1 #ifndef _LINUX_VIRTIO_BLK_H
2 #define _LINUX_VIRTIO_BLK_H
3 #include <linux/virtio_config.h>
5 /* The ID for virtio_block */
6 #define VIRTIO_ID_BLOCK 2
9 #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
10 #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
11 #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
13 struct virtio_blk_config
15 /* The capacity (in 512-byte sectors). */
17 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
19 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
21 } __attribute__((packed));
23 /* These two define direction. */
24 #define VIRTIO_BLK_T_IN 0
25 #define VIRTIO_BLK_T_OUT 1
27 /* This bit says it's a scsi command, not an actual read or write. */
28 #define VIRTIO_BLK_T_SCSI_CMD 2
30 /* Barrier before this op. */
31 #define VIRTIO_BLK_T_BARRIER 0x80000000
33 /* This is the first element of the read scatter-gather list. */
34 struct virtio_blk_outhdr
40 /* Sector (ie. 512 byte offset) */
44 /* And this is the final byte of the write scatter-gather list. */
45 #define VIRTIO_BLK_S_OK 0
46 #define VIRTIO_BLK_S_IOERR 1
47 #define VIRTIO_BLK_S_UNSUPP 2
48 #endif /* _LINUX_VIRTIO_BLK_H */