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 have 100 * the same offset in virtblk_req as the non-zoned 101 * status field above. 102 */ 103 struct { 104 u8 status; 105 u8 reserved[7]; 106 __le64 append_sector; 107 } zone_append_in_hdr; 108 }; 109 110 size_t in_hdr_len; 111 112 struct sg_table sg_table; 113 struct scatterlist sg[]; 114 }; 115 116 static inline blk_status_t virtblk_result(u8 status) 117 { 118 switch (status) { 119 case VIRTIO_BLK_S_OK: 120 return BLK_STS_OK; 121 case VIRTIO_BLK_S_UNSUPP: 122 return BLK_STS_NOTSUPP; 123 case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE: 124 return BLK_STS_ZONE_OPEN_RESOURCE; 125 case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE: 126 return BLK_STS_ZONE_ACTIVE_RESOURCE; 127 case VIRTIO_BLK_S_IOERR: 128 case VIRTIO_BLK_S_ZONE_UNALIGNED_WP: 129 default: 130 return BLK_STS_IOERR; 131 } 132 } 133 134 static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) 135 { 136 struct virtio_blk *vblk = hctx->queue->queuedata; 137 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 138 139 return vq; 140 } 141 142 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) 143 { 144 struct scatterlist out_hdr, in_hdr, *sgs[3]; 145 unsigned int num_out = 0, num_in = 0; 146 147 sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); 148 sgs[num_out++] = &out_hdr; 149 150 if (vbr->sg_table.nents) { 151 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) 152 sgs[num_out++] = vbr->sg_table.sgl; 153 else 154 sgs[num_out + num_in++] = vbr->sg_table.sgl; 155 } 156 157 sg_init_one(&in_hdr, &vbr->status, vbr->in_hdr_len); 158 sgs[num_out + num_in++] = &in_hdr; 159 160 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); 161 } 162 163 static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap) 164 { 165 unsigned short segments = blk_rq_nr_discard_segments(req); 166 unsigned short n = 0; 167 struct virtio_blk_discard_write_zeroes *range; 168 struct bio *bio; 169 u32 flags = 0; 170 171 if (unmap) 172 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; 173 174 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); 175 if (!range) 176 return -ENOMEM; 177 178 /* 179 * Single max discard segment means multi-range discard isn't 180 * supported, and block layer only runs contiguity merge like 181 * normal RW request. So we can't reply on bio for retrieving 182 * each range info. 183 */ 184 if (queue_max_discard_segments(req->q) == 1) { 185 range[0].flags = cpu_to_le32(flags); 186 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); 187 range[0].sector = cpu_to_le64(blk_rq_pos(req)); 188 n = 1; 189 } else { 190 __rq_for_each_bio(bio, req) { 191 u64 sector = bio->bi_iter.bi_sector; 192 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; 193 194 range[n].flags = cpu_to_le32(flags); 195 range[n].num_sectors = cpu_to_le32(num_sectors); 196 range[n].sector = cpu_to_le64(sector); 197 n++; 198 } 199 } 200 201 WARN_ON_ONCE(n != segments); 202 203 req->special_vec.bv_page = virt_to_page(range); 204 req->special_vec.bv_offset = offset_in_page(range); 205 req->special_vec.bv_len = sizeof(*range) * segments; 206 req->rq_flags |= RQF_SPECIAL_PAYLOAD; 207 208 return 0; 209 } 210 211 static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr) 212 { 213 if (blk_rq_nr_phys_segments(req)) 214 sg_free_table_chained(&vbr->sg_table, 215 VIRTIO_BLK_INLINE_SG_CNT); 216 } 217 218 static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req, 219 struct virtblk_req *vbr) 220 { 221 int err; 222 223 if (!blk_rq_nr_phys_segments(req)) 224 return 0; 225 226 vbr->sg_table.sgl = vbr->sg; 227 err = sg_alloc_table_chained(&vbr->sg_table, 228 blk_rq_nr_phys_segments(req), 229 vbr->sg_table.sgl, 230 VIRTIO_BLK_INLINE_SG_CNT); 231 if (unlikely(err)) 232 return -ENOMEM; 233 234 return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl); 235 } 236 237 static void virtblk_cleanup_cmd(struct request *req) 238 { 239 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) 240 kfree(bvec_virt(&req->special_vec)); 241 } 242 243 static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, 244 struct request *req, 245 struct virtblk_req *vbr) 246 { 247 size_t in_hdr_len = sizeof(vbr->status); 248 bool unmap = false; 249 u32 type; 250 u64 sector = 0; 251 252 /* Set fields for all request types */ 253 vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); 254 255 switch (req_op(req)) { 256 case REQ_OP_READ: 257 type = VIRTIO_BLK_T_IN; 258 sector = blk_rq_pos(req); 259 break; 260 case REQ_OP_WRITE: 261 type = VIRTIO_BLK_T_OUT; 262 sector = blk_rq_pos(req); 263 break; 264 case REQ_OP_FLUSH: 265 type = VIRTIO_BLK_T_FLUSH; 266 break; 267 case REQ_OP_DISCARD: 268 type = VIRTIO_BLK_T_DISCARD; 269 break; 270 case REQ_OP_WRITE_ZEROES: 271 type = VIRTIO_BLK_T_WRITE_ZEROES; 272 unmap = !