1 // SPDX-License-Identifier: GPL-2.0-only
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 <scsi/scsi_cmnd.h>
15 #include <linux/idr.h>
16 #include <linux/blk-mq.h>
17 #include <linux/blk-mq-virtio.h>
18 #include <linux/numa.h>
21 #define VQ_NAME_LEN 16
22 #define MAX_DISCARD_SEGMENTS 256u
25 static DEFINE_IDA(vd_index_ida);
27 static struct workqueue_struct *virtblk_wq;
29 struct virtio_blk_vq {
32 char name[VQ_NAME_LEN];
33 } ____cacheline_aligned_in_smp;
36 struct virtio_device *vdev;
38 /* The disk structure for the kernel. */
41 /* Block layer tags. */
42 struct blk_mq_tag_set tag_set;
44 /* Process context for config space updates */
45 struct work_struct config_work;
47 /* What host tells us, plus 2 for header & tailer. */
48 unsigned int sg_elems;
50 /* Ida index - used to track minor number allocations. */
55 struct virtio_blk_vq *vqs;
59 #ifdef CONFIG_VIRTIO_BLK_SCSI
60 struct scsi_request sreq; /* for SCSI passthrough, must be first */
61 u8 sense[SCSI_SENSE_BUFFERSIZE];
62 struct virtio_scsi_inhdr in_hdr;
64 struct virtio_blk_outhdr out_hdr;
66 struct scatterlist sg[];
69 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
71 switch (vbr->status) {
74 case VIRTIO_BLK_S_UNSUPP:
75 return BLK_STS_NOTSUPP;
82 * If this is a packet command we need a couple of additional headers. Behind
83 * the normal outhdr we put a segment with the scsi command block, and before
84 * the normal inhdr we put the sense data and the inhdr with additional status
87 #ifdef CONFIG_VIRTIO_BLK_SCSI
88 static int virtblk_add_req_scsi(struct virtqueue *vq, struct virtblk_req *vbr,
89 struct scatterlist *data_sg, bool have_data)
91 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
92 unsigned int num_out = 0, num_in = 0;
94 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
95 sgs[num_out++] = &hdr;
96 sg_init_one(&cmd, vbr->sreq.cmd, vbr->sreq.cmd_len);
97 sgs[num_out++] = &cmd;
100 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
101 sgs[num_out++] = data_sg;
103 sgs[num_out + num_in++] = data_sg;
106 sg_init_one(&sense, vbr->sense, SCSI_SENSE_BUFFERSIZE);
107 sgs[num_out + num_in++] = &sense;
108 sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
109 sgs[num_out + num_in++] = &inhdr;
110 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
111 sgs[num_out + num_in++] = &status;
113 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
116 static inline void virtblk_scsi_request_done(struct request *req)
118 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
119 struct virtio_blk *vblk = req->q->queuedata;
120 struct scsi_request *sreq = &vbr->sreq;
122 sreq->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual);
123 sreq->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len);
124 sreq->result = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
127 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
128 unsigned int cmd, unsigned long data)
130 struct gendisk *disk = bdev->bd_disk;
131 struct virtio_blk *vblk = disk->private_data;
134 * Only allow the generic SCSI ioctls if the host can support it.
136 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
139 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
140 (void __user *)data);
143 static inline int virtblk_add_req_scsi(struct virtqueue *vq,
144 struct virtblk_req *vbr, struct scatterlist *data_sg,
149 static inline void virtblk_scsi_request_done(struct request *req)
152 #define virtblk_ioctl NULL
153 #endif /* CONFIG_VIRTIO_BLK_SCSI */
155 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
156 struct scatterlist *data_sg, bool have_data)
158 struct scatterlist hdr, status, *sgs[3];
159 unsigned int num_out = 0, num_in = 0;
161 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
162 sgs[num_out++] = &hdr;
165 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
166 sgs[num_out++] = data_sg;
168 sgs[num_out + num_in++] = data_sg;
171 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
172 sgs[num_out + num_in++] = &status;
174 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
177 static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap)
179 unsigned short segments = blk_rq_nr_discard_segments(req);
180 unsigned short n = 0;
181 struct virtio_blk_discard_write_zeroes *range;
186 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
188 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
192 __rq_for_each_bio(bio, req) {
193 u64 sector = bio->bi_iter.bi_sector;
194 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
