2 #include <linux/spinlock.h>
3 #include <linux/slab.h>
4 #include <linux/blkdev.h>
5 #include <linux/hdreg.h>
6 #include <linux/module.h>
7 #include <linux/mutex.h>
8 #include <linux/interrupt.h>
9 #include <linux/virtio.h>
10 #include <linux/virtio_blk.h>
11 #include <linux/scatterlist.h>
12 #include <linux/string_helpers.h>
13 #include <scsi/scsi_cmnd.h>
14 #include <linux/idr.h>
15 #include <linux/blk-mq.h>
16 #include <linux/blk-mq-virtio.h>
17 #include <linux/numa.h>
20 #define VQ_NAME_LEN 16
21 #define MAX_DISCARD_SEGMENTS 256u
24 static DEFINE_IDA(vd_index_ida);
26 static struct workqueue_struct *virtblk_wq;
28 struct virtio_blk_vq {
31 char name[VQ_NAME_LEN];
32 } ____cacheline_aligned_in_smp;
35 struct virtio_device *vdev;
37 /* The disk structure for the kernel. */
40 /* Block layer tags. */
41 struct blk_mq_tag_set tag_set;
43 /* Process context for config space updates */
44 struct work_struct config_work;
46 /* What host tells us, plus 2 for header & tailer. */
47 unsigned int sg_elems;
49 /* Ida index - used to track minor number allocations. */
54 struct virtio_blk_vq *vqs;
58 #ifdef CONFIG_VIRTIO_BLK_SCSI
59 struct scsi_request sreq; /* for SCSI passthrough, must be first */
60 u8 sense[SCSI_SENSE_BUFFERSIZE];
61 struct virtio_scsi_inhdr in_hdr;
63 struct virtio_blk_outhdr out_hdr;
65 struct scatterlist sg[];
68 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
70 switch (vbr->status) {
73 case VIRTIO_BLK_S_UNSUPP:
74 return BLK_STS_NOTSUPP;
81 * If this is a packet command we need a couple of additional headers. Behind
82 * the normal outhdr we put a segment with the scsi command block, and before
83 * the normal inhdr we put the sense data and the inhdr with additional status
86 #ifdef CONFIG_VIRTIO_BLK_SCSI
87 static int virtblk_add_req_scsi(struct virtqueue *vq, struct virtblk_req *vbr,
88 struct scatterlist *data_sg, bool have_data)
90 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
91 unsigned int num_out = 0, num_in = 0;
93 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
94 sgs[num_out++] = &hdr;
95 sg_init_one(&cmd, vbr->sreq.cmd, vbr->sreq.cmd_len);
96 sgs[num_out++] = &cmd;
99 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
100 sgs[num_out++] = data_sg;
102 sgs[num_out + num_in++] = data_sg;
105 sg_init_one(&sense, vbr->sense, SCSI_SENSE_BUFFERSIZE);
106 sgs[num_out + num_in++] = &sense;
107 sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
108 sgs[num_out + num_in++] = &inhdr;
109 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
110 sgs[num_out + num_in++] = &status;
112 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
115 static inline void virtblk_scsi_request_done(struct request *req)
117 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
118 struct virtio_blk *vblk = req->q->queuedata;
119 struct scsi_request *sreq = &vbr->sreq;
121 sreq->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual);
122 sreq->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len);
123 sreq->result = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
126 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
127 unsigned int cmd, unsigned long data)
129 struct gendisk *disk = bdev->bd_disk;
130 struct virtio_blk *vblk = disk->private_data;
133 * Only allow the generic SCSI ioctls if the host can support it.
