1 // SPDX-License-Identifier: GPL-2.0-only 2 //#define DEBUG 3 #include <linux/spinlock.h> 4 #include <linux/slab.h> 5 #include <linux/blkdev.h> 6 #include <linux/hdreg.h> 7 #include <linux/module.h> 8 #include <linux/mutex.h> 9 #include <linux/interrupt.h> 10 #include <linux/virtio.h> 11 #include <linux/virtio_blk.h> 12 #include <linux/scatterlist.h> 13 #include <linux/string_helpers.h> 14 #include <linux/idr.h> 15 #include <linux/blk-mq.h> 16 #include <linux/blk-mq-virtio.h> 17 #include <linux/numa.h> 18 #include <linux/vmalloc.h> 19 #include <uapi/linux/virtio_ring.h> 20 21 #define PART_BITS 4 22 #define VQ_NAME_LEN 16 23 #define MAX_DISCARD_SEGMENTS 256u 24 25 /* The maximum number of sg elements that fit into a virtqueue */ 26 #define VIRTIO_BLK_MAX_SG_ELEMS 32768 27 28 #ifdef CONFIG_ARCH_NO_SG_CHAIN 29 #define VIRTIO_BLK_INLINE_SG_CNT 0 30 #else 31 #define VIRTIO_BLK_INLINE_SG_CNT 2 32 #endif 33 34 static unsigned int num_request_queues; 35 module_param(num_request_queues, uint, 0644); 36 MODULE_PARM_DESC(num_request_queues, 37 "Limit the number of request queues to use for blk device. " 38 "0 for no limit. " 39 "Values > nr_cpu_ids truncated to nr_cpu_ids."); 40 41 static unsigned int poll_queues; 42 module_param(poll_queues, uint, 0644); 43 MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); 44 45 static int major; 46 static DEFINE_IDA(vd_index_ida); 47 48 static struct workqueue_struct *virtblk_wq; 49 50 struct virtio_blk_vq { 51 struct virtqueue *vq; 52 spinlock_t lock; 53 char name[VQ_NAME_LEN]; 54 } ____cacheline_aligned_in_smp; 55 56 struct virtio_blk { 57 /* 58 * This mutex must be held by anything that may run after 59 * virtblk_remove() sets vblk->vdev to NULL. 60 * 61 * blk-mq, virtqueue processing, and sysfs attribute code paths are 62 * shut down before vblk->vdev is set to NULL and therefore do not need 63 * to hold this mutex. 64 */ 65 struct mutex vdev_mutex; 66 struct virtio_device *vdev; 67 68 /* The disk structure for the kernel. */ 69 struct gendisk *disk; 70 71 /* Block layer tags. */ 72 struct blk_mq_tag_set tag_set; 73 74 /* Process context for config space updates */ 75 struct work_struct config_work; 76 77 /* Ida index - used to track minor number allocations. */ 78 int index; 79 80 /* num of vqs */ 81 int num_vqs; 82 int io_queues[HCTX_MAX_TYPES]; 83 struct virtio_blk_vq *vqs; 84 85 /* For zoned device */ 86 unsigned int zone_sectors; 87 }; 88 89 struct virtblk_req { 90 /* Out header */ 91 struct virtio_blk_outhdr out_hdr; 92 93 /* In header */ 94 union { 95 u8 status; 96 97 /* 98 * The zone append command has an extended in header. 99 * The status field in zone_append_in_hdr must always 100 * be the last byte. 101 */ 102 struct { 103 __virtio64 sector; 104 u8 status; 105 } zone_append; 106 } in_hdr; 107 108 size_t in_hdr_len; 109 110 struct sg_table sg_table; 111 struct scatterlist sg[]; 112 }; 113 114 static inline blk_status_t virtblk_result(u8 status) 115 { 116 switch (status) { 117 case VIRTIO_BLK_S_OK: 118 return BLK_STS_OK; 119 case VIRTIO_BLK_S_UNSUPP: 120 return BLK_STS_NOTSUPP; 121 case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE: 122 return BLK_STS_ZONE_OPEN_RESOURCE; 123 case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE: 124 return BLK_STS_ZONE_ACTIVE_RESOURCE; 125 case VIRTIO_BLK_S_IOERR: 126 case VIRTIO_BLK_S_ZONE_UNALIGNED_WP: 127 default: 128 return BLK_STS_IOERR; 129 } 130 } 131 132 static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) 133 { 134 struct virtio_blk *vblk = hctx->queue->queuedata; 135 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 136 137 return vq; 138 } 139 140 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) 141 { 142 struct scatterlist out_hdr, in_hdr, *sgs[3]; 143 unsigned int num_out = 0, num_in = 0; 144 145 sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); 146 sgs[num_out++] = &out_hdr; 147 148 if (vbr->sg_table.nents) { 149 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) 150 sgs[num_out++] = vbr->sg_table.sgl; 151 else 152 sgs[num_out + num_in++] = vbr->sg_table.sgl; 153 } 154 155 sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len); 156 sgs[num_out + num_in++] = &in_hdr; 157 158 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); 159 } 160 161 static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap) 162 { 163 unsigned short segments = blk_rq_nr_discard_segments(req); 164 unsigned short n = 0; 165 struct virtio_blk_discard_write_zeroes *range; 166 struct bio *bio; 167 u32 flags = 0; 168 169 if (unmap) 170 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; 171 172 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); 173 if (!range) 174 return -ENOMEM; 175 176 /* 177 * Single max discard segment means multi-range discard isn't 178 * supported, and block layer only runs contiguity merge like 179 * normal RW request. So we can't reply on bio for retrieving 180 * each range info. 181 */ 182 if (queue_max_discard_segments(req->q) == 1) { 183 range[0].flags = cpu_to_le32(flags); 184 range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); 185 range[0].sector = cpu_to_le64(blk_rq_pos(req)); 186 n = 1; 187 } else { 188 __rq_for_each_bio(bio, req) { 189 u64 sector = bio->bi_iter.bi_sector; 190 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; 191 192 range[n].flags = cpu_to_le32(flags); 193 range[n].num_sectors = cpu_to_le32(num_sectors); 194 range[n].sector = cpu_to_le64(sector); 195 n++; 196 } 197 } 198 199 WARN_ON_ONCE(n != segments); 200 201 bvec_set_virt(&req->special_vec, range, sizeof(*range) * segments); 202 req->rq_flags |= RQF_SPECIAL_PAYLOAD; 203 204 return 0; 205 } 206 207 static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr) 