[linux-2.6-block.git] / include / linux / virtio_blk.h

#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/types.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>

/* 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*/
#define VIRTIO_BLK_F_SCSI	7	/* Supports scsi command passthru */
#define VIRTIO_BLK_F_FLUSH	9	/* Cache flush command support */

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));

/*
 * Command types
 *
 * Usage is a bit tricky as some bits are used as flags and some are not.
 *
 * Rules:
 *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
 *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
 *   and may not be combined with any of the other flags.
 */

/* 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

/* Cache flush command */
#define VIRTIO_BLK_T_FLUSH	4

/* 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;
};

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
#define VIRTIO_BLK_S_UNSUPP	2
#endif /* _LINUX_VIRTIO_BLK_H */
Commit	Line	Data
e467cde2 RR	1	#ifndef _LINUX_VIRTIO_BLK_H
e467cde2 RR	2	#define _LINUX_VIRTIO_BLK_H
674bfc23 RR	3	/* This header is BSD licensed so anyone can use the definitions to implement
674bfc23 RR	4	* compatible drivers/servers. */
982f8184	5	#include <linux/types.h>
e95646c3	6	#include <linux/virtio_ids.h>
e467cde2 RR	7	#include <linux/virtio_config.h>
e467cde2 RR	8
e467cde2	9	/* Feature bits */
a586d4f6 RR	10	#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
	11	#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
	12	#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
48e4043d	13	#define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */
3ef53609	14	#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
066f4d82	15	#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
1cde26f9	16	#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
f1b0ef06	17	#define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */
1d589bb1	18
1842f23c	19	struct virtio_blk_config {
a586d4f6	20	/* The capacity (in 512-byte sectors). */
7757f09c	21	__u64 capacity;
a586d4f6	22	/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
7757f09c	23	__u32 size_max;
a586d4f6	24	/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
7757f09c	25	__u32 seg_max;
48e4043d RH	26	/* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
48e4043d RH	27	struct virtio_blk_geometry {
7757f09c	28	__u16 cylinders;
48e4043d RH	29	__u8 heads;
	30	__u8 sectors;
	31	} geometry;
066f4d82 CB	32	/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
066f4d82 CB	33	__u32 blk_size;
a586d4f6	34	} __attribute__((packed));
e467cde2	35
f1b0ef06 CH	36	/*
	37	* Command types
	38	*
	39	* Usage is a bit tricky as some bits are used as flags and some are not.
	40	*
	41	* Rules:
	42	* VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
	43	* VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
	44	* and may not be combined with any of the other flags.
	45	*/
	46
e467cde2 RR	47	/* These two define direction. */
	48	#define VIRTIO_BLK_T_IN 0
	49	#define VIRTIO_BLK_T_OUT 1
	50
	51	/* This bit says it's a scsi command, not an actual read or write. */
	52	#define VIRTIO_BLK_T_SCSI_CMD 2
	53
f1b0ef06 CH	54	/* Cache flush command */
	55	#define VIRTIO_BLK_T_FLUSH 4
	56
e467cde2 RR	57	/* Barrier before this op. */
	58	#define VIRTIO_BLK_T_BARRIER 0x80000000
	59
	60	/* This is the first element of the read scatter-gather list. */
1842f23c	61	struct virtio_blk_outhdr {
e467cde2 RR	62	/* VIRTIO_BLK_T* */
	63	__u32 type;
	64	/* io priority. */
	65	__u32 ioprio;
	66	/* Sector (ie. 512 byte offset) */
	67	__u64 sector;
e467cde2 RR	68	};
e467cde2 RR	69
1cde26f9 HR	70	struct virtio_scsi_inhdr {
	71	__u32 errors;
	72	__u32 data_len;
	73	__u32 sense_len;
	74	__u32 residual;
	75	};
	76
cb38fa23	77	/* And this is the final byte of the write scatter-gather list. */
e467cde2 RR	78	#define VIRTIO_BLK_S_OK 0
	79	#define VIRTIO_BLK_S_IOERR 1
	80	#define VIRTIO_BLK_S_UNSUPP 2
e467cde2	81	#endif /* _LINUX_VIRTIO_BLK_H */