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/numa.h> 17 #include <linux/vmalloc.h> 18 #include <uapi/linux/virtio_ring.h> 19 20 #define PART_BITS 4 21 #define VQ_NAME_LEN 16 22 #define MAX_DISCARD_SEGMENTS 256u 23 24 /* The maximum number of sg elements that fit into a virtqueue */ 25 #define VIRTIO_BLK_MAX_SG_ELEMS 32768 26 27 #ifdef CONFIG_ARCH_NO_SG_CHAIN 28 #define VIRTIO_BLK_INLINE_SG_CNT 0 29 #else 30 #define VIRTIO_BLK_INLINE_SG_CNT 2 31 #endif 32 33 static unsigned int num_request_queues; 34 module_param(num_request_queues, uint, 0644); 35 MODULE_PARM_DESC(num_request_queues, 36 "Limit the number of request queues to use for blk device. " 37 "0 for no limit. " 38 "Values > nr_cpu_ids truncated to nr_cpu_ids."); 39 40 static unsigned int poll_queues; 41 module_param(poll_queues, uint, 0644); 42 MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); 43 44 static int major; 45 static DEFINE_IDA(vd_index_ida); 46 47 static struct workqueue_struct *virtblk_wq; 48 49 struct virtio_blk_vq { 50 struct virtqueue *vq; 51 spinlock_t lock; 52 char name[VQ_NAME_LEN]; 53 } ____cacheline_aligned_in_smp; 54 55 struct virtio_blk { 56 /* 57 * This mutex must be held by anything that may run after 58 * virtblk_remove() sets vblk->vdev to NULL. 59 * 60 * blk-mq, virtqueue processing, and sysfs attribute code paths are 61 * shut down before vblk->vdev is set to NULL and therefore do not need 62 * to hold this mutex. 63 */ 64 struct mutex vdev_mutex; 65 struct virtio_device *vdev; 66 67 /* The disk structure for the kernel. */ 68 struct gendisk *disk; 69 70 /* Block layer tags. */ 71 struct blk_mq_tag_set tag_set; 72 73 /* Process context for config space updates */ 74 struct work_struct config_work; 75 76 /* Ida index - used to track minor number allocations. */ 77 int index; 78 79 /* num of vqs */ 80 int num_vqs; 81 int io_queues[HCTX_MAX_TYPES]; 82 struct virtio_blk_vq *vqs; 83 84 /* For zoned device */ 85 unsigned int zone_sectors; 86 }; 87 88 struct virtblk_req { 89 /* Out header */ 90 struct virtio_blk_outhdr out_hdr; 91 92 /* In header */ 93 union { 94 u8 status; 95 96 /* 97 * The zone append command has an extended in header. 98 * The status field in zone_append_in_hdr must always 99 * be the last byte. 100 */ 101 struct { 102 __virtio64 sector; 103 u8 status; 104 } zone_append; 105 } in_hdr; 106 107 size_t in_hdr_len; 108 109 struct sg_table sg_table; 110 struct scatterlist sg[]; 111 }; 112 113 static inline blk_status_t virtblk_result(u8 status) 114 { 115 switch (status) { 116 case VIRTIO_BLK_S_OK: 117 return BLK_STS_OK; 118 case VIRTIO_BLK_S_UNSUPP: 119 return BLK_STS_NOTSUPP; 120 case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE: 121 return BLK_STS_ZONE_OPEN_RESOURCE; 122 case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE: 123 return BLK_STS_ZONE_ACTIVE_RESOURCE; 124 case VIRTIO_BLK_S_IOERR: 125 case VIRTIO_BLK_S_ZONE_UNALIGNED_WP: 126 default: 127 return BLK_STS_IOERR; 128 } 129 } 130 131 static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) 132 { 133 struct virtio_blk *vblk = hctx->queue->queuedata; 134 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 135 136 return vq; 137 } 138 139 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) 140 { 141 struct scatterlist out_hdr, in_hdr, *sgs[3]; 142 unsigned int num_out = 0, num_in = 0; 143 144 sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); 145 sgs[num_out++] = &out_hdr; 146 147 if (vbr->sg_table.nents) { 148 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) 149 sgs[num_out++] = vbr->sg_table.sgl; 150 else 151 sgs[num_out + num_in++] = vbr->sg_table.sgl; 152 } 153 154 sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len); 155 sgs[num_out + num_in++] = &in_hdr; 156 157 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); 158 } 159 160 static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap) 161 { 162 unsigned short segments = blk_rq_nr_discard_segments(req); 163 unsigned short n = 0; 164 struct virtio_blk_discard_write_zeroes *range; 165 struct bio *bio; 166 u32 flags = 0; 167 168 if (unmap) 169 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; 170 171 range = kmalloc_objs(*range, segments, GFP_ATOMIC); 172 if (!range) 173 return -ENOMEM; 174 175 /* 176 * Single max discard segment means multi-range discard isn't 177 * supported, and block layer only runs contiguity merge like 178 * normal RW request. So we can't reply on bio for retrieving 179 * each range info. 180 */ 181 if (queue_max_discard_segments(req->q) == 1) { 182 range[0].flags = cpu_to_le32(flags); 183 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); 184 range[0].sector = cpu_to_le64(blk_rq_pos(req)); 185 n = 1; 186 } else { 187 __rq_for_each_bio(bio, req) { 188 u64 sector = bio->bi_iter.bi_sector; 189 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; 190 191 range[n].flags = cpu_to_le32(flags); 192 range[n].num_sectors = cpu_to_le32(num_sectors); 193 range[n].sector = cpu_to_le64(sector); 194 n++; 195 } 196 } 197 198 WARN_ON_ONCE(n != segments); 199 200 bvec_set_virt(&req->special_vec, range, sizeof(*range) * segments); 201 req->rq_flags |= RQF_SPECIAL_PAYLOAD; 202 203 return 0; 204 } 205 206 static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr) 207 { 208 if (blk_rq_nr_phys_segments(req)) 209 sg_free_table_chained(&vbr->sg_table, 210 VIRTIO_BLK_INLINE_SG_CNT); 211 } 212 213 static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req, 214 struct virtblk_req *vbr) 215 { 216 int err; 217 218 if (!blk_rq_nr_phys_segments(req)) 219 return 0; 220 221 vbr->sg_table.sgl = vbr->sg; 222 err = sg_alloc_table_chained(&vbr->sg_table, 223 blk_rq_nr_phys_segments(req), 224 vbr->sg_table.sgl, 225 VIRTIO_BLK_INLINE_SG_CNT); 226 if (unlikely(err)) 227 return -ENOMEM; 228 229 return blk_rq_map_sg(req, vbr->sg_table.sgl); 230 } 231 232 static void virtblk_cleanup_cmd(struct request *req) 233 { 234 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) 235 kfree(bvec_virt(&req->special_vec)); 236 } 237 238 static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, 239 struct request *req, 240 struct virtblk_req *vbr) 241 { 242 size_t in_hdr_len = sizeof(vbr->in_hdr.status); 243 bool unmap = false; 244 u32 type; 245 u64 sector = 0; 246 247 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req))) 248 return BLK_STS_NOTSUPP; 249 250 /* Set fields for all request types */ 251 vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); 252 253 switch (req_op(req)) { 254 case REQ_OP_READ: 255 type = VIRTIO_BLK_T_IN; 256 sector = blk_rq_pos(req); 257 break; 258 case REQ_OP_WRITE: 259 type = VIRTIO_BLK_T_OUT; 260 sector = blk_rq_pos(req); 261 break; 262 case REQ_OP_FLUSH: 263 type = VIRTIO_BLK_T_FLUSH; 264 break; 265 case REQ_OP_DISCARD: 266 type = VIRTIO_BLK_T_DISCARD; 267 break; 268 case REQ_OP_WRITE_ZEROES: 269 type = VIRTIO_BLK_T_WRITE_ZEROES; 270 unmap = !