208 { 209 if (blk_rq_nr_phys_segments(req)) 210 sg_free_table_chained(&vbr->sg_table, 211 VIRTIO_BLK_INLINE_SG_CNT); 212 } 213 214 static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req, 215 struct virtblk_req *vbr) 216 { 217 int err; 218 219 if (!blk_rq_nr_phys_segments(req)) 220 return 0; 221 222 vbr->sg_table.sgl = vbr->sg; 223 err = sg_alloc_table_chained(&vbr->sg_table, 224 blk_rq_nr_phys_segments(req), 225 vbr->sg_table.sgl, 226 VIRTIO_BLK_INLINE_SG_CNT); 227 if (unlikely(err)) 228 return -ENOMEM; 229 230 return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl); 231 } 232 233 static void virtblk_cleanup_cmd(struct request *req) 234 { 235 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) 236 kfree(bvec_virt(&req->special_vec)); 237 } 238 239 static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, 240 struct request *req, 241 struct virtblk_req *vbr) 242 { 243 size_t in_hdr_len = sizeof(vbr->in_hdr.status); 244 bool unmap = false; 245 u32 type; 246 u64 sector = 0; 247 248 if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req))) 249 return BLK_STS_NOTSUPP; 250 251 /* Set fields for all request types */ 252 vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); 253 254 switch (req_op(req)) { 255 case REQ_OP_READ: 256 type = VIRTIO_BLK_T_IN; 257 sector = blk_rq_pos(req); 258 break; 259 case REQ_OP_WRITE: 260 type = VIRTIO_BLK_T_OUT; 261 sector = blk_rq_pos(req); 262 break; 263 case REQ_OP_FLUSH: 264 type = VIRTIO_BLK_T_FLUSH; 265 break; 266 case REQ_OP_DISCARD: 267 type = VIRTIO_BLK_T_DISCARD; 268 break; 269 case REQ_OP_WRITE_ZEROES: 270 type = VIRTIO_BLK_T_WRITE_ZEROES; 271 unmap = !(req->cmd_flags & REQ_NOUNMAP); 272 break; 273 case REQ_OP_SECURE_ERASE: 274 type = VIRTIO_BLK_T_SECURE_ERASE; 275 break; 276 case REQ_OP_ZONE_OPEN: 277 type = VIRTIO_BLK_T_ZONE_OPEN; 278 sector = blk_rq_pos(req); 279 break; 280 case REQ_OP_ZONE_CLOSE: 281 type = VIRTIO_BLK_T_ZONE_CLOSE; 282 sector = blk_rq_pos(req); 283 break; 284 case REQ_OP_ZONE_FINISH: 285 type = VIRTIO_BLK_T_ZONE_FINISH; 286 sector = blk_rq_pos(req); 287 break; 288 case REQ_OP_ZONE_APPEND: 289 type = VIRTIO_BLK_T_ZONE_APPEND; 290 sector = blk_rq_pos(req); 291 in_hdr_len = sizeof(vbr->in_hdr.zone_append); 292 break; 293 case REQ_OP_ZONE_RESET: 294 type = VIRTIO_BLK_T_ZONE_RESET; 295 sector = blk_rq_pos(req); 296 break; 297 case REQ_OP_ZONE_RESET_ALL: 298 type = VIRTIO_BLK_T_ZONE_RESET_ALL; 299 break; 300 case REQ_OP_DRV_IN: 301 /* 302 * Out header has already been prepared by the caller (virtblk_get_id() 303 * or virtblk_submit_zone_report()), nothing to do here. 304 */ 305 return 0; 306 default: 307 WARN_ON_ONCE(1); 308 return BLK_STS_IOERR; 309 } 310 311 /* Set fields for non-REQ_OP_DRV_IN request types */ 312 vbr->in_hdr_len = in_hdr_len; 313 vbr->out_hdr.type = cpu_to_virtio32(vdev, type); 314 vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector); 315 316 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES || 317 type == VIRTIO_BLK_T_SECURE_ERASE) { 318 if (virtblk_setup_discard_write_zeroes_erase(req, unmap)) 319 return BLK_STS_RESOURCE; 320 } 321 322 return 0; 323 } 324 325 /* 326 * The status byte is always the last byte of the virtblk request 327 * in-header. This helper fetches its value for all in-header formats 328 * that are currently defined. 329 */ 330 static inline u8 virtblk_vbr_status(struct virtblk_req *vbr) 331 { 332 return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1); 333 } 334 335 static inline void virtblk_request_done(struct request *req) 336 { 337 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 338 blk_status_t status = virtblk_result(virtblk_vbr_status(vbr)); 339 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 340 341 virtblk_unmap_data(req, vbr); 342 virtblk_cleanup_cmd(req); 343 344 if (req_op(req) == REQ_OP_ZONE_APPEND) 345 req->__sector = virtio64_to_cpu(vblk->vdev, 346 vbr->in_hdr.zone_append.sector); 347 348 blk_mq_end_request(req, status); 349 } 350 351 static void virtblk_done(struct virtqueue *vq) 352 { 353 struct virtio_blk *vblk = vq->vdev->priv; 354 bool req_done = false; 355 int qid = vq->index; 356 struct virtblk_req *vbr; 357 unsigned long flags; 358 unsigned int len; 359 360 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 361 do { 362 virtqueue_disable_cb(vq); 363 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { 364 struct request *req = blk_mq_rq_from_pdu(vbr); 365 366 if (likely(!blk_should_fake_timeout(req->q))) 367 blk_mq_complete_request(req); 368 req_done = true; 369 } 370 } while (!virtqueue_enable_cb(vq)); 371 372 /* In case queue is stopped waiting for more buffers. */ 373 if (req_done) 374 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 375 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 376 } 377 378 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) 379 { 380 struct virtio_blk *vblk = hctx->queue->queuedata; 381 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; 382 bool kick; 383 384 spin_lock_irq(&vq->lock); 385 kick = virtqueue_kick_prepare(vq->vq); 386 spin_unlock_irq(&vq->lock); 387 388 if (kick) 389 virtqueue_notify(vq->vq); 390 } 391 392 static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) 393 { 394 virtblk_cleanup_cmd(req); 395 switch (rc) { 396 case -ENOSPC: 397 return BLK_STS_DEV_RESOURCE; 398 case -ENOMEM: 399 return BLK_STS_RESOURCE; 400 default: 401 return BLK_STS_IOERR; 402 } 403 } 404 405 static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, 406 struct virtio_blk *vblk, 407 struct request *req, 408 struct virtblk_req *vbr) 409 { 410 blk_status_t status; 411 int num; 412 413 status = virtblk_setup_cmd(vblk->vdev, req, vbr); 414 if (unlikely(status)) 415 return status; 416 417 num = virtblk_map_data(hctx, req, vbr); 418 if (unlikely(num < 0)) 419 return virtblk_fail_to_queue(req, -ENOMEM); 420 vbr->sg_table.nents = num; 421 422 blk_mq_start_request(req); 423 424 return BLK_STS_OK; 425 } 426 427 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, 428 const struct blk_mq_queue_data *bd) 429 { 430 struct virtio_blk *vblk = hctx->queue->queuedata; 431 struct request *req = bd->rq; 432 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 433 unsigned long flags; 434 int qid = hctx->queue_num; 435 bool notify = false; 436 blk_status_t status; 437 int err; 438 439 status = virtblk_prep_rq(hctx, vblk, req, vbr); 440 if (unlikely(status)) 441 return status; 442 443 spin_lock_irqsave(&vblk->vqs[qid].lock, flags); 444 err = virtblk_add_req(vblk->vqs[qid].vq, vbr); 445 if (err) { 446 virtqueue_kick(vblk->vqs[qid].vq); 447 /* Don't stop the queue if -ENOMEM: we may have failed to 448 * bounce the buffer due to global resource outage. 449 */ 450 if (err == -ENOSPC) 451 blk_mq_stop_hw_queue(hctx); 452 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 453 virtblk_unmap_data(req, vbr); 454 return virtblk_fail_to_queue(req, err); 455 } 456 457 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) 458 notify = true; 459 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); 460 461 if (notify) 462 virtqueue_notify(vblk->vqs[qid].vq); 463 return BLK_STS_OK; 464 } 465 466 static bool virtblk_prep_rq_batch(struct request *req) 467 { 468 struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; 469 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 470 471 return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; 472 } 473 474 static void virtblk_add_req_batch(struct virtio_blk_vq *vq, 475 struct rq_list *rqlist) 476 { 477 struct request *req; 478 unsigned long flags; 479 bool kick; 480 481 spin_lock_irqsave(&vq->lock, flags); 482 483 while ((req = rq_list_pop(rqlist))) { 484 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); 485 int err; 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 if (kick) 499 virtqueue_notify(vq->vq); 500 } 501 502 static void virtio_queue_rqs(struct rq_list *rqlist) 503 { 504 struct rq_list submit_list = { }; 505 struct rq_list requeue_list = { }; 506 struct virtio_blk_vq *vq = NULL; 507 struct request *req; 508 509 while ((req = rq_list_pop(rqlist))) { 510 struct virtio_blk_vq *this_vq = get_virtio_blk_vq(req->mq_hctx); 511 512 if (vq && vq != this_vq) 513 virtblk_add_req_batch(vq, &submit_list); 514 vq = this_vq; 515 516 if (virtblk_prep_rq_batch(req)) 517 rq_list_add_tail(&submit_list, req); 518 else 519 rq_list_add_tail(&requeue_list, req); 520 } 521 522 if (vq) 523 virtblk_add_req_batch(vq, &submit_list); 524 *rqlist = requeue_list; 525 } 526 527 #ifdef CONFIG_BLK_DEV_ZONED 528 static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, 529 unsigned int nr_zones, 530 size_t *buflen) 531 { 532 struct request_queue *q = vblk->disk->queue; 533 size_t bufsize; 534 void *buf; 535 536 nr_zones = min_t(unsigned int, nr_zones, 537 get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); 538 539 bufsize = sizeof(struct virtio_blk_zone_report) + 540 nr_zones * sizeof(struct virtio_blk_zone_descriptor); 541 bufsize = min_t(size_t, bufsize, 542 queue_max_hw_sectors(q) << SECTOR_SHIFT); 543 bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); 544 545 while (bufsize >= sizeof(struct virtio_blk_zone_report)) { 546 buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); 547 if (buf) { 548 *buflen = bufsize; 549 return buf; 550 } 551 bufsize >>= 1; 552 } 553 554 return NULL; 555 } 556 557 static int virtblk_submit_zone_report(struct virtio_blk *vblk, 558 char *report_buf, size_t report_len, 559 sector_t sector) 560 { 561 struct request_queue *q = vblk->disk->queue; 562 struct request *req; 563 struct virtblk_req *vbr; 564 int err; 565 566 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 567 if (IS_ERR(req)) 568 return PTR_ERR(req); 569 570 vbr = blk_mq_rq_to_pdu(req); 571 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 572 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); 573 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); 574 575 err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); 576 if (err) 577 goto out; 578 579 blk_execute_rq(req, false); 580 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 581 out: 582 blk_mq_free_request(req); 583 return err; 584 } 585 586 static int virtblk_parse_zone(struct virtio_blk *vblk, 587 struct virtio_blk_zone_descriptor *entry, 588 unsigned int idx, report_zones_cb cb, void *data) 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 cb(&zone, idx, data); 655 } 656 657 static int virtblk_report_zones(struct gendisk *disk, sector_t sector, 658 unsigned int nr_zones, report_zones_cb cb, 659 void *data) 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 if (!nz) 693 break; 694 695 for (i = 0; i < nz && zone_idx < nr_zones; i++) { 696 ret = virtblk_parse_zone(vblk, &report->zones[i], 697 zone_idx, cb, data); 698 if (ret) 699 goto fail_report; 700 701 sector = virtio64_to_cpu(vblk->vdev, 702 report->zones[i].z_start) + 703 vblk->zone_sectors; 704 zone_idx++; 705 } 706 } 707 708 if (zone_idx > 0) 709 ret = zone_idx; 710 else 711 ret = -EINVAL; 712 fail_report: 713 mutex_unlock(&vblk->vdev_mutex); 714 kvfree(report); 715 return ret; 716 } 717 718 static int virtblk_read_zoned_limits(struct virtio_blk *vblk, 719 struct queue_limits *lim) 720 { 721 struct virtio_device *vdev = vblk->vdev; 722 u32 v, wg; 723 724 dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); 725 726 lim->features |= BLK_FEAT_ZONED; 727 728 