diff options
Diffstat (limited to 'drivers/block/virtio_blk.c')
| -rw-r--r-- | drivers/block/virtio_blk.c | 1737 |
1 files changed, 1737 insertions, 0 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c new file mode 100644 index 0000000000..225c86c74d --- /dev/null +++ b/drivers/block/virtio_blk.c @@ -0,0 +1,1737 @@ +// SPDX-License-Identifier: GPL-2.0-only +//#define DEBUG +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/blkdev.h> +#include <linux/hdreg.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/interrupt.h> +#include <linux/virtio.h> +#include <linux/virtio_blk.h> +#include <linux/scatterlist.h> +#include <linux/string_helpers.h> +#include <linux/idr.h> +#include <linux/blk-mq.h> +#include <linux/blk-mq-virtio.h> +#include <linux/numa.h> +#include <linux/vmalloc.h> +#include <uapi/linux/virtio_ring.h> + +#define PART_BITS 4 +#define VQ_NAME_LEN 16 +#define MAX_DISCARD_SEGMENTS 256u + +/* The maximum number of sg elements that fit into a virtqueue */ +#define VIRTIO_BLK_MAX_SG_ELEMS 32768 + +#ifdef CONFIG_ARCH_NO_SG_CHAIN +#define VIRTIO_BLK_INLINE_SG_CNT 0 +#else +#define VIRTIO_BLK_INLINE_SG_CNT 2 +#endif + +static unsigned int num_request_queues; +module_param(num_request_queues, uint, 0644); +MODULE_PARM_DESC(num_request_queues, + "Limit the number of request queues to use for blk device. " + "0 for no limit. " + "Values > nr_cpu_ids truncated to nr_cpu_ids."); + +static unsigned int poll_queues; +module_param(poll_queues, uint, 0644); +MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); + +static int major; +static DEFINE_IDA(vd_index_ida); + +static struct workqueue_struct *virtblk_wq; + +struct virtio_blk_vq { + struct virtqueue *vq; + spinlock_t lock; + char name[VQ_NAME_LEN]; +} ____cacheline_aligned_in_smp; + +struct virtio_blk { + /* + * This mutex must be held by anything that may run after + * virtblk_remove() sets vblk->vdev to NULL. + * + * blk-mq, virtqueue processing, and sysfs attribute code paths are + * shut down before vblk->vdev is set to NULL and therefore do not need + * to hold this mutex. + */ + struct mutex vdev_mutex; + struct virtio_device *vdev; + + /* The disk structure for the kernel. */ + struct gendisk *disk; + + /* Block layer tags. */ + struct blk_mq_tag_set tag_set; + + /* Process context for config space updates */ + struct work_struct config_work; + + /* Ida index - used to track minor number allocations. */ + int index; + + /* num of vqs */ + int num_vqs; + int io_queues[HCTX_MAX_TYPES]; + struct virtio_blk_vq *vqs; + + /* For zoned device */ + unsigned int zone_sectors; +}; + +struct virtblk_req { + /* Out header */ + struct virtio_blk_outhdr out_hdr; + + /* In header */ + union { + u8 status; + + /* + * The zone append command has an extended in header. + * The status field in zone_append_in_hdr must always + * be the last byte. + */ + struct { + __virtio64 sector; + u8 status; + } zone_append; + } in_hdr; + + size_t in_hdr_len; + + struct sg_table sg_table; + struct scatterlist sg[]; +}; + +static inline blk_status_t virtblk_result(u8 status) +{ + switch (status) { + case VIRTIO_BLK_S_OK: + return BLK_STS_OK; + case VIRTIO_BLK_S_UNSUPP: + return BLK_STS_NOTSUPP; + case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE: + return BLK_STS_ZONE_OPEN_RESOURCE; + case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE: + return BLK_STS_ZONE_ACTIVE_RESOURCE; + case VIRTIO_BLK_S_IOERR: + case VIRTIO_BLK_S_ZONE_UNALIGNED_WP: + default: + return BLK_STS_IOERR; + } +} + +static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) +{ + struct virtio_blk *vblk = hctx->queue->queuedata; + struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; + + return vq; +} + +static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) +{ + struct scatterlist out_hdr, in_hdr, *sgs[3]; + unsigned int num_out = 0, num_in = 0; + + sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); + sgs[num_out++] = &out_hdr; + + if (vbr->sg_table.nents) { + if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) + sgs[num_out++] = vbr->sg_table.sgl; + else + sgs[num_out + num_in++] = vbr->sg_table.sgl; + } + + sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len); + sgs[num_out + num_in++] = &in_hdr; + + return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); +} + +static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap) +{ + unsigned short segments = blk_rq_nr_discard_segments(req); + unsigned short n = 0; + struct virtio_blk_discard_write_zeroes *range; + struct bio *bio; + u32 flags = 0; + + if (unmap) + flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; + + range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); + if (!range) + return -ENOMEM; + + /* + * Single max discard segment means multi-range discard isn't + * supported, and block layer only runs contiguity merge like + * normal RW request. So we can't reply on bio for retrieving + * each range info. + */ + if (queue_max_discard_segments(req->q) == 1) { + range[0].flags = cpu_to_le32(flags); + range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); + range[0].sector = cpu_to_le64(blk_rq_pos(req)); + n = 1; + } else { + __rq_for_each_bio(bio, req) { + u64 sector = bio->bi_iter.bi_sector; + u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; + + range[n].flags = cpu_to_le32(flags); + range[n].num_sectors = cpu_to_le32(num_sectors); + range[n].sector = cpu_to_le64(sector); + n++; + } + } + + WARN_ON_ONCE(n != segments); + + bvec_set_virt(&req->special_vec, range, sizeof(*range) * segments); + req->rq_flags |= RQF_SPECIAL_PAYLOAD; + + return 0; +} + +static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr) +{ + if (blk_rq_nr_phys_segments(req)) + sg_free_table_chained(&vbr->sg_table, + VIRTIO_BLK_INLINE_SG_CNT); +} + +static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req, + struct virtblk_req *vbr) +{ + int err; + + if (!blk_rq_nr_phys_segments(req)) + return 0; + + vbr->sg_table.sgl = vbr->sg; + err = sg_alloc_table_chained(&vbr->sg_table, + blk_rq_nr_phys_segments(req), + vbr->sg_table.sgl, + VIRTIO_BLK_INLINE_SG_CNT); + if (unlikely(err)) + return -ENOMEM; + + return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl); +} + +static void virtblk_cleanup_cmd(struct request *req) +{ + if (req->rq_flags & RQF_SPECIAL_PAYLOAD) + kfree(bvec_virt(&req->special_vec)); +} + +static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, + struct request *req, + struct virtblk_req *vbr) +{ + size_t in_hdr_len = sizeof(vbr->in_hdr.status); + bool unmap = false; + u32 type; + u64 sector = 0; + + if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req))) + return BLK_STS_NOTSUPP; + + /* Set fields for all request types */ + vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); + + switch (req_op(req)) { + case REQ_OP_READ: + type = VIRTIO_BLK_T_IN; + sector = blk_rq_pos(req); + break; + case REQ_OP_WRITE: + type = VIRTIO_BLK_T_OUT; + sector = blk_rq_pos(req); + break; + case REQ_OP_FLUSH: + type = VIRTIO_BLK_T_FLUSH; + break; + case REQ_OP_DISCARD: + type = VIRTIO_BLK_T_DISCARD; + break; + case REQ_OP_WRITE_ZEROES: + type = VIRTIO_BLK_T_WRITE_ZEROES; + unmap = !(req->cmd_flags & REQ_NOUNMAP); + break; + case REQ_OP_SECURE_ERASE: + type = VIRTIO_BLK_T_SECURE_ERASE; + break; + case REQ_OP_ZONE_OPEN: + type = VIRTIO_BLK_T_ZONE_OPEN; + sector = blk_rq_pos(req); + break; + case REQ_OP_ZONE_CLOSE: + type = VIRTIO_BLK_T_ZONE_CLOSE; + sector = blk_rq_pos(req); + break; + case REQ_OP_ZONE_FINISH: + type = VIRTIO_BLK_T_ZONE_FINISH; + sector = blk_rq_pos(req); + break; + case REQ_OP_ZONE_APPEND: + type = VIRTIO_BLK_T_ZONE_APPEND; + sector = blk_rq_pos(req); + in_hdr_len = sizeof(vbr->in_hdr.zone_append); + break; + case REQ_OP_ZONE_RESET: + type = VIRTIO_BLK_T_ZONE_RESET; + sector = blk_rq_pos(req); + break; + case REQ_OP_ZONE_RESET_ALL: + type = VIRTIO_BLK_T_ZONE_RESET_ALL; + break; + case REQ_OP_DRV_IN: + /* + * Out header has already been prepared by the caller (virtblk_get_id() + * or virtblk_submit_zone_report()), nothing to do here. + */ + return 0; + default: + WARN_ON_ONCE(1); + return BLK_STS_IOERR; + } + + /* Set fields for non-REQ_OP_DRV_IN request types */ + vbr->in_hdr_len = in_hdr_len; + vbr->out_hdr.type = cpu_to_virtio32(vdev, type); + vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector); + + if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES || + type == VIRTIO_BLK_T_SECURE_ERASE) { + if (virtblk_setup_discard_write_zeroes_erase(req, unmap)) + return BLK_STS_RESOURCE; + } + + return 0; +} + +/* + * The status byte is always the last byte of the virtblk request + * in-header. This helper fetches its value for all in-header formats + * that are currently defined. + */ +static inline u8 virtblk_vbr_status(struct virtblk_req *vbr) +{ + return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1); +} + +static inline void virtblk_request_done(struct request *req) +{ + struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); + blk_status_t status = virtblk_result(virtblk_vbr_status(vbr)); + struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; + + virtblk_unmap_data(req, vbr); + virtblk_cleanup_cmd(req); + + if (req_op(req) == REQ_OP_ZONE_APPEND) + req->__sector = virtio64_to_cpu(vblk->vdev, + vbr->in_hdr.zone_append.sector); + + blk_mq_end_request(req, status); +} + +static void virtblk_done(struct virtqueue *vq) +{ + struct virtio_blk *vblk = vq->vdev->priv; + bool req_done = false; + int qid = vq->index; + struct virtblk_req *vbr; + unsigned long flags; + unsigned int len; + + spin_lock_irqsave(&vblk->vqs[qid].lock, flags); + do { + virtqueue_disable_cb(vq); + while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { + struct request *req = blk_mq_rq_from_pdu(vbr); + + if (likely(!blk_should_fake_timeout(req->q))) + blk_mq_complete_request(req); + req_done = true; + } + if (unlikely(virtqueue_is_broken(vq))) + break; + } while (!virtqueue_enable_cb(vq)); + + /* In case queue is stopped waiting for more buffers. */ + if (req_done) + blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); + spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); +} + +static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) +{ + struct virtio_blk *vblk = hctx->queue->queuedata; + struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; + bool kick; + + spin_lock_irq(&vq->lock); + kick = virtqueue_kick_prepare(vq->vq); + spin_unlock_irq(&vq->lock); + + if (kick) + virtqueue_notify(vq->vq); +} + +static blk_status_t virtblk_fail_to_queue(struct request *req, int rc) +{ + virtblk_cleanup_cmd(req); + switch (rc) { + case -ENOSPC: + return BLK_STS_DEV_RESOURCE; + case -ENOMEM: + return BLK_STS_RESOURCE; + default: + return BLK_STS_IOERR; + } +} + +static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, + struct virtio_blk *vblk, + struct request *req, + struct virtblk_req *vbr) +{ + blk_status_t status; + int num; + + status = virtblk_setup_cmd(vblk->vdev, req, vbr); + if (unlikely(status)) + return status; + + num = virtblk_map_data(hctx, req, vbr); + if (unlikely(num < 0)) + return virtblk_fail_to_queue(req, -ENOMEM); + vbr->sg_table.nents = num; + + blk_mq_start_request(req); + + return BLK_STS_OK; +} + +static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct virtio_blk *vblk = hctx->queue->queuedata; + struct