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 <linux/idr.h>
15 #include <linux/blk-mq.h>
16 #include <linux/blk-mq-virtio.h>
17 #include <linux/numa.h>
18 #include <uapi/linux/virtio_ring.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;
37 * This mutex must be held by anything that may run after
38 * virtblk_remove() sets vblk->vdev to NULL.
40 * blk-mq, virtqueue processing, and sysfs attribute code paths are
41 * shut down before vblk->vdev is set to NULL and therefore do not need
44 struct mutex vdev_mutex;
45 struct virtio_device *vdev;
47 /* The disk structure for the kernel. */
50 /* Block layer tags. */
51 struct blk_mq_tag_set tag_set;
53 /* Process context for config space updates */
54 struct work_struct config_work;
57 * Tracks references from block_device_operations open/release and
58 * virtio_driver probe/remove so this object can be freed once no
63 /* What host tells us, plus 2 for header & tailer. */
64 unsigned int sg_elems;
66 /* Ida index - used to track minor number allocations. */
71 struct virtio_blk_vq *vqs;
75 struct virtio_blk_outhdr out_hdr;
77 struct scatterlist sg[];
80 static inline blk_status_t virtblk_result(struct virtblk_req *vbr)
82 switch (vbr->status) {
85 case VIRTIO_BLK_S_UNSUPP:
86 return BLK_STS_NOTSUPP;
92 static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
93 struct scatterlist *data_sg, bool have_data)
95 struct scatterlist hdr, status, *sgs[3];
96 unsigned int num_out = 0, num_in = 0;
98 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
99 sgs[num_out++] = &hdr;
102 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
103 sgs[num_out++] = data_sg;
105 sgs[num_out + num_in++] = data_sg;
108 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
109 sgs[num_out + num_in++] = &status;
111 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
114 static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap)
116 unsigned short segments = blk_rq_nr_discard_segments(req);
117 unsigned short n = 0;
118 struct virtio_blk_discard_write_zeroes *range;
123 flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
125 range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
129 __rq_for_each_bio(bio, req) {
130 u64 sector = bio->bi_iter.bi_sector;
131 u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
133 range[n].flags = cpu_to_le32(flags);
134 range[n].num_sectors = cpu_to_le32(num_sectors);
135 range[n].sector = cpu_to_le64(sector);
139 req->special_vec.bv_page = virt_to_page(range);
140 req->special_vec.bv_offset = offset_in_page(range);
141 req->special_vec.bv_len = sizeof(*range) * segments;
142 req->rq_flags |= RQF_SPECIAL_PAYLOAD;
147 static inline void virtblk_request_done(struct request *req)
149 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
151 if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
152 kfree(page_address(req->special_vec.bv_page) +
153 req->special_vec.bv_offset);
156 blk_mq_end_request(req, virtblk_result(vbr));
159 static void virtblk_done(struct virtqueue *vq)
161 struct virtio_blk *vblk = vq->vdev->priv;
162 bool req_done = false;
164 struct virtblk_req *vbr;
168 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
170 virtqueue_disable_cb(vq);
171 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
172 struct request *req = blk_mq_rq_from_pdu(vbr);
174 blk_mq_complete_request(req);
177 if (unlikely(virtqueue_is_broken(vq)))
179 } while (!virtqueue_enable_cb(vq));
181 /* In case queue is stopped waiting for more buffers. */
183 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
184 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
187 static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
189 struct virtio_blk *vblk = hctx->queue->queuedata;
190 struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
193 spin_lock_irq(&vq->lock);
194 kick = virtqueue_kick_prepare(vq->vq);
195 spin_unlock_irq(&vq->lock);
198 virtqueue_notify(vq->vq);
201 static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
202 const struct blk_mq_queue_data *bd)
204 struct virtio_blk *vblk = hctx->queue->queuedata;
205 struct request *req = bd->rq;
206 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
209 int qid = hctx->queue_num;
215 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
217 switch (req_op(req)) {
223 type = VIRTIO_BLK_T_FLUSH;
226 type = VIRTIO_BLK_T_DISCARD;
228 case REQ_OP_WRITE_ZEROES:
229 type = VIRTIO_BLK_T_WRITE_ZEROES;
230 unmap = !(req->cmd_flags & REQ_NOUNMAP);
233 type = VIRTIO_BLK_T_GET_ID;
237 return BLK_STS_IOERR;
240 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type);
241 vbr->out_hdr.sector = type ?