196 range[n].flags = cpu_to_le32(flags);
197 range[n].num_sectors = cpu_to_le32(num_sectors);
198 range[n].sector = cpu_to_le64(sector);
202 req->special_vec.bv_page = virt_to_page(range);
203 req->special_vec.bv_offset = offset_in_page(range);
204 req->special_vec.bv_len = sizeof(*range) * segments;
205 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
210 static inline void virtblk_request_done(struct request *req)
212 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
214 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
215 kfree(page_address(req->special_vec.bv_page) +
216 req->special_vec.bv_offset);
219 switch (req_op(req)) {
221 case REQ_OP_SCSI_OUT:
222 virtblk_scsi_request_done(req);
226 blk_mq_end_request(req, virtblk_result(vbr));
229 static void virtblk_done(struct virtqueue *vq)
231 struct virtio_blk *vblk = vq->vdev->priv;
232 bool req_done = false;
234 struct virtblk_req *vbr;
238 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
240 virtqueue_disable_cb(vq);
241 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
242 struct request *req = blk_mq_rq_from_pdu(vbr);
244 blk_mq_complete_request(req);
247 if (unlikely(virtqueue_is_broken(vq)))
249 } while (!virtqueue_enable_cb(vq));
251 /* In case queue is stopped waiting for more buffers. */
253 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
254 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
257 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
259 struct virtio_blk *vblk = hctx->queue->queuedata;
260 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
263 spin_lock_irq(&vq->lock);
264 kick = virtqueue_kick_prepare(vq->vq);
265 spin_unlock_irq(&vq->lock);
268 virtqueue_notify(vq->vq);
271 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
272 const struct blk_mq_queue_data *bd)
274 struct virtio_blk *vblk = hctx->queue->queuedata;
275 struct request *req = bd->rq;
276 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
279 int qid = hctx->queue_num;
285 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
287 switch (req_op(req)) {
293 type = VIRTIO_BLK_T_FLUSH;
296 type = VIRTIO_BLK_T_DISCARD;
298 case REQ_OP_WRITE_ZEROES:
299 type = VIRTIO_BLK_T_WRITE_ZEROES;
300 unmap = !(req->cmd_flags & REQ_NOUNMAP);
303 case REQ_OP_SCSI_OUT:
304 type = VIRTIO_BLK_T_SCSI_CMD;
307 type = VIRTIO_BLK_T_GET_ID;
311 return BLK_STS_IOERR;
314 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
315 vbr->out_hdr.sector = type ?
316 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
317 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
319 blk_mq_start_request(req);
321 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
322 err = virtblk_setup_discard_write_zeroes(req, unmap);
324 return BLK_STS_RESOURCE;
327 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
329 if (rq_data_dir(req) == WRITE)
330 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
332 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
335 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
336 if (blk_rq_is_scsi(req))
337 err = virtblk_add_req_scsi(vblk->vqs[qid].vq, vbr, vbr->sg, num);
339 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
341 virtqueue_kick(vblk->vqs[qid].vq);
342 blk_mq_stop_hw_queue(hctx);
343 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
344 /* Out of mem doesn't actually happen, since we fall back
345 * to direct descriptors */
346 if (err == -ENOMEM || err == -ENOSPC)
347 return BLK_STS_DEV_RESOURCE;
348 return BLK_STS_IOERR;
351 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
353 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
356 virtqueue_notify(vblk->vqs[qid].vq);
360 /* return id (s/n) string for *disk to *id_str
362 static int virtblk_get_id(struct gendisk *disk, char *id_str)
364 struct virtio_blk *vblk = disk->private_data;
365 struct request_queue *q = vblk->disk->queue;
369 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
373 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
377 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
378 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
380 blk_put_request(req);
384 /* We provide getgeo only to please some old bootloader/partitioning tools */
385 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
387 struct virtio_blk *vblk = bd->bd_disk->private_data;
389 /* see if the host passed in geometry config */
390 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
391 virtio_cread(vblk->vdev, struct virtio_blk_config,
