From 1cde26f928863d90e9e7c1217880c8450464d305 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Mon, 18 May 2009 14:41:30 +0200 Subject: [PATCH] virtio_blk: SG_IO passthru support Add support for SG_IO passthru to virtio_blk. We add the scsi command block after the normal outhdr, and the scsi inhdr with full status information aswell as the sense buffer before the regular inhdr. [hch: forward ported, added the VIRTIO_BLK_F_SCSI flags, some comments and tested the whole beast] [axboe: updated to use ->resid and not dual-path the byte count] Signed-off-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Rusty Russell (+ checkpatch.pl tweak) Signed-off-by: Jens Axboe --- drivers/block/virtio_blk.c | 64 +++++++++++++++++++++++++++++--------- include/linux/virtio_blk.h | 8 +++++ 2 files changed, 58 insertions(+), 14 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index dfe9ee5f1696..62275dbdf2eb 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -37,6 +37,7 @@ struct virtblk_req struct list_head list; struct request *req; struct virtio_blk_outhdr out_hdr; + struct virtio_scsi_inhdr in_hdr; u8 status; }; @@ -49,7 +50,9 @@ static void blk_done(struct virtqueue *vq) spin_lock_irqsave(&vblk->lock, flags); while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) { + unsigned int nr_bytes; int error; + switch (vbr->status) { case VIRTIO_BLK_S_OK: error = 0; @@ -62,6 +65,12 @@ static void blk_done(struct virtqueue *vq) break; } + if (blk_pc_request(vbr->req)) { + vbr->req->resid_len = vbr->in_hdr.residual; + vbr->req->sense_len = vbr->in_hdr.sense_len; + vbr->req->errors = vbr->in_hdr.errors; + } + __blk_end_request_all(vbr->req, error); list_del(&vbr->list); mempool_free(vbr, vblk->pool); @@ -74,7 +83,7 @@ static void blk_done(struct virtqueue *vq) static bool do_req(struct request_queue *q, struct virtio_blk *vblk, struct request *req) { - unsigned long num, out, in; + unsigned long num, out = 0, in = 0; struct virtblk_req *vbr; vbr = mempool_alloc(vblk->pool, GFP_ATOMIC); @@ -99,18 +108,36 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, if (blk_barrier_rq(vbr->req)) vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER; - sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr)); - num = blk_rq_map_sg(q, vbr->req, vblk->sg+1); - sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status)); + sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); - if (rq_data_dir(vbr->req) == WRITE) { - vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; - out = 1 + num; - in = 1; - } else { - vbr->out_hdr.type |= VIRTIO_BLK_T_IN; - out = 1; - in = 1 + num; + /* + * If this is a packet command we need a couple of additional headers. + * Behind the normal outhdr we put a segment with the scsi command + * block, and before the normal inhdr we put the sense data and the + * inhdr with additional status information before the normal inhdr. + */ + if (blk_pc_request(vbr->req)) + sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len); + + num = blk_rq_map_sg(q, vbr->req, vblk->sg + out); + + if (blk_pc_request(vbr->req)) { + sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, 96); + sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr, + sizeof(vbr->in_hdr)); + } + + sg_set_buf(&vblk->sg[num + out + in++], &vbr->status, + sizeof(vbr->status)); + + if (num) { + if (rq_data_dir(vbr->req) == WRITE) { + vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; + out += num; + } else { + vbr->out_hdr.type |= VIRTIO_BLK_T_IN; + in += num; + } } if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr)) { @@ -148,8 +175,16 @@ static void do_virtblk_request(struct request_queue *q) static int virtblk_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, unsigned long data) { - return scsi_cmd_ioctl(bdev->bd_disk->queue, - bdev->bd_disk, mode, cmd, + struct gendisk *disk = bdev->bd_disk; + struct virtio_blk *vblk = disk->private_data; + + /* + * Only allow the generic SCSI ioctls if the host can support it. + */ + if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI)) + return -ENOIOCTLCMD; + + return scsi_cmd_ioctl(disk->queue, disk, mode, cmd, (void __user *)data); } @@ -356,6 +391,7 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_BLK_F_BARRIER, 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_SCSI, }; static struct virtio_driver virtio_blk = { diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index 94c56d29869d..4dbcbc1c3481 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -15,6 +15,7 @@ #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ +#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ struct virtio_blk_config { @@ -55,6 +56,13 @@ struct virtio_blk_outhdr __u64 sector; }; +struct virtio_scsi_inhdr { + __u32 errors; + __u32 data_len; + __u32 sense_len; + __u32 residual; +}; + /* And this is the final byte of the write scatter-gather list. */ #define VIRTIO_BLK_S_OK 0 #define VIRTIO_BLK_S_IOERR 1