(req->cmd_flags & REQ_NOUNMAP); 273 break; 274 case REQ_OP_SECURE_ERASE: 275 type = VIRTIO_BLK_T_SECURE_ERASE; 276 break; 277 case REQ_OP_ZONE_OPEN: 278 type = VIRTIO_BLK_T_ZONE_OPEN; 279 sector = blk_rq_pos(req); 280 break; 281 case REQ_OP_ZONE_CLOSE: 282 type = VIRTIO_BLK_T_ZONE_CLOSE; 283 sector = blk_rq_pos(req); 284 break; 285 case REQ_OP_ZONE_FINISH: 286 type = VIRTIO_BLK_T_ZONE_FINISH; 287 sector = blk_rq_pos(req); 288 break; 289 case REQ_OP_ZONE_APPEND: 290 type = VIRTIO_BLK_T_ZONE_APPEND; 291 sector = blk_rq_pos(req); 292 in_hdr_len = sizeof(vbr->zone_append_in_hdr); 293 break; 294 case REQ_OP_ZONE_RESET: 295 type = VIRTIO_BLK_T_ZONE_RESET; 296 sector = blk_rq_pos(req); 297 break; 298 case REQ_OP_ZONE_RESET_ALL: 299 type = VIRTIO_BLK_T_ZONE_RESET_ALL; 300 break; 301 case REQ_OP_DRV_IN: 302 /* Out header already filled in, nothing to do */ 303 return 0; 304 default: 305 WARN_ON_ONCE(1); 306 return BLK_STS_IOERR; 307 } 308 309 /* Set fields for non-REQ_OP_DRV_IN request types */ 310 vbr->in_hdr_len = in_hdr_len; 311 vbr->out_hdr.type = cpu_to_virtio32(vdev, type); 312 vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector); 313 314 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES || 315 type == VIRTIO_BLK_T_SECURE_ERASE) { 316 if (virtblk_setup_discard_write_zeroes_erase(req, unmap)) 317 return BLK_STS_RESOURCE; 318 } 319 320 return 0; 321 } 322 323 static inline void virtblk_request_done(struct request *req) 324 { 325 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 326 blk_status_t status = virtblk_result(vbr->status); 327 328 virtblk_unmap_data(req, vbr); 329 virtblk_cleanup_cmd(req); 330 331 if (req_op(req) == REQ_OP_ZONE_APPEND) 332 req->__sector = le64_to_cpu(vbr->zone_append_in_hdr.append_sector); 333 334 blk_mq_end_request(req, status); 335 } 336 337 static void virtblk_done(struct virtqueue *vq) 338 { 339 struct virtio_blk *vblk = vq->vdev->priv; 340 bool req_done = false; 341 int qid = vq->index; 342 struct virtblk_req *vbr; 343 unsigned long flags; 344 unsigned int len; 345 346 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 347 do { 348 virtqueue_disable_cb(vq); 349 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { 350 struct request *req = blk_mq_rq_from_pdu(vbr); 351 352 if (likely(!blk_should_fake_timeout(req->q))) 353 blk_mq_complete_request(req); 354 req_done = true; 355 } 356 if (unlikely(virtqueue_is_broken(vq))) 357 break; 358 } while (!virtqueue_enable_cb(vq)); 359 360 /* In case queue is stopped waiting for more buffers. */ 361 if (req_done) 362 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 363 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 364 } 365 366 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) 367 { 368 struct virtio_blk *vblk = hctx->queue->queuedata; 369 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 370 bool kick; 371 372 spin_lock_irq(&vq->lock); 373 kick = virtqueue_kick_prepare(vq->vq); 374 spin_unlock_irq(&vq->lock); 375 376 if (kick) 377 virtqueue_notify(vq->vq); 378 } 379 380 static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) 381 { 382 virtblk_cleanup_cmd(req); 383 switch (rc) { 384 case -ENOSPC: 385 return BLK_STS_DEV_RESOURCE; 386 case -ENOMEM: 387 return BLK_STS_RESOURCE; 388 default: 389 return BLK_STS_IOERR; 390 } 391 } 392 393 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, 394 struct virtio_blk *vblk, 395 struct request *req, 396 struct virtblk_req *vbr) 397 { 398 blk_status_t status; 399 int num; 400 401 status = virtblk_setup_cmd(vblk->vdev, req, vbr); 402 if (unlikely(status)) 403 return status; 404 405 num = virtblk_map_data(hctx, req, vbr); 406 if (unlikely(num < 0)) 407 return virtblk_fail_to_queue(req, -ENOMEM); 408 vbr->sg_table.nents = num; 409 410 blk_mq_start_request(req); 411 412 return BLK_STS_OK; 413 } 414 415 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, 416 const struct blk_mq_queue_data *bd) 417 { 418 struct virtio_blk *vblk = hctx->queue->queuedata; 419 struct request *req = bd->rq; 420 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 421 unsigned long flags; 422 int qid = hctx->queue_num; 423 bool notify = false; 424 blk_status_t status; 425 int err; 426 427 status = virtblk_prep_rq(hctx, vblk, req, vbr); 428 if (unlikely(status)) 429 return status; 430 431 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 432 err = virtblk_add_req(vblk->vqs[qid].vq, vbr); 433 if (err) { 434 virtqueue_kick(vblk->vqs[qid].vq); 435 /* Don't stop the queue if -ENOMEM: we may have failed to 436 * bounce the buffer due to global resource outage. 437 */ 438 if (err == -ENOSPC) 439 blk_mq_stop_hw_queue(hctx); 440 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 441 virtblk_unmap_data(req, vbr); 442 return virtblk_fail_to_queue(req, err); 443 } 444 445 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) 446 notify = true; 447 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 448 449 if (notify) 450 virtqueue_notify(vblk->vqs[qid].vq); 451 return BLK_STS_OK; 452 } 453 454 static bool virtblk_prep_rq_batch(struct request *req) 455 { 456 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 457 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 458 459 req->mq_hctx->tags->rqs[req->tag] = req; 460 461 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 462 } 463 464 static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, 465 struct request **rqlist) 466 { 467 unsigned long flags; 468 int err; 469 bool kick; 470 471 spin_lock_irqsave(&vq->lock, flags); 472 473 while (!rq_list_empty(*rqlist)) { 474 struct request *req = rq_list_pop(rqlist); 475 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 476 477 err = virtblk_add_req(vq->vq, vbr); 478 if (err) { 479 virtblk_unmap_data(req, vbr); 480 virtblk_cleanup_cmd(req); 481 blk_mq_requeue_request(req, true); 482 } 483 } 484 485 kick = virtqueue_kick_prepare(vq->vq); 486 spin_unlock_irqrestore(&vq->lock, flags); 487 488 return kick; 489 } 490 491 static void virtio_queue_rqs(struct request **rqlist) 492 { 493 struct request *req, *next, *prev = NULL; 494 struct request *requeue_list = NULL; 495 496 rq_list_for_each_safe(rqlist, req, next) { 497 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); 498 bool kick; 499 500 if (!virtblk_prep_rq_batch(req)) { 501 