242 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req));
243 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req));
245 blk_mq_start_request(req);
247 if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
248 err = virtblk_setup_discard_write_zeroes(req, unmap);
250 return BLK_STS_RESOURCE;
253 num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
255 if (rq_data_dir(req) == WRITE)
256 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
258 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
261 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
262 err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
264 virtqueue_kick(vblk->vqs[qid].vq);
265 /* Don't stop the queue if -ENOMEM: we may have failed to
266 * bounce the buffer due to global resource outage.
269 blk_mq_stop_hw_queue(hctx);
270 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
273 return BLK_STS_DEV_RESOURCE;
275 return BLK_STS_RESOURCE;
277 return BLK_STS_IOERR;
281 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
283 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
286 virtqueue_notify(vblk->vqs[qid].vq);
290 /* return id (s/n) string for *disk to *id_str
292 static int virtblk_get_id(struct gendisk *disk, char *id_str)
294 struct virtio_blk *vblk = disk->private_data;
295 struct request_queue *q = vblk->disk->queue;
299 req = blk_get_request(q, REQ_OP_DRV_IN, 0);
303 err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
307 blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
308 err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req)));
310 blk_put_request(req);
314 static void virtblk_get(struct virtio_blk *vblk)
316 refcount_inc(&vblk->refs);
319 static void virtblk_put(struct virtio_blk *vblk)
321 if (refcount_dec_and_test(&vblk->refs)) {
322 ida_simple_remove(&vd_index_ida, vblk->index);
323 mutex_destroy(&vblk->vdev_mutex);
328 static int virtblk_open(struct block_device *bd, fmode_t mode)
330 struct virtio_blk *vblk = bd->bd_disk->private_data;
333 mutex_lock(&vblk->vdev_mutex);
340 mutex_unlock(&vblk->vdev_mutex);
344 static void virtblk_release(struct gendisk *disk, fmode_t mode)
346 struct virtio_blk *vblk = disk->private_data;
351 /* We provide getgeo only to please some old bootloader/partitioning tools */
352 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
354 struct virtio_blk *vblk = bd->bd_disk->private_data;
357 mutex_lock(&vblk->vdev_mutex);
364 /* see if the host passed in geometry config */
365 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
366 virtio_cread(vblk->vdev, struct virtio_blk_config,
367 geometry.cylinders, &geo->cylinders);
368 virtio_cread(vblk->vdev, struct virtio_blk_config,
369 geometry.heads, &geo->heads);
370 virtio_cread(vblk->vdev, struct virtio_blk_config,
371 geometry.sectors, &geo->sectors);
373 /* some standard values, similar to sd */
375 geo->sectors = 1 << 5;
376 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
379 mutex_unlock(&vblk->vdev_mutex);
383 static const struct block_device_operations virtblk_fops = {
384 .owner = THIS_MODULE,
385 .open = virtblk_open,
386 .release = virtblk_release,
387 .getgeo = virtblk_getgeo,
390 static int index_to_minor(int index)
392 return index << PART_BITS;
395 static int minor_to_index(int minor)
397 return minor >> PART_BITS;
400 static ssize_t serial_show(struct device *dev,
401 struct device_attribute *attr, char *buf)
403 struct gendisk *disk = dev_to_disk(dev);
406 /* sysfs gives us a PAGE_SIZE buffer */
407 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
409 buf[VIRTIO_BLK_ID_BYTES] = '\0';
410 err = virtblk_get_id(disk, buf);
414 if (err == -EIO) /* Unsupported? Make it empty. */
420 static DEVICE_ATTR_RO(serial);
422 /* The queue's logical block size must be set before calling this */
423 static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
425 struct virtio_device *vdev = vblk->vdev;
426 struct request_queue *q = vblk->disk->queue;
427 char cap_str_2[10], cap_str_10[10];
428 unsigned long long nblocks;
431 /* Host must always specify the capacity. */
432 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
434 /* If capacity is too big, truncate with warning. */
435 if ((sector_t)capacity != capacity) {
436 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
437 (unsigned long long)capacity);
438 capacity = (sector_t)-1;
441 nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
443 string_get_size(nblocks, queue_logical_block_size(q),