135 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
138 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
139 (void __user *)data);
142 static inline int virtblk_add_req_scsi(struct virtqueue *vq,
143 struct virtblk_req *vbr, struct scatterlist *data_sg,
148 static inline void virtblk_scsi_request_done(struct request *req)
151 #define virtblk_ioctl NULL
152 #endif /* CONFIG_VIRTIO_BLK_SCSI */
154 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
155 struct scatterlist *data_sg, bool have_data)
157 struct scatterlist hdr, status, *sgs[3];
158 unsigned int num_out = 0, num_in = 0;
160 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
161 sgs[num_out++] = &hdr;
164 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
165 sgs[num_out++] = data_sg;
167 sgs[num_out + num_in++] = data_sg;
170 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
171 sgs[num_out + num_in++] = &status;
173 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
176 static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap)
178 unsigned short segments = blk_rq_nr_discard_segments(req);
179 unsigned short n = 0;
180 struct virtio_blk_discard_write_zeroes *range;
185 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
187 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
191 __rq_for_each_bio(bio, req) {
192 u64 sector = bio->bi_iter.bi_sector;
193 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
195 range[n].flags = cpu_to_le32(flags);
196 range[n].num_sectors = cpu_to_le32(num_sectors);
197 range[n].sector = cpu_to_le64(sector);
201 req->special_vec.bv_page = virt_to_page(range);
202 req->special_vec.bv_offset = offset_in_page(range);
203 req->special_vec.bv_len = sizeof(*range) * segments;
204 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
209 static inline void virtblk_request_done(struct request *req)
211 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
213 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
214 kfree(page_address(req->special_vec.bv_page) +
215 req->special_vec.bv_offset);
218 switch (req_op(req)) {
220 case REQ_OP_SCSI_OUT:
221 virtblk_scsi_request_done(req);
225 blk_mq_end_request(req, virtblk_result(vbr));
228 static void virtblk_done(struct virtqueue *vq)
230 struct virtio_blk *vblk = vq->vdev->priv;
231 bool req_done = false;
233 struct virtblk_req *vbr;
237 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
239 virtqueue_disable_cb(vq);
240 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
241 struct request *req = blk_mq_rq_from_pdu(vbr);
243 blk_mq_complete_request(req);
246 if (unlikely(virtqueue_is_broken(vq)))
248 } while (!virtqueue_enable_cb(vq));
250 /* In case queue is stopped waiting for more buffers. */
252 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
253 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
256 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
258 struct virtio_blk *vblk = hctx->queue->queuedata;
259 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
262 spin_lock_irq(&vq->lock);
263 kick = virtqueue_kick_prepare(vq->vq);
264 spin_unlock_irq(&vq->lock);
267 virtqueue_notify(vq->vq);
270 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
271 const struct blk_mq_queue_data *bd)
273 struct virtio_blk *vblk = hctx->queue->queuedata;
274 struct request *req = bd->rq;
275 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
278 int qid = hctx->queue_num;
284 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
286 switch (req_op(req)) {
292 type = VIRTIO_BLK_T_FLUSH;
295 type = VIRTIO_BLK_T_DISCARD;
297 case REQ_OP_WRITE_ZEROES:
298 type = VIRTIO_BLK_T_WRITE_ZEROES;
299 unmap = !(req->cmd_flags & REQ_NOUNMAP);
302 case REQ_OP_SCSI_OUT:
303 type = VIRTIO_BLK_T_SCSI_CMD;
306 type = VIRTIO_BLK_T_GET_ID;
310 return BLK_STS_IOERR;
313 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
314 vbr->out_hdr.sector = type ?