rq_list_move(rqlist, &requeue_list, req, prev); 502 req = prev; 503 if (!req) 504 continue; 505 } 506 507 if (!next || req->mq_hctx != next->mq_hctx) { 508 req->rq_next = NULL; 509 kick = virtblk_add_req_batch(vq, rqlist); 510 if (kick) 511 virtqueue_notify(vq->vq); 512 513 *rqlist = next; 514 prev = NULL; 515 } else 516 prev = req; 517 } 518 519 *rqlist = requeue_list; 520 } 521 522 #ifdef CONFIG_BLK_DEV_ZONED 523 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 524 unsigned int nr_zones, 525 unsigned int zone_sectors, 526 size_t *buflen) 527 { 528 struct request_queue *q = vblk->disk->queue; 529 size_t bufsize; 530 void *buf; 531 532 nr_zones = min_t(unsigned int, nr_zones, 533 get_capacity(vblk->disk) >> ilog2(zone_sectors)); 534 535 bufsize = sizeof(struct virtio_blk_zone_report) + 536 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 537 bufsize = min_t(size_t, bufsize, 538 queue_max_hw_sectors(q) << SECTOR_SHIFT); 539 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 540 541 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 542 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 543 if (buf) { 544 *buflen = bufsize; 545 return buf; 546 } 547 bufsize >>= 1; 548 } 549 550 return NULL; 551 } 552 553 static int virtblk_submit_zone_report(struct virtio_blk *vblk, 554 char *report_buf, size_t report_len, 555 sector_t sector) 556 { 557 struct request_queue *q = vblk->disk->queue; 558 struct request *req; 559 struct virtblk_req *vbr; 560 int err; 561 562 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 563 if (IS_ERR(req)) 564 return PTR_ERR(req); 565 566 vbr = blk_mq_rq_to_pdu(req); 567 vbr->in_hdr_len = sizeof(vbr->status); 568 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 569 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 570 571 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); 572 if (err) 573 goto out; 574 575 blk_execute_rq(req, false); 576 err = blk_status_to_errno(virtblk_result(vbr->status)); 577 out: 578 blk_mq_free_request(req); 579 return err; 580 } 581 582 static int virtblk_parse_zone(struct virtio_blk *vblk, 583 struct virtio_blk_zone_descriptor *entry, 584 unsigned int idx, unsigned int zone_sectors, 585 report_zones_cb cb, void *data) 586 { 587 struct blk_zone zone = { }; 588 589 if (entry->z_type != VIRTIO_BLK_ZT_SWR && 590 entry->z_type != VIRTIO_BLK_ZT_SWP && 591 entry->z_type != VIRTIO_BLK_ZT_CONV) { 592 dev_err(&vblk->vdev->dev, "invalid zone type %#x\n", 593 entry->z_type); 594 return -EINVAL; 595 } 596 597 zone.type = entry->z_type; 598 zone.cond = entry->z_state; 599 zone.len = zone_sectors; 600 zone.capacity = le64_to_cpu(entry->z_cap); 601 zone.start = le64_to_cpu(entry->z_start); 602 if (zone.cond == BLK_ZONE_COND_FULL) 603 zone.wp = zone.start + zone.len; 604 else 605 zone.wp = le64_to_cpu(entry->z_wp); 606 607 return cb(&zone, idx, data); 608 } 609 610 static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 611 unsigned int nr_zones, report_zones_cb cb, 612 void *data) 613 { 614 struct virtio_blk *vblk = disk->private_data; 615 struct virtio_blk_zone_report *report; 616 unsigned int zone_sectors = vblk->zone_sectors; 617 unsigned int nz, i; 618 int ret, zone_idx = 0; 619 size_t buflen; 620 621 if (WARN_ON_ONCE(!vblk->zone_sectors)) 622 return -EOPNOTSUPP; 623 624 report = virtblk_alloc_report_buffer(vblk, nr_zones, 625 zone_sectors, &buflen); 626 if (!report) 627 return -ENOMEM; 628 629 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { 630 memset(report, 0, buflen); 631 632 ret = virtblk_submit_zone_report(vblk, (char *)report, 633 buflen, sector); 634 if (ret) { 635 if (ret > 0) 636 ret = -EIO; 637 goto out_free; 638 } 639 nz = min((unsigned int)le64_to_cpu(report->nr_zones), nr_zones); 640 if (!nz) 641 break; 642 643 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 644 ret = virtblk_parse_zone(vblk, &report->zones[i], 645 zone_idx, zone_sectors, cb, data); 646 if (ret) 647 goto out_free; 648 sector = le64_to_cpu(report->zones[i].z_start) + zone_sectors; 649 zone_idx++; 650 } 651 } 652 653 if (zone_idx > 0) 654 ret = zone_idx; 655 else 656 ret = -EINVAL; 657 out_free: 658 kvfree(report); 659 return ret; 660 } 661 662 static void virtblk_revalidate_zones(struct virtio_blk *vblk) 663 { 664 u8 model; 665 666 if (!vblk->zone_sectors) 667 return; 668 669 virtio_cread(vblk->vdev, struct virtio_blk_config, 670 zoned.model, &model); 671 if (!blk_revalidate_disk_zones(vblk->disk, NULL)) 672 set_capacity_and_notify(vblk->disk, 0); 673 } 674 675 static int virtblk_probe_zoned_device(struct virtio_device *vdev, 676 struct virtio_blk *vblk, 677 struct request_queue *q) 678 { 679 u32 v; 680 u8 model; 681 int ret; 682 683 virtio_cread(vdev, struct virtio_blk_config, 684 zoned.model, &model); 685 686 switch (model) { 687 case VIRTIO_BLK_Z_NONE: 688 return 0; 689 case VIRTIO_BLK_Z_HM: 690 break; 691 case VIRTIO_BLK_Z_HA: 692 /* 693 * Present the host-aware device as a regular drive. 694 * TODO It is possible to add an option to make it appear 695 * in the system as a zoned drive. 