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