kernel-ark/include/linux/virtio_blk.h
Ryan Harper 48e4043d45 virtio: add virtio disk geometry feature
Rather than faking up some geometry, allow the backend to push the disk
geometry via virtio pci config option.  Keep the old geo code around for
compatibility.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified to single struct)
2008-05-02 21:50:51 +10:00

56 lines
1.5 KiB
C

#ifndef _LINUX_VIRTIO_BLK_H
#define _LINUX_VIRTIO_BLK_H
#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 */
struct virtio_blk_config
{
/* The capacity (in 512-byte sectors). */
__le64 capacity;
/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
__le32 size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
__le32 seg_max;
/* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
struct virtio_blk_geometry {
__le16 cylinders;
__u8 heads;
__u8 sectors;
} geometry;
} __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 */