444 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
445 string_get_size(nblocks, queue_logical_block_size(q),
446 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
448 dev_notice(&vdev->dev,
449 "[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
450 vblk->disk->disk_name,
451 resize ? "new size: " : "",
453 queue_logical_block_size(q),
457 set_capacity_revalidate_and_notify(vblk->disk, capacity, true);
460 static void virtblk_config_changed_work(struct work_struct *work)
462 struct virtio_blk *vblk =
463 container_of(work, struct virtio_blk, config_work);
465 virtblk_update_capacity(vblk, true);
468 static void virtblk_config_changed(struct virtio_device *vdev)
470 struct virtio_blk *vblk = vdev->priv;
472 queue_work(virtblk_wq, &vblk->config_work);
475 static int init_vq(struct virtio_blk *vblk)
479 vq_callback_t **callbacks;
481 struct virtqueue **vqs;
482 unsigned short num_vqs;
483 struct virtio_device *vdev = vblk->vdev;
484 struct irq_affinity desc = { 0, };
486 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
487 struct virtio_blk_config, num_queues,
492 num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
494 vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
498 names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
499 callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
500 vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
501 if (!names || !callbacks || !vqs) {
506 for (i = 0; i < num_vqs; i++) {
507 callbacks[i] = virtblk_done;
508 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
509 names[i] = vblk->vqs[i].name;
512 /* Discover virtqueues and write information to configuration. */
513 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
517 for (i = 0; i < num_vqs; i++) {
518 spin_lock_init(&vblk->vqs[i].lock);
519 vblk->vqs[i].vq = vqs[i];
521 vblk->num_vqs = num_vqs;
533 * Legacy naming scheme used for virtio devices. We are stuck with it for
534 * virtio blk but don't ever use it for any new driver.
536 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
538 const int base = 'z' - 'a' + 1;
539 char *begin = buf + strlen(prefix);
540 char *end = buf + buflen;
550 *--p = 'a' + (index % unit);
551 index = (index / unit) - 1;
552 } while (index >= 0);
554 memmove(begin, p, end - p);
555 memcpy(buf, prefix, strlen(prefix));
560 static int virtblk_get_cache_mode(struct virtio_device *vdev)
565 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
566 struct virtio_blk_config, wce,
570 * If WCE is not configurable and flush is not available,
571 * assume no writeback cache is in use.
574 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
579 static void virtblk_update_cache_mode(struct virtio_device *vdev)
581 u8 writeback = virtblk_get_cache_mode(vdev);
582 struct virtio_blk *vblk = vdev->priv;
584 blk_queue_write_cache(vblk->disk->queue, writeback, false);
585 revalidate_disk(vblk->disk);
588 static const char *const virtblk_cache_types[] = {
589 "write through", "write back"
593 cache_type_store(struct device *dev, struct device_attribute *attr,
594 const char *buf, size_t count)
596 struct gendisk *disk = dev_to_disk(dev);
597 struct virtio_blk *vblk = disk->private_data;
598 struct virtio_device *vdev = vblk->vdev;
601 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
602 i = sysfs_match_string(virtblk_cache_types, buf);
606 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
607 virtblk_update_cache_mode(vdev);
612 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
614 struct gendisk *disk = dev_to_disk(dev);
615 struct virtio_blk *vblk = disk->private_data;
616 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
618 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
619 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
622 static DEVICE_ATTR_RW(cache_type);
624 static struct attribute *virtblk_attrs[] = {
625 &dev_attr_serial.attr,
626 &dev_attr_cache_type.attr,
630 static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
631 struct attribute *a, int n)
633 struct device *dev = container_of(kobj, struct device, kobj);
634 struct gendisk *disk = dev_to_disk(dev);
635 struct virtio_blk *vblk = disk->private_data;
636 struct virtio_device *vdev = vblk->vdev;
638 if (a == &dev_attr_cache_type.attr &&
639 !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
645 static const struct attribute_group virtblk_attr_group = {
646 .attrs = virtblk_attrs,
647 .is_visible = virtblk_attrs_are_visible,