request *req = bd->rq; + struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); + unsigned long flags; + int qid = hctx->queue_num; + bool notify = false; + blk_status_t status; + int err; + + status = virtblk_prep_rq(hctx, vblk, req, vbr); + if (unlikely(status)) + return status; + + spin_lock_irqsave(&vblk->vqs[qid].lock, flags); + err = virtblk_add_req(vblk->vqs[qid].vq, vbr); + if (err) { + virtqueue_kick(vblk->vqs[qid].vq); + /* Don't stop the queue if -ENOMEM: we may have failed to + * bounce the buffer due to global resource outage. + */ + if (err == -ENOSPC) + blk_mq_stop_hw_queue(hctx); + spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); + virtblk_unmap_data(req, vbr); + return virtblk_fail_to_queue(req, err); + } + + if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) + notify = true; + spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); + + if (notify) + virtqueue_notify(vblk->vqs[qid].vq); + return BLK_STS_OK; +} + +static bool virtblk_prep_rq_batch(struct request *req) +{ + struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; + struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); + + req->mq_hctx->tags->rqs[req->tag] = req; + + return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; +} + +static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, + struct request **rqlist) +{ + unsigned long flags; + int err; + bool kick; + + spin_lock_irqsave(&vq->lock, flags); + + while (!rq_list_empty(*rqlist)) { + struct request *req = rq_list_pop(rqlist); + struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); + + err = virtblk_add_req(vq->vq, vbr); + if (err) { + virtblk_unmap_data(req, vbr); + virtblk_cleanup_cmd(req); + blk_mq_requeue_request(req, true); + } + } + + kick = virtqueue_kick_prepare(vq->vq); + spin_unlock_irqrestore(&vq->lock, flags); + + return kick; +} + +static void virtio_queue_rqs(struct request **rqlist) +{ + struct request *req, *next, *prev = NULL; + struct request *requeue_list = NULL; + + rq_list_for_each_safe(rqlist, req, next) { + struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); + bool kick; + + if (!virtblk_prep_rq_batch(req)) { + rq_list_move(rqlist, &requeue_list, req, prev); + req = prev; + if (!req) + continue; + } + + if (!next || req->mq_hctx != next->mq_hctx) { + req->rq_next = NULL; + kick = virtblk_add_req_batch(vq, rqlist); + if (kick) + virtqueue_notify(vq->vq); + + *rqlist = next; + prev = NULL; + } else + prev = req; + } + + *rqlist = requeue_list; +} + +#ifdef CONFIG_BLK_DEV_ZONED +static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, + unsigned int nr_zones, + size_t *buflen) +{ + struct request_queue *q = vblk->disk->queue; + size_t bufsize; + void *buf; + + nr_zones = min_t(unsigned int, nr_zones, + get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors)); + + bufsize = sizeof(struct virtio_blk_zone_report) + + nr_zones * sizeof(struct virtio_blk_zone_descriptor); + bufsize = min_t(size_t, bufsize, + queue_max_hw_sectors(q) << SECTOR_SHIFT); + bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); + + while (bufsize >= sizeof(struct virtio_blk_zone_report)) { + buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); + if (buf) { + *buflen = bufsize; + return buf; + } + bufsize >>= 1; + } + + return NULL; +} + +static int virtblk_submit_zone_report(struct virtio_blk *vblk, + char *report_buf, size_t report_len, + sector_t sector) +{ + struct request_queue *q = vblk->disk->queue; + struct request *req; + struct virtblk_req *vbr; + int err; + + req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); + if (IS_ERR(req)) + return PTR_ERR(req); + + vbr = blk_mq_rq_to_pdu(req); + vbr->in_hdr_len = sizeof(vbr->in_hdr.status); + vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); + vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); + + err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); + if (err) + goto out; + + blk_execute_rq(req, false); + err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); +out: + blk_mq_free_request(req); + return err; +} + +static int virtblk_parse_zone(struct virtio_blk *vblk, + struct virtio_blk_zone_descriptor *entry, + unsigned int idx, report_zones_cb cb, void *data) +{ + struct blk_zone zone = { }; + + zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start); + if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk)) + zone.len = vblk->zone_sectors; + else + zone.len = get_capacity(vblk->disk) - zone.start; + zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap); + zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp); + + switch (entry->z_type) { + case VIRTIO_BLK_ZT_SWR: + zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ; + break; + case VIRTIO_BLK_ZT_SWP: + zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF; + break; + case VIRTIO_BLK_ZT_CONV: + zone.type = BLK_ZONE_TYPE_CONVENTIONAL; + break; + default: + dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n", + zone.start, entry->z_type); + return -EIO; + } + + switch (entry->z_state) { + case VIRTIO_BLK_ZS_EMPTY: + zone.cond = BLK_ZONE_COND_EMPTY; + break; + case VIRTIO_BLK_ZS_CLOSED: + zone.cond = BLK_ZONE_COND_CLOSED; + break; + case VIRTIO_BLK_ZS_FULL: + zone.cond = BLK_ZONE_COND_FULL; + zone.wp = zone.start + zone.len; + break; + case VIRTIO_BLK_ZS_EOPEN: + zone.cond = BLK_ZONE_COND_EXP_OPEN; + break; + case VIRTIO_BLK_ZS_IOPEN: + zone.cond = BLK_ZONE_COND_IMP_OPEN; + break; + case VIRTIO_BLK_ZS_NOT_WP: + zone.cond = BLK_ZONE_COND_NOT_WP; + break; + case VIRTIO_BLK_ZS_RDONLY: + zone.cond = BLK_ZONE_COND_READONLY; + zone.wp = ULONG_MAX; + break; + case VIRTIO_BLK_ZS_OFFLINE: + zone.cond = BLK_ZONE_COND_OFFLINE; + zone.wp = ULONG_MAX; + break; + default: + dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n", + zone.start, entry->z_state); + return -EIO; + } + + /* + * The callback below checks the validity of the reported + * entry data, no need to further validate it here. + */ + return cb(&zone, idx, data); +} + +static int virtblk_report_zones(struct gendisk *disk, sector_t sector, + unsigned int nr_zones, report_zones_cb cb, + void *data) +{ + struct virtio_blk *vblk = disk->private_data; + struct virtio_blk_zone_report *report; + unsigned long long nz, i; + size_t buflen; + unsigned int zone_idx = 0; + int ret; + + if (WARN_ON_ONCE(!vblk->zone_sectors)) + return -EOPNOTSUPP; + + report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen); + if (!report) + return -ENOMEM; + + mutex_lock(&vblk->vdev_mutex); + + if (!vblk->vdev) { + ret = -ENXIO; + goto fail_report; + } + + while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { + memset(report, 0, buflen); + + ret = virtblk_submit_zone_report(vblk, (char *)report, + buflen, sector); + if (ret) + goto fail_report; + + nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones), + nr_zones); + if (!nz) + break; + + for (i = 0; i < nz && zone_idx < nr_zones; i++) { + ret = virtblk_parse_zone(vblk, &report->zones[i], + zone_idx, cb, data); + if (ret) + goto fail_report; + + sector = virtio64_to_cpu(vblk->vdev, + report->zones[i].z_start) + + vblk->zone_sectors; + zone_idx++; + } + } + + if (zone_idx > 0) + ret = zone_idx; + else + ret = -EINVAL; +fail_report: + mutex_unlock(&vblk->vdev_mutex); + kvfree(report); + return ret; +} + +static void virtblk_revalidate_zones(struct virtio_blk *vblk) +{ + u8 model; + + virtio_cread(vblk->vdev, struct virtio_blk_config, + zoned.model, &model); + switch (model) { + default: + dev_err(&vblk->vdev->dev, "unknown zone model %d\n", model); + fallthrough; + case VIRTIO_BLK_Z_NONE: + case VIRTIO_BLK_Z_HA: + disk_set_zoned(vblk->disk, BLK_ZONED_NONE); + return; + case VIRTIO_BLK_Z_HM: + WARN_ON_ONCE(!vblk->zone_sectors); + if (!blk_revalidate_disk_zones(vblk->disk, NULL)) + set_capacity_and_notify(vblk->disk, 0); + } +} + +static int virtblk_probe_zoned_device(struct virtio_device *vdev, + struct virtio_blk *vblk, + struct request_queue *q) +{ + u32 v, wg; + u8 model; + + virtio_cread(vdev, struct virtio_blk_config, + zoned.model, &model); + + switch (model) { + case VIRTIO_BLK_Z_NONE: + case VIRTIO_BLK_Z_HA: + /* Present the host-aware device as non-zoned */ + return 0; + case VIRTIO_BLK_Z_HM: + break; + default: + dev_err(&vdev->dev, "unsupported zone model %d\n", model); + return -EINVAL; + } + + dev_dbg(&vdev->dev, "probing host-managed zoned device\n"); + + disk_set_zoned(vblk->disk, BLK_ZONED_HM); + blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q); + + virtio_cread(vdev, struct virtio_blk_config, + zoned.max_open_zones, &v); + disk_set_max_open_zones(vblk->disk, v); + dev_dbg(&vdev->dev, "max open zones = %u\n", v); + + virtio_cread(vdev, struct virtio_blk_config, + zoned.max_active_zones, &v); + disk_set_max_active_zones(vblk->disk, v); + dev_dbg(&vdev->dev, "max active zones = %u\n", v); + + virtio_cread(vdev, struct virtio_blk_config, + zoned.write_granularity, &wg); + if (!wg) { + dev_warn(&vdev->dev, "zero write granularity reported\n"); + return -ENODEV; + } + blk_queue_physical_block_size(q, wg); + blk_queue_io_min(q, wg); + + dev_dbg(&vdev->dev, "write granularity = %u\n", wg); + + /* + * virtio ZBD specification doesn't require zones to be a power of + * two sectors in size, but the code in this driver expects that. + */ + virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, + &vblk->zone_sectors); + if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) { + dev_err(&vdev->dev, + "zoned device with non power of two zone size %u\n", + vblk->zone_sectors); + return -ENODEV; + } + blk_queue_chunk_sectors(q, vblk->zone_sectors); + dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors); + + if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { + dev_warn(&vblk->vdev->dev, + "ignoring negotiated F_DISCARD for zoned device\n"); + blk_queue_max_discard_sectors(q, 0); + } + + virtio_cread(vdev, struct virtio_blk_config, + zoned.max_append_sectors, &v); + if (!v) { + dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); + return -ENODEV; + } + if ((v << SECTOR_SHIFT) < wg) { + dev_err(&vdev->dev, + "write granularity %u exceeds max_append_sectors %u limit\n", + wg, v); + return -ENODEV; + } + blk_queue_max_zone_append_sectors(q, v); + dev_dbg(&vdev->dev, "max append sectors = %u\n", v); + + return blk_revalidate_disk_zones(vblk->disk, NULL); +} + +#else + +/* + * Zoned block device support is not configured in this kernel. + * Host-managed zoned devices can't be supported, but others are + * good to go as regular block devices. + */ +#define virtblk_report_zones NULL + +static inline void virtblk_revalidate_zones(struct virtio_blk *vblk) +{ +} + +static inline int virtblk_probe_zoned_device(struct virtio_device *vdev, + struct virtio_blk *vblk, struct request_queue *q) +{ + u8 model; + + virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model); + if (model == VIRTIO_BLK_Z_HM) { + dev_err(&vdev->dev, + "virtio_blk: zoned devices are not supported"); + return -EOPNOTSUPP; + } + + return 0; +} +#endif /* CONFIG_BLK_DEV_ZONED */ + +/* return id (s/n) string for *disk to *id_str + */ +static int virtblk_get_id(struct gendisk *disk, char *id_str) +{ + struct virtio_blk *vblk = disk->private_data; + struct request_queue *q = vblk->disk->queue; + struct request *req; + struct virtblk_req *vbr; + int