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 34static unsigned int num_request_queues; 35module_param(num_request_queues, uint, 0644); 36MODULE_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 41static unsigned int poll_queues; 42module_param(poll_queues, uint, 0644); 43MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); 44 45static int major; 46static DEFINE_IDA(vd_index_ida); 47 48static struct workqueue_struct *virtblk_wq; 49 50struct virtio_blk_vq { 51 struct virtqueue *vq; 52 spinlock_t lock; 53 char name[VQ_NAME_LEN]; 54} ____cacheline_aligned_in_smp; 55 56struct 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 89struct 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 114static 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 132static 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 140static 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 161static 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 207static 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 214static 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 233static 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 239static 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 */ 330static inline u8 virtblk_vbr_status(struct virtblk_req *vbr) 331{ 332 return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1); 333} 334 335static 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 351static void virtblk_done(struct virtqueue *vq) 352{ 353 struct virtio_blk *vblk = vq->vdev->priv; 354 bool req_done = false; 355 int qid = vq->index; 356 struct virtblk_req *vbr; 357 unsigned long flags; 358 unsigned int len; 359 360 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 361 do { 362 virtqueue_disable_cb(vq); 363 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { 364 struct request *req = blk_mq_rq_from_pdu(vbr); 365 366 if (likely(!blk_should_fake_timeout(req->q))) 367 blk_mq_complete_request(req); 368 req_done = true; 369 } 370 if (unlikely(virtqueue_is_broken(vq))) 371 break; 372 } while (!virtqueue_enable_cb(vq)); 373 374 /* In case queue is stopped waiting for more buffers. */ 375 if (req_done) 376 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 377 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 378} 379 380static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) 381{ 382 struct virtio_blk *vblk = hctx->queue->queuedata; 383 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 384 bool kick; 385 386 spin_lock_irq(&vq->lock); 387 kick = virtqueue_kick_prepare(vq->vq); 388 spin_unlock_irq(&vq->lock); 389 390 if (kick) 391 virtqueue_notify(vq->vq); 392} 393 394static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) 395{ 396 virtblk_cleanup_cmd(req); 397 switch (rc) { 398 case -ENOSPC: 399 return BLK_STS_DEV_RESOURCE; 400 case -ENOMEM: 401 return BLK_STS_RESOURCE; 402 default: 403 return BLK_STS_IOERR; 404 } 405} 406 407static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, 408 struct virtio_blk *vblk, 409 struct request *req, 410 struct virtblk_req *vbr) 411{ 412 blk_status_t status; 413 int num; 414 415 status = virtblk_setup_cmd(vblk->vdev, req, vbr); 416 if (unlikely(status)) 417 return status; 418 419 num = virtblk_map_data(hctx, req, vbr); 420 if (unlikely(num < 0)) 421 return virtblk_fail_to_queue(req, -ENOMEM); 422 vbr->sg_table.nents = num; 423 424 blk_mq_start_request(req); 425 426 return BLK_STS_OK; 427} 428 429static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, 430 const struct blk_mq_queue_data *bd) 431{ 432 struct virtio_blk *vblk = hctx->queue->queuedata; 433 struct request *req = bd->rq; 434 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 435 unsigned long flags; 436 int qid = hctx->queue_num; 437 bool notify = false; 438 blk_status_t status; 439 int err; 440 441 status = virtblk_prep_rq(hctx, vblk, req, vbr); 442 if (unlikely(status)) 443 return status; 444 445 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 446 err = virtblk_add_req(vblk->vqs[qid].vq, vbr); 447 if (err) { 448 virtqueue_kick(vblk->vqs[qid].vq); 449 /* Don't stop the queue if -ENOMEM: we may have failed to 450 * bounce the buffer due to global resource outage. 451 */ 452 if (err == -ENOSPC) 453 blk_mq_stop_hw_queue(hctx); 454 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 455 virtblk_unmap_data(req, vbr); 456 return virtblk_fail_to_queue(req, err); 457 } 458 459 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) 460 notify = true; 461 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 462 463 if (notify) 464 virtqueue_notify(vblk->vqs[qid].vq); 465 return BLK_STS_OK; 466} 467 468static bool virtblk_prep_rq_batch(struct request *req) 469{ 470 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 471 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 472 473 req->mq_hctx->tags->rqs[req->tag] = req; 474 475 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 476} 477 478static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, 479 struct request **rqlist) 480{ 481 unsigned long flags; 482 int err; 483 bool kick; 484 485 