drivers/block/virtio_blk.c

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