(req->cmd_flags & REQ_NOUNMAP); 271 break; 272 case REQ_OP_SECURE_ERASE: 273 type = VIRTIO_BLK_T_SECURE_ERASE; 274 break; 275 case REQ_OP_ZONE_OPEN: 276 type = VIRTIO_BLK_T_ZONE_OPEN; 277 sector = blk_rq_pos(req); 278 break; 279 case REQ_OP_ZONE_CLOSE: 280 type = VIRTIO_BLK_T_ZONE_CLOSE; 281 sector = blk_rq_pos(req); 282 break; 283 case REQ_OP_ZONE_FINISH: 284 type = VIRTIO_BLK_T_ZONE_FINISH; 285 sector = blk_rq_pos(req); 286 break; 287 case REQ_OP_ZONE_APPEND: 288 type = VIRTIO_BLK_T_ZONE_APPEND; 289 sector = blk_rq_pos(req); 290 in_hdr_len = sizeof(vbr->in_hdr.zone_append); 291 break; 292 case REQ_OP_ZONE_RESET: 293 type = VIRTIO_BLK_T_ZONE_RESET; 294 sector = blk_rq_pos(req); 295 break; 296 case REQ_OP_ZONE_RESET_ALL: 297 type = VIRTIO_BLK_T_ZONE_RESET_ALL; 298 break; 299 case REQ_OP_DRV_IN: 300 /* 301 * Out header has already been prepared by the caller (virtblk_get_id() 302 * or virtblk_submit_zone_report()), nothing to do here. 303 */ 304 return 0; 305 default: 306 WARN_ON_ONCE(1); 307 return BLK_STS_IOERR; 308 } 309 310 /* Set fields for non-REQ_OP_DRV_IN request types */ 311 vbr->in_hdr_len = in_hdr_len; 312 vbr->out_hdr.type = cpu_to_virtio32(vdev, type); 313 vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector); 314 315 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES || 316 type == VIRTIO_BLK_T_SECURE_ERASE) { 317 if (virtblk_setup_discard_write_zeroes_erase(req, unmap)) 318 return BLK_STS_RESOURCE; 319 } 320 321 return 0; 322 } 323 324 /* 325 * The status byte is always the last byte of the virtblk request 326 * in-header. This helper fetches its value for all in-header formats 327 * that are currently defined. 328 */ 329 static inline u8 virtblk_vbr_status(struct virtblk_req *vbr) 330 { 331 return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1); 332 } 333 334 static inline void virtblk_request_done(struct request *req) 335 { 336 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 337 blk_status_t status = virtblk_result(virtblk_vbr_status(vbr)); 338 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 339 340 virtblk_unmap_data(req, vbr); 341 virtblk_cleanup_cmd(req); 342 343 if (req_op(req) == REQ_OP_ZONE_APPEND) 344 req->__sector = virtio64_to_cpu(vblk->vdev, 345 vbr->in_hdr.zone_append.sector); 346 347 blk_mq_end_request(req, status); 348 } 349 350 static void virtblk_done(struct virtqueue *vq) 351 { 352 struct virtio_blk *vblk = vq->vdev->priv; 353 bool req_done = false; 354 int qid = vq->index; 355 struct virtblk_req *vbr; 356 unsigned long flags; 357 unsigned int len; 358 359 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 360 do { 361 virtqueue_disable_cb(vq); 362 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { 363 struct request *req = blk_mq_rq_from_pdu(vbr); 364 365 if (likely(!blk_should_fake_timeout(req->q))) 366 blk_mq_complete_request(req); 367 req_done = true; 368 } 369 } while (!virtqueue_enable_cb(vq)); 370 371 /* In case queue is stopped waiting for more buffers. */ 372 if (req_done) 373 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 374 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 375 } 376 377 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) 378 { 379 struct virtio_blk *vblk = hctx->queue->queuedata; 380 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 381 bool kick; 382 383 spin_lock_irq(&vq->lock); 384 kick = virtqueue_kick_prepare(vq->vq); 385 spin_unlock_irq(&vq->lock); 386 387 if (kick) 388 virtqueue_notify(vq->vq); 389 } 390 391 static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) 392 { 393 virtblk_cleanup_cmd(req); 394 switch (rc) { 395 case -ENOSPC: 396 return BLK_STS_DEV_RESOURCE; 397 case -ENOMEM: 398 return BLK_STS_RESOURCE; 399 default: 400 return BLK_STS_IOERR; 401 } 402 } 403 404 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, 405 struct virtio_blk *vblk, 406 struct request *req, 407 struct virtblk_req *vbr) 408 { 409 blk_status_t status; 410 int num; 411 412 status = virtblk_setup_cmd(vblk->vdev, req, vbr); 413 if (unlikely(status)) 414 return status; 415 416 num = virtblk_map_data(hctx, req, vbr); 417 if (unlikely(num < 0)) 418 return virtblk_fail_to_queue(req, -ENOMEM); 419 vbr->sg_table.nents = num; 420 421 blk_mq_start_request(req); 422 423 return BLK_STS_OK; 424 } 425 426 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, 427 const struct blk_mq_queue_data *bd) 428 { 429 struct virtio_blk *vblk = hctx->queue->queuedata; 430 struct request *req = bd->rq; 431 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 432 unsigned long flags; 433 int qid = hctx->queue_num; 434 bool notify = false; 435 blk_status_t status; 436 int err; 437 438 status = virtblk_prep_rq(hctx, vblk, req, vbr); 439 if (unlikely(status)) 440 return status; 441 442 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 443 err = virtblk_add_req(vblk->vqs[qid].vq, vbr); 444 if (err) { 445 virtqueue_kick(vblk->vqs[qid].vq); 446 /* Don't stop the queue if -ENOMEM: we may have failed to 447 * bounce the buffer due to global resource outage. 