650 static const struct attribute_group *virtblk_attr_groups[] = {
655 static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq,
656 unsigned int hctx_idx, unsigned int numa_node)
658 struct virtio_blk *vblk = set->driver_data;
659 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
661 sg_init_table(vbr->sg, vblk->sg_elems);
665 static int virtblk_map_queues(struct blk_mq_tag_set *set)
667 struct virtio_blk *vblk = set->driver_data;
669 return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT],
673 static const struct blk_mq_ops virtio_mq_ops = {
674 .queue_rq = virtio_queue_rq,
675 .commit_rqs = virtio_commit_rqs,
676 .complete = virtblk_request_done,
677 .init_request = virtblk_init_request,
678 .map_queues = virtblk_map_queues,
681 static unsigned int virtblk_queue_depth;
682 module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
684 static int virtblk_probe(struct virtio_device *vdev)
686 struct virtio_blk *vblk;
687 struct request_queue *q;
690 u32 v, blk_size, max_size, sg_elems, opt_io_size;
692 u8 physical_block_exp, alignment_offset;
694 if (!vdev->config->get) {
695 dev_err(&vdev->dev, "%s failure: config access disabled\n",
700 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
706 /* We need to know how many segments before we allocate. */
707 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
708 struct virtio_blk_config, seg_max,
711 /* We need at least one SG element, whatever they say. */
712 if (err || !sg_elems)
715 /* We need an extra sg elements at head and tail. */
717 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
723 /* This reference is dropped in virtblk_remove(). */
724 refcount_set(&vblk->refs, 1);
725 mutex_init(&vblk->vdev_mutex);
728 vblk->sg_elems = sg_elems;
730 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
736 /* FIXME: How many partitions? How long is a piece of string? */
737 vblk->disk = alloc_disk(1 << PART_BITS);
743 /* Default queue sizing is to fill the ring. */
744 if (!virtblk_queue_depth) {
745 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
746 /* ... but without indirect descs, we use 2 descs per req */
747 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
748 virtblk_queue_depth /= 2;
751 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
752 vblk->tag_set.ops = &virtio_mq_ops;
753 vblk->tag_set.queue_depth = virtblk_queue_depth;
754 vblk->tag_set.numa_node = NUMA_NO_NODE;
755 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
756 vblk->tag_set.cmd_size =
757 sizeof(struct virtblk_req) +
758 sizeof(struct scatterlist) * sg_elems;
759 vblk->tag_set.driver_data = vblk;
760 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
762 err = blk_mq_alloc_tag_set(&vblk->tag_set);
766 q = blk_mq_init_queue(&vblk->tag_set);
771 vblk->disk->queue = q;
775 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
777 vblk->disk->major = major;
778 vblk->disk->first_minor = index_to_minor(index);
779 vblk->disk->private_data = vblk;
780 vblk->disk->fops = &virtblk_fops;
781 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
784 /* configure queue flush support */
785 virtblk_update_cache_mode(vdev);
787 /* If disk is read-only in the host, the guest should obey */
788 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
789 set_disk_ro(vblk->disk, 1);
791 /* We can handle whatever the host told us to handle. */
792 blk_queue_max_segments(q, vblk->sg_elems-2);
794 /* No real sector limit. */
795 blk_queue_max_hw_sectors(q, -1U);
797 max_size = virtio_max_dma_size(vdev);
799 /* Host can optionally specify maximum segment size and number of
801 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
802 struct virtio_blk_config, size_max, &v);
804 max_size = min(max_size, v);
806 blk_queue_max_segment_size(q, max_size);
808 /* Host can optionally specify the block size of the device */
809 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
810 struct virtio_blk_config, blk_size,
813 blk_queue_logical_block_size(q, blk_size);
815 blk_size = queue_logical_block_size(q);
817 /* Use topology information if available */
818 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
819 struct virtio_blk_config, physical_block_exp,
820 &physical_block_exp);
821 if (!err && physical_block_exp)
822 blk_queue_physical_block_size(q,
823 blk_size * (1 << physical_block_exp));
825 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
826 struct virtio_blk_config, alignment_offset,
828 if (!err && alignment_offset)