696 */ 697 return 0; 698 default: 699 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 700 return -EINVAL; 701 } 702 703 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 704 705 disk_set_zoned(vblk->disk, BLK_ZONED_HM); 706 blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); 707 708 virtio_cread(vdev, struct virtio_blk_config, 709 zoned.max_open_zones, &v); 710 disk_set_max_open_zones(vblk->disk, le32_to_cpu(v)); 711 712 dev_dbg(&vdev->dev, "max open zones = %u\n", le32_to_cpu(v)); 713 714 virtio_cread(vdev, struct virtio_blk_config, 715 zoned.max_active_zones, &v); 716 disk_set_max_active_zones(vblk->disk, le32_to_cpu(v)); 717 dev_dbg(&vdev->dev, "max active zones = %u\n", le32_to_cpu(v)); 718 719 virtio_cread(vdev, struct virtio_blk_config, 720 zoned.write_granularity, &v); 721 if (!v) { 722 dev_warn(&vdev->dev, "zero write granularity reported\n"); 723 return -ENODEV; 724 } 725 blk_queue_physical_block_size(q, le32_to_cpu(v)); 726 blk_queue_io_min(q, le32_to_cpu(v)); 727 728 dev_dbg(&vdev->dev, "write granularity = %u\n", le32_to_cpu(v)); 729 730 /* 731 * virtio ZBD specification doesn't require zones to be a power of 732 * two sectors in size, but the code in this driver expects that. 733 */ 734 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, &v); 735 vblk->zone_sectors = le32_to_cpu(v); 736 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 737 dev_err(&vdev->dev, 738 "zoned device with non power of two zone size %u\n", 739 vblk->zone_sectors); 740 return -ENODEV; 741 } 742 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 743 744 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 745 dev_warn(&vblk->vdev->dev, 746 "ignoring negotiated F_DISCARD for zoned device\n"); 747 blk_queue_max_discard_sectors(q, 0); 748 } 749 750 ret = blk_revalidate_disk_zones(vblk->disk, NULL); 751 if (!ret) { 752 virtio_cread(vdev, struct virtio_blk_config, 753 zoned.max_append_sectors, &v); 754 if (!v) { 755 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 756 return -ENODEV; 757 } 758 blk_queue_max_zone_append_sectors(q, le32_to_cpu(v)); 759 dev_dbg(&vdev->dev, "max append sectors = %u\n", le32_to_cpu(v)); 760 } 761 762 return ret; 763 } 764 765 static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev) 766 { 767 return virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED); 768 } 769 #else 770 771 /* 772 * Zoned block device support is not configured in this kernel. 773 * We only need to define a few symbols to avoid compilation errors. 774 */ 775 #define virtblk_report_zones NULL 776 static inline void virtblk_revalidate_zones(struct virtio_blk *vblk) 777 { 778 } 779 static inline int virtblk_probe_zoned_device(struct virtio_device *vdev, 780 struct virtio_blk *vblk, struct request_queue *q) 781 { 782 return -EOPNOTSUPP; 783 } 784 785 static inline bool virtblk_has_zoned_feature(struct virtio_device *vdev) 786 { 787 return false; 788 } 789 #endif /* CONFIG_BLK_DEV_ZONED */ 790 791 /* return id (s/n) string for *disk to *id_str 792 */ 793 static int virtblk_get_id(struct gendisk *disk, char *id_str) 794 { 795 struct virtio_blk *vblk = disk->private_data; 796 struct request_queue *q = vblk->disk->queue; 797 struct request *req; 798 struct virtblk_req *vbr; 799 int err; 800 801 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 802 if (IS_ERR(req)) 803 return PTR_ERR(req); 804 805 vbr = blk_mq_rq_to_pdu(req); 806 vbr->in_hdr_len = sizeof(vbr->status); 807 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 808 vbr->out_hdr.sector = 0; 809 810 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 811 if (err) 812 goto out; 813 814 blk_execute_rq(req, false); 815 err = blk_status_to_errno(virtblk_result(vbr->status)); 816 out: 817 blk_mq_free_request(req); 818 return err; 819 } 820 821 /* We provide getgeo only to please some old bootloader/partitioning tools */ 822 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 823 { 824 struct virtio_blk *vblk = bd->bd_disk->private_data; 825 int ret = 0; 826 827 mutex_lock(&vblk->vdev_mutex); 828 829 if (!vblk->vdev) { 830 ret = -ENXIO; 831 goto out; 832 } 833 834 /* see if the host passed in geometry config */ 835 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 836 virtio_cread(vblk->vdev, struct virtio_blk_config, 837 geometry.cylinders, &geo->cylinders); 838 virtio_cread(vblk->vdev, struct virtio_blk_config, 839 geometry.heads, &geo->heads); 840 virtio_cread(vblk->vdev, struct virtio_blk_config, 841 geometry.sectors, &geo->sectors); 842 } else { 843 /* some standard values, similar to sd */ 844 geo->heads = 1 << 6; 845 geo->sectors = 1 << 5; 846 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 847 } 848 out: 849 mutex_unlock(&vblk->vdev_mutex); 850 return ret; 851 } 852 853 static void virtblk_free_disk(struct gendisk *disk) 854 { 855 struct virtio_blk *vblk = disk->private_data; 856 857 ida_free(&vd_index_ida, vblk->index); 858 mutex_destroy(&vblk->vdev_mutex); 859 kfree(vblk); 860 } 861 862 static const struct block_device_operations virtblk_fops = { 863 .owner = THIS_MODULE, 864 .getgeo = virtblk_getgeo, 865 .free_disk = virtblk_free_disk, 866 .report_zones = virtblk_report_zones, 867 }; 868 869 static int index_to_minor(int index) 870 { 871 return index << PART_BITS; 872 } 873 874 static int minor_to_index(int minor) 875 { 876 return minor >> PART_BITS; 877 } 878 879 static ssize_t serial_show(struct device *dev, 880 struct device_attribute *attr, char *buf) 881 { 882 struct gendisk *disk = dev_to_disk(dev); 883 int err; 884 885 /* sysfs gives us a PAGE_SIZE buffer */ 886 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 887 888 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 889 err = virtblk_get_id(disk, buf); 890 if (!err) 891 return strlen(buf); 892 893 if (err == -EIO) /* Unsupported? Make it empty. */ 894 return 0; 895 896 return err; 897 } 898 899 static DEVICE_ATTR_RO(serial); 900 901 /* The queue's logical block size must be set before calling this */ 902 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 