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 <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ checkpatch.pl tweak)
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index 94c56d2..4dbcbc1 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 @@
__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