315 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
316 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
318 blk_mq_start_request(req);
320 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
321 err = virtblk_setup_discard_write_zeroes(req, unmap);
323 return BLK_STS_RESOURCE;
326 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
328 if (rq_data_dir(req) == WRITE)
329 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
331 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
334 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
335 if (blk_rq_is_scsi(req))
336 err = virtblk_add_req_scsi(vblk->vqs[qid].vq, vbr, vbr->sg, num);
338 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
340 virtqueue_kick(vblk->vqs[qid].vq);
341 blk_mq_stop_hw_queue(hctx);
342 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
343 /* Out of mem doesn't actually happen, since we fall back
344 * to direct descriptors */
345 if (err == -ENOMEM || err == -ENOSPC)
346 return BLK_STS_DEV_RESOURCE;
347 return BLK_STS_IOERR;
350 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
352 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
355 virtqueue_notify(vblk->vqs[qid].vq);
359 /* return id (s/n) string for *disk to *id_str
361 static int virtblk_get_id(struct gendisk *disk, char *id_str)
363 struct virtio_blk *vblk = disk->private_data;
364 struct request_queue *q = vblk->disk->queue;
368 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
372 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
376 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
377 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
379 blk_put_request(req);
383 /* We provide getgeo only to please some old bootloader/partitioning tools */
384 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
386 struct virtio_blk *vblk = bd->bd_disk->private_data;
388 /* see if the host passed in geometry config */
389 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
390 virtio_cread(vblk->vdev, struct virtio_blk_config,
391 geometry.cylinders, &geo->cylinders);
392 virtio_cread(vblk->vdev, struct virtio_blk_config,
393 geometry.heads, &geo->heads);
394 virtio_cread(vblk->vdev, struct virtio_blk_config,
395 geometry.sectors, &geo->sectors);
397 /* some standard values, similar to sd */
399 geo->sectors = 1 << 5;
400 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
405 static const struct block_device_operations virtblk_fops = {
406 .ioctl = virtblk_ioctl,
407 .owner = THIS_MODULE,
408 .getgeo = virtblk_getgeo,
411 static int index_to_minor(int index)
413 return index << PART_BITS;
416 static int minor_to_index(int minor)
418 return minor >> PART_BITS;
421 static ssize_t serial_show(struct device *dev,
422 struct device_attribute *attr, char *buf)
424 struct gendisk *disk = dev_to_disk(dev);
427 /* sysfs gives us a PAGE_SIZE buffer */
428 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
430 buf[VIRTIO_BLK_ID_BYTES] = '\0';
431 err = virtblk_get_id(disk, buf);
435 if (err == -EIO) /* Unsupported? Make it empty. */
441 static DEVICE_ATTR_RO(serial);
443 /* The queue's logical block size must be set before calling this */
444 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
446 struct virtio_device *vdev = vblk->vdev;
447 struct request_queue *q = vblk->disk->queue;
448 char cap_str_2[10], cap_str_10[10];
449 unsigned long long nblocks;
452 /* Host must always specify the capacity. */
453 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
455 /* If capacity is too big, truncate with warning. */
456 if ((sector_t)capacity != capacity) {
457 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
458 (unsigned long long)capacity);
459 capacity = (sector_t)-1;
462 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
464 string_get_size(nblocks, queue_logical_block_size(q),
465 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
466 string_get_size(nblocks, queue_logical_block_size(q),
467 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
469 dev_notice(&vdev->dev,
470 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
471 vblk->disk->disk_name,
472 resize ? "new size: " : "",
474 queue_logical_block_size(q),
478 set_capacity(vblk->disk, capacity);
481 static void virtblk_config_changed_work(struct work_struct *work)
483 struct virtio_blk *vblk =
484 container_of(work, struct virtio_blk, config_work);
485 char *envp[] = { "RESIZE=1", NULL };
487 virtblk_update_capacity(vblk, true);
488 revalidate_disk(vblk->disk);
489 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
492 static void virtblk_config_changed(struct virtio_device *vdev)
494 struct virtio_blk *vblk = vdev->priv;
496 queue_work(virtblk_wq, &vblk->config_work);
499 static int init_vq(struct virtio_blk *vblk)
503 vq_callback_t **callbacks;
505 struct virtqueue **vqs;
506 unsigned short num_vqs;
507 struct virtio_device *vdev = vblk->vdev;
508 struct irq_affinity desc = { 0, };
510 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
511 struct virtio_blk_config, num_queues,
516 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
518 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
522 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
523 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
524 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
525 if (!names || !callbacks || !vqs) {
530 for (i = 0; i < num_vqs; i++) {
531 callbacks[i] = virtblk_done;
532 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
533 names[i] = vblk->vqs[i].name;
536 /* Discover virtqueues and write information to configuration. */
537 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
541 for (i = 0; i < num_vqs; i++) {
542 spin_lock_init(&vblk->vqs[i].lock);
543 vblk->vqs[i].vq = vqs[i];
545 vblk->num_vqs = num_vqs;
557 * Legacy naming scheme used for virtio devices. We are stuck with it for
558 * virtio blk but don't ever use it for any new driver.