903 { 904 struct virtio_device *vdev = vblk->vdev; 905 struct request_queue *q = vblk->disk->queue; 906 char cap_str_2[10], cap_str_10[10]; 907 unsigned long long nblocks; 908 u64 capacity; 909 910 /* Host must always specify the capacity. */ 911 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 912 913 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 914 915 string_get_size(nblocks, queue_logical_block_size(q), 916 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 917 string_get_size(nblocks, queue_logical_block_size(q), 918 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 919 920 dev_notice(&vdev->dev, 921 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 922 vblk->disk->disk_name, 923 resize ? "new size: " : "", 924 nblocks, 925 queue_logical_block_size(q), 926 cap_str_10, 927 cap_str_2); 928 929 set_capacity_and_notify(vblk->disk, capacity); 930 } 931 932 static void virtblk_config_changed_work(struct work_struct *work) 933 { 934 struct virtio_blk *vblk = 935 container_of(work, struct virtio_blk, config_work); 936 937 virtblk_revalidate_zones(vblk); 938 virtblk_update_capacity(vblk, true); 939 } 940 941 static void virtblk_config_changed(struct virtio_device *vdev) 942 { 943 struct virtio_blk *vblk = vdev->priv; 944 945 queue_work(virtblk_wq, &vblk->config_work); 946 } 947 948 static int init_vq(struct virtio_blk *vblk) 949 { 950 int err; 951 int i; 952 vq_callback_t **callbacks; 953 const char **names; 954 struct virtqueue **vqs; 955 unsigned short num_vqs; 956 unsigned int num_poll_vqs; 957 struct virtio_device *vdev = vblk->vdev; 958 struct irq_affinity desc = { 0, }; 959 960 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 961 struct virtio_blk_config, num_queues, 962 &num_vqs); 963 if (err) 964 num_vqs = 1; 965 966 if (!err && !num_vqs) { 967 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 968 return -EINVAL; 969 } 970 971 num_vqs = min_t(unsigned int, 972 min_not_zero(num_request_queues, nr_cpu_ids), 973 num_vqs); 974 975 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 976 977 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 978 vblk->io_queues[HCTX_TYPE_READ] = 0; 979 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 980 981 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 982 vblk->io_queues[HCTX_TYPE_DEFAULT], 983 vblk->io_queues[HCTX_TYPE_READ], 984 vblk->io_queues[HCTX_TYPE_POLL]); 985 986 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 987 if (!vblk->vqs) 988 return -ENOMEM; 989 990 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); 991 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); 992 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 993 if (!names || !callbacks || !vqs) { 994 err = -ENOMEM; 995 goto out; 996 } 997 998 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 999 callbacks[i] = virtblk_done; 1000 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); 1001 names[i] = vblk->vqs[i].name; 1002 } 1003 1004 for (; i < num_vqs; i++) { 1005 callbacks[i] = NULL; 1006 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%d", i); 1007 names[i] = vblk->vqs[i].name; 1008 } 1009 1010 /* Discover virtqueues and write information to configuration. */ 1011 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 1012 if (err) 1013 goto out; 1014 1015 for (i = 0; i < num_vqs; i++) { 1016 spin_lock_init(&vblk->vqs[i].lock); 1017 vblk->vqs[i].vq = vqs[i]; 1018 } 1019 vblk->num_vqs = num_vqs; 1020 1021 out: 1022 kfree(vqs); 1023 kfree(callbacks); 1024 kfree(names); 1025 if (err) 1026 kfree(vblk->vqs); 1027 return err; 1028 } 1029 1030 /* 1031 * Legacy naming scheme used for virtio devices. We are stuck with it for 1032 * virtio blk but don't ever use it for any new driver. 1033 */ 1034 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1035 { 1036 const int base = 'z' - 'a' + 1; 1037 char *begin = buf + strlen(prefix); 1038 char *end = buf + buflen; 1039 char *p; 1040 int unit; 1041 1042 p = end - 1; 1043 *p = '\0'; 1044 unit = base; 1045 do { 1046 if (p == begin) 1047 return -EINVAL; 1048 *--p = 'a' + (index % unit); 1049 index = (index / unit) - 1; 1050 } while (index >= 0); 1051 1052 memmove(begin, p, end - p); 1053 memcpy(buf, prefix, strlen(prefix)); 1054 1055 return 0; 1056 } 1057 1058 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1059 { 1060 u8 writeback; 1061 int err; 1062 1063 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1064 struct virtio_blk_config, wce, 1065 &writeback); 1066 1067 /* 1068 * If WCE is not configurable and flush is not available, 1069 * assume no writeback cache is in use. 1070 */ 1071 if (err) 1072 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1073 1074 return writeback; 1075 } 1076 1077 static void virtblk_update_cache_mode(struct virtio_device *vdev) 1078 { 1079 u8 writeback = virtblk_get_cache_mode(vdev); 1080 struct virtio_blk *vblk = vdev->priv; 1081 1082 blk_queue_write_cache(vblk->disk->queue, writeback, false); 1083 } 1084 1085 static const char *const virtblk_cache_types[] = { 1086 "write through", "write back" 1087 }; 1088 1089 static ssize_t 1090 cache_type_store(struct device *dev, struct device_attribute *attr, 1091 const char *buf, size_t count) 1092 { 1093 struct gendisk *disk = dev_to_disk(dev); 1094 struct virtio_blk *vblk = disk->private_data; 1095 struct virtio_device *vdev = vblk->vdev; 1096 int i; 1097 1098 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1099 i = sysfs_match_string(virtblk_cache_types, buf); 1100 if (i < 0) 1101 return i; 1102 1103 