spin_lock_irqsave(&vq->lock, flags); 486 487 while (!rq_list_empty(*rqlist)) { 488 struct request *req = rq_list_pop(rqlist); 489 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 490 491 err = virtblk_add_req(vq->vq, vbr); 492 if (err) { 493 virtblk_unmap_data(req, vbr); 494 virtblk_cleanup_cmd(req); 495 blk_mq_requeue_request(req, true); 496 } 497 } 498 499 kick = virtqueue_kick_prepare(vq->vq); 500 spin_unlock_irqrestore(&vq->lock, flags); 501 502 return kick; 503} 504 505static void virtio_queue_rqs(struct request **rqlist) 506{ 507 struct request *req, *next, *prev = NULL; 508 struct request *requeue_list = NULL; 509 510 rq_list_for_each_safe(rqlist, req, next) { 511 struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); 512 bool kick; 513 514 if (!virtblk_prep_rq_batch(req)) { 515 rq_list_move(rqlist, &requeue_list, req, prev); 516 req = prev; 517 if (!req) 518 continue; 519 } 520 521 if (!next || req->mq_hctx != next->mq_hctx) { 522 req->rq_next = NULL; 523 kick = virtblk_add_req_batch(vq, rqlist); 524 if (kick) 525 virtqueue_notify(vq->vq); 526 527 *rqlist = next; 528 prev = NULL; 529 } else 530 prev = req; 531 } 532 533 *rqlist = requeue_list; 534} 535 536#ifdef CONFIG_BLK_DEV_ZONED 537static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 538 unsigned int nr_zones, 539 size_t *buflen) 540{ 541 struct request_queue *q = vblk->disk->queue; 542 size_t bufsize; 543 void *buf; 544 545 nr_zones = min_t(unsigned int, nr_zones, 546 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); 547 548 bufsize = sizeof(struct virtio_blk_zone_report) + 549 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 550 bufsize = min_t(size_t, bufsize, 551 queue_max_hw_sectors(q) << SECTOR_SHIFT); 552 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 553 554 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 555 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 556 if (buf) { 557 *buflen = bufsize; 558 return buf; 559 } 560 bufsize >>= 1; 561 } 562 563 return NULL; 564} 565 566static int virtblk_submit_zone_report(struct virtio_blk *vblk, 567 char *report_buf, size_t report_len, 568 sector_t sector) 569{ 570 struct request_queue *q = vblk->disk->queue; 571 struct request *req; 572 struct virtblk_req *vbr; 573 int err; 574 575 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 576 if (IS_ERR(req)) 577 return PTR_ERR(req); 578 579 vbr = blk_mq_rq_to_pdu(req); 580 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 581 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 582 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 583 584 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); 585 if (err) 586 goto out; 587 588 blk_execute_rq(req, false); 589 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 590out: 591 blk_mq_free_request(req); 592 return err; 593} 594 595static int virtblk_parse_zone(struct virtio_blk *vblk, 596 struct virtio_blk_zone_descriptor *entry, 597 unsigned int idx, report_zones_cb cb, void *data) 598{ 599 struct blk_zone zone = { }; 600 601 zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start); 602 if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk)) 603 zone.len = vblk->zone_sectors; 604 else 605 zone.len = get_capacity(vblk->disk) - zone.start; 606 zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap); 607 zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp); 608 609 switch (entry->z_type) { 610 case VIRTIO_BLK_ZT_SWR: 611 zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ; 612 break; 613 case VIRTIO_BLK_ZT_SWP: 614 zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF; 615 break; 616 case VIRTIO_BLK_ZT_CONV: 617 zone.type = BLK_ZONE_TYPE_CONVENTIONAL; 618 break; 619 default: 620 dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n", 621 zone.start, entry->z_type); 622 return -EIO; 623 } 624 625 switch (entry->z_state) { 626 case VIRTIO_BLK_ZS_EMPTY: 627 zone.cond = BLK_ZONE_COND_EMPTY; 628 break; 629 case VIRTIO_BLK_ZS_CLOSED: 630 zone.cond = BLK_ZONE_COND_CLOSED; 631 break; 632 case VIRTIO_BLK_ZS_FULL: 633 zone.cond = BLK_ZONE_COND_FULL; 634 zone.wp = zone.start + zone.len; 635 break; 636 case VIRTIO_BLK_ZS_EOPEN: 637 zone.cond = BLK_ZONE_COND_EXP_OPEN; 638 break; 639 case VIRTIO_BLK_ZS_IOPEN: 640 zone.cond = BLK_ZONE_COND_IMP_OPEN; 641 break; 642 case VIRTIO_BLK_ZS_NOT_WP: 643 zone.cond = BLK_ZONE_COND_NOT_WP; 644 break; 645 case VIRTIO_BLK_ZS_RDONLY: 646 zone.cond = BLK_ZONE_COND_READONLY; 647 zone.wp = ULONG_MAX; 648 break; 649 case VIRTIO_BLK_ZS_OFFLINE: 650 zone.cond = BLK_ZONE_COND_OFFLINE; 651 zone.wp = ULONG_MAX; 652 break; 653 default: 654 dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n", 655 zone.start, entry->z_state); 656 return -EIO; 657 } 658 659 /* 660 * The callback below checks the validity of the reported 661 * entry data, no need to further validate it here. 662 */ 663 return cb(&zone, idx, data); 664} 665 666static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 667 unsigned int nr_zones, report_zones_cb cb, 668 void *data) 669{ 670 struct virtio_blk *vblk = disk->private_data; 671 struct