560 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
562 const int base = 'z' - 'a' + 1;
563 char *begin = buf + strlen(prefix);
564 char *end = buf + buflen;
574 *--p = 'a' + (index % unit);
575 index = (index / unit) - 1;
576 } while (index >= 0);
578 memmove(begin, p, end - p);
579 memcpy(buf, prefix, strlen(prefix));
584 static int virtblk_get_cache_mode(struct virtio_device *vdev)
589 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
590 struct virtio_blk_config, wce,
594 * If WCE is not configurable and flush is not available,
595 * assume no writeback cache is in use.
598 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
603 static void virtblk_update_cache_mode(struct virtio_device *vdev)
605 u8 writeback = virtblk_get_cache_mode(vdev);
606 struct virtio_blk *vblk = vdev->priv;
608 blk_queue_write_cache(vblk->disk->queue, writeback, false);
609 revalidate_disk(vblk->disk);
612 static const char *const virtblk_cache_types[] = {
613 "write through", "write back"
617 cache_type_store(struct device *dev, struct device_attribute *attr,
618 const char *buf, size_t count)
620 struct gendisk *disk = dev_to_disk(dev);
621 struct virtio_blk *vblk = disk->private_data;
622 struct virtio_device *vdev = vblk->vdev;
625 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
626 i = sysfs_match_string(virtblk_cache_types, buf);
630 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
631 virtblk_update_cache_mode(vdev);
636 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
638 struct gendisk *disk = dev_to_disk(dev);
639 struct virtio_blk *vblk = disk->private_data;
640 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
642 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
643 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
646 static DEVICE_ATTR_RW(cache_type);
648 static struct attribute *virtblk_attrs[] = {
649 &dev_attr_serial.attr,
650 &dev_attr_cache_type.attr,
654 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
655 struct attribute *a, int n)
657 struct device *dev = container_of(kobj, struct device, kobj);
658 struct gendisk *disk = dev_to_disk(dev);
659 struct virtio_blk *vblk = disk->private_data;
660 struct virtio_device *vdev = vblk->vdev;
662 if (a == &dev_attr_cache_type.attr &&
663 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
669 static const struct attribute_group virtblk_attr_group = {
670 .attrs = virtblk_attrs,
671 .is_visible = virtblk_attrs_are_visible,
674 static const struct attribute_group *virtblk_attr_groups[] = {
679 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
680 unsigned int hctx_idx, unsigned int numa_node)
682 struct virtio_blk *vblk = set->driver_data;
683 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
685 #ifdef CONFIG_VIRTIO_BLK_SCSI
686 vbr->sreq.sense = vbr->sense;
688 sg_init_table(vbr->sg, vblk->sg_elems);
692 static int virtblk_map_queues(struct blk_mq_tag_set *set)
694 struct virtio_blk *vblk = set->driver_data;
696 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
700 #ifdef CONFIG_VIRTIO_BLK_SCSI
701 static void virtblk_initialize_rq(struct request *req)
703 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
705 scsi_req_init(&vbr->sreq);
709 static const struct blk_mq_ops virtio_mq_ops = {
710 .queue_rq = virtio_queue_rq,
711 .commit_rqs = virtio_commit_rqs,
712 .complete = virtblk_request_done,
713 .init_request = virtblk_init_request,
714 #ifdef CONFIG_VIRTIO_BLK_SCSI
715 .initialize_rq_fn = virtblk_initialize_rq,
717 .map_queues = virtblk_map_queues,
720 static unsigned int virtblk_queue_depth;
721 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
723 static int virtblk_probe(struct virtio_device *vdev)
725 struct virtio_blk *vblk;
726 struct request_queue *q;
729 u32 v, blk_size, max_size, sg_elems, opt_io_size;
731 u8 physical_block_exp, alignment_offset;
733 if (!vdev->config->get) {