392 geometry.cylinders, &geo->cylinders);
393 virtio_cread(vblk->vdev, struct virtio_blk_config,
394 geometry.heads, &geo->heads);
395 virtio_cread(vblk->vdev, struct virtio_blk_config,
396 geometry.sectors, &geo->sectors);
398 /* some standard values, similar to sd */
400 geo->sectors = 1 << 5;
401 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
406 static const struct block_device_operations virtblk_fops = {
407 .ioctl = virtblk_ioctl,
408 .owner = THIS_MODULE,
409 .getgeo = virtblk_getgeo,
412 static int index_to_minor(int index)
414 return index << PART_BITS;
417 static int minor_to_index(int minor)
419 return minor >> PART_BITS;
422 static ssize_t serial_show(struct device *dev,
423 struct device_attribute *attr, char *buf)
425 struct gendisk *disk = dev_to_disk(dev);
428 /* sysfs gives us a PAGE_SIZE buffer */
429 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
431 buf[VIRTIO_BLK_ID_BYTES] = '\0';
432 err = virtblk_get_id(disk, buf);
436 if (err == -EIO) /* Unsupported? Make it empty. */
442 static DEVICE_ATTR_RO(serial);
444 /* The queue's logical block size must be set before calling this */
445 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
447 struct virtio_device *vdev = vblk->vdev;
448 struct request_queue *q = vblk->disk->queue;
449 char cap_str_2[10], cap_str_10[10];
450 unsigned long long nblocks;
453 /* Host must always specify the capacity. */
454 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
456 /* If capacity is too big, truncate with warning. */
457 if ((sector_t)capacity != capacity) {
458 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
459 (unsigned long long)capacity);
460 capacity = (sector_t)-1;
463 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
465 string_get_size(nblocks, queue_logical_block_size(q),
466 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
467 string_get_size(nblocks, queue_logical_block_size(q),
468 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
470 dev_notice(&vdev->dev,
471 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
472 vblk->disk->disk_name,
473 resize ? "new size: " : "",
475 queue_logical_block_size(q),
479 set_capacity(vblk->disk, capacity);
482 static void virtblk_config_changed_work(struct work_struct *work)
484 struct virtio_blk *vblk =
485 container_of(work, struct virtio_blk, config_work);
486 char *envp[] = { "RESIZE=1", NULL };
488 virtblk_update_capacity(vblk, true);
489 revalidate_disk(vblk->disk);
490 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
493 static void virtblk_config_changed(struct virtio_device *vdev)
495 struct virtio_blk *vblk = vdev->priv;
497 queue_work(virtblk_wq, &vblk->config_work);
500 static int init_vq(struct virtio_blk *vblk)
504 vq_callback_t **callbacks;
506 struct virtqueue **vqs;
507 unsigned short num_vqs;
508 struct virtio_device *vdev = vblk->vdev;
509 struct irq_affinity desc = { 0, };
511 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
512 struct virtio_blk_config, num_queues,
517 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
519 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
523 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
524 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
525 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
526 if (!names || !callbacks || !vqs) {
531 for (i = 0; i < num_vqs; i++) {
532 callbacks[i] = virtblk_done;
533 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
534 names[i] = vblk->vqs[i].name;
537 /* Discover virtqueues and write information to configuration. */
538 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
542 for (i = 0; i < num_vqs; i++) {
543 spin_lock_init(&vblk->vqs[i].lock);
544 vblk->vqs[i].vq = vqs[i];
546 vblk->num_vqs = num_vqs;
558 * Legacy naming scheme used for virtio devices. We are stuck with it for
559 * virtio blk but don't ever use it for any new driver.
561 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
563 const int base = 'z' - 'a' + 1;
564 char *begin = buf + strlen(prefix);
565 char *end = buf + buflen;
575 *--p = 'a' + (index % unit);
576 index = (index / unit) - 1;
577 } while (index >= 0);
579 memmove(begin, p, end - p);
580 memcpy(buf, prefix, strlen(prefix));
585 static int virtblk_get_cache_mode(struct virtio_device *vdev)
590 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
591 struct virtio_blk_config, wce,
595 * If WCE is not configurable and flush is not available,
596 * assume no writeback cache is in use.