virtio_blk_zone_report *report; 672 unsigned long long nz, i; 673 size_t buflen; 674 unsigned int zone_idx = 0; 675 int ret; 676 677 if (WARN_ON_ONCE(!vblk->zone_sectors)) 678 return -EOPNOTSUPP; 679 680 report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen); 681 if (!report) 682 return -ENOMEM; 683 684 mutex_lock(&vblk->vdev_mutex); 685 686 if (!vblk->vdev) { 687 ret = -ENXIO; 688 goto fail_report; 689 } 690 691 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { 692 memset(report, 0, buflen); 693 694 ret = virtblk_submit_zone_report(vblk, (char *)report, 695 buflen, sector); 696 if (ret) 697 goto fail_report; 698 699 nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones), 700 nr_zones); 701 if (!nz) 702 break; 703 704 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 705 ret = virtblk_parse_zone(vblk, &report->zones[i], 706 zone_idx, cb, data); 707 if (ret) 708 goto fail_report; 709 710 sector = virtio64_to_cpu(vblk->vdev, 711 report->zones[i].z_start) + 712 vblk->zone_sectors; 713 zone_idx++; 714 } 715 } 716 717 if (zone_idx > 0) 718 ret = zone_idx; 719 else 720 ret = -EINVAL; 721fail_report: 722 mutex_unlock(&vblk->vdev_mutex); 723 kvfree(report); 724 return ret; 725} 726 727static void virtblk_revalidate_zones(struct virtio_blk *vblk) 728{ 729 u8 model; 730 731 virtio_cread(vblk->vdev, struct virtio_blk_config, 732 zoned.model, &model); 733 switch (model) { 734 default: 735 dev_err(&vblk->vdev->dev, "unknown zone model %d\n", model); 736 fallthrough; 737 case VIRTIO_BLK_Z_NONE: 738 case VIRTIO_BLK_Z_HA: 739 disk_set_zoned(vblk->disk, BLK_ZONED_NONE); 740 return; 741 case VIRTIO_BLK_Z_HM: 742 WARN_ON_ONCE(!vblk->zone_sectors); 743 if (!blk_revalidate_disk_zones(vblk->disk, NULL)) 744 set_capacity_and_notify(vblk->disk, 0); 745 } 746} 747 748static int virtblk_probe_zoned_device(struct virtio_device *vdev, 749 struct virtio_blk *vblk, 750 struct request_queue *q) 751{ 752 u32 v, wg; 753 u8 model; 754 755 virtio_cread(vdev, struct virtio_blk_config, 756 zoned.model, &model); 757 758 switch (model) { 759 case VIRTIO_BLK_Z_NONE: 760 case VIRTIO_BLK_Z_HA: 761 /* Present the host-aware device as non-zoned */ 762 return 0; 763 case VIRTIO_BLK_Z_HM: 764 break; 765 default: 766 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 767 return -EINVAL; 768 } 769 770 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 771 772 disk_set_zoned(vblk->disk, BLK_ZONED_HM); 773 blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); 774 775 virtio_cread(vdev, struct virtio_blk_config, 776 zoned.max_open_zones, &v); 777 disk_set_max_open_zones(vblk->disk, v); 778 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 779 780 virtio_cread(vdev, struct virtio_blk_config, 781 zoned.max_active_zones, &v); 782 disk_set_max_active_zones(vblk->disk, v); 783 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 784 785 virtio_cread(vdev, struct virtio_blk_config, 786 zoned.write_granularity, &wg); 787 if (!wg) { 788 dev_warn(&vdev->dev, "zero write granularity reported\n"); 789 return -ENODEV; 790 } 791 blk_queue_physical_block_size(q, wg); 792 blk_queue_io_min(q, wg); 793 794 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 795 796 /* 797 * virtio ZBD specification doesn't require zones to be a power of 798 * two sectors in size, but the code in this driver expects that. 799 */ 800 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 801 &vblk->zone_sectors); 802 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 803 dev_err(&vdev->dev, 804 "zoned device with non power of two zone size %u\n", 805 vblk->zone_sectors); 806 return -ENODEV; 807 } 808 blk_queue_chunk_sectors(q, vblk->zone_sectors); 809 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 810 811 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 812 dev_warn(&vblk->vdev->dev, 813 "ignoring negotiated F_DISCARD for zoned device\n"); 814 blk_queue_max_discard_sectors(q, 0); 815 } 816 817 virtio_cread(vdev, struct virtio_blk_config, 818 zoned.max_append_sectors, &v); 819 if (!v) { 820 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 821 return -ENODEV; 822 } 823 if ((v << SECTOR_SHIFT) < wg) { 824 dev_err(&vdev->dev, 825 "write granularity %u exceeds max_append_sectors %u limit\n", 826 wg, v); 827 return -ENODEV; 828 } 829 blk_queue_max_zone_append_sectors(q, v); 830 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 831 832 return blk_revalidate_disk_zones(vblk->disk, NULL); 833} 834 835#else 836 837/* 838 * Zoned block device support is not configured in this kernel. 839 * Host-managed zoned devices can't be supported, but others are 840 * good to go as regular block devices. 