virtio_cread(vdev, struct virtio_blk_config, 729 zoned.max_open_zones, &v); 730 lim->max_open_zones = v; 731 dev_dbg(&vdev->dev, "max open zones = %u\n", v); 732 733 virtio_cread(vdev, struct virtio_blk_config, 734 zoned.max_active_zones, &v); 735 lim->max_active_zones = v; 736 dev_dbg(&vdev->dev, "max active zones = %u\n", v); 737 738 virtio_cread(vdev, struct virtio_blk_config, 739 zoned.write_granularity, &wg); 740 if (!wg) { 741 dev_warn(&vdev->dev, "zero write granularity reported\n"); 742 return -ENODEV; 743 } 744 lim->physical_block_size = wg; 745 lim->io_min = wg; 746 747 dev_dbg(&vdev->dev, "write granularity = %u\n", wg); 748 749 /* 750 * virtio ZBD specification doesn't require zones to be a power of 751 * two sectors in size, but the code in this driver expects that. 752 */ 753 virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, 754 &vblk->zone_sectors); 755 if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { 756 dev_err(&vdev->dev, 757 "zoned device with non power of two zone size %u\n", 758 vblk->zone_sectors); 759 return -ENODEV; 760 } 761 lim->chunk_sectors = vblk->zone_sectors; 762 dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); 763 764 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 765 dev_warn(&vblk->vdev->dev, 766 "ignoring negotiated F_DISCARD for zoned device\n"); 767 lim->max_hw_discard_sectors = 0; 768 } 769 770 virtio_cread(vdev, struct virtio_blk_config, 771 zoned.max_append_sectors, &v); 772 if (!v) { 773 dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); 774 return -ENODEV; 775 } 776 if ((v << SECTOR_SHIFT) < wg) { 777 dev_err(&vdev->dev, 778 "write granularity %u exceeds max_append_sectors %u limit\n", 779 wg, v); 780 return -ENODEV; 781 } 782 lim->max_hw_zone_append_sectors = v; 783 dev_dbg(&vdev->dev, "max append sectors = %u\n", v); 784 785 return 0; 786 } 787 #else 788 /* 789 * Zoned block device support is not configured in this kernel, host-managed 790 * zoned devices can't be supported. 791 */ 792 #define virtblk_report_zones NULL 793 static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk, 794 struct queue_limits *lim) 795 { 796 dev_err(&vblk->vdev->dev, 797 "virtio_blk: zoned devices are not supported"); 798 return -EOPNOTSUPP; 799 } 800 #endif /* CONFIG_BLK_DEV_ZONED */ 801 802 /* return id (s/n) string for *disk to *id_str 803 */ 804 static int virtblk_get_id(struct gendisk *disk, char *id_str) 805 { 806 struct virtio_blk *vblk = disk->private_data; 807 struct request_queue *q = vblk->disk->queue; 808 struct request *req; 809 struct virtblk_req *vbr; 810 int err; 811 812 req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); 813 if (IS_ERR(req)) 814 return PTR_ERR(req); 815 816 vbr = blk_mq_rq_to_pdu(req); 817 vbr->in_hdr_len = sizeof(vbr->in_hdr.status); 818 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); 819 vbr->out_hdr.sector = 0; 820 821 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); 822 if (err) 823 goto out; 824 825 blk_execute_rq(req, false); 826 err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); 827 out: 828 blk_mq_free_request(req); 829 return err; 830 } 831 832 /* We provide getgeo only to please some old bootloader/partitioning tools */ 833 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 834 { 835 struct virtio_blk *vblk = bd->bd_disk->private_data; 836 int ret = 0; 837 838 mutex_lock(&vblk->vdev_mutex); 839 840 if (!vblk->vdev) { 841 ret = -ENXIO; 842 goto out; 843 } 844 845 /* see if the host passed in geometry config */ 846 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 847 virtio_cread(vblk->vdev, struct virtio_blk_config, 848 geometry.cylinders, &geo->cylinders); 849 virtio_cread(vblk->vdev, struct virtio_blk_config, 850 geometry.heads, &geo->heads); 851 virtio_cread(vblk->vdev, struct virtio_blk_config, 852 geometry.sectors, &geo->sectors); 853 } else { 854 /* some standard values, similar to sd */ 855 geo->heads = 1 << 6; 856 geo->sectors = 1 << 5; 857 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 858 } 859 out: 860 mutex_unlock(&vblk->vdev_mutex); 861 return ret; 862 } 863 864 static void virtblk_free_disk(struct gendisk *disk) 865 { 866 struct virtio_blk *vblk = disk->private_data; 867 868 ida_free(&vd_index_ida, vblk->index); 869 mutex_destroy(&vblk->vdev_mutex); 870 kfree(vblk); 871 } 872 873 static const struct block_device_operations virtblk_fops = { 874 .owner = THIS_MODULE, 875 .getgeo = virtblk_getgeo, 876 .free_disk = virtblk_free_disk, 877 .report_zones = virtblk_report_zones, 878 }; 879 880 static int index_to_minor(int index) 881 { 882 return index << PART_BITS; 883 } 884 885 static int minor_to_index(int minor) 886 { 887 return minor >> PART_BITS; 888 } 889 890 static ssize_t serial_show(struct device *dev, 891 struct device_attribute *attr, char *buf) 892 { 893 struct gendisk *disk = dev_to_disk(dev); 894 int err; 895 896 /* sysfs gives us a PAGE_SIZE buffer */ 897 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 898 899 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 900 err = virtblk_get_id(disk, buf); 901 if (!err) 902 return strlen(buf); 903 904 if (err == -EIO) /* Unsupported? Make it empty. */ 905 return 0; 906 907 return err; 908 } 909 910 static DEVICE_ATTR_RO(serial); 911 912 /* The queue's logical block size must be set before calling this */ 913 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) 914 { 915 struct virtio_device *vdev = vblk->vdev; 916 struct request_queue *q = vblk->disk->queue; 917 char cap_str_2[10], cap_str_10[10]; 918 unsigned long long nblocks; 919 u64 capacity; 920 921 /* Host must always specify the capacity. */ 922 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 923 924 