599 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
604 static void virtblk_update_cache_mode(struct virtio_device *vdev)
606 u8 writeback = virtblk_get_cache_mode(vdev);
607 struct virtio_blk *vblk = vdev->priv;
609 blk_queue_write_cache(vblk->disk->queue, writeback, false);
610 revalidate_disk(vblk->disk);
613 static const char *const virtblk_cache_types[] = {
614 "write through", "write back"
618 cache_type_store(struct device *dev, struct device_attribute *attr,
619 const char *buf, size_t count)
621 struct gendisk *disk = dev_to_disk(dev);
622 struct virtio_blk *vblk = disk->private_data;
623 struct virtio_device *vdev = vblk->vdev;
626 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
627 i = sysfs_match_string(virtblk_cache_types, buf);
631 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
632 virtblk_update_cache_mode(vdev);
637 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
639 struct gendisk *disk = dev_to_disk(dev);
640 struct virtio_blk *vblk = disk->private_data;
641 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
643 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
644 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
647 static DEVICE_ATTR_RW(cache_type);
649 static struct attribute *virtblk_attrs[] = {
650 &dev_attr_serial.attr,
651 &dev_attr_cache_type.attr,
655 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
656 struct attribute *a, int n)
658 struct device *dev = container_of(kobj, struct device, kobj);
659 struct gendisk *disk = dev_to_disk(dev);
660 struct virtio_blk *vblk = disk->private_data;
661 struct virtio_device *vdev = vblk->vdev;
663 if (a == &dev_attr_cache_type.attr &&
664 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
670 static const struct attribute_group virtblk_attr_group = {
671 .attrs = virtblk_attrs,
672 .is_visible = virtblk_attrs_are_visible,
675 static const struct attribute_group *virtblk_attr_groups[] = {
680 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
681 unsigned int hctx_idx, unsigned int numa_node)
683 struct virtio_blk *vblk = set->driver_data;
684 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
686 #ifdef CONFIG_VIRTIO_BLK_SCSI
687 vbr->sreq.sense = vbr->sense;
689 sg_init_table(vbr->sg, vblk->sg_elems);
693 static int virtblk_map_queues(struct blk_mq_tag_set *set)
695 struct virtio_blk *vblk = set->driver_data;
697 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
701 #ifdef CONFIG_VIRTIO_BLK_SCSI
702 static void virtblk_initialize_rq(struct request *req)
704 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
706 scsi_req_init(&vbr->sreq);
710 static const struct blk_mq_ops virtio_mq_ops = {
711 .queue_rq = virtio_queue_rq,
712 .commit_rqs = virtio_commit_rqs,
713 .complete = virtblk_request_done,
714 .init_request = virtblk_init_request,
715 #ifdef CONFIG_VIRTIO_BLK_SCSI
716 .initialize_rq_fn = virtblk_initialize_rq,
718 .map_queues = virtblk_map_queues,
721 static unsigned int virtblk_queue_depth;
722 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
724 static int virtblk_probe(struct virtio_device *vdev)
726 struct virtio_blk *vblk;
727 struct request_queue *q;
730 u32 v, blk_size, max_size, sg_elems, opt_io_size;
732 u8 physical_block_exp, alignment_offset;
734 if (!vdev->config->get) {
735 dev_err(&vdev->dev, "%s failure: config access disabled\n",
740 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
746 /* We need to know how many segments before we allocate. */
747 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
748 struct virtio_blk_config, seg_max,
751 /* We need at least one SG element, whatever they say. */
752 if (err || !sg_elems)
755 /* We need an extra sg elements at head and tail. */
757 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
764 vblk->sg_elems = sg_elems;
766 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
772 /* FIXME: How many partitions? How long is a piece of string? */
773 vblk->disk = alloc_disk(1 << PART_BITS);
779 /* Default queue sizing is to fill the ring. */
780 if (!virtblk_queue_depth) {
781 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
782 /* ... but without indirect descs, we use 2 descs per req */
783 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
784 virtblk_queue_depth /= 2;
787 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
788 vblk->tag_set.ops = &virtio_mq_ops;
789 vblk->tag_set.queue_depth = virtblk_queue_depth;
790 vblk->tag_set.numa_node = NUMA_NO_NODE;
791 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
792 vblk->tag_set.cmd_size =
793 sizeof(struct virtblk_req) +
794 sizeof(struct scatterlist) * sg_elems;
795 vblk->tag_set.driver_data = vblk;
796 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
798 err = blk_mq_alloc_tag_set(&vblk->tag_set);
802 q = blk_mq_init_queue(&vblk->tag_set);
807 vblk->disk->queue = q;
811 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
813 vblk->disk->major = major;
814 vblk->disk->first_minor = index_to_minor(index);
815 vblk->disk->private_data = vblk;
816 vblk->disk->fops = &virtblk_fops;
817 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
820 /* configure queue flush support */
821 virtblk_update_cache_mode(vdev);
823 /* If disk is read-only in the host, the guest should obey */
824 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
825 set_disk_ro(vblk->disk, 1);
827 /* We can handle whatever the host told us to handle. */
828 blk_queue_max_segments(q, vblk->sg_elems-2);
830 /* No real sector limit. */
831 blk_queue_max_hw_sectors(q, -1U);