841 */ 842#define virtblk_report_zones NULL 843 844static inline void virtblk_revalidate_zones(struct virtio_blk *vblk) 845{ 846} 847 848static inline int virtblk_probe_zoned_device(struct virtio_device *vdev, 849 struct virtio_blk *vblk, struct request_queue *q) 850{ 851 u8 model; 852 853 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); 854 if (model == VIRTIO_BLK_Z_HM) { 855 dev_err(&vdev->dev, 856 "virtio_blk: zoned devices are not supported"); 857 return -EOPNOTSUPP; 858 } 859 860 return 0; 861} 862#endif /* CONFIG_BLK_DEV_ZONED */ 863 864/* return id (s/n) string for *disk to *id_str 865 */ 866static int virtblk_get_id(struct gendisk *disk, char *id_str) 867{ 868 struct virtio_blk *vblk = disk->private_data; 869 struct request_queue *q = vblk->disk->queue; 870 struct request *req; 871 struct virtblk_req *vbr; 872 int err; 873 874 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 875 if (IS_ERR(req)) 876 return PTR_ERR(req); 877 878 vbr = blk_mq_rq_to_pdu(req); 879 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 880 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 881 vbr->out_hdr.sector = 0; 882 883 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 884 if (err) 885 goto out; 886 887 blk_execute_rq(req, false); 888 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 889out: 890 blk_mq_free_request(req); 891 return err; 892} 893 894/* We provide getgeo only to please some old bootloader/partitioning tools */ 895static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 896{ 897 struct virtio_blk *vblk = bd->bd_disk->private_data; 898 int ret = 0; 899 900 mutex_lock(&vblk->vdev_mutex); 901 902 if (!vblk->vdev) { 903 ret = -ENXIO; 904 goto out; 905 } 906 907 /* see if the host passed in geometry config */ 908 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 909 virtio_cread(vblk->vdev, struct virtio_blk_config, 910 geometry.cylinders, &geo->cylinders); 911 virtio_cread(vblk->vdev, struct virtio_blk_config, 912 geometry.heads, &geo->heads); 913 virtio_cread(vblk->vdev, struct virtio_blk_config, 914 geometry.sectors, &geo->sectors); 915 } else { 916 /* some standard values, similar to sd */ 917 geo->heads = 1 << 6; 918 geo->sectors = 1 << 5; 919 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 920 } 921out: 922 mutex_unlock(&vblk->vdev_mutex); 923 return ret; 924} 925 926static void virtblk_free_disk(struct gendisk *disk) 927{ 928 struct virtio_blk *vblk = disk->private_data; 929 930 ida_free(&vd_index_ida, vblk->index); 931 mutex_destroy(&vblk->vdev_mutex); 932 kfree(vblk); 933} 934 935static const struct block_device_operations virtblk_fops = { 936 .owner = THIS_MODULE, 937 .getgeo = virtblk_getgeo, 938 .free_disk = virtblk_free_disk, 939 .report_zones = virtblk_report_zones, 940}; 941 942static int index_to_minor(int index) 943{ 944 return index << PART_BITS; 945} 946 947static int minor_to_index(int minor) 948{ 949 return minor >> PART_BITS; 950} 951 952static ssize_t serial_show(struct device *dev, 953 struct device_attribute *attr, char *buf) 954{ 955 struct gendisk *disk = dev_to_disk(dev); 956 int err; 957 958 /* sysfs gives us a PAGE_SIZE buffer */ 959 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 960 961 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 962 err = virtblk_get_id(disk, buf); 963 if (!err) 964 return strlen(buf); 965 966 if (err == -EIO) /* Unsupported? Make it empty. */ 967 return 0; 968 969 return err; 970} 971 972static DEVICE_ATTR_RO(serial); 973 974/* The queue's logical block size must be set before calling this */ 975static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 976{ 977 struct virtio_device *vdev = vblk->vdev; 978 struct request_queue *q = vblk->disk->queue; 979 char cap_str_2[10], cap_str_10[10]; 980 unsigned long long nblocks; 981 u64 capacity; 982 983 /* Host must always specify the capacity. */ 984 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 985 986 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 987 988 string_get_size(nblocks, queue_logical_block_size(q), 989 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 990 string_get_size(nblocks, queue_logical_block_size(q), 991 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 992 993 dev_notice(&vdev->dev, 994 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 995 vblk->disk->disk_name, 996 resize ? "new size: " : "", 997 nblocks, 998 queue_logical_block_size(q), 999 cap_str_10, 1000 cap_str_2); 1001 1002 set_capacity_and_notify(vblk->disk, capacity); 1003} 1004 1005static void virtblk_config_changed_work(struct work_struct *work) 1006{ 1007 struct virtio_blk *vblk = 1008 container_of(work, struct virtio_blk, config_work); 1009 1010 virtblk_revalidate_zones(vblk); 1011 virtblk_update_capacity(vblk, true); 1012} 1013 1014static void virtblk_config_changed(struct virtio_device *vdev) 1015{ 1016 struct virtio_blk *vblk = vdev->priv; 1017 1018 queue_work(virtblk_wq, &vblk->config_work); 1019} 1020 1021static int init_vq(struct virtio_blk *vblk) 1022{ 1023 int err; 1024 unsigned short i; 1025 vq_callback_t **callbacks; 1026 const char **names; 1027 struct virtqueue **vqs; 1028 unsigned short num_vqs; 1029 unsigned short num_poll_vqs; 1030 struct virtio_device *vdev = vblk->vdev; 1031 struct irq_affinity desc = { 0, }; 1032 1033 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 1034 struct virtio_blk_config, num_queues, 1035 &num_vqs); 1036 if (err) 1037 num_vqs = 1; 1038 1039 if (!err && !num_vqs) { 1040 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 1041 return -EINVAL; 1042 } 1043 1044 num_vqs = min_t(unsigned int, 1045 min_not_zero(num_request_queues, nr_cpu_ids), 1046 num_vqs); 1047 1048 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 1049 1050 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 1051 vblk->io_queues[HCTX_TYPE_READ] = 0; 1052 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 1053 1054 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 1055 vblk->io_queues[HCTX_TYPE_DEFAULT], 1056 vblk->io_queues[HCTX_TYPE_READ], 1057 vblk->io_queues[HCTX_TYPE_POLL]); 1058 1059 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 1060 if (!vblk->vqs) 1061 return -ENOMEM; 1062 1063 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); 1064 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); 1065 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1066 if (!names || !callbacks || !vqs) { 1067 err = -ENOMEM; 1068 goto out; 1069 } 1070 1071 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1072 callbacks[i] = virtblk_done; 1073 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1074 names[i] = vblk->vqs[i].name; 1075 } 1076 1077 for (; i < num_vqs; i++) { 1078 callbacks[i] = NULL; 1079 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1080 names[i] = vblk->vqs[i].name; 1081 } 1082 1083 /* Discover virtqueues and write information to configuration. */ 1084 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 1085 if (err) 1086 goto out; 1087 1088 for (i = 0; i < num_vqs; i++) { 1089 spin_lock_init(&vblk->vqs[i].lock); 1090 vblk->vqs[i].vq = vqs[i]; 1091 } 1092 vblk->num_vqs = num_vqs; 1093 1094out: 1095 kfree(vqs); 1096 kfree(callbacks); 1097 kfree(names); 1098 if (err) 1099 kfree(vblk->vqs); 1100 return err; 1101} 1102 1103/* 1104 * Legacy naming scheme used for virtio devices. We are stuck with it for 1105 * virtio blk but don't ever use it for any new driver. 1106 */ 1107static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1108{ 1109 const int base = 'z' - 'a' + 1; 1110 char *begin = buf + strlen(prefix); 1111 char *end = buf + buflen; 1112 char *p; 1113 int unit; 1114 1115 p = end - 1; 1116 *p = '\0'; 1117 unit = base; 1118 do { 1119 if (p == begin) 1120 return -EINVAL; 1121 *--p = 'a' + (index % unit); 1122 index = (index / unit) - 1; 1123 } while (index >= 0); 1124 1125 memmove(begin, p, end - p); 1126 memcpy(buf, prefix, strlen(prefix)); 1127 1128 return 0; 1129} 1130 1131static int virtblk_get_cache_mode(struct virtio_device *vdev) 1132{ 1133 u8 writeback; 1134 int err; 1135 1136 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1137 struct virtio_blk_config, wce, 1138 &writeback); 1139 1140 /* 1141 * If WCE is not configurable and flush is not available, 1142 * assume no writeback cache is in use. 1143 */ 1144 if (err) 1145 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1146 1147 return writeback; 1148} 1149 1150static void virtblk_update_cache_mode(struct virtio_device *vdev) 1151{ 1152 u8 writeback = virtblk_get_cache_mode(vdev); 1153 struct virtio_blk *vblk = vdev->priv; 1154 1155 blk_queue_write_cache(vblk->disk->queue, writeback, false); 1156} 1157 1158static const char *const virtblk_cache_types[] = { 1159 "write through", "write back" 1160}; 1161 1162static ssize_t 1163cache_type_store(struct device *dev, struct device_attribute *attr, 1164 const char *buf, size_t count) 1165{ 1166 struct gendisk *disk = dev_to_disk(dev); 1167 struct virtio_blk *vblk = disk->private_data; 1168 struct virtio_device *vdev = vblk->vdev; 1169 int i; 1170 1171 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1172 i = sysfs_match_string(virtblk_cache_types, buf); 1173 if (i < 0) 1174 return i; 1175 1176 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1177 virtblk_update_cache_mode(vdev); 1178 return count; 1179} 1180 1181static ssize_t 1182cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1183{ 1184 struct gendisk *disk = dev_to_disk(dev); 1185 struct virtio_blk *vblk = disk->private_data; 1186 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1187 1188 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1189 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1190} 1191 1192static DEVICE_ATTR_RW(cache_type); 1193 1194static struct attribute *virtblk_attrs[] = { 1195 &dev_attr_serial.attr, 1196 &dev_attr_cache_type.attr, 1197 NULL, 1198}; 1199 1200static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1201 struct attribute *a, int n) 1202{ 1203 struct device *dev = kobj_to_dev(kobj); 1204 struct gendisk *disk = dev_to_disk(dev); 1205 struct virtio_blk *vblk = disk->private_data; 1206 struct virtio_device *vdev = vblk->vdev; 1207 1208 if (a == &dev_attr_cache_type.attr && 1209 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1210 return S_IRUGO; 1211 1212 return a->mode; 1213} 1214 1215static const struct attribute_group virtblk_attr_group = { 1216 .attrs = virtblk_attrs, 1217 .is_visible = virtblk_attrs_are_visible, 1218}; 1219 1220static const struct attribute_group *virtblk_attr_groups[] = { 1221 &virtblk_attr_group, 1222 NULL, 1223}; 1224 1225static void virtblk_map_queues(struct blk_mq_tag_set *set) 1226{ 1227 struct virtio_blk *vblk = set->driver_data; 1228 int i, qoff; 1229 1230 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1231 struct blk_mq_queue_map *map = &set->map[i]; 1232 1233 map->nr_queues = vblk->io_queues[i]; 1234 map->queue_offset = qoff; 1235 qoff += map->nr_queues; 1236 1237 if (map->nr_queues == 0) 1238 continue; 1239 1240 /* 1241 * Regular queues have interrupts and hence CPU affinity is 1242 * defined by the core virtio code, but polling queues have 1243 * no interrupts so we let the block layer assign CPU affinity. 