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1104 virtblk_update_cache_mode(vdev); 1105 return count; 1106 } 1107 1108 static ssize_t 1109 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1110 { 1111 struct gendisk *disk = dev_to_disk(dev); 1112 struct virtio_blk *vblk = disk->private_data; 1113 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1114 1115 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1116 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1117 } 1118 1119 static DEVICE_ATTR_RW(cache_type); 1120 1121 static struct attribute *virtblk_attrs[] = { 1122 &dev_attr_serial.attr, 1123 &dev_attr_cache_type.attr, 1124 NULL, 1125 }; 1126 1127 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1128 struct attribute *a, int n) 1129 { 1130 struct device *dev = kobj_to_dev(kobj); 1131 struct gendisk *disk = dev_to_disk(dev); 1132 struct virtio_blk *vblk = disk->private_data; 1133 struct virtio_device *vdev = vblk->vdev; 1134 1135 if (a == &dev_attr_cache_type.attr && 1136 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1137 return S_IRUGO; 1138 1139 return a->mode; 1140 } 1141 1142 static const struct attribute_group virtblk_attr_group = { 1143 .attrs = virtblk_attrs, 1144 .is_visible = virtblk_attrs_are_visible, 1145 }; 1146 1147 static const struct attribute_group *virtblk_attr_groups[] = { 1148 &virtblk_attr_group, 1149 NULL, 1150 }; 1151 1152 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1153 { 1154 struct virtio_blk *vblk = set->driver_data; 1155 int i, qoff; 1156 1157 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1158 struct blk_mq_queue_map *map = &set->map[i]; 1159 1160 map->nr_queues = vblk->io_queues[i]; 1161 map->queue_offset = qoff; 1162 qoff += map->nr_queues; 1163 1164 if (map->nr_queues == 0) 1165 continue; 1166 1167 /* 1168 * Regular queues have interrupts and hence CPU affinity is 1169 * defined by the core virtio code, but polling queues have 1170 * no interrupts so we let the block layer assign CPU affinity. 1171 */ 1172 if (i == HCTX_TYPE_POLL) 1173 blk_mq_map_queues(&set->map[i]); 1174 else 1175 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1176 } 1177 } 1178 1179 static void virtblk_complete_batch(struct io_comp_batch *iob) 1180 { 1181 struct request *req; 1182 1183 rq_list_for_each(&iob->req_list, req) { 1184 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1185 virtblk_cleanup_cmd(req); 1186 } 1187 blk_mq_end_request_batch(iob); 1188 } 1189 1190 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1191 { 1192 struct virtio_blk *vblk = hctx->queue->queuedata; 1193 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1194 struct virtblk_req *vbr; 1195 unsigned long flags; 1196 unsigned int len; 1197 int found = 0; 1198 1199 spin_lock_irqsave(&vq->lock, flags); 1200 1201 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1202 struct request *req = blk_mq_rq_from_pdu(vbr); 1203 1204 found++; 1205 if (!blk_mq_add_to_batch(req, iob, vbr->status, 1206 virtblk_complete_batch)) 1207 blk_mq_complete_request(req); 1208 } 1209 1210 if (found) 1211 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1212 1213 spin_unlock_irqrestore(&vq->lock, flags); 1214 1215 return found; 1216 } 1217 1218 static const struct blk_mq_ops virtio_mq_ops = { 1219 .queue_rq = virtio_queue_rq, 1220 .queue_rqs = virtio_queue_rqs, 1221 .commit_rqs = virtio_commit_rqs, 1222 .complete = virtblk_request_done, 1223 .map_queues = virtblk_map_queues, 1224 .poll = virtblk_poll, 1225 }; 1226 1227 static unsigned int virtblk_queue_depth; 1228 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1229 1230 static int virtblk_probe(struct virtio_device *vdev) 1231 { 1232 struct virtio_blk *vblk; 1233 struct request_queue *q; 1234 int err, index; 1235 1236 u32 v, blk_size, max_size, sg_elems, opt_io_size; 1237 u32 max_discard_segs = 0; 1238 u32 discard_granularity = 0; 1239 u16 min_io_size; 1240 u8 physical_block_exp, alignment_offset; 1241 unsigned int queue_depth; 1242 1243 if (!vdev->config->get) { 1244 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1245 __func__); 1246 return -EINVAL; 1247 } 1248 1249 err = ida_alloc_range(&vd_index_ida, 0, 1250 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1251 if (err < 0) 1252 goto out; 1253 index = err; 1254 1255 /* We need to know how many segments before we allocate. */ 1256 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1257 struct virtio_blk_config, seg_max, 1258 &sg_elems); 1259 1260 /* We need at least one SG element, whatever they say. */ 1261 if (err || !sg_elems) 1262 sg_elems = 1; 1263 1264 /* Prevent integer overflows and honor max vq size */ 1265 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1266 1267 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1268 if (!vblk) { 1269 err = -ENOMEM; 1270 goto out_free_index; 1271 } 1272 1273 mutex_init(&vblk->vdev_mutex); 1274 1275 vblk->vdev = vdev; 1276 1277 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1278 1279 err = init_vq(vblk); 1280 if (err) 1281 goto out_free_vblk; 1282 1283 /* Default queue sizing is to fill the ring. */ 1284 if (!virtblk_queue_depth) { 1285 queue_depth = vblk->vqs[0].vq->num_free; 1286 /* ... but without indirect descs, we use 2 descs per req */ 1287 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1288 queue_depth /= 2; 1289 } else { 1290 queue_depth = virtblk_queue_depth; 1291 } 1292 1293 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1294 vblk->tag_set.ops = &virtio_mq_ops; 1295 vblk->tag_set.queue_depth = queue_depth; 1296 vblk->tag_set.numa_node = NUMA_NO_NODE; 1297 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1298 vblk->tag_set.cmd_size = 1299 sizeof(struct virtblk_req) + 1300 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1301 vblk->tag_set.driver_data = vblk; 1302 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1303 vblk->tag_set.nr_maps = 1; 1304 if (vblk->io_queues[HCTX_TYPE_POLL]) 1305 vblk->tag_set.nr_maps = 3; 1306 1307 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1308 if (err) 1309 goto out_free_vq; 1310 1311 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); 1312 if (IS_ERR(vblk->disk)) { 1313 err = PTR_ERR(vblk->disk); 1314 goto out_free_tags; 1315 } 1316 q = vblk->disk->queue; 1317 1318 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1319 1320 vblk->disk->major = major; 1321 vblk->disk->first_minor = index_to_minor(index); 1322 vblk->disk->minors = 1 << PART_BITS; 1323 vblk->disk->private_data = vblk; 1324 vblk->disk->fops = &virtblk_fops; 1325 vblk->index = index; 1326 1327 /* configure queue flush support */ 1328 virtblk_update_cache_mode(vdev); 1329 1330 /* If disk is read-only in the host, the guest should obey */ 1331 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1332 set_disk_ro(vblk->disk, 1); 1333 1334 /* We can handle whatever the host told us to handle. */ 1335 blk_queue_max_segments(q, sg_elems); 1336 1337 /* No real sector limit. */ 1338 blk_queue_max_hw_sectors(q, UINT_MAX); 1339 1340 max_size = virtio_max_dma_size(vdev); 1341 1342 /* Host can optionally specify maximum segment size and number of 1343 * segments. */ 1344 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1345 struct virtio_blk_config, size_max, &v); 1346 if (!err) 1347 max_size = min(max_size, v); 1348 1349 blk_queue_max_segment_size(q, max_size); 1350 1351 /* Host can optionally specify the block size of the device */ 1352 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1353 struct virtio_blk_config, blk_size, 1354 &blk_size); 1355 if (!err) { 1356 err = blk_validate_block_size(blk_size); 1357 if (err) { 1358 dev_err(&vdev->dev, 1359 "virtio_blk: invalid block size: 0x%x\n", 1360 blk_size); 1361 goto out_cleanup_disk; 1362 } 1363 1364 blk_queue_logical_block_size(q, blk_size); 1365 } else 1366 blk_size = queue_logical_block_size(q); 1367 1368 /* Use topology information if available */ 1369 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1370 struct virtio_blk_config, physical_block_exp, 1371 &physical_block_exp); 1372 if (!err && physical_block_exp) 1373 blk_queue_physical_block_size(q, 1374 blk_size * (1 << physical_block_exp)); 1375 1376 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1377 struct virtio_blk_config, alignment_offset, 1378 &alignment_offset); 1379 if (!err && alignment_offset) 1380 blk_queue_alignment_offset(q, blk_size * alignment_offset); 1381 1382 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1383 struct virtio_blk_config, min_io_size, 1384 &min_io_size); 1385 if (!err && min_io_size) 1386 blk_queue_io_min(q, blk_size * min_io_size); 1387 1388 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1389 struct virtio_blk_config, opt_io_size, 1390 &opt_io_size); 1391 if (!err && opt_io_size) 1392 blk_queue_io_opt(q, blk_size * opt_io_size); 1393 1394 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1395 virtio_cread(vdev, struct virtio_blk_config, 1396 discard_sector_alignment, &discard_granularity); 1397 1398 virtio_cread(vdev, struct virtio_blk_config, 1399 max_discard_sectors, &v); 1400 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); 1401 1402 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1403 &max_discard_segs); 1404 } 1405 1406 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1407 virtio_cread(vdev, struct virtio_blk_config, 1408 max_write_zeroes_sectors, &v); 1409 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); 1410 } 1411 1412 /* The discard and secure erase limits are combined since the Linux 1413 * block layer uses the same limit for both commands. 1414 * 1415 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1416 * are negotiated, we will use the minimum between the limits. 1417 * 1418 * discard sector alignment is set to the minimum between discard_sector_alignment 1419 * and secure_erase_sector_alignment. 1420 * 1421 * max discard sectors is set to the minimum between max_discard_seg and 1422 * max_secure_erase_seg. 1423 */ 1424 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1425 1426 virtio_cread(vdev, struct virtio_blk_config, 1427 secure_erase_sector_alignment, &v); 1428 1429 /* secure_erase_sector_alignment should not be zero, the device should set a 1430 * valid number of sectors. 1431 */ 1432 if (!v) { 1433 dev_err(&vdev->dev, 1434 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1435 err = -EINVAL; 1436 goto out_cleanup_disk; 1437 } 1438 1439 discard_granularity = min_not_zero(discard_granularity, v); 1440 1441 virtio_cread(vdev, struct virtio_blk_config, 1442 max_secure_erase_sectors, &v); 1443 1444 /* max_secure_erase_sectors should not be zero, the device should set a 1445 * valid number of sectors. 