448 */ 449 if (err == -ENOSPC) 450 blk_mq_stop_hw_queue(hctx); 451 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 452 virtblk_unmap_data(req, vbr); 453 return virtblk_fail_to_queue(req, err); 454 } 455 456 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) 457 notify = true; 458 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 459 460 if (notify) 461 virtqueue_notify(vblk->vqs[qid].vq); 462 return BLK_STS_OK; 463 } 464 465 static bool virtblk_prep_rq_batch(struct request *req) 466 { 467 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 468 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 469 470 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 471 } 472 473 static void virtblk_add_req_batch(struct virtio_blk_vq *vq, 474 struct rq_list *rqlist) 475 { 476 struct request *req; 477 unsigned long flags; 478 bool kick; 479 480 spin_lock_irqsave(&vq->lock, flags); 481 482 while ((req = rq_list_pop(rqlist))) { 483 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 484 int err; 485 486 err = virtblk_add_req(vq->vq, vbr); 487 if (err) { 488 virtblk_unmap_data(req, vbr); 489 virtblk_cleanup_cmd(req); 490 blk_mq_requeue_request(req, true); 491 } 492 } 493 494 kick = virtqueue_kick_prepare(vq->vq); 495 spin_unlock_irqrestore(&vq->lock, flags); 496 497 if (kick) 498 virtqueue_notify(vq->vq); 499 } 500 501 static void virtio_queue_rqs(struct rq_list *rqlist) 502 { 503 struct rq_list submit_list = { }; 504 struct rq_list requeue_list = { }; 505 struct virtio_blk_vq *vq = NULL; 506 struct request *req; 507 508 while ((req = rq_list_pop(rqlist))) { 509 struct virtio_blk_vq *this_vq = get_virtio_blk_vq(req->mq_hctx); 510 511 if (vq && vq != this_vq) 512 virtblk_add_req_batch(vq, &submit_list); 513 vq = this_vq; 514 515 if (virtblk_prep_rq_batch(req)) 516 rq_list_add_tail(&submit_list, req); 517 else 518 rq_list_add_tail(&requeue_list, req); 519 } 520 521 if (vq) 522 virtblk_add_req_batch(vq, &submit_list); 523 *rqlist = requeue_list; 524 } 525 526 #ifdef CONFIG_BLK_DEV_ZONED 527 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 528 unsigned int nr_zones, 529 size_t *buflen) 530 { 531 struct request_queue *q = vblk->disk->queue; 532 size_t bufsize; 533 void *buf; 534 535 nr_zones = min_t(unsigned int, nr_zones, 536 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); 537 538 bufsize = sizeof(struct virtio_blk_zone_report) + 539 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 540 bufsize = min_t(size_t, bufsize, 541 queue_max_hw_sectors(q) << SECTOR_SHIFT); 542 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 543 544 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 545 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 546 if (buf) { 547 *buflen = bufsize; 548 return buf; 549 } 550 bufsize >>= 1; 551 } 552 553 return NULL; 554 } 555 556 static int virtblk_submit_zone_report(struct virtio_blk *vblk, 557 char *report_buf, size_t report_len, 558 sector_t sector) 559 { 560 struct request_queue *q = vblk->disk->queue; 561 struct request *req; 562 struct virtblk_req *vbr; 563 int err; 564 565 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 566 if (IS_ERR(req)) 567 return PTR_ERR(req); 568 569 vbr = blk_mq_rq_to_pdu(req); 570 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 571 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 572 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 573 574 err = blk_rq_map_kern(req, report_buf, report_len, GFP_KERNEL); 575 if (err) 576 goto out; 577 578 blk_execute_rq(req, false); 579 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 580 out: 581 blk_mq_free_request(req); 582 return err; 583 } 584 585 static int virtblk_parse_zone(struct virtio_blk *vblk, 586 struct virtio_blk_zone_descriptor *entry, 587 unsigned int idx, 588 struct blk_report_zones_args *args) 589 { 590 struct blk_zone zone = { }; 591 592 zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start); 593 if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk)) 594 zone.len = vblk->zone_sectors; 595 else 596 zone.len = get_capacity(vblk->disk) - zone.start; 597 zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap); 598 zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp); 599 600 switch (entry->z_type) { 601 case VIRTIO_BLK_ZT_SWR: 602 zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ; 603 break; 604 case VIRTIO_BLK_ZT_SWP: 605 zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF; 606 break; 607 case VIRTIO_BLK_ZT_CONV: 608 zone.type = BLK_ZONE_TYPE_CONVENTIONAL; 609 break; 610 default: 611 dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n", 612 zone.start, entry->z_type); 613 return -EIO; 614 } 615 616 switch (entry->z_state) { 617 case VIRTIO_BLK_ZS_EMPTY: 618 zone.cond = BLK_ZONE_COND_EMPTY; 619 break; 620 case VIRTIO_BLK_ZS_CLOSED: 621 zone.cond = BLK_ZONE_COND_CLOSED; 622 break; 623 case VIRTIO_BLK_ZS_FULL: 624 zone.cond = BLK_ZONE_COND_FULL; 625 zone.wp = zone.start + zone.len; 626 break; 627 case VIRTIO_BLK_ZS_EOPEN: 628 zone.cond = BLK_ZONE_COND_EXP_OPEN; 629 break; 630 case VIRTIO_BLK_ZS_IOPEN: 631 zone.cond = BLK_ZONE_COND_IMP_OPEN; 632 break; 633 case VIRTIO_BLK_ZS_NOT_WP: 634 zone.cond = BLK_ZONE_COND_NOT_WP; 635 break; 636 case VIRTIO_BLK_ZS_RDONLY: 637 zone.cond = BLK_ZONE_COND_READONLY; 638 zone.wp = ULONG_MAX; 639 break; 640 case VIRTIO_BLK_ZS_OFFLINE: 641 zone.cond = BLK_ZONE_COND_OFFLINE; 642 zone.wp = ULONG_MAX; 643 break; 644 default: 645 dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n", 646 zone.start, entry->z_state); 647 return -EIO; 648 } 649 650 /* 651 * The callback below checks the validity of the reported 652 * entry data, no need to further validate it here. 653 */ 654 return disk_report_zone(vblk->disk, &zone, idx, args); 655 } 656 657 static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 658 unsigned int nr_zones, 659 struct blk_report_zones_args *args) 660 { 661 struct virtio_blk *vblk = disk->private_data; 662 struct virtio_blk_zone_report *report; 663 unsigned long long nz, i; 664 size_t buflen; 665 unsigned int zone_idx = 0; 666 int