1244 */ 1245 if (i == HCTX_TYPE_POLL) 1246 blk_mq_map_queues(&set->map[i]); 1247 else 1248 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1249 } 1250} 1251 1252static void virtblk_complete_batch(struct io_comp_batch *iob) 1253{ 1254 struct request *req; 1255 1256 rq_list_for_each(&iob->req_list, req) { 1257 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1258 virtblk_cleanup_cmd(req); 1259 } 1260 blk_mq_end_request_batch(iob); 1261} 1262 1263static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1264{ 1265 struct virtio_blk *vblk = hctx->queue->queuedata; 1266 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1267 struct virtblk_req *vbr; 1268 unsigned long flags; 1269 unsigned int len; 1270 int found = 0; 1271 1272 spin_lock_irqsave(&vq->lock, flags); 1273 1274 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1275 struct request *req = blk_mq_rq_from_pdu(vbr); 1276 1277 found++; 1278 if (!blk_mq_complete_request_remote(req) && 1279 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1280 virtblk_complete_batch)) 1281 virtblk_request_done(req); 1282 } 1283 1284 if (found) 1285 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1286 1287 spin_unlock_irqrestore(&vq->lock, flags); 1288 1289 return found; 1290} 1291 1292static const struct blk_mq_ops virtio_mq_ops = { 1293 .queue_rq = virtio_queue_rq, 1294 .queue_rqs = virtio_queue_rqs, 1295 .commit_rqs = virtio_commit_rqs, 1296 .complete = virtblk_request_done, 1297 .map_queues = virtblk_map_queues, 1298 .poll = virtblk_poll, 1299}; 1300 1301static unsigned int virtblk_queue_depth; 1302module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1303 1304static int virtblk_probe(struct virtio_device *vdev) 1305{ 1306 struct virtio_blk *vblk; 1307 struct request_queue *q; 1308 int err, index; 1309 1310 u32 v, blk_size, max_size, sg_elems, opt_io_size; 1311 u32 max_discard_segs = 0; 1312 u32 discard_granularity = 0; 1313 u16 min_io_size; 1314 u8 physical_block_exp, alignment_offset; 1315 unsigned int queue_depth; 1316 size_t max_dma_size; 1317 1318 if (!vdev->config->get) { 1319 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1320 __func__); 1321 return -EINVAL; 1322 } 1323 1324 err = ida_alloc_range(&vd_index_ida, 0, 1325 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1326 if (err < 0) 1327 goto out; 1328 index = err; 1329 1330 /* We need to know how many segments before we allocate. */ 1331 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1332 struct virtio_blk_config, seg_max, 1333 &sg_elems); 1334 1335 /* We need at least one SG element, whatever they say. */ 1336 if (err || !sg_elems) 1337 sg_elems = 1; 1338 1339 /* Prevent integer overflows and honor max vq size */ 1340 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1341 1342 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1343 if (!vblk) { 1344 err = -ENOMEM; 1345 goto out_free_index; 1346 } 1347 1348 mutex_init(&vblk->vdev_mutex); 1349 1350 vblk->vdev = vdev; 1351 1352 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1353 1354 err = init_vq(vblk); 1355 if (err) 1356 goto out_free_vblk; 1357 1358 /* Default queue sizing is to fill the ring. */ 1359 if (!virtblk_queue_depth) { 1360 queue_depth = vblk->vqs[0].vq->num_free; 1361 /* ... but without indirect descs, we use 2 descs per req */ 1362 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1363 queue_depth /= 2; 1364 } else { 1365 queue_depth = virtblk_queue_depth; 1366 } 1367 1368 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1369 vblk->tag_set.ops = &virtio_mq_ops; 1370 vblk->tag_set.queue_depth = queue_depth; 1371 vblk->tag_set.numa_node = NUMA_NO_NODE; 1372 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1373 vblk->tag_set.cmd_size = 1374 sizeof(struct virtblk_req) + 1375 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1376 vblk->tag_set.driver_data = vblk; 1377 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1378 vblk->tag_set.nr_maps = 1; 1379 if (vblk->io_queues[HCTX_TYPE_POLL]) 1380 vblk->tag_set.nr_maps = 3; 1381 1382 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1383 if (err) 1384 goto out_free_vq; 1385 1386 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); 1387 if (IS_ERR(vblk->disk)) { 1388 err = PTR_ERR(vblk->disk); 1389 goto out_free_tags; 1390 } 1391 q = vblk->disk->queue; 1392 1393 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1394 1395 vblk->disk->major = major; 1396 vblk->disk->first_minor = index_to_minor(index); 1397 vblk->disk->minors = 1 << PART_BITS; 1398 vblk->disk->private_data = vblk; 1399 