833 max_size = virtio_max_dma_size(vdev);
835 /* Host can optionally specify maximum segment size and number of
837 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
838 struct virtio_blk_config, size_max, &v);
840 max_size = min(max_size, v);
842 blk_queue_max_segment_size(q, max_size);
844 /* Host can optionally specify the block size of the device */
845 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
846 struct virtio_blk_config, blk_size,
849 blk_queue_logical_block_size(q, blk_size);
851 blk_size = queue_logical_block_size(q);
853 /* Use topology information if available */
854 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
855 struct virtio_blk_config, physical_block_exp,
856 &physical_block_exp);
857 if (!err && physical_block_exp)
858 blk_queue_physical_block_size(q,
859 blk_size * (1 << physical_block_exp));
861 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
862 struct virtio_blk_config, alignment_offset,
864 if (!err && alignment_offset)
865 blk_queue_alignment_offset(q, blk_size * alignment_offset);
867 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
868 struct virtio_blk_config, min_io_size,
870 if (!err && min_io_size)
871 blk_queue_io_min(q, blk_size * min_io_size);
873 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
874 struct virtio_blk_config, opt_io_size,
876 if (!err && opt_io_size)
877 blk_queue_io_opt(q, blk_size * opt_io_size);
879 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
880 q->limits.discard_granularity = blk_size;
882 virtio_cread(vdev, struct virtio_blk_config,
883 discard_sector_alignment, &v);
884 q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
886 virtio_cread(vdev, struct virtio_blk_config,
887 max_discard_sectors, &v);
888 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
890 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
892 blk_queue_max_discard_segments(q,
894 MAX_DISCARD_SEGMENTS));
896 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
899 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
900 virtio_cread(vdev, struct virtio_blk_config,
901 max_write_zeroes_sectors, &v);
902 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
905 virtblk_update_capacity(vblk, false);
906 virtio_device_ready(vdev);
908 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
912 blk_mq_free_tag_set(&vblk->tag_set);
914 put_disk(vblk->disk);
916 vdev->config->del_vqs(vdev);
920 ida_simple_remove(&vd_index_ida, index);
925 static void virtblk_remove(struct virtio_device *vdev)
927 struct virtio_blk *vblk = vdev->priv;
928 int index = vblk->index;
931 /* Make sure no work handler is accessing the device. */
932 flush_work(&vblk->config_work);
934 del_gendisk(vblk->disk);
935 blk_cleanup_queue(vblk->disk->queue);
937 blk_mq_free_tag_set(&vblk->tag_set);
939 /* Stop all the virtqueues. */
940 vdev->config->reset(vdev);
942 refc = kref_read(&disk_to_dev(vblk->disk)->kobj.kref);
943 put_disk(vblk->disk);
944 vdev->config->del_vqs(vdev);
948 /* Only free device id if we don't have any users */
950 ida_simple_remove(&vd_index_ida, index);
953 #ifdef CONFIG_PM_SLEEP
954 static int virtblk_freeze(struct virtio_device *vdev)
956 struct virtio_blk *vblk = vdev->priv;
958 /* Ensure we don't receive any more interrupts */
959 vdev->config->reset(vdev);
961 /* Make sure no work handler is accessing the device. */
962 flush_work(&vblk->config_work);
964 blk_mq_quiesce_queue(vblk->disk->queue);
966 vdev->config->del_vqs(vdev);
970 static int virtblk_restore(struct virtio_device *vdev)
972 struct virtio_blk *vblk = vdev->priv;
975 ret = init_vq(vdev->priv);
979 virtio_device_ready(vdev);
981 blk_mq_unquiesce_queue(vblk->disk->queue);
986 static const struct virtio_device_id id_table[] = {
987 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
991 static unsigned int features_legacy[] = {
992 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
993 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
994 #ifdef CONFIG_VIRTIO_BLK_SCSI
997 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
998 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1001 static unsigned int features[] = {
1002 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1003 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1004 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1005 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1008 static struct virtio_driver virtio_blk = {
1009 .feature_table = features,
1010 .feature_table_size = ARRAY_SIZE(features),
1011 .feature_table_legacy = features_legacy,
1012 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1013 .driver.name = KBUILD_MODNAME,
1014 .driver.owner = THIS_MODULE,
1015 .id_table = id_table,
1016 .probe = virtblk_probe,
1017 .remove = virtblk_remove,
1018 .config_changed = virtblk_config_changed,
1019 #ifdef CONFIG_PM_SLEEP
1020 .freeze = virtblk_freeze,
1021 .restore = virtblk_restore,
1025 static int __init init(void)
1029 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
1033 major = register_blkdev(0, "virtblk");
1036 goto out_destroy_workqueue;
1039 error = register_virtio_driver(&virtio_blk);
1041 goto out_unregister_blkdev;
1044 out_unregister_blkdev:
1045 unregister_blkdev(major, "virtblk");
1046 out_destroy_workqueue:
1047 destroy_workqueue(virtblk_wq);
1051 static void __exit fini(void)
1053 unregister_virtio_driver(&virtio_blk);
1054 unregister_blkdev(major, "virtblk");
1055 destroy_workqueue(virtblk_wq);
1060 MODULE_DEVICE_TABLE(virtio, id_table);
1061 MODULE_DESCRIPTION("Virtio block driver");
1062 MODULE_LICENSE("GPL");