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); 925 926 string_get_size(nblocks, queue_logical_block_size(q), 927 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 928 string_get_size(nblocks, queue_logical_block_size(q), 929 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 930 931 dev_notice(&vdev->dev, 932 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", 933 vblk->disk->disk_name, 934 resize ? "new size: " : "", 935 nblocks, 936 queue_logical_block_size(q), 937 cap_str_10, 938 cap_str_2); 939 940 set_capacity_and_notify(vblk->disk, capacity); 941 } 942 943 static void virtblk_config_changed_work(struct work_struct *work) 944 { 945 struct virtio_blk *vblk = 946 container_of(work, struct virtio_blk, config_work); 947 948 virtblk_update_capacity(vblk, true); 949 } 950 951 static void virtblk_config_changed(struct virtio_device *vdev) 952 { 953 struct virtio_blk *vblk = vdev->priv; 954 955 queue_work(virtblk_wq, &vblk->config_work); 956 } 957 958 static int init_vq(struct virtio_blk *vblk) 959 { 960 int err; 961 unsigned short i; 962 struct virtqueue_info *vqs_info; 963 struct virtqueue **vqs; 964 unsigned short num_vqs; 965 unsigned short num_poll_vqs; 966 struct virtio_device *vdev = vblk->vdev; 967 struct irq_affinity desc = { 0, }; 968 969 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, 970 struct virtio_blk_config, num_queues, 971 &num_vqs); 972 if (err) 973 num_vqs = 1; 974 975 if (!err && !num_vqs) { 976 dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); 977 return -EINVAL; 978 } 979 980 num_vqs = min_t(unsigned int, 981 min_not_zero(num_request_queues, nr_cpu_ids), 982 num_vqs); 983 984 num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); 985 986 vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; 987 vblk->io_queues[HCTX_TYPE_READ] = 0; 988 vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 989 990 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 991 vblk->io_queues[HCTX_TYPE_DEFAULT], 992 vblk->io_queues[HCTX_TYPE_READ], 993 vblk->io_queues[HCTX_TYPE_POLL]); 994 995 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); 996 if (!vblk->vqs) 997 return -ENOMEM; 998 999 vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL); 1000 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); 1001 if (!vqs_info || !vqs) { 1002 err = -ENOMEM; 1003 goto out; 1004 } 1005 1006 for (i = 0; i < num_vqs - num_poll_vqs; i++) { 1007 vqs_info[i].callback = virtblk_done; 1008 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); 1009 vqs_info[i].name = vblk->vqs[i].name; 1010 } 1011 1012 for (; i < num_vqs; i++) { 1013 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); 1014 vqs_info[i].name = vblk->vqs[i].name; 1015 } 1016 1017 /* Discover virtqueues and write information to configuration. */ 1018 err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc); 1019 if (err) 1020 goto out; 1021 1022 for (i = 0; i < num_vqs; i++) { 1023 spin_lock_init(&vblk->vqs[i].lock); 1024 vblk->vqs[i].vq = vqs[i]; 1025 } 1026 vblk->num_vqs = num_vqs; 1027 1028 out: 1029 kfree(vqs); 1030 kfree(vqs_info); 1031 if (err) 1032 kfree(vblk->vqs); 1033 return err; 1034 } 1035 1036 /* 1037 * Legacy naming scheme used for virtio devices. We are stuck with it for 1038 * virtio blk but don't ever use it for any new driver. 1039 */ 1040 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 1041 { 1042 const int base = 'z' - 'a' + 1; 1043 char *begin = buf + strlen(prefix); 1044 char *end = buf + buflen; 1045 char *p; 1046 int unit; 1047 1048 p = end - 1; 1049 *p = '\0'; 1050 unit = base; 1051 do { 1052 if (p == begin) 1053 return -EINVAL; 1054 *--p = 'a' + (index % unit); 1055 index = (index / unit) - 1; 1056 } while (index >= 0); 1057 1058 memmove(begin, p, end - p); 1059 memcpy(buf, prefix, strlen(prefix)); 1060 1061 return 0; 1062 } 1063 1064 static int virtblk_get_cache_mode(struct virtio_device *vdev) 1065 { 1066 u8 writeback; 1067 int err; 1068 1069 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 1070 struct virtio_blk_config, wce, 1071 &writeback); 1072 1073 /* 1074 * If WCE is not configurable and flush is not available, 1075 * assume no writeback cache is in use. 1076 */ 1077 if (err) 1078 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); 1079 1080 return writeback; 1081 } 1082 1083 static const char *const virtblk_cache_types[] = { 1084 "write through", "write back" 1085 }; 1086 1087 static ssize_t 1088 cache_type_store(struct device *dev, struct device_attribute *attr, 1089 const char *buf, size_t count) 1090 { 1091 struct gendisk *disk = dev_to_disk(dev); 1092 struct virtio_blk *vblk = disk->private_data; 1093 struct virtio_device *vdev = vblk->vdev; 1094 struct queue_limits lim; 1095 int i; 1096 1097 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 1098 i = sysfs_match_string(virtblk_cache_types, buf); 1099 if (i < 0) 1100 return i; 1101 1102 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 1103 1104 lim = queue_limits_start_update(disk->queue); 1105 if (virtblk_get_cache_mode(vdev)) 1106 lim.features |= BLK_FEAT_WRITE_CACHE; 1107 else 1108 lim.features &= ~BLK_FEAT_WRITE_CACHE; 1109 blk_mq_freeze_queue(disk->queue); 1110 i = queue_limits_commit_update(disk->queue, &lim); 1111 blk_mq_unfreeze_queue(disk->queue); 1112 if (i) 1113 return i; 1114 return count; 1115 } 1116 1117 static ssize_t 1118 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) 1119 { 1120 struct gendisk *disk = dev_to_disk(dev); 1121 struct virtio_blk *vblk = disk->private_data; 1122 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 1123 1124 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 1125 return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); 