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#ifndef _LINUX_VIRTIO_BLK_H
#define _LINUX_VIRTIO_BLK_H
/* This header is BSD licensed so anyone can use the definitions to implement
* compatible drivers/servers. */
#include <linux/virtio_config.h>
/* The ID for virtio_block */
#define VIRTIO_ID_BLOCK 2
/* Feature bits */
#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
#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*/
struct virtio_blk_config
{
/* The capacity (in 512-byte sectors). */
__u64 capacity;
/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
__u32 size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
__u32 seg_max;
/* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
struct virtio_blk_geometry {
__u16 cylinders;
__u8 heads;
__u8 sectors;
} geometry;
/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
__u32 blk_size;
} __attribute__((packed));
/* These two define direction. */
#define VIRTIO_BLK_T_IN 0
#define VIRTIO_BLK_T_OUT 1
/* This bit says it's a scsi command, not an actual read or write. */
#define VIRTIO_BLK_T_SCSI_CMD 2
/* Barrier before this op. */
#define VIRTIO_BLK_T_BARRIER 0x80000000
/* This is the first element of the read scatter-gather list. */
struct virtio_blk_outhdr
{
/* VIRTIO_BLK_T* */
__u32 type;
/* io priority. */
__u32 ioprio;
/* Sector (ie. 512 byte offset) */
__u64 sector;
};
/* And this is the final byte of the write scatter-gather list. */
#define VIRTIO_BLK_S_OK 0
#define VIRTIO_BLK_S_IOERR 1
#define VIRTIO_BLK_S_UNSUPP 2
#endif /* _LINUX_VIRTIO_BLK_H */
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