1 #ifndef _LINUX_VIRTIO_BLK_H 2 #define _LINUX_VIRTIO_BLK_H 3 #include <linux/virtio_config.h> 4 5 /* The ID for virtio_block */ 6 #define VIRTIO_ID_BLOCK 2 7 8 /* Feature bits */ 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 */ 12 #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ 13 #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ 14 15 struct virtio_blk_config 16 { 17 /* The capacity (in 512-byte sectors). */ 18 __u64 capacity; 19 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 20 __u32 size_max; 21 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 22 __u32 seg_max; 23 /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */ 24 struct virtio_blk_geometry { 25 __u16 cylinders; 26 __u8 heads; 27 __u8 sectors; 28 } geometry; 29 } __attribute__((packed)); 30 31 /* These two define direction. */ 32 #define VIRTIO_BLK_T_IN 0 33 #define VIRTIO_BLK_T_OUT 1 34 35 /* This bit says it's a scsi command, not an actual read or write. */ 36 #define VIRTIO_BLK_T_SCSI_CMD 2 37 38 /* Barrier before this op. */ 39 #define VIRTIO_BLK_T_BARRIER 0x80000000 40 41 /* This is the first element of the read scatter-gather list. */ 42 struct virtio_blk_outhdr 43 { 44 /* VIRTIO_BLK_T* */ 45 __u32 type; 46 /* io priority. */ 47 __u32 ioprio; 48 /* Sector (ie. 512 byte offset) */ 49 __u64 sector; 50 }; 51 52 /* And this is the final byte of the write scatter-gather list. */ 53 #define VIRTIO_BLK_S_OK 0 54 #define VIRTIO_BLK_S_IOERR 1 55 #define VIRTIO_BLK_S_UNSUPP 2 56 #endif /* _LINUX_VIRTIO_BLK_H */ 57