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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/linux/virtio_blk.h
1 #ifndef _LINUX_VIRTIO_BLK_H
2 #define _LINUX_VIRTIO_BLK_H
3 /* This header is BSD licensed so anyone can use the definitions to implement
4 * compatible drivers/servers. */
5 #include <linux/virtio_config.h>
7 /* The ID for virtio_block */
8 #define VIRTIO_ID_BLOCK 2
11 #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
12 #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
13 #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
14 #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */
15 #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
16 #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
18 struct virtio_blk_config
20 /* The capacity (in 512-byte sectors). */
22 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
24 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
26 /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
27 struct virtio_blk_geometry
{
32 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
34 } __attribute__((packed
));
36 /* These two define direction. */
37 #define VIRTIO_BLK_T_IN 0
38 #define VIRTIO_BLK_T_OUT 1
40 /* This bit says it's a scsi command, not an actual read or write. */
41 #define VIRTIO_BLK_T_SCSI_CMD 2
43 /* Barrier before this op. */
44 #define VIRTIO_BLK_T_BARRIER 0x80000000
46 /* This is the first element of the read scatter-gather list. */
47 struct virtio_blk_outhdr
53 /* Sector (ie. 512 byte offset) */
57 /* And this is the final byte of the write scatter-gather list. */
58 #define VIRTIO_BLK_S_OK 0
59 #define VIRTIO_BLK_S_IOERR 1
60 #define VIRTIO_BLK_S_UNSUPP 2
61 #endif /* _LINUX_VIRTIO_BLK_H */