Linux kernel mirror (for testing)
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linux
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
15struct 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. */
42struct 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 */