829 blk_queue_alignment_offset(q, blk_size * alignment_offset);
831 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
832 struct virtio_blk_config, min_io_size,
834 if (!err && min_io_size)
835 blk_queue_io_min(q, blk_size * min_io_size);
837 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
838 struct virtio_blk_config, opt_io_size,
840 if (!err && opt_io_size)
841 blk_queue_io_opt(q, blk_size * opt_io_size);
843 if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
844 q->limits.discard_granularity = blk_size;
846 virtio_cread(vdev, struct virtio_blk_config,
847 discard_sector_alignment, &v);
848 q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
850 virtio_cread(vdev, struct virtio_blk_config,
851 max_discard_sectors, &v);
852 blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
854 virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
856 blk_queue_max_discard_segments(q,
858 MAX_DISCARD_SEGMENTS));
860 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
863 if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
864 virtio_cread(vdev, struct virtio_blk_config,
865 max_write_zeroes_sectors, &v);
866 blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
869 virtblk_update_capacity(vblk, false);
870 virtio_device_ready(vdev);
872 device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
876 blk_mq_free_tag_set(&vblk->tag_set);
878 put_disk(vblk->disk);
880 vdev->config->del_vqs(vdev);
885 ida_simple_remove(&vd_index_ida, index);
890 static void virtblk_remove(struct virtio_device *vdev)
892 struct virtio_blk *vblk = vdev->priv;
894 /* Make sure no work handler is accessing the device. */
895 flush_work(&vblk->config_work);
897 del_gendisk(vblk->disk);
898 blk_cleanup_queue(vblk->disk->queue);
900 blk_mq_free_tag_set(&vblk->tag_set);
902 mutex_lock(&vblk->vdev_mutex);
904 /* Stop all the virtqueues. */
905 vdev->config->reset(vdev);
907 /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
910 put_disk(vblk->disk);
911 vdev->config->del_vqs(vdev);
914 mutex_unlock(&vblk->vdev_mutex);
919 #ifdef CONFIG_PM_SLEEP
920 static int virtblk_freeze(struct virtio_device *vdev)
922 struct virtio_blk *vblk = vdev->priv;
924 /* Ensure we don't receive any more interrupts */
925 vdev->config->reset(vdev);
927 /* Make sure no work handler is accessing the device. */
928 flush_work(&vblk->config_work);
930 blk_mq_quiesce_queue(vblk->disk->queue);
932 vdev->config->del_vqs(vdev);
936 static int virtblk_restore(struct virtio_device *vdev)
938 struct virtio_blk *vblk = vdev->priv;
941 ret = init_vq(vdev->priv);
945 virtio_device_ready(vdev);
947 blk_mq_unquiesce_queue(vblk->disk->queue);
952 static const struct virtio_device_id id_table[] = {
953 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
957 static unsigned int features_legacy[] = {
958 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
959 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
960 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
961 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
964 static unsigned int features[] = {
965 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
966 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
967 VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
968 VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
971 static struct virtio_driver virtio_blk = {
972 .feature_table = features,
973 .feature_table_size = ARRAY_SIZE(features),
974 .feature_table_legacy = features_legacy,
975 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
976 .driver.name = KBUILD_MODNAME,
977 .driver.owner = THIS_MODULE,
978 .id_table = id_table,
979 .probe = virtblk_probe,
980 .remove = virtblk_remove,
981 .config_changed = virtblk_config_changed,
982 #ifdef CONFIG_PM_SLEEP
983 .freeze = virtblk_freeze,
984 .restore = virtblk_restore,
988 static int __init init(void)
992 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
996 major = register_blkdev(0, "virtblk");
999 goto out_destroy_workqueue;
1002 error = register_virtio_driver(&virtio_blk);
1004 goto out_unregister_blkdev;
1007 out_unregister_blkdev:
1008 unregister_blkdev(major, "virtblk");
1009 out_destroy_workqueue:
1010 destroy_workqueue(virtblk_wq);
1014 static void __exit fini(void)
1016 unregister_virtio_driver(&virtio_blk);
1017 unregister_blkdev(major, "virtblk");
1018 destroy_workqueue(virtblk_wq);
1023 MODULE_DEVICE_TABLE(virtio, id_table);
1024 MODULE_DESCRIPTION("Virtio block driver");
1025 MODULE_LICENSE("GPL");