe = virtblk_probe, 1659 .remove = virtblk_remove, 1660 .config_changed = virtblk_config_changed, 1661 #ifdef CONFIG_PM_SLEEP 1662 .freeze = virtblk_freeze, 1663 .restore = virtblk_restore, 1664 #endif 1665 }; 1666 1667 static int __init virtio_blk_init(void) 1668 { 1669 int error; 1670 1671 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1672 if (!virtblk_wq) 1673 return -ENOMEM; 1674 1675 major = register_blkdev(0, "virtblk"); 1676 if (major < 0) { 1677 error = major; 1678 goto out_destroy_workqueue; 1679 } 1680 1681 error = register_virtio_driver(&virtio_blk); 1682 if (error) 1683 goto out_unregister_blkdev; 1684 return 0; 1685 1686 out_unregister_blkdev: 1687 unregister_blkdev(major, "virtblk"); 1688 out_destroy_workqueue: 1689 destroy_workqueue(virtblk_wq); 1690 return error; 1691 } 1692 1693 static void __exit virtio_blk_fini(void) 1694 { 1695 unregister_virtio_driver(&virtio_blk); 1696 unregister_blkdev(major, "virtblk"); 1697 destroy_workqueue(virtblk_wq); 1698 } 1699 module_init(virtio_blk_init); 1700 module_exit(virtio_blk_fini); 1701 1702 MODULE_DEVICE_TABLE(virtio, id_table); 1703 MODULE_DESCRIPTION("Virtio block driver"); 1704 MODULE_LICENSE("GPL"); 1705