1446 */ 1447 if (!v) { 1448 dev_err(&vdev->dev, 1449 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1450 err = -EINVAL; 1451 goto out_cleanup_disk; 1452 } 1453 1454 blk_queue_max_secure_erase_sectors(q, v); 1455 1456 virtio_cread(vdev, struct virtio_blk_config, 1457 max_secure_erase_seg, &v); 1458 1459 /* max_secure_erase_seg should not be zero, the device should set a 1460 * valid number of segments 1461 */ 1462 if (!v) { 1463 dev_err(&vdev->dev, 1464 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1465 err = -EINVAL; 1466 goto out_cleanup_disk; 1467 } 1468 1469 max_discard_segs = min_not_zero(max_discard_segs, v); 1470 } 1471 1472 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1473 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1474 /* max_discard_seg and discard_granularity will be 0 only 1475 * if max_discard_seg and discard_sector_alignment fields in the virtio 1476 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1477 * In this case, we use default values. 1478 */ 1479 if (!max_discard_segs) 1480 max_discard_segs = sg_elems; 1481 1482 blk_queue_max_discard_segments(q, 1483 min(max_discard_segs, MAX_DISCARD_SEGMENTS)); 1484 1485 if (discard_granularity) 1486 q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT; 1487 else 1488 q->limits.discard_granularity = blk_size; 1489 } 1490 1491 virtblk_update_capacity(vblk, false); 1492 virtio_device_ready(vdev); 1493 1494 if (virtblk_has_zoned_feature(vdev)) { 1495 err = virtblk_probe_zoned_device(vdev, vblk, q); 1496 if (err) 1497 goto out_cleanup_disk; 1498 } 1499 1500 dev_info(&vdev->dev, "blk config size: %zu\n", 1501 sizeof(struct virtio_blk_config)); 1502 1503 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1504 if (err) 1505 goto out_cleanup_disk; 1506 1507 return 0; 1508 1509 out_cleanup_disk: 1510 put_disk(vblk->disk); 1511 out_free_tags: 1512 blk_mq_free_tag_set(&vblk->tag_set); 1513 out_free_vq: 1514 vdev->config->del_vqs(vdev); 1515 kfree(vblk->vqs); 1516 out_free_vblk: 1517 kfree(vblk); 1518 out_free_index: 1519 ida_free(&vd_index_ida, index); 1520 out: 1521 return err; 1522 } 1523 1524 static void virtblk_remove(struct virtio_device *vdev) 1525 { 1526 struct virtio_blk *vblk = vdev->priv; 1527 1528 /* Make sure no work handler is accessing the device. */ 1529 flush_work(&vblk->config_work); 1530 1531 del_gendisk(vblk->disk); 1532 blk_mq_free_tag_set(&vblk->tag_set); 1533 1534 mutex_lock(&vblk->vdev_mutex); 1535 1536 /* Stop all the virtqueues. */ 1537 virtio_reset_device(vdev); 1538 1539 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1540 vblk->vdev = NULL; 1541 1542 vdev->config->del_vqs(vdev); 1543 kfree(vblk->vqs); 1544 1545 mutex_unlock(&vblk->vdev_mutex); 1546 1547 put_disk(vblk->disk); 1548 } 1549 1550 #ifdef CONFIG_PM_SLEEP 1551 static int virtblk_freeze(struct virtio_device *vdev) 1552 { 1553 struct virtio_blk *vblk = vdev->priv; 1554 1555 /* Ensure we don't receive any more interrupts */ 1556 virtio_reset_device(vdev); 1557 1558 /* Make sure no work handler is accessing the device. */ 1559 flush_work(&vblk->config_work); 1560 1561 blk_mq_quiesce_queue(vblk->disk->queue); 1562 1563 vdev->config->del_vqs(vdev); 1564 kfree(vblk->vqs); 1565 1566 return 0; 1567 } 1568 1569 static int virtblk_restore(struct virtio_device *vdev) 1570 { 1571 struct virtio_blk *vblk = vdev->priv; 1572 int ret; 1573 1574 ret = init_vq(vdev->priv); 1575 if (ret) 1576 return ret; 1577 1578 virtio_device_ready(vdev); 1579 1580 blk_mq_unquiesce_queue(vblk->disk->queue); 1581 return 0; 1582 } 1583 #endif 1584 1585 static const struct virtio_device_id id_table[] = { 1586 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1587 { 0 }, 1588 }; 1589 1590 static unsigned int features_legacy[] = { 1591 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1592 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1593 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1594 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1595 VIRTIO_BLK_F_SECURE_ERASE, 1596 } 1597 ; 1598 static unsigned int features[] = { 1599 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1600 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1601 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1602 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1603 VIRTIO_BLK_F_SECURE_ERASE, 1604 #ifdef CONFIG_BLK_DEV_ZONED 1605 VIRTIO_BLK_F_ZONED, 1606 #endif /* CONFIG_BLK_DEV_ZONED */ 1607 }; 1608 1609 static struct virtio_driver virtio_blk = { 1610 .feature_table = features, 1611 .feature_table_size = ARRAY_SIZE(features), 1612 .feature_table_legacy = features_legacy, 1613 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1614 .driver.name = KBUILD_MODNAME, 1615 .driver.owner = THIS_MODULE, 1616 .id_table = id_table, 1617 .probe = virtblk_probe, 1618 .remove = virtblk_remove, 1619 .config_changed = virtblk_config_changed, 1620 #ifdef CONFIG_PM_SLEEP 1621 .freeze = virtblk_freeze, 1622 .restore = virtblk_restore, 1623 #endif 1624 }; 1625 1626 static int __init virtio_blk_init(void) 1627 { 1628 int error; 1629 1630 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1631 if (!virtblk_wq) 1632 return -ENOMEM; 1633 1634 major = register_blkdev(0, "virtblk"); 1635 if (major < 0) { 1636 error = major; 1637 goto out_destroy_workqueue; 1638 } 1639 1640 error = register_virtio_driver(&virtio_blk); 1641 if (error) 1642 goto out_unregister_blkdev; 1643 return 0; 1644 1645 out_unregister_blkdev: 1646 unregister_blkdev(major, "virtblk"); 1647 out_destroy_workqueue: 1648 destroy_workqueue(virtblk_wq); 1649 return error; 1650 } 1651 1652 static void __exit virtio_blk_fini(void) 1653 { 1654 unregister_virtio_driver(&virtio_blk); 1655 unregister_blkdev(major, "virtblk"); 1656 destroy_workqueue(virtblk_wq); 1657 } 1658 module_init(virtio_blk_init); 1659 module_exit(virtio_blk_fini); 1660 1661 MODULE_DEVICE_TABLE(virtio, id_table); 1662 MODULE_DESCRIPTION("Virtio block driver"); 1663 MODULE_LICENSE("GPL"); 1664