vblk->disk->fops = &virtblk_fops; 1400 vblk->index = index; 1401 1402 /* configure queue flush support */ 1403 virtblk_update_cache_mode(vdev); 1404 1405 /* If disk is read-only in the host, the guest should obey */ 1406 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1407 set_disk_ro(vblk->disk, 1); 1408 1409 /* We can handle whatever the host told us to handle. */ 1410 blk_queue_max_segments(q, sg_elems); 1411 1412 /* No real sector limit. */ 1413 blk_queue_max_hw_sectors(q, UINT_MAX); 1414 1415 max_dma_size = virtio_max_dma_size(vdev); 1416 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1417 1418 /* Host can optionally specify maximum segment size and number of 1419 * segments. */ 1420 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1421 struct virtio_blk_config, size_max, &v); 1422 if (!err) 1423 max_size = min(max_size, v); 1424 1425 blk_queue_max_segment_size(q, max_size); 1426 1427 /* Host can optionally specify the block size of the device */ 1428 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1429 struct virtio_blk_config, blk_size, 1430 &blk_size); 1431 if (!err) { 1432 err = blk_validate_block_size(blk_size); 1433 if (err) { 1434 dev_err(&vdev->dev, 1435 "virtio_blk: invalid block size: 0x%x\n", 1436 blk_size); 1437 goto out_cleanup_disk; 1438 } 1439 1440 blk_queue_logical_block_size(q, blk_size); 1441 } else 1442 blk_size = queue_logical_block_size(q); 1443 1444 /* Use topology information if available */ 1445 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1446 struct virtio_blk_config, physical_block_exp, 1447 &physical_block_exp); 1448 if (!err && physical_block_exp) 1449 blk_queue_physical_block_size(q, 1450 blk_size * (1 << physical_block_exp)); 1451 1452 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1453 struct virtio_blk_config, alignment_offset, 1454 &alignment_offset); 1455 if (!err && alignment_offset) 1456 blk_queue_alignment_offset(q, blk_size * alignment_offset); 1457 1458 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1459 struct virtio_blk_config, min_io_size, 1460 &min_io_size); 1461 if (!err && min_io_size) 1462 blk_queue_io_min(q, blk_size * min_io_size); 1463 1464 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1465 struct virtio_blk_config, opt_io_size, 1466 &opt_io_size); 1467 if (!err && opt_io_size) 1468 blk_queue_io_opt(q, blk_size * opt_io_size); 1469 1470 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1471 virtio_cread(vdev, struct virtio_blk_config, 1472 discard_sector_alignment, &discard_granularity); 1473 1474 virtio_cread(vdev, struct virtio_blk_config, 1475 max_discard_sectors, &v); 1476 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); 1477 1478 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1479 &max_discard_segs); 1480 } 1481 1482 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1483 virtio_cread(vdev, struct virtio_blk_config, 1484 max_write_zeroes_sectors, &v); 1485 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); 1486 } 1487 1488 /* The discard and secure erase limits are combined since the Linux 1489 * block layer uses the same limit for both commands. 1490 * 1491 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1492 * are negotiated, we will use the minimum between the limits. 1493 * 1494 * discard sector alignment is set to the minimum between discard_sector_alignment 1495 * and secure_erase_sector_alignment. 1496 * 1497 * max discard sectors is set to the minimum between max_discard_seg and 1498 * max_secure_erase_seg. 1499 */ 1500 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1501 1502 virtio_cread(vdev, struct virtio_blk_config, 1503 secure_erase_sector_alignment, &v); 1504 1505 /* secure_erase_sector_alignment should not be zero, the device should set a 1506 * valid number of sectors. 1507 */ 1508 if (!v) { 1509 dev_err(&vdev->dev, 1510 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1511 err = -EINVAL; 1512 goto out_cleanup_disk; 1513 } 1514 1515 discard_granularity = min_not_zero(discard_granularity, v); 1516 1517 virtio_cread(vdev, struct virtio_blk_config, 1518 max_secure_erase_sectors, &v); 1519 1520 /* max_secure_erase_sectors should not be zero, the device should set a 1521 * valid number of sectors. 1522 */ 1523 if (!v) { 1524 dev_err(&vdev->dev, 1525 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1526 err = -EINVAL; 1527 goto out_cleanup_disk; 1528 } 1529 1530 blk_queue_max_secure_erase_sectors(q, v); 1531 1532 virtio_cread(vdev, struct virtio_blk_config, 1533 max_secure_erase_seg, &v); 1534 1535 /* max_secure_erase_seg should not be zero, the device should set a 1536 * valid number of segments 1537 */ 1538 if (!v) { 1539 dev_err(&vdev->dev, 1540 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1541 err = -EINVAL; 1542 goto out_cleanup_disk; 1543 } 1544 1545 max_discard_segs = min_not_zero(max_discard_segs, v); 1546 } 1547 1548 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1549 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1550 /* max_discard_seg and discard_granularity will be 0 only 1551 * if max_discard_seg and discard_sector_alignment fields in the virtio 1552 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1553 * In this case, we use default values. 