ret; 667 668 if (WARN_ON_ONCE(!vblk->zone_sectors)) 669 return -EOPNOTSUPP; 670 671 report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen); 672 if (!report) 673 return -ENOMEM; 674 675 mutex_lock(&vblk->vdev_mutex); 676 677 if (!vblk->vdev) { 678 ret = -ENXIO; 679 goto fail_report; 680 } 681 682 while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { 683 memset(report, 0, buflen); 684 685 ret = virtblk_submit_zone_report(vblk, (char *)report, 686 buflen, sector); 687 if (ret) 688 goto fail_report; 689 690 nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones), 691 nr_zones); 692 nz = min_t(u64, nz, 693 (buflen - sizeof(*report)) / sizeof(report->zones[0])); 694 if (!nz) 695 break; 696 697 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 698 ret = virtblk_parse_zone(vblk, &report->zones[i], 699 zone_idx, args); 700 if (ret) 701 goto fail_report; 702 703 sector = virtio64_to_cpu(vblk->vdev, 704 report->zones[i].z_start) + 705 vblk->zone_sectors; 706 zone_idx++; 707 } 708 } 709 710 if (zone_idx > 0) 711 ret = zone_idx; 712 else 713 ret = -EINVAL; 714 fail_report: 715 mutex_unlock(&vblk->vdev_mutex); 716 kvfree(report); 717 return ret; 718 } 719 720 static int virtblk_read_zoned_limits(struct virtio_blk *vblk, 721 struct queue_limits *lim) 722 { 723 struct virtio_device *vdev = vblk->vdev; 724 u32 v, wg; 725 726 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 727 728 lim->features |= BLK_FEAT_ZONED; 729 730 virtio_cread(vdev, struct virtio_blk_config, 731 zoned.max_open_zones, &v); 732 lim->max_open_zones = v; 733 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 734 735 virtio_cread(vdev, struct virtio_blk_config, 736 zoned.max_active_zones, &v); 737 lim->max_active_zones = v; 738 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 739 740 virtio_cread(vdev, struct virtio_blk_config, 741 zoned.write_granularity, &wg); 742 if (!wg) { 743 dev_warn(&vdev->dev, "zero write granularity reported\n"); 744 return -ENODEV; 745 } 746 lim->zone_write_granularity = wg; 747 lim->physical_block_size = wg; 748 lim->io_min = wg; 749 750 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 751 752 /* 753 * virtio ZBD specification doesn't require zones to be a power of 754 * two sectors in size, but the code in this driver expects that. 755 */ 756 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 757 &vblk->zone_sectors); 758 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 759 dev_err(&vdev->dev, 760 "zoned device with non power of two zone size %u\n", 761 vblk->zone_sectors); 762 return -ENODEV; 763 } 764 lim->chunk_sectors = vblk->zone_sectors; 765 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 766 767 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 768 dev_warn(&vblk->vdev->dev, 769 "ignoring negotiated F_DISCARD for zoned device\n"); 770 lim->max_hw_discard_sectors = 0; 771 } 772 773 virtio_cread(vdev, struct virtio_blk_config, 774 zoned.max_append_sectors, &v); 775 if (!v) { 776 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 777 return -ENODEV; 778 } 779 if ((v << SECTOR_SHIFT) < wg) { 780 dev_err(&vdev->dev, 781 "write granularity %u exceeds max_append_sectors %u limit\n", 782 wg, v); 783 return -ENODEV; 784 } 785 lim->max_hw_zone_append_sectors = v; 786 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 787 788 return 0; 789 } 790 #else 791 /* 792 * Zoned block device support is not configured in this kernel, host-managed 793 * zoned devices can't be supported. 794 */ 795 #define virtblk_report_zones NULL 796 static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk, 797 struct queue_limits *lim) 798 { 799 dev_err(&vblk->vdev->dev, 800 "virtio_blk: zoned devices are not supported"); 801 return -EOPNOTSUPP; 802 } 803 #endif /* CONFIG_BLK_DEV_ZONED */ 804 805 /* return id (s/n) string for *disk to *id_str 806 */ 807 static int virtblk_get_id(struct gendisk *disk, char *id_str) 808 { 809 struct virtio_blk *vblk = disk->private_data; 810 struct request_queue *q = vblk->disk->queue; 811 struct request *req; 812 struct virtblk_req *vbr; 813 int err; 814 815 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 816 if (IS_ERR(req)) 817 return PTR_ERR(req); 818 819 vbr = blk_mq_rq_to_pdu(req); 820 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 821 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 822 vbr->out_hdr.sector = 0; 823 824 err = blk_rq_map_kern(req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 825 if (err) 826 goto out; 827 828 blk_execute_rq(req, false); 829 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 830 out: 831 blk_mq_free_request(req); 832 return err; 833 } 834 835 /* We provide getgeo only to please some old bootloader/partitioning tools */ 836 static int virtblk_getgeo(struct gendisk *disk, struct hd_geometry *geo) 837 { 838 struct virtio_blk *vblk = disk->private_data; 839 int ret = 0; 840 841 mutex_lock(&vblk->vdev_mutex); 842 843 if (!vblk->vdev) { 844 ret = -ENXIO; 845 goto out; 846 } 847 848 /* see if the host passed in geometry config */ 849 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 850 virtio_cread(vblk->vdev, struct virtio_blk_config, 851 geometry.cylinders, &geo->cylinders); 852 virtio_cread(vblk->vdev, struct virtio_blk_config, 853 geometry.heads, &geo->heads); 854 virtio_cread(vblk->vdev, struct virtio_blk_config, 855 geometry.sectors, &geo->sectors); 856 } else { 857 /* some standard values, similar to sd */ 858 geo->heads = 1 << 6; 859 geo->sectors = 1 << 5; 860 geo->cylinders = get_capacity(disk) >> 11; 861 } 862 out: 863 mutex_unlock(&vblk->vdev_mutex); 864 return ret; 865 } 866 867 static void virtblk_free_disk(struct gendisk *disk) 868 { 869 struct virtio_blk *vblk = disk->private_data; 870 871 ida_free(&vd_index_ida, vblk->index); 872 mutex_destroy(&vblk->vdev_mutex); 873 kfree(vblk); 874 } 875 876 static const struct block_device_operations virtblk_fops = { 877 .owner = THIS_MODULE, 878 .getgeo = virtblk_getgeo, 879 .free_disk = virtblk_free_disk, 880 .report_zones = virtblk_report_zones, 881 }; 882 883 static int index_to_minor(int index) 884 { 885 return index << PART_BITS; 886 } 887 888 static int minor_to_index(int minor) 889 { 890 return minor >> PART_BITS; 891 } 892 893 static ssize_t serial_show(struct device *dev, 894 struct device_attribute *attr, char *buf) 895 { 896 struct gendisk *disk = dev_to_disk(dev); 897 int err; 898 899 /* sysfs gives us a PAGE_SIZE buffer */ 900 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 901 902 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 903 err = virtblk_get_id(disk, buf); 904 if (!err) 905 return strlen(buf); 906 907 if (err == -EIO) /* Unsupported? Make it empty. */ 908 return 0; 909 910 return err; 911 } 912 913 static DEVICE_ATTR_RO(serial); 914 915 /* The queue's logical block size must be set before calling this */ 916 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 917 { 918 struct virtio_device *vdev = vblk->vdev; 919 struct request_queue *q = vblk->disk->queue; 920 char cap_str_2[10], cap_str_10[10]; 921 unsigned long long nblocks; 922 u64 capacity; 923 924 /* Host must always specify the capacity. */ 925 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 926 927 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 928 929 string_get_size(nblocks, queue_logical_block_size(q), 930 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 931 string_get_size(nblocks, queue_logical_block_size(q), 932 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 933 934 dev_notice(&vdev->dev, 935 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 936 vblk->disk->disk_name, 937 resize ? "new size: " : "", 938 nblocks, 939 queue_logical_block_size(q), 940 cap_str_10, 941 cap_str_2); 942 943 set_capacity_and_notify(vblk->disk, capacity); 944 } 945 946 static void virtblk_config_changed_work(struct work_struct *work) 947 { 948 struct virtio_blk *vblk = 949 container_of(work, struct virtio_blk, config_work); 950 951 virtblk_update_capacity(vblk, true); 952 } 953 954 static void virtblk_config_changed(struct virtio_device *vdev) 955 { 956 struct virtio_blk *vblk = vdev->priv; 957 958 queue_work(virtblk_wq, &vblk->config_work); 959 } 960 961 static int init_vq(struct virtio_blk *vblk) 962 { 963 int err; 964 unsigned short i; 965 struct virtqueue_info *vqs_info; 966 struct virtqueue **vqs; 967 unsigned short num_vqs; 968 unsigned short num_poll_vqs; 969 struct virtio_device *vdev = vblk->vdev; 970 struct irq_affinity desc = { 0, }; 971 972 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 973 struct virtio_blk_config, num_queues, 974 &num_vqs); 975 if (err) 976 num_vqs = 1; 977 978 if (!err && !num_vqs) { 979 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 980 return -EINVAL; 981 } 982 983 num_vqs = blk_mq_num_possible_queues( 984 min_not_zero(num_request_queues, num_vqs)); 985 986 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 987 988 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 989 vblk->io_queues[HCTX_TYPE_READ] = 0; 990 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 991 992 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 993 vblk->io_queues[HCTX_TYPE_DEFAULT], 994 vblk->io_queues[HCTX_TYPE_READ], 995 vblk->io_queues[HCTX_TYPE_POLL]); 996 997 vblk->vqs = kmalloc_objs(*vblk->vqs, num_vqs); 998 if (!vblk->vqs) 999 return -ENOMEM; 1000 1001 vqs_info = kzalloc_objs(*vqs_info, num_vqs); 1002 vqs = kmalloc_objs(*vqs, num_vqs); 1003 if (!vqs_info || !vqs) { 1004 err = -ENOMEM; 1005 goto out; 1006 } 1007 1008 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1009 vqs_info[i].callback = virtblk_done; 1010 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1011 vqs_info[i].name = vblk->vqs[i].name; 1012 } 1013 1014 for (; i < num_vqs; i++) { 1015 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1016 vqs_info[i].name = vblk->vqs[i].name; 1017 } 1018 1019 /* Discover virtqueues and write information to configuration. */ 1020 err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc); 1021 if (err) 1022 goto out; 1023 1024 for (i = 0; i < num_vqs; i++) { 1025 spin_lock_init(&vblk->vqs[i].lock); 1026 vblk->vqs[i].vq = vqs[i]; 1027 } 1028 vblk->num_vqs = num_vqs; 1029 1030 out: 1031 kfree(vqs); 1032 kfree(vqs_info); 1033 if (err) { 1034 kfree(vblk->vqs); 1035 /* 1036 * Set to NULL to prevent freeing vqs again during freezing. 1037 */ 1038 vblk->vqs = NULL; 1039 } 1040 return err; 1041 } 1042 1043 /* 1044 * Legacy naming scheme used for virtio devices. We are stuck with it for 1045 * virtio blk but don't ever use it for any new driver. 1046 */ 1047 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1048 { 1049 const int base = 'z' - 'a' + 1; 1050 char *begin = buf + strlen(prefix); 1051 char *end = buf + buflen; 1052 char *p; 1053 int unit; 1054 1055 p = end - 1; 1056 *p = '\0'; 1057 unit = base; 1058 do { 1059 if (p == begin) 1060 return -EINVAL; 1061 *--p = 'a' + (index % unit); 1062 index = (index / unit) - 1; 1063 } while (index >= 0); 1064 1065 memmove(begin, p, end - p); 1066 memcpy(buf, prefix, strlen(prefix)); 1067 1068 return 0; 1069 } 1070 1071 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1072 { 1073 u8 writeback; 1074 int err; 1075 1076 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1077 struct virtio_blk_config, wce, 1078 &writeback); 1079 1080 /* 1081 * If WCE is not configurable and flush is not available, 1082 * assume no writeback cache is in use. 1083 */ 1084 if (err) 1085 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1086 1087 return writeback; 1088 } 1089 1090 static const char *const virtblk_cache_types[] = { 1091 "write through", "write back" 1092 }; 1093 1094 static ssize_t 1095 cache_type_store(struct device *dev, struct device_attribute *attr, 1096 const char *buf, size_t count) 1097 { 1098 struct gendisk *disk = dev_to_disk(dev); 1099 struct virtio_blk *vblk = disk->private_data; 1100 struct virtio_device *vdev = vblk->vdev; 1101 struct queue_limits lim; 1102 int i; 1103 1104 