err; + + req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); + if (IS_ERR(req)) + return PTR_ERR(req); + + vbr = blk_mq_rq_to_pdu(req); + vbr->in_hdr_len = sizeof(vbr->in_hdr.status); + vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID); + vbr->out_hdr.sector = 0; + + err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); + if (err) + goto out; + + blk_execute_rq(req, false); + err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status)); +out: + blk_mq_free_request(req); + return err; +} + +/* We provide getgeo only to please some old bootloader/partitioning tools */ +static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) +{ + struct virtio_blk *vblk = bd->bd_disk->private_data; + int ret = 0; + + mutex_lock(&vblk->vdev_mutex); + + if (!vblk->vdev) { + ret = -ENXIO; + goto out; + } + + /* see if the host passed in geometry config */ + if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { + virtio_cread(vblk->vdev, struct virtio_blk_config, + geometry.cylinders, &geo->cylinders); + virtio_cread(vblk->vdev, struct virtio_blk_config, + geometry.heads, &geo->heads); + virtio_cread(vblk->vdev, struct virtio_blk_config, + geometry.sectors, &geo->sectors); + } else { + /* some standard values, similar to sd */ + geo->heads = 1 << 6; + geo->sectors = 1 << 5; + geo->cylinders = get_capacity(bd->bd_disk) >> 11; + } +out: + mutex_unlock(&vblk->vdev_mutex); + return ret; +} + +static void virtblk_free_disk(struct gendisk *disk) +{ + struct virtio_blk *vblk = disk->private_data; + + ida_free(&vd_index_ida, vblk->index); + mutex_destroy(&vblk->vdev_mutex); + kfree(vblk); +} + +static const struct block_device_operations virtblk_fops = { + .owner = THIS_MODULE, + .getgeo = virtblk_getgeo, + .free_disk = virtblk_free_disk, + .report_zones = virtblk_report_zones, +}; + +static int index_to_minor(int index) +{ + return index << PART_BITS; +} + +static int minor_to_index(int minor) +{ + return minor >> PART_BITS; +} + +static ssize_t serial_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + int err; + + /* sysfs gives us a PAGE_SIZE buffer */ + BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); + + buf[VIRTIO_BLK_ID_BYTES] = '\0'; + err = virtblk_get_id(disk, buf); + if (!err) + return strlen(buf); + + if (err == -EIO) /* Unsupported? Make it empty. */ + return 0; + + return err; +} + +static DEVICE_ATTR_RO(serial); + +/* The queue's logical block size must be set before calling this */ +static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) +{ + struct virtio_device *vdev = vblk->vdev; + struct request_queue *q = vblk->disk->queue; + char cap_str_2[10], cap_str_10[10]; + unsigned long long nblocks; + u64 capacity; + + /* Host must always specify the capacity. */ + virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); + + nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); + + string_get_size(nblocks, queue_logical_block_size(q), + STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); + string_get_size(nblocks, queue_logical_block_size(q), + STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); + + dev_notice(&vdev->dev, + "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", + vblk->disk->disk_name, + resize ? "new size: " : "", + nblocks, + queue_logical_block_size(q), + cap_str_10, + cap_str_2); + + set_capacity_and_notify(vblk->disk, capacity); +} + +static void virtblk_config_changed_work(struct work_struct *work) +{ + struct virtio_blk *vblk = + container_of(work, struct virtio_blk, config_work); + + virtblk_revalidate_zones(vblk); + virtblk_update_capacity(vblk, true); +} + +static void virtblk_config_changed(struct virtio_device *vdev) +{ + struct virtio_blk *vblk = vdev->priv; + + queue_work(virtblk_wq, &vblk->config_work); +} + +static int init_vq(struct virtio_blk *vblk) +{ + int err; + unsigned short i; + vq_callback_t **callbacks; + const char **names; + struct virtqueue **vqs; + unsigned short num_vqs; + unsigned short num_poll_vqs; + struct virtio_device *vdev = vblk->vdev; + struct irq_affinity desc = { 0, }; + + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, + struct virtio_blk_config, num_queues, + &num_vqs); + if (err) + num_vqs = 1; + + if (!err && !num_vqs) { + dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); + return -EINVAL; + } + + num_vqs = min_t(unsigned int, + min_not_zero(num_request_queues, nr_cpu_ids), + num_vqs); + + num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); + + vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; + vblk->io_queues[HCTX_TYPE_READ] = 0; + vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; + + dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", + vblk->io_queues[HCTX_TYPE_DEFAULT], + vblk->io_queues[HCTX_TYPE_READ], + vblk->io_queues[HCTX_TYPE_POLL]); + + vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); + if (!vblk->vqs) + return -ENOMEM; + + names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); + callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); + vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); + if (!names || !callbacks || !vqs) { + err = -ENOMEM; + goto out; + } + + for (i = 0; i < num_vqs - num_poll_vqs; i++) { + callbacks[i] = virtblk_done; + snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%u", i); + names[i] = vblk->vqs[i].name; + } + + for (; i < num_vqs; i++) { + callbacks[i] = NULL; + snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%u", i); + names[i] = vblk->vqs[i].name; + } + + /* Discover virtqueues and write information to configuration. */ + err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); + if (err) + goto out; + + for (i = 0; i < num_vqs; i++) { + spin_lock_init(&vblk->vqs[i].lock); + vblk->vqs[i].vq = vqs[i]; + } + vblk->num_vqs = num_vqs; + +out: + kfree(vqs); + kfree(callbacks); + kfree(names); + if (err) + kfree(vblk->vqs); + return err; +} + +/* + * Legacy naming scheme used for virtio devices. We are stuck with it for + * virtio blk but don't ever use it for any new driver. + */ +static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) +{ + const int base = 'z' - 'a' + 1; + char *begin = buf + strlen(prefix); + char *end = buf + buflen; + char *p; + int unit; + + p = end - 1; + *p = '\0'; + unit = base; + do { + if (p == begin) + return -EINVAL; + *--p = 'a' + (index % unit); + index = (index / unit) - 1; + } while (index >= 0); + + memmove(begin, p, end - p); + memcpy(buf, prefix, strlen(prefix)); + + return 0; +} + +static int virtblk_get_cache_mode(struct virtio_device *vdev) +{ + u8 writeback; + int err; + + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, + struct virtio_blk_config, wce, + &writeback); + + /* + * If WCE is not configurable and flush is not available, + * assume no writeback cache is in use. + */ + if (err) + writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); + + return writeback; +} + +static void virtblk_update_cache_mode(struct virtio_device *vdev) +{ + u8 writeback = virtblk_get_cache_mode(vdev); + struct virtio_blk *vblk = vdev->priv; + + blk_queue_write_cache(vblk->disk->queue, writeback, false); +} + +static const char *const virtblk_cache_types[] = { + "write through", "write back" +}; + +static ssize_t +cache_type_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct gendisk *disk = dev_to_disk(dev); + struct virtio_blk *vblk = disk->private_data; + struct virtio_device *vdev = vblk->vdev; + int i; + + BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); + i = sysfs_match_string(virtblk_cache_types, buf); + if (i < 0) + return i; + + virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); + virtblk_update_cache_mode(vdev); + return count; +} + +static ssize_t +cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct virtio_blk *vblk = disk->private_data; + u8 writeback = virtblk_get_cache_mode(vblk->vdev); + + BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); + return sysfs_emit(buf, "%s\n", virtblk_cache_types[writeback]); +} + +static DEVICE_ATTR_RW(cache_type); + +static struct attribute *virtblk_attrs[] = { + &dev_attr_serial.attr, + &dev_attr_cache_type.attr, + NULL, +}; + +static umode_t virtblk_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct gendisk *disk = dev_to_disk(dev); + struct virtio_blk *vblk = disk->private_data; + struct virtio_device *vdev = vblk->vdev; + + if (a == &dev_attr_cache_type.attr && + !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) + return S_IRUGO; + + return a->mode; +} + +static const struct attribute_group virtblk_attr_group = { + .attrs = virtblk_attrs, + .is_visible = virtblk_attrs_are_visible, +}; + +static const struct attribute_group *virtblk_attr_groups[] = { + &virtblk_attr_group, + NULL, +}; + +static void virtblk_map_queues(struct blk_mq_tag_set *set) +{ + struct virtio_blk *vblk = set->driver_data; + int i, qoff; + + for (i = 0, qoff = 0; i < set->nr_maps; i++) { + struct blk_mq_queue_map *map = &set->map[i]; + + map->nr_queues = vblk->io_queues[i]; + map->queue_offset = qoff; + qoff += map->nr_queues; + + if (map->nr_queues == 0) + continue; + + /* + * Regular queues have interrupts and hence CPU affinity is + * defined by the core virtio code, but polling queues have + * no interrupts so we let the block layer assign CPU affinity. + */ + if (i == HCTX_TYPE_POLL) + blk_mq_map_queues(&set->map[i]); + else + blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); + } +} + +static void virtblk_complete_batch(struct io_comp_batch *iob) +{ + struct request *req; + + rq_list_for_each(&iob->req_list, req) { + virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); + virtblk_cleanup_cmd(req); + } + blk_mq_end_request_batch(iob); +} + +static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) +{ + struct virtio_blk *vblk = hctx->queue->queuedata; + struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); + struct virtblk_req *vbr; + unsigned long flags; + unsigned int len; + int found = 0; + + spin_lock_irqsave(&vq->lock, flags); + + while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { + struct request *req = blk_mq_rq_from_pdu(vbr); + + found++; + if (!blk_mq_complete_request_remote(req) && + !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr), + virtblk_complete_batch)) + virtblk_request_done(req); + } + + if (found) + blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); + + spin_unlock_irqrestore(&vq->lock, flags); + + return found; +} + +static const struct blk_mq_ops virtio_mq_ops = { + .queue_rq = virtio_queue_rq, + .queue_rqs = virtio_queue_rqs, + .commit_rqs = virtio_commit_rqs, + .complete = virtblk_request_done, + .map_queues = virtblk_map_queues, + .poll = virtblk_poll, +}; + +static unsigned int virtblk_queue_depth; +module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); + +static int virtblk_probe(struct virtio_device *vdev) +{ + struct virtio_blk *vblk; + struct request_queue *q; + int err, index; + + u32 v, blk_size, max_size, sg_elems, opt_io_size; + u32 max_discard_segs = 0; + u32 discard_granularity = 0; + u16 min_io_size; + u8 physical_block_exp, alignment_offset; + unsigned int queue_depth; + size_t max_dma_size; + + if (!vdev->config->get) { + dev_err(&vdev->dev, "%s failure: config access disabled\n", + __func__); + return -EINVAL; + } + + err = ida_alloc_range(&vd_index_ida, 0, + minor_to_index(1 << MINORBITS) - 1, GFP_KERNEL); + if (err < 0) + goto out; + index = err; + + /* We need to know how many segments before we allocate. */ + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, + struct virtio_blk_config, seg_max, + &sg_elems); + + /* We need at least one SG element, whatever they say. */ + if (err || !sg_elems) + sg_elems = 1; + + /* Prevent integer overflows and honor max vq size */ + sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); + + vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); + if (!vblk) { + err = -ENOMEM; + goto out_free_index; + } + + mutex_init(&vblk->vdev_mutex); + + vblk->vdev = vdev; + + INIT_WORK(&vblk->config_work, virtblk_config_changed_work); + + err = init_vq(vblk); + if (err) + goto out_free_vblk; + + /* Default queue sizing is to fill the ring. */ + if (!virtblk_queue_depth) { + queue_depth = vblk->vqs[0].vq->num_free; + /* ... but without indirect descs, we use 2 descs per req */ + if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) + queue_depth /= 2; + } else { + queue_depth = virtblk_queue_depth; + } + + memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); + vblk->tag_set.ops = &virtio_mq_ops; + vblk->tag_set.queue_depth = queue_depth; + vblk->tag_set.numa_node = NUMA_NO_NODE; + vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; + vblk->tag_set.cmd_size = + sizeof(struct virtblk_req) + + sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; + vblk->tag_set.driver_data = vblk; + vblk->tag_set.nr_hw_queues = vblk->num_vqs; + vblk->tag_set.nr_maps = 1; + if (vblk->io_queues[HCTX_TYPE_POLL]) + vblk->tag_set.nr_maps = 3; + + err = blk_mq_alloc_tag_set(&vblk->tag_set); + if (err) + goto out_free_vq; + + vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); + if (IS_ERR(vblk->disk)) { + err = PTR_ERR(vblk->disk); + goto out_free_tags; + } + q = vblk->disk->queue; + + virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); + + vblk->disk->major = major; + vblk->disk->first_minor = index_to_minor(index); + vblk->disk->minors = 1 << PART_BITS; + vblk->disk->private_data = vblk; + vblk->disk->fops = &virtblk_fops; + vblk->index = index; + + /* configure queue flush support */ + virtblk_update_cache_mode(vdev); + + /* If disk is read-only in the host, the guest should obey */ + if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) + set_disk_ro(vblk->disk, 1); + + /* We can handle whatever the host told us to handle. */ + blk_queue_max_segments(q, sg_elems); + + /* No real sector limit. */ + blk_queue_max_hw_sectors(q, UINT_MAX); + + max_dma_size = virtio_max_dma_size(vdev); + max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size; + + /* Host can optionally specify maximum segment size and number of + * segments. */ + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, + struct virtio_blk_config, size_max, &v); + if (!err) + max_size = min(max_size, v); + + blk_queue_max_segment_size(q, max_size); + + /* Host can optionally specify the block size of the device */ + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, + struct virtio_blk_config, blk_size, + &blk_size); + if (!err) { + err = blk_validate_block_size(blk_size); + if (err) { + dev_err(&vdev->dev, + "virtio_blk: invalid block size: 0x%x\n", + blk_size); + goto out_cleanup_disk; + } + + blk_queue_logical_block_size(q, blk_size); + } else + blk_size = queue_logical_block_size(q); + + /* Use topology information if available */ + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, + struct virtio_blk_config, physical_block_exp, + &physical_block_exp); + if (!err && physical_block_exp) + blk_queue_physical_block_size(q, + blk_size * (1 << physical_block_exp)); + + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, + struct virtio_blk_config, alignment_offset, + &alignment_offset); + if (!err && alignment_offset) + blk_queue_alignment_offset(q, blk_size * alignment_offset); + + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, + struct virtio_blk_config, min_io_size, + &min_io_size); + if (!err && min_io_size) + blk_queue_io_min(q, blk_size * min_io_size); + + err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, + struct virtio_blk_config, opt_io_size, + &opt_io_size); + if (!err && opt_io_size) + blk_queue_io_opt(q, blk_size * opt_io_size); + + if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { + virtio_cread(vdev, struct virtio_blk_config, + discard_sector_alignment, &discard_granularity); + + virtio_cread(vdev, struct virtio_blk_config, + max_discard_sectors, &v); + blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); + + virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, + &max_discard_segs); + } + + if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { + virtio_cread(vdev, struct virtio_blk_config, + max_write_zeroes_sectors, &v); + blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); + } + + /* The discard and secure erase limits are combined since the Linux + * block layer uses the same limit for both commands. + * + * If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features + * are negotiated, we will use the minimum between the limits. + * + * discard sector alignment is set to the minimum between discard_sector_alignment + * and secure_erase_sector_alignment. + * + * max discard sectors is set to the minimum between max_discard_seg and + * max_secure_erase_seg. + */ + if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { + + virtio_cread(vdev, struct virtio_blk_config, + secure_erase_sector_alignment, &v); + + /* secure_erase_sector_alignment should not be zero, the device should set a + * valid number of sectors. + */ + if (!v) { + dev_err(&vdev->dev, + "virtio_blk: secure_erase_sector_alignment can't be 0\n"); + err = -EINVAL; + goto out_cleanup_disk; + } + + discard_granularity = min_not_zero(discard_granularity, v); + + virtio_cread(vdev, struct virtio_blk_config, + max_secure_erase_sectors, &v); + + /* max_secure_erase_sectors should not be zero, the device should set a + * valid number of sectors. + */ + if (!v) { + dev_err(&vdev->dev, + "virtio_blk: max_secure_erase_sectors can't be 0\n"); + err = -EINVAL; + goto out_cleanup_disk; + } + + blk_queue_max_secure_erase_sectors(q, v); + + virtio_cread(vdev, struct virtio_blk_config, + max_secure_erase_seg, &v); + + /* max_secure_erase_seg should not be zero, the device should set a + * valid number of segments + */ + if (!v) { + dev_err(&vdev->dev, + "virtio_blk: max_secure_erase_seg can't be 0\n"); + err = -EINVAL; + goto out_cleanup_disk; + } + + max_discard_segs = min_not_zero(max_discard_segs, v); + } + + if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) || + virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) { + /* max_discard_seg and discard_granularity will be 0 only + * if max_discard_seg and discard_sector_alignment fields in the virtio + * config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated. + * In this case, we use default values. + */ + if (!max_discard_segs) + max_discard_segs = sg_elems; + + blk_queue_max_discard_segments(q, + min(max_discard_segs, MAX_DISCARD_SEGMENTS)); + + if (discard_granularity) + q->limits.discard_granularity = discard_granularity << SECTOR_SHIFT; + else + q->limits.discard_granularity = blk_size; + } + + virtblk_update_capacity(vblk, false); + virtio_device_ready(vdev); + + /* + * All steps that follow use the VQs therefore they need to be + * placed after the virtio_device_ready() call above. + */ + if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) { + err = virtblk_probe_zoned_device(vdev, vblk, q); + if (err) + goto out_cleanup_disk; + } + + err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); + if (err) + goto out_cleanup_disk; + + return 0; + +out_cleanup_disk: + put_disk(vblk->disk); +out_free_tags: + blk_mq_free_tag_set(&vblk->tag_set); +out_free_vq: + vdev->config->del_vqs(vdev); + kfree(vblk->vqs); +out_free_vblk: + kfree(vblk); +out_free_index: + ida_free(&vd_index_ida, index); +out: + return err; +} + +static void virtblk_remove(struct virtio_device *vdev) +{ + struct virtio_blk *vblk = vdev->priv; + + /* Make sure no work handler is accessing the device. */ + flush_work(&vblk->config_work); + + del_gendisk(vblk->disk); + blk_mq_free_tag_set(&vblk->tag_set); + + mutex_lock(&vblk->vdev_mutex); + + /* Stop all the virtqueues. */ + virtio_reset_device(vdev); + + /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ + vblk->vdev = NULL; + + vdev->config->del_vqs(vdev); + kfree(vblk->vqs); + + mutex_unlock(&vblk->vdev_mutex); + + put_disk(vblk->disk); +} + +#ifdef CONFIG_PM_SLEEP +static int virtblk_freeze(struct virtio_device *vdev) +{ + struct virtio_blk *vblk = vdev->priv; + + /* Ensure we don't receive any more interrupts */ + virtio_reset_device(vdev); + + /* Make sure no work handler is accessing the device. */ + flush_work(&vblk->config_work); + + blk_mq_quiesce_queue(vblk->disk->queue); + + vdev->config->del_vqs(vdev); + kfree(vblk->vqs); + + return 0; +} + +static int virtblk_restore(struct virtio_device *vdev) +{ + struct virtio_blk *vblk = vdev->priv; + int ret; + + ret = init_vq(vdev->priv); + if (ret) + return ret; + + virtio_device_ready(vdev); + + blk_mq_unquiesce_queue(vblk->disk->queue); + return 0; +} +#endif + +static const struct virtio_device_id id_table[] = { + { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static unsigned int features_legacy[] = { + VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, + VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, + VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, + VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, + VIRTIO_BLK_F_SECURE_ERASE, +} +; +static unsigned int features[] = { + VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, + VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, + VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, + VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, + VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED, +}; + +static struct virtio_driver virtio_blk = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), + .feature_table_legacy = features_legacy, + .feature_table_size_legacy = ARRAY_SIZE(features_legacy), + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = id_table, + .probe = virtblk_probe, + .remove = virtblk_remove, + .config_changed = virtblk_config_changed, +#ifdef CONFIG_PM_SLEEP + .freeze = virtblk_freeze, + .restore = virtblk_restore, +#endif +}; + +static int __init virtio_blk_init(void) +{ + int error; + + virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); + if (!virtblk_wq) + return -ENOMEM; + + major = register_blkdev(0, "virtblk"); + if (major < 0) { + error = major; + goto out_destroy_workqueue; + } + + error = register_virtio_driver(&virtio_blk); + if (error) + goto out_unregister_blkdev; + return 0; + +out_unregister_blkdev: + unregister_blkdev(major, "virtblk"); +out_destroy_workqueue: + destroy_workqueue(virtblk_wq); + return error; +} + +static void __exit virtio_blk_fini(void) +{ + unregister_virtio_driver(&virtio_blk); + unregister_blkdev(major, "virtblk"); + destroy_workqueue(virtblk_wq); +} +module_init(virtio_blk_init); +module_exit(virtio_blk_fini); + +MODULE_DEVICE_TABLE(virtio, id_table); +MODULE_DESCRIPTION("Virtio block driver"); +MODULE_LICENSE("GPL"); |