1554 */ 1555 if (!max_discard_segs) 1556 max_discard_segs = sg_elems; 1557 1558 blk_queue_max_discard_segments(q, 1559 min(max_discard_segs, MAX_DISCARD_SEGMENTS)); 1560 1561 if (discard_granularity) 1562 q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT; 1563 else 1564 q->limits.discard_granularity = blk_size; 1565 } 1566 1567 virtblk_update_capacity(vblk, false); 1568 virtio_device_ready(vdev); 1569 1570 /* 1571 * All steps that follow use the VQs therefore they need to be 1572 * placed after the virtio_device_ready() call above. 1573 */ 1574 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1575 err = virtblk_probe_zoned_device(vdev, vblk, q); 1576 if (err) 1577 goto out_cleanup_disk; 1578 } 1579 1580 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1581 if (err) 1582 goto out_cleanup_disk; 1583 1584 return 0; 1585 1586out_cleanup_disk: 1587 put_disk(vblk->disk); 1588out_free_tags: 1589 blk_mq_free_tag_set(&vblk->tag_set); 1590out_free_vq: 1591 vdev->config->del_vqs(vdev); 1592 kfree(vblk->vqs); 1593out_free_vblk: 1594 kfree(vblk); 1595out_free_index: 1596 ida_free(&vd_index_ida, index); 1597out: 1598 return err; 1599} 1600 1601static void virtblk_remove(struct virtio_device *vdev) 1602{ 1603 struct virtio_blk *vblk = vdev->priv; 1604 1605 /* Make sure no work handler is accessing the device. */ 1606 flush_work(&vblk->config_work); 1607 1608 del_gendisk(vblk->disk); 1609 blk_mq_free_tag_set(&vblk->tag_set); 1610 1611 mutex_lock(&vblk->vdev_mutex); 1612 1613 /* Stop all the virtqueues. */ 1614 virtio_reset_device(vdev); 1615 1616 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1617 vblk->vdev = NULL; 1618 1619 vdev->config->del_vqs(vdev); 1620 kfree(vblk->vqs); 1621 1622 mutex_unlock(&vblk->vdev_mutex); 1623 1624 put_disk(vblk->disk); 1625} 1626 1627#ifdef CONFIG_PM_SLEEP 1628static int virtblk_freeze(struct virtio_device *vdev) 1629{ 1630 struct virtio_blk *vblk = vdev->priv; 1631 1632 /* Ensure no requests in virtqueues before deleting vqs. */ 1633 blk_mq_freeze_queue(vblk->disk->queue); 1634 1635 /* Ensure we don't receive any more interrupts */ 1636 virtio_reset_device(vdev); 1637 1638 /* Make sure no work handler is accessing the device. */ 1639 flush_work(&vblk->config_work); 1640 1641 vdev->config->del_vqs(vdev); 1642 kfree(vblk->vqs); 1643 1644 return 0; 1645} 1646 1647static int virtblk_restore(struct virtio_device *vdev) 1648{ 1649 struct virtio_blk *vblk = vdev->priv; 1650 int ret; 1651 1652 ret = init_vq(vdev->priv); 1653 if (ret) 1654 return ret; 1655 1656 virtio_device_ready(vdev); 1657 1658 blk_mq_unfreeze_queue(vblk->disk->queue); 1659 return 0; 1660} 1661#endif 1662 1663static const struct virtio_device_id id_table[] = { 1664 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1665 { 0 }, 1666}; 1667 1668static unsigned int features_legacy[] = { 1669 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1670 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1671 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1672 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1673 VIRTIO_BLK_F_SECURE_ERASE, 1674} 1675; 1676static unsigned int features[] = { 1677 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1678 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1679 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1680 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1681 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1682}; 1683 1684static struct virtio_driver virtio_blk = { 1685 .feature_table = features, 1686 .feature_table_size = ARRAY_SIZE(features), 1687 .feature_table_legacy = features_legacy, 1688 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1689 .driver.name = KBUILD_MODNAME, 1690 .driver.owner = THIS_MODULE, 1691 .id_table = id_table, 1692 .probe = virtblk_probe, 1693 .remove = virtblk_remove, 1694 .config_changed = virtblk_config_changed, 1695#ifdef CONFIG_PM_SLEEP 1696 .freeze = virtblk_freeze, 1697 .restore = virtblk_restore, 1698#endif 1699}; 1700 1701static int __init virtio_blk_init(void) 1702{ 1703 int error; 1704 1705 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1706 if (!virtblk_wq) 1707 return -ENOMEM; 1708 1709 major = register_blkdev(0, "virtblk"); 1710 if (major < 0) { 1711 error = major; 1712 goto out_destroy_workqueue; 1713 } 1714 1715 error = register_virtio_driver(&virtio_blk); 1716 if (error) 1717 goto out_unregister_blkdev; 1718 return 0; 1719 1720out_unregister_blkdev: 1721 unregister_blkdev(major, "virtblk"); 1722out_destroy_workqueue: 1723 destroy_workqueue(virtblk_wq); 1724 return error; 1725} 1726 1727static void __exit virtio_blk_fini(void) 1728{ 1729 unregister_virtio_driver(&virtio_blk); 1730 unregister_blkdev(major, "virtblk"); 1731 destroy_workqueue(virtblk_wq); 1732} 1733module_init(virtio_blk_init); 1734module_exit(virtio_blk_fini); 1735 1736MODULE_DEVICE_TABLE(virtio, id_table); 1737MODULE_DESCRIPTION("Virtio block driver"); 1738MODULE_LICENSE("GPL"); 1739