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1105 i = sysfs_match_string(virtblk_cache_types, buf); 1106 if (i < 0) 1107 return i; 1108 1109 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1110 1111 lim = queue_limits_start_update(disk->queue); 1112 if (virtblk_get_cache_mode(vdev)) 1113 lim.features |= BLK_FEAT_WRITE_CACHE; 1114 else 1115 lim.features &= ~BLK_FEAT_WRITE_CACHE; 1116 i = queue_limits_commit_update_frozen(disk->queue, &lim); 1117 if (i) 1118 return i; 1119 return count; 1120 } 1121 1122 static ssize_t 1123 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1124 { 1125 struct gendisk *disk = dev_to_disk(dev); 1126 struct virtio_blk *vblk = disk->private_data; 1127 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1128 1129 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1130 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1131 } 1132 1133 static DEVICE_ATTR_RW(cache_type); 1134 1135 static struct attribute *virtblk_attrs[] = { 1136 &dev_attr_serial.attr, 1137 &dev_attr_cache_type.attr, 1138 NULL, 1139 }; 1140 1141 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1142 struct attribute *a, int n) 1143 { 1144 struct device *dev = kobj_to_dev(kobj); 1145 struct gendisk *disk = dev_to_disk(dev); 1146 struct virtio_blk *vblk = disk->private_data; 1147 struct virtio_device *vdev = vblk->vdev; 1148 1149 if (a == &dev_attr_cache_type.attr && 1150 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1151 return S_IRUGO; 1152 1153 return a->mode; 1154 } 1155 1156 static const struct attribute_group virtblk_attr_group = { 1157 .attrs = virtblk_attrs, 1158 .is_visible = virtblk_attrs_are_visible, 1159 }; 1160 1161 static const struct attribute_group *virtblk_attr_groups[] = { 1162 &virtblk_attr_group, 1163 NULL, 1164 }; 1165 1166 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1167 { 1168 struct virtio_blk *vblk = set->driver_data; 1169 int i, qoff; 1170 1171 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1172 struct blk_mq_queue_map *map = &set->map[i]; 1173 1174 map->nr_queues = vblk->io_queues[i]; 1175 map->queue_offset = qoff; 1176 qoff += map->nr_queues; 1177 1178 if (map->nr_queues == 0) 1179 continue; 1180 1181 /* 1182 * Regular queues have interrupts and hence CPU affinity is 1183 * defined by the core virtio code, but polling queues have 1184 * no interrupts so we let the block layer assign CPU affinity. 1185 */ 1186 if (i == HCTX_TYPE_POLL) 1187 blk_mq_map_queues(&set->map[i]); 1188 else 1189 blk_mq_map_hw_queues(&set->map[i], 1190 &vblk->vdev->dev, 0); 1191 } 1192 } 1193 1194 static 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 1205 static 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 u8 status = virtblk_vbr_status(vbr); 1219 1220 found++; 1221 if (!blk_mq_complete_request_remote(req) && 1222 !blk_mq_add_to_batch(req, iob, status != VIRTIO_BLK_S_OK, 1223 virtblk_complete_batch)) 1224 virtblk_request_done(req); 1225 } 1226 1227 if (found) 1228 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1229 1230 spin_unlock_irqrestore(&vq->lock, flags); 1231 1232 return found; 1233 } 1234 1235 static const struct blk_mq_ops virtio_mq_ops = { 1236 .queue_rq = virtio_queue_rq, 1237 .queue_rqs = virtio_queue_rqs, 1238 .commit_rqs = virtio_commit_rqs, 1239 .complete = virtblk_request_done, 1240 .map_queues = virtblk_map_queues, 1241 .poll = virtblk_poll, 1242 }; 1243 1244 static unsigned int virtblk_queue_depth; 1245 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1246 1247 static int virtblk_read_limits(struct virtio_blk *vblk, 1248 struct queue_limits *lim) 1249 { 1250 struct virtio_device *vdev = vblk->vdev; 1251 u32 v, max_size, sg_elems, opt_io_size; 1252 u32 max_discard_segs = 0; 1253 u32 discard_granularity = 0; 1254 u16 min_io_size; 1255 u8 physical_block_exp, alignment_offset; 1256 size_t max_dma_size; 1257 int err; 1258 1259 /* We need to know how many segments before we allocate. */ 1260 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1261 struct virtio_blk_config, seg_max, 1262 &sg_elems); 1263 1264 /* We need at least one SG element, whatever they say. */ 1265 if (err || !sg_elems) 1266 sg_elems = 1; 1267 1268 /* Prevent integer overflows and honor max vq size */ 1269 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1270 1271 /* We can handle whatever the host told us to handle. */ 1272 lim->max_segments = sg_elems; 1273 1274 /* No real sector limit. */ 1275 lim->max_hw_sectors = UINT_MAX; 1276 1277 max_dma_size = virtio_max_dma_size(vdev); 1278 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1279 1280 /* Host can optionally specify maximum segment size and number of 1281 * segments. */ 1282 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1283 struct virtio_blk_config, size_max, &v); 1284 if (!err) 1285 max_size = min(max_size, v); 1286 1287 lim->max_segment_size = max_size; 1288 1289 /* Host can optionally specify the block size of the device */ 1290 virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1291 struct virtio_blk_config, blk_size, 1292 &lim->logical_block_size); 1293 1294 /* Use topology information if available */ 1295 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1296 struct virtio_blk_config, physical_block_exp, 1297 &physical_block_exp); 1298 if (!err && physical_block_exp) 1299 lim->physical_block_size = 1300 lim->logical_block_size * (1 << physical_block_exp); 1301 1302 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1303 struct virtio_blk_config, alignment_offset, 1304 &alignment_offset); 1305 if (!err && alignment_offset) 1306 lim->alignment_offset = 1307 lim->logical_block_size * alignment_offset; 1308 1309 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1310 struct virtio_blk_config, min_io_size, 1311 &min_io_size); 1312 if (!err && min_io_size) 1313 lim->io_min = lim->logical_block_size * min_io_size; 1314 1315 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1316 struct virtio_blk_config, opt_io_size, 1317 &opt_io_size); 1318 if (!err && opt_io_size) 1319 lim->io_opt = lim->logical_block_size * opt_io_size; 1320 1321 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1322 virtio_cread(vdev, struct virtio_blk_config, 1323 discard_sector_alignment, &discard_granularity); 1324 1325 virtio_cread(vdev, struct virtio_blk_config, 1326 max_discard_sectors, &v); 1327 lim->max_hw_discard_sectors = v ? v : UINT_MAX; 1328 1329 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1330 &max_discard_segs); 1331 } 1332 1333 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1334 virtio_cread(vdev, struct virtio_blk_config, 1335 max_write_zeroes_sectors, &v); 1336 lim->max_write_zeroes_sectors = v ? v : UINT_MAX; 1337 } 1338 1339 /* The discard and secure erase limits are combined since the Linux 1340 * block layer uses the same limit for both commands. 