diff options
Diffstat (limited to 'drivers/block/virtio_blk.c')
| -rw-r--r-- | drivers/block/virtio_blk.c | 106 |
1 files changed, 103 insertions, 3 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index d624cc8eddc3..ad5f9ce8f3f9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -37,6 +37,10 @@ MODULE_PARM_DESC(num_request_queues, "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); @@ -74,6 +78,7 @@ struct virtio_blk { /* num of vqs */ int num_vqs; + int io_queues[HCTX_MAX_TYPES]; struct virtio_blk_vq *vqs; }; @@ -512,6 +517,7 @@ static int init_vq(struct virtio_blk *vblk) const char **names; struct virtqueue **vqs; unsigned short num_vqs; + unsigned int num_poll_vqs; struct virtio_device *vdev = vblk->vdev; struct irq_affinity desc = { 0, }; @@ -520,6 +526,7 @@ static int init_vq(struct virtio_blk *vblk) &num_vqs); if (err) num_vqs = 1; + if (!err && !num_vqs) { dev_err(&vdev->dev, "MQ advertised but zero queues reported\n"); return -EINVAL; @@ -529,6 +536,17 @@ static int init_vq(struct virtio_blk *vblk) 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; @@ -541,12 +559,18 @@ static int init_vq(struct virtio_blk *vblk) goto out; } - for (i = 0; i < num_vqs; i++) { + for (i = 0; i < num_vqs - num_poll_vqs; i++) { callbacks[i] = virtblk_done; snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", 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.%d", 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) @@ -692,16 +716,89 @@ static const struct attribute_group *virtblk_attr_groups[] = { static int 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); + } + + return 0; +} + +static void virtblk_complete_batch(struct io_comp_batch *iob) +{ + struct request *req; - return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT], - vblk->vdev, 0); + 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 = hctx->driver_data; + 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_add_to_batch(req, iob, vbr->status, + virtblk_complete_batch)) + blk_mq_complete_request(req); + } + + if (found) + blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); + + spin_unlock_irqrestore(&vq->lock, flags); + + return found; +} + +static int virtblk_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, + unsigned int hctx_idx) +{ + struct virtio_blk *vblk = data; + struct virtio_blk_vq *vq = &vblk->vqs[hctx_idx]; + + WARN_ON(vblk->tag_set.tags[hctx_idx] != hctx->tags); + hctx->driver_data = vq; + return 0; } static const struct blk_mq_ops virtio_mq_ops = { .queue_rq = virtio_queue_rq, .commit_rqs = virtio_commit_rqs, + .init_hctx = virtblk_init_hctx, .complete = virtblk_request_done, .map_queues = virtblk_map_queues, + .poll = virtblk_poll, }; static unsigned int virtblk_queue_depth; @@ -778,6 +875,9 @@ static int virtblk_probe(struct virtio_device *vdev) 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) |