734 dev_err(&vdev->dev, "%s failure: config access disabled\n",
739 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
745 /* We need to know how many segments before we allocate. */
746 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
747 struct virtio_blk_config, seg_max,
750 /* We need at least one SG element, whatever they say. */
751 if (err || !sg_elems)
754 /* We need an extra sg elements at head and tail. */
756 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
763 vblk->sg_elems = sg_elems;
765 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
771 /* FIXME: How many partitions? How long is a piece of string? */
772 vblk->disk = alloc_disk(1 << PART_BITS);
778 /* Default queue sizing is to fill the ring. */
779 if (!virtblk_queue_depth) {
780 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
781 /* ... but without indirect descs, we use 2 descs per req */
782 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
783 virtblk_queue_depth /= 2;
786 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
787 vblk->tag_set.ops = &virtio_mq_ops;
788 vblk->tag_set.queue_depth = virtblk_queue_depth;
789 vblk->tag_set.numa_node = NUMA_NO_NODE;
790 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
791 vblk->tag_set.cmd_size =
792 sizeof(struct virtblk_req) +
793 sizeof(struct scatterlist) * sg_elems;
794 vblk->tag_set.driver_data = vblk;
795 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
797 err = blk_mq_alloc_tag_set(&vblk->tag_set);
801 q = blk_mq_init_queue(&vblk->tag_set);
806 vblk->disk->queue = q;
810 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
812 vblk->disk->major = major;
813 vblk->disk->first_minor = index_to_minor(index);
814 vblk->disk->private_data = vblk;
815 vblk->disk->fops = &virtblk_fops;
816 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
819 /* configure queue flush support */
820 virtblk_update_cache_mode(vdev);
822 /* If disk is read-only in the host, the guest should obey */
823 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
824 set_disk_ro(vblk->disk, 1);
826 /* We can handle whatever the host told us to handle. */
827 blk_queue_max_segments(q, vblk->sg_elems-2);
829 /* No real sector limit. */
830 blk_queue_max_hw_sectors(q, -1U);
832 max_size = virtio_max_dma_size(vdev);
834 /* Host can optionally specify maximum segment size and number of
836 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
837 struct virtio_blk_config, size_max, &v);
839 max_size = min(max_size, v);
841 blk_queue_max_segment_size(q, max_size);
843 /* Host can optionally specify the block size of the device */
844 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
845 struct virtio_blk_config, blk_size,
848 blk_queue_logical_block_size(q, blk_size);
850 blk_size = queue_logical_block_size(q);
852 /* Use topology information if available */
853 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
854 struct virtio_blk_config, physical_block_exp,
855 &physical_block_exp);
856 if (!err && physical_block_exp)
857 blk_queue_physical_block_size(q,
858 blk_size * (1 << physical_block_exp));
860 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
861 struct virtio_blk_config, alignment_offset,
863 if (!err && alignment_offset)
864 blk_queue_alignment_offset(q, blk_size * alignment_offset);
866 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
867 struct virtio_blk_config, min_io_size,
869 if (!err && min_io_size)
870 blk_queue_io_min(q, blk_size * min_io_size);
872 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
873 struct virtio_blk_config, opt_io_size,
875 if (!err && opt_io_size)
876 blk_queue_io_opt(q, blk_size * opt_io_size);
878 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
879 q->limits.discard_granularity = blk_size;
881 virtio_cread(vdev, struct virtio_blk_config,
882 discard_sector_alignment, &v);
883 q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