1126 } 1127 1128 static DEVICE_ATTR_RW(cache_type); 1129 1130 static struct attribute *virtblk_attrs[] = { 1131 &dev_attr_serial.attr, 1132 &dev_attr_cache_type.attr, 1133 NULL, 1134 }; 1135 1136 static umode_t virtblk_attrs_are_visible(struct kobject *kobj, 1137 struct attribute *a, int n) 1138 { 1139 struct device *dev = kobj_to_dev(kobj); 1140 struct gendisk *disk = dev_to_disk(dev); 1141 struct virtio_blk *vblk = disk->private_data; 1142 struct virtio_device *vdev = vblk->vdev; 1143 1144 if (a == &dev_attr_cache_type.attr && 1145 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 1146 return S_IRUGO; 1147 1148 return a->mode; 1149 } 1150 1151 static const struct attribute_group virtblk_attr_group = { 1152 .attrs = virtblk_attrs, 1153 .is_visible = virtblk_attrs_are_visible, 1154 }; 1155 1156 static const struct attribute_group *virtblk_attr_groups[] = { 1157 &virtblk_attr_group, 1158 NULL, 1159 }; 1160 1161 static void virtblk_map_queues(struct blk_mq_tag_set *set) 1162 { 1163 struct virtio_blk *vblk = set->driver_data; 1164 int i, qoff; 1165 1166 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1167 struct blk_mq_queue_map *map = &set->map[i]; 1168 1169 map->nr_queues = vblk->io_queues[i]; 1170 map->queue_offset = qoff; 1171 qoff += map->nr_queues; 1172 1173 if (map->nr_queues == 0) 1174 continue; 1175 1176 /* 1177 * Regular queues have interrupts and hence CPU affinity is 1178 * defined by the core virtio code, but polling queues have 1179 * no interrupts so we let the block layer assign CPU affinity. 1180 */ 1181 if (i == HCTX_TYPE_POLL) 1182 blk_mq_map_queues(&set->map[i]); 1183 else 1184 blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); 1185 } 1186 } 1187 1188 static void virtblk_complete_batch(struct io_comp_batch *iob) 1189 { 1190 struct request *req; 1191 1192 rq_list_for_each(&iob->req_list, req) { 1193 virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); 1194 virtblk_cleanup_cmd(req); 1195 } 1196 blk_mq_end_request_batch(iob); 1197 } 1198 1199 static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1200 { 1201 struct virtio_blk *vblk = hctx->queue->queuedata; 1202 struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); 1203 struct virtblk_req *vbr; 1204 unsigned long flags; 1205 unsigned int len; 1206 int found = 0; 1207 1208 spin_lock_irqsave(&vq->lock, flags); 1209 1210 while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { 1211 struct request *req = blk_mq_rq_from_pdu(vbr); 1212 1213 found++; 1214 if (!blk_mq_complete_request_remote(req) && 1215 !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), 1216 virtblk_complete_batch)) 1217 virtblk_request_done(req); 1218 } 1219 1220 if (found) 1221 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); 1222 1223 spin_unlock_irqrestore(&vq->lock, flags); 1224 1225 return found; 1226 } 1227 1228 static const struct blk_mq_ops virtio_mq_ops = { 1229 .queue_rq = virtio_queue_rq, 1230 .queue_rqs = virtio_queue_rqs, 1231 .commit_rqs = virtio_commit_rqs, 1232 .complete = virtblk_request_done, 1233 .map_queues = virtblk_map_queues, 1234 .poll = virtblk_poll, 1235 }; 1236 1237 static unsigned int virtblk_queue_depth; 1238 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); 1239 1240 static int virtblk_read_limits(struct virtio_blk *vblk, 1241 struct queue_limits *lim) 1242 { 1243 struct virtio_device *vdev = vblk->vdev; 1244 u32 v, max_size, sg_elems, opt_io_size; 1245 u32 max_discard_segs = 0; 1246 u32 discard_granularity = 0; 1247 u16 min_io_size; 1248 u8 physical_block_exp, alignment_offset; 1249 size_t max_dma_size; 1250 int err; 1251 1252 /* We need to know how many segments before we allocate. */ 1253 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 1254 struct virtio_blk_config, seg_max, 1255 &sg_elems); 1256 1257 /* We need at least one SG element, whatever they say. */ 1258 if (err || !sg_elems) 1259 sg_elems = 1; 1260 1261 /* Prevent integer overflows and honor max vq size */ 1262 sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); 1263 1264 /* We can handle whatever the host told us to handle. */ 1265 lim->max_segments = sg_elems; 1266 1267 /* No real sector limit. */ 1268 lim->max_hw_sectors = UINT_MAX; 1269 1270 max_dma_size = virtio_max_dma_size(vdev); 1271 max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; 1272 1273 /* Host can optionally specify maximum segment size and number of 1274 * segments. */ 1275 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 1276 struct virtio_blk_config, size_max, &v); 1277 if (!err) 1278 max_size = min(max_size, v); 1279 1280 lim->max_segment_size = max_size; 1281 1282 /* Host can optionally specify the block size of the device */ 1283 virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 1284 struct virtio_blk_config, blk_size, 1285 &lim->logical_block_size); 1286 1287 /* Use topology information if available */ 1288 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1289 struct virtio_blk_config, physical_block_exp, 1290 &physical_block_exp); 1291 if (!err && physical_block_exp) 1292 lim->physical_block_size = 1293 lim->logical_block_size * (1 << physical_block_exp); 1294 1295 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1296 struct virtio_blk_config, alignment_offset, 1297 &alignment_offset); 1298 if (!err && alignment_offset) 1299 lim->alignment_offset = 1300 lim->logical_block_size * alignment_offset; 1301 1302 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1303 struct virtio_blk_config, min_io_size, 1304 &min_io_size); 1305 if (!err && min_io_size) 1306 lim->io_min = lim->logical_block_size * min_io_size; 1307 1308 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 1309 struct