1341 * 1342 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1343 * are negotiated, we will use the minimum between the limits. 1344 * 1345 * discard sector alignment is set to the minimum between discard_sector_alignment 1346 * and secure_erase_sector_alignment. 1347 * 1348 * max discard sectors is set to the minimum between max_discard_seg and 1349 * max_secure_erase_seg. 1350 */ 1351 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1352 1353 virtio_cread(vdev, struct virtio_blk_config, 1354 secure_erase_sector_alignment, &v); 1355 1356 /* secure_erase_sector_alignment should not be zero, the device should set a 1357 * valid number of sectors. 1358 */ 1359 if (!v) { 1360 dev_err(&vdev->dev, 1361 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1362 return -EINVAL; 1363 } 1364 1365 discard_granularity = min_not_zero(discard_granularity, v); 1366 1367 virtio_cread(vdev, struct virtio_blk_config, 1368 max_secure_erase_sectors, &v); 1369 1370 /* max_secure_erase_sectors should not be zero, the device should set a 1371 * valid number of sectors. 1372 */ 1373 if (!v) { 1374 dev_err(&vdev->dev, 1375 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1376 return -EINVAL; 1377 } 1378 1379 lim->max_secure_erase_sectors = v; 1380 1381 virtio_cread(vdev, struct virtio_blk_config, 1382 max_secure_erase_seg, &v); 1383 1384 /* max_secure_erase_seg should not be zero, the device should set a 1385 * valid number of segments 1386 */ 1387 if (!v) { 1388 dev_err(&vdev->dev, 1389 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1390 return -EINVAL; 1391 } 1392 1393 max_discard_segs = min_not_zero(max_discard_segs, v); 1394 } 1395 1396 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1397 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1398 /* max_discard_seg and discard_granularity will be 0 only 1399 * if max_discard_seg and discard_sector_alignment fields in the virtio 1400 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1401 * In this case, we use default values. 1402 */ 1403 if (!max_discard_segs) 1404 max_discard_segs = sg_elems; 1405 1406 lim->max_discard_segments = 1407 min(max_discard_segs, MAX_DISCARD_SEGMENTS); 1408 1409 if (discard_granularity) 1410 lim->discard_granularity = 1411 discard_granularity << SECTOR_SHIFT; 1412 else 1413 lim->discard_granularity = lim->logical_block_size; 1414 } 1415 1416 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1417 u8 model; 1418 1419 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); 1420 switch (model) { 1421 case VIRTIO_BLK_Z_NONE: 1422 case VIRTIO_BLK_Z_HA: 1423 /* treat host-aware devices as non-zoned */ 1424 return 0; 1425 case VIRTIO_BLK_Z_HM: 1426 err = virtblk_read_zoned_limits(vblk, lim); 1427 if (err) 1428 return err; 1429 break; 1430 default: 1431 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 1432 return -EINVAL; 1433 } 1434 } 1435 1436 return 0; 1437 } 1438 1439 static int virtblk_probe(struct virtio_device *vdev) 1440 { 1441 struct virtio_blk *vblk; 1442 struct queue_limits lim = { 1443 .features = BLK_FEAT_ROTATIONAL, 1444 .logical_block_size = SECTOR_SIZE, 1445 }; 1446 int err, index; 1447 unsigned int queue_depth; 1448 1449 if (!vdev->config->get) { 1450 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1451 __func__); 1452 return -EINVAL; 1453 } 1454 1455 err = ida_alloc_range(&vd_index_ida, 0, 1456 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1457 if (err < 0) 1458 goto out; 1459 index = err; 1460 1461 vdev->priv = vblk = kmalloc_obj(*vblk); 1462 if (!vblk) { 1463 err = -ENOMEM; 1464 goto out_free_index; 1465 } 1466 1467 mutex_init(&vblk->vdev_mutex); 1468 1469 vblk->vdev = vdev; 1470 1471 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1472 1473 err = init_vq(vblk); 1474 if (err) 1475 goto out_free_vblk; 1476 1477 /* Default queue sizing is to fill the ring. */ 1478 if (!virtblk_queue_depth) { 1479 queue_depth = vblk->vqs[0].vq->num_free; 1480 /* ... but without indirect descs, we use 2 descs per req */ 1481 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1482 queue_depth /= 2; 1483 } else { 1484 queue_depth = virtblk_queue_depth; 1485 } 1486 1487 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1488 vblk->tag_set.ops = &virtio_mq_ops; 1489 vblk->tag_set.queue_depth = queue_depth; 1490 vblk->tag_set.numa_node = NUMA_NO_NODE; 1491 vblk->tag_set.cmd_size = 1492 sizeof(struct virtblk_req) + 1493 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1494 vblk->tag_set.driver_data = vblk; 1495 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1496 vblk->tag_set.nr_maps = 1; 1497 if (vblk->io_queues[HCTX_TYPE_POLL]) 1498 vblk->tag_set.nr_maps = 3; 1499 1500 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1501 if (err) 1502 goto out_free_vq; 1503 1504 err = virtblk_read_limits(vblk, &lim); 1505 if (err) 1506 goto out_free_tags; 1507 1508 if (virtblk_get_cache_mode(vdev)) 1509 lim.features |= BLK_FEAT_WRITE_CACHE; 1510 1511 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk); 1512 if (IS_ERR(vblk->disk)) { 1513 err = PTR_ERR(vblk->disk); 1514 goto out_free_tags; 1515 } 1516 1517 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1518 1519 vblk->disk->major = major; 1520 vblk->disk->first_minor = index_to_minor(index); 1521 vblk->disk->minors = 1 << PART_BITS; 1522 vblk->disk->private_data = vblk; 1523 vblk->disk->fops = &virtblk_fops; 1524 vblk->index = index; 1525 1526 /* If disk is read-only in the host, the guest should obey */ 1527 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1528 set_disk_ro(vblk->disk, 1); 1529 1530 virtblk_update_capacity(vblk, false); 1531 virtio_device_ready(vdev); 1532 1533 /* 1534 * All steps that follow use the VQs therefore they need to be 1535 * placed after the virtio_device_ready() call above. 