include/linux/virtio_blk.h

   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_CONFIG_BLK_F     0x40
  10 #define VIRTIO_BLK_F_BARRIER    1       /* Does host support barriers? */
  11
  12 /* The capacity (in 512-byte sectors). */
  13 #define VIRTIO_CONFIG_BLK_F_CAPACITY    0x41
  14 /* The maximum segment size. */
  15 #define VIRTIO_CONFIG_BLK_F_SIZE_MAX    0x42
  16 /* The maximum number of segments. */
  17 #define VIRTIO_CONFIG_BLK_F_SEG_MAX     0x43
  18
  19 /* These two define direction. */
  20 #define VIRTIO_BLK_T_IN         0
  21 #define VIRTIO_BLK_T_OUT        1
  22
  23 /* This bit says it's a scsi command, not an actual read or write. */
  24 #define VIRTIO_BLK_T_SCSI_CMD   2
  25
  26 /* Barrier before this op. */
  27 #define VIRTIO_BLK_T_BARRIER    0x80000000
  28
  29 /* This is the first element of the read scatter-gather list. */
  30 struct virtio_blk_outhdr
  31 {
  32         /* VIRTIO_BLK_T* */
  33         __u32 type;
  34         /* io priority. */
  35         __u32 ioprio;
  36         /* Sector (ie. 512 byte offset) */
  37         __u64 sector;
  38         /* Where to put reply. */
  39         __u64 id;
  40 };
  41
  42 #define VIRTIO_BLK_S_OK         0
  43 #define VIRTIO_BLK_S_IOERR      1
  44 #define VIRTIO_BLK_S_UNSUPP     2
  45
  46 /* This is the first element of the write scatter-gather list */
  47 struct virtio_blk_inhdr
  48 {
  49         unsigned char status;
  50 };
  51 #endif /* _LINUX_VIRTIO_BLK_H */