virtio_blk_config, opt_io_size, 1310 &opt_io_size); 1311 if (!err && opt_io_size) 1312 lim->io_opt = lim->logical_block_size * opt_io_size; 1313 1314 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { 1315 virtio_cread(vdev, struct virtio_blk_config, 1316 discard_sector_alignment, &discard_granularity); 1317 1318 virtio_cread(vdev, struct virtio_blk_config, 1319 max_discard_sectors, &v); 1320 lim->max_hw_discard_sectors = v ? v : UINT_MAX; 1321 1322 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, 1323 &max_discard_segs); 1324 } 1325 1326 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { 1327 virtio_cread(vdev, struct virtio_blk_config, 1328 max_write_zeroes_sectors, &v); 1329 lim->max_write_zeroes_sectors = v ? v : UINT_MAX; 1330 } 1331 1332 /* The discard and secure erase limits are combined since the Linux 1333 * block layer uses the same limit for both commands. 1334 * 1335 * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features 1336 * are negotiated, we will use the minimum between the limits. 1337 * 1338 * discard sector alignment is set to the minimum between discard_sector_alignment 1339 * and secure_erase_sector_alignment. 1340 * 1341 * max discard sectors is set to the minimum between max_discard_seg and 1342 * max_secure_erase_seg. 1343 */ 1344 if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1345 1346 virtio_cread(vdev, struct virtio_blk_config, 1347 secure_erase_sector_alignment, &v); 1348 1349 /* secure_erase_sector_alignment should not be zero, the device should set a 1350 * valid number of sectors. 1351 */ 1352 if (!v) { 1353 dev_err(&vdev->dev, 1354 "virtio_blk: secure_erase_sector_alignment can't be 0\n"); 1355 return -EINVAL; 1356 } 1357 1358 discard_granularity = min_not_zero(discard_granularity, v); 1359 1360 virtio_cread(vdev, struct virtio_blk_config, 1361 max_secure_erase_sectors, &v); 1362 1363 /* max_secure_erase_sectors should not be zero, the device should set a 1364 * valid number of sectors. 1365 */ 1366 if (!v) { 1367 dev_err(&vdev->dev, 1368 "virtio_blk: max_secure_erase_sectors can't be 0\n"); 1369 return -EINVAL; 1370 } 1371 1372 lim->max_secure_erase_sectors = v; 1373 1374 virtio_cread(vdev, struct virtio_blk_config, 1375 max_secure_erase_seg, &v); 1376 1377 /* max_secure_erase_seg should not be zero, the device should set a 1378 * valid number of segments 1379 */ 1380 if (!v) { 1381 dev_err(&vdev->dev, 1382 "virtio_blk: max_secure_erase_seg can't be 0\n"); 1383 return -EINVAL; 1384 } 1385 1386 max_discard_segs = min_not_zero(max_discard_segs, v); 1387 } 1388 1389 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || 1390 virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { 1391 /* max_discard_seg and discard_granularity will be 0 only 1392 * if max_discard_seg and discard_sector_alignment fields in the virtio 1393 * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. 1394 * In this case, we use default values. 1395 */ 1396 if (!max_discard_segs) 1397 max_discard_segs = sg_elems; 1398 1399 lim->max_discard_segments = 1400 min(max_discard_segs, MAX_DISCARD_SEGMENTS); 1401 1402 if (discard_granularity) 1403 lim->discard_granularity = 1404 discard_granularity << SECTOR_SHIFT; 1405 else 1406 lim->discard_granularity = lim->logical_block_size; 1407 } 1408 1409 if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { 1410 u8 model; 1411 1412 virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); 1413 switch (model) { 1414 case VIRTIO_BLK_Z_NONE: 1415 case VIRTIO_BLK_Z_HA: 1416 /* treat host-aware devices as non-zoned */ 1417 return 0; 1418 case VIRTIO_BLK_Z_HM: 1419 err = virtblk_read_zoned_limits(vblk, lim); 1420 if (err) 1421 return err; 1422 break; 1423 default: 1424 dev_err(&vdev->dev, "unsupported zone model %d\n", model); 1425 return -EINVAL; 1426 } 1427 } 1428 1429 return 0; 1430 } 1431 1432 static int virtblk_probe(struct virtio_device *vdev) 1433 { 1434 struct virtio_blk *vblk; 1435 struct queue_limits lim = { 1436 .features = BLK_FEAT_ROTATIONAL, 1437 .logical_block_size = SECTOR_SIZE, 1438 }; 1439 int err, index; 1440 unsigned int queue_depth; 1441 1442 if (!vdev->config->get) { 1443 dev_err(&vdev->dev, "%s failure: config access disabled\n", 1444 __func__); 1445 return -EINVAL; 1446 } 1447 1448 err = ida_alloc_range(&vd_index_ida, 0, 1449 minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); 1450 if (err < 0) 1451 goto out; 1452 index = err; 1453 1454 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 1455 if (!vblk) { 1456 err = -ENOMEM; 1457 goto out_free_index; 1458 } 1459 1460 mutex_init(&vblk->vdev_mutex); 1461 1462 vblk->vdev = vdev; 1463 1464 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 1465 1466 err = init_vq(vblk); 1467 if (err) 1468 goto out_free_vblk; 1469 1470 /* Default queue sizing is to fill the ring. */ 1471 if (!virtblk_queue_depth) { 1472 queue_depth = vblk->vqs[0].vq->num_free; 1473 /* ... but without indirect descs, we use 2 descs per req */ 1474 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) 1475 queue_depth /= 2; 1476 } else { 1477 queue_depth = virtblk_queue_depth; 1478 } 1479 1480 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); 1481 vblk->tag_set.ops = &virtio_mq_ops; 1482 vblk->tag_set.queue_depth = queue_depth; 1483 vblk->tag_set.numa_node = NUMA_NO_NODE; 1484 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; 1485 vblk->tag_set.cmd_size = 1486 sizeof(struct virtblk_req) + 1487 sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; 1488 vblk->tag_set.driver_data = vblk; 1489 vblk->tag_set.nr_hw_queues = vblk->num_vqs; 1490 vblk->tag_set.nr_maps = 1; 1491 if (vblk->io_queues[HCTX_TYPE_POLL]) 1492 vblk->tag_set.nr_maps = 3; 1493 1494 err = blk_mq_alloc_tag_set(&vblk->tag_set); 1495 if (err) 1496 goto out_free_vq; 1497 1498 err = virtblk_read_limits(vblk, &lim); 1499 if (err) 1500 goto out_free_tags; 1501 1502 if (virtblk_get_cache_mode(vdev)) 1503 lim.features |= BLK_FEAT_WRITE_CACHE; 1504 1505 vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk); 1506 if (IS_ERR(vblk->disk)) { 1507 err = PTR_ERR(vblk->disk); 1508 goto out_free_tags; 1509 } 1510 1511 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 1512 1513 vblk->disk->major = major; 1514 vblk->disk->first_minor = index_to_minor(index); 1515 vblk->disk->minors = 1 << PART_BITS; 1516 vblk->disk->private_data = vblk; 1517 vblk->disk->fops = &virtblk_fops; 1518 vblk->index = index; 1519 1520 /* If disk is read-only in the host, the guest should obey */ 1521 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 1522 set_disk_ro(vblk->disk, 1); 1523 1524 virtblk_update_capacity(vblk, false); 1525 virtio_device_ready(vdev); 1526 1527 /* 1528 * All steps that follow use the VQs therefore they need to be 1529 * placed after the virtio_device_ready() call above. 1530 */ 1531 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && 1532 (lim.features & BLK_FEAT_ZONED)) { 1533 err = blk_revalidate_disk_zones(vblk->disk); 1534 if (err) 1535 goto out_cleanup_disk; 1536 } 1537 1538 err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); 1539 if (err) 1540 goto out_cleanup_disk; 1541 1542 return 0; 1543 1544 out_cleanup_disk: 1545 put_disk(vblk->disk); 1546 out_free_tags: 1547 blk_mq_free_tag_set(&vblk->tag_set); 1548 out_free_vq: 1549 vdev->config->del_vqs(vdev); 1550 kfree(vblk->vqs); 1551 out_free_vblk: 1552 kfree(vblk); 1553 out_free_index: 1554 ida_free(&vd_index_ida, index); 1555 out: 1556 return err; 1557 } 1558 1559 static void virtblk_remove(struct virtio_device *vdev) 1560 { 1561 struct virtio_blk *vblk = vdev->priv; 1562 1563 /* Make sure no work handler is accessing the device. */ 1564 flush_work(&vblk->config_work); 1565 1566 del_gendisk(vblk->disk); 1567 blk_mq_free_tag_set(&vblk->tag_set); 1568 1569 mutex_lock(&vblk->vdev_mutex); 1570 1571 /* Stop all the virtqueues. */ 1572 virtio_reset_device(vdev); 1573 1574 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ 1575 vblk->vdev = NULL; 1576 1577 vdev->config->del_vqs(vdev); 1578 kfree(vblk->vqs); 1579 1580 mutex_unlock(&vblk->vdev_mutex); 1581 1582 put_disk(vblk->disk); 1583 } 1584 1585 #ifdef CONFIG_PM_SLEEP 1586 static int virtblk_freeze(struct virtio_device *vdev) 1587 { 1588 struct virtio_blk *vblk = vdev->priv; 1589 struct request_queue *q = vblk->disk->queue; 1590 1591 /* Ensure no requests in virtqueues before deleting vqs. */ 1592 blk_mq_freeze_queue(q); 1593 blk_mq_quiesce_queue_nowait(q); 1594 blk_mq_unfreeze_queue(q); 1595 1596 /* Ensure we don't receive any more interrupts */ 1597 virtio_reset_device(vdev); 1598 1599 /* Make sure no work handler is accessing the device. */ 1600 flush_work(&vblk->config_work); 1601 1602 vdev->config->del_vqs(vdev); 1603 kfree(vblk->vqs); 1604 1605 return 0; 1606 } 1607 1608 static int virtblk_restore(struct virtio_device *vdev) 1609 { 1610 struct virtio_blk *vblk = vdev->priv; 1611 int ret; 1612 1613 ret = init_vq(vdev->priv); 1614 if (ret) 1615 return ret; 1616 1617 virtio_device_ready(vdev); 1618 blk_mq_unquiesce_queue(vblk->disk->queue); 1619 1620 return 0; 1621 } 1622 #endif 1623 1624 static const struct virtio_device_id id_table[] = { 1625 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 1626 { 0 }, 1627 }; 1628 1629 static unsigned int features_legacy[] = { 1630 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1631 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1632 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1633 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1634 VIRTIO_BLK_F_SECURE_ERASE, 1635 } 1636 ; 1637 static unsigned int features[] = { 1638 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 1639 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, 1640 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, 1641 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, 1642 VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, 1643 }; 1644 1645 static struct virtio_driver virtio_blk = { 1646 .feature_table = features, 1647 .feature_table_size = ARRAY_SIZE(features), 1648 .feature_table_legacy = features_legacy, 1649 .feature_table_size_legacy = ARRAY_SIZE(features_legacy), 1650 .driver.name = KBUILD_MODNAME, 1651 .id_table = id_table, 1652 .probe = virtblk_probe, 1653 .remove = virtblk_remove, 1654 .config_changed = virtblk_config_changed, 1655 #ifdef CONFIG_PM_SLEEP 1656 .freeze = virtblk_freeze, 1657 .restore = virtblk_restore, 1658 #endif 1659 }; 1660 1661 static int __init virtio_blk_init(void) 1662 { 1663 int error; 1664 1665 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 1666 if (!virtblk_wq) 1667 return -ENOMEM; 1668 1669 major = register_blkdev(0, "virtblk"); 1670 if (major < 0) { 1671 error = major; 1672 goto out_destroy_workqueue; 1673 } 1674 1675 error = register_virtio_driver(&virtio_blk); 1676 if (error) 1677 goto out_unregister_blkdev; 1678 return 0; 1679 1680 out_unregister_blkdev: 1681 unregister_blkdev(major, "virtblk"); 1682 out_destroy_workqueue: 1683 destroy_workqueue(virtblk_wq); 1684 return error; 1685 } 1686 1687 static void __exit virtio_blk_fini(void) 1688 { 1689 unregister_virtio_driver(&virtio_blk); 1690 unregister_blkdev(major, "virtblk"); 1691 destroy_workqueue(virtblk_wq); 1692 } 1693 module_init(virtio_blk_init); 1694 module_exit(virtio_blk_fini); 1695 1696 MODULE_DEVICE_TABLE(virtio, id_table); 1697 MODULE_DESCRIPTION("Virtio block driver"); 1698 MODULE_LICENSE("GPL"); 1699