1536 */ 1537 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && 1538 (lim.features & BLK_FEAT_ZONED)) { 1539 err = blk_revalidate_disk_zones(vblk->disk); 1540 if (err) 1541 goto out_cleanup_disk; 1542 } 1543 1544 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1545 if (err) 1546 goto out_cleanup_disk; 1547 1548 return 0; 1549 1550 out_cleanup_disk: 1551 put_disk(vblk->disk); 1552 out_free_tags: 1553 blk_mq_free_tag_set(&vblk->tag_set); 1554 out_free_vq: 1555 vdev->config->del_vqs(vdev); 1556 kfree(vblk->vqs); 1557 out_free_vblk: 1558 kfree(vblk); 1559 out_free_index: 1560 ida_free(&vd_index_ida, index); 1561 out: 1562 return err; 1563 } 1564 1565 static void virtblk_remove(struct virtio_device *vdev) 1566 { 1567 struct virtio_blk *vblk = vdev->priv; 1568 1569 /* Make sure no work handler is accessing the device. */ 1570 flush_work(&vblk->config_work); 1571 1572 del_gendisk(vblk->disk); 1573 blk_mq_free_tag_set(&vblk->tag_set); 1574 1575 mutex_lock(&vblk->vdev_mutex); 1576 1577 /* Stop all the virtqueues. */ 1578 virtio_reset_device(vdev); 1579 1580 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1581 vblk->vdev = NULL; 1582 1583 vdev->config->del_vqs(vdev); 1584 kfree(vblk->vqs); 1585 1586 mutex_unlock(&vblk->vdev_mutex); 1587 1588 put_disk(vblk->disk); 1589 } 1590 1591 static int virtblk_freeze_priv(struct virtio_device *vdev) 1592 { 1593 struct virtio_blk *vblk = vdev->priv; 1594 struct request_queue *q = vblk->disk->queue; 1595 unsigned int memflags; 1596 1597 /* Ensure no requests in virtqueues before deleting vqs. */ 1598 memflags = blk_mq_freeze_queue(q); 1599 blk_mq_quiesce_queue_nowait(q); 1600 blk_mq_unfreeze_queue(q, memflags); 1601 1602 /* Ensure we don't receive any more interrupts */ 1603 virtio_reset_device(vdev); 1604 1605 /* Make sure no work handler is accessing the device. */ 1606 flush_work(&vblk->config_work); 1607 1608 vdev->config->del_vqs(vdev); 1609 kfree(vblk->vqs); 1610 /* 1611 * Set to NULL to prevent freeing vqs again after a failed vqs 1612 * allocation during resume. Note that kfree() already handles NULL 1613 * pointers safely. 1614 */ 1615 vblk->vqs = NULL; 1616 1617 return 0; 1618 } 1619 1620 static int virtblk_restore_priv(struct virtio_device *vdev) 1621 { 1622 struct virtio_blk *vblk = vdev->priv; 1623 int ret; 1624 1625 ret = init_vq(vdev->priv); 1626 if (ret) 1627 return ret; 1628 1629 virtio_device_ready(vdev); 1630 blk_mq_unquiesce_queue(vblk->disk->queue); 1631 1632 return 0; 1633 } 1634 1635 #ifdef CONFIG_PM_SLEEP 1636 static int virtblk_freeze(struct virtio_device *vdev) 1637 { 1638 return virtblk_freeze_priv(vdev); 1639 } 1640 1641 static int virtblk_restore(struct virtio_device *vdev) 1642 { 1643 return virtblk_restore_priv(vdev); 1644 } 1645 #endif 1646 1647 static int virtblk_reset_prepare(struct virtio_device *vdev) 1648 { 1649 return virtblk_freeze_priv(vdev); 1650 } 1651 1652 static int virtblk_reset_done(struct virtio_device *vdev) 1653 { 1654 return virtblk_restore_priv(vdev); 1655 } 1656 1657 static const struct virtio_device_id id_table[] = { 1658 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1659 { 0 }, 1660 }; 1661 1662 static unsigned int features_legacy[] = { 1663 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1664 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1665 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1666 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1667 VIRTIO_BLK_F_SECURE_ERASE, 1668 } 1669 ; 1670 static unsigned int features[] = { 1671 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1672 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1673 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1674 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1675 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1676 }; 1677 1678 static struct virtio_driver virtio_blk = { 1679 .feature_table = features, 1680 .feature_table_size = ARRAY_SIZE(features), 1681 .feature_table_legacy = features_legacy, 1682 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1683 .driver.name = KBUILD_MODNAME, 1684 .id_table = id_table, 1685 .probe = virtblk_probe, 1686 .remove = virtblk_remove, 1687 .config_changed = virtblk_config_changed, 1688 #ifdef CONFIG_PM_SLEEP 1689 .freeze = virtblk_freeze, 1690 .restore = virtblk_restore, 1691 #endif 1692 .reset_prepare = virtblk_reset_prepare, 1693 .reset_done = virtblk_reset_done, 1694 }; 1695 1696 static int __init virtio_blk_init(void) 1697 { 1698 int error; 1699 1700 virtblk_wq = alloc_workqueue("virtio-blk", WQ_PERCPU, 0); 1701 if (!virtblk_wq) 1702 return -ENOMEM; 1703 1704 major = register_blkdev(0, "virtblk"); 1705 if (major < 0) { 1706 error = major; 1707 goto out_destroy_workqueue; 1708 } 1709 1710 error = register_virtio_driver(&virtio_blk); 1711 if (error) 1712 goto out_unregister_blkdev; 1713 return 0; 1714 1715 out_unregister_blkdev: 1716 unregister_blkdev(major, "virtblk"); 1717 out_destroy_workqueue: 1718 destroy_workqueue(virtblk_wq); 1719 return error; 1720 } 1721 1722 static void __exit virtio_blk_fini(void) 1723 { 1724 unregister_virtio_driver(&virtio_blk); 1725 unregister_blkdev(major, "virtblk"); 1726 destroy_workqueue(virtblk_wq); 1727 } 1728 module_init(virtio_blk_init); 1729 module_exit(virtio_blk_fini); 1730 1731 MODULE_DEVICE_TABLE(virtio, id_table); 1732 MODULE_DESCRIPTION("Virtio block driver"); 1733 MODULE_LICENSE("GPL"); 1734