885 virtio_cread(vdev, struct virtio_blk_config,
886 max_discard_sectors, &v);
887 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
889 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
891 blk_queue_max_discard_segments(q,
893 MAX_DISCARD_SEGMENTS));
895 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
898 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
899 virtio_cread(vdev, struct virtio_blk_config,
900 max_write_zeroes_sectors, &v);
901 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
904 virtblk_update_capacity(vblk, false);
905 virtio_device_ready(vdev);
907 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
911 blk_mq_free_tag_set(&vblk->tag_set);
913 put_disk(vblk->disk);
915 vdev->config->del_vqs(vdev);
919 ida_simple_remove(&vd_index_ida, index);
924 static void virtblk_remove(struct virtio_device *vdev)
926 struct virtio_blk *vblk = vdev->priv;
927 int index = vblk->index;
930 /* Make sure no work handler is accessing the device. */
931 flush_work(&vblk->config_work);
933 del_gendisk(vblk->disk);
934 blk_cleanup_queue(vblk->disk->queue);
936 blk_mq_free_tag_set(&vblk->tag_set);
938 /* Stop all the virtqueues. */
939 vdev->config->reset(vdev);
941 refc = kref_read(&disk_to_dev(vblk->disk)->kobj.kref);
942 put_disk(vblk->disk);
943 vdev->config->del_vqs(vdev);
947 /* Only free device id if we don't have any users */
949 ida_simple_remove(&vd_index_ida, index);
952 #ifdef CONFIG_PM_SLEEP
953 static int virtblk_freeze(struct virtio_device *vdev)
955 struct virtio_blk *vblk = vdev->priv;
957 /* Ensure we don't receive any more interrupts */
958 vdev->config->reset(vdev);
960 /* Make sure no work handler is accessing the device. */
961 flush_work(&vblk->config_work);
963 blk_mq_quiesce_queue(vblk->disk->queue);
965 vdev->config->del_vqs(vdev);
969 static int virtblk_restore(struct virtio_device *vdev)
971 struct virtio_blk *vblk = vdev->priv;
974 ret = init_vq(vdev->priv);
978 virtio_device_ready(vdev);
980 blk_mq_unquiesce_queue(vblk->disk->queue);
985 static const struct virtio_device_id id_table[] = {
986 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
990 static unsigned int features_legacy[] = {
991 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
992 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
993 #ifdef CONFIG_VIRTIO_BLK_SCSI
996 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
997 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1000 static unsigned int features[] = {
1001 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1002 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1003 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1004 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1007 static struct virtio_driver virtio_blk = {
1008 .feature_table = features,
1009 .feature_table_size = ARRAY_SIZE(features),
1010 .feature_table_legacy = features_legacy,
1011 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1012 .driver.name = KBUILD_MODNAME,
1013 .driver.owner = THIS_MODULE,
1014 .id_table = id_table,
1015 .probe = virtblk_probe,
1016 .remove = virtblk_remove,
1017 .config_changed = virtblk_config_changed,
1018 #ifdef CONFIG_PM_SLEEP
1019 .freeze = virtblk_freeze,
1020 .restore = virtblk_restore,
1024 static int __init init(void)
1028 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
1032 major = register_blkdev(0, "virtblk");
1035 goto out_destroy_workqueue;
1038 error = register_virtio_driver(&virtio_blk);
1040 goto out_unregister_blkdev;
1043 out_unregister_blkdev:
1044 unregister_blkdev(major, "virtblk");
1045 out_destroy_workqueue:
1046 destroy_workqueue(virtblk_wq);
1050 static void __exit fini(void)
1052 unregister_virtio_driver(&virtio_blk);
1053 unregister_blkdev(major, "virtblk");
1054 destroy_workqueue(virtblk_wq);
1059 MODULE_DEVICE_TABLE(virtio, id_table);
1060 MODULE_DESCRIPTION("Virtio block driver");
1061 MODULE_LICENSE("GPL");