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/types.h> 6 #include <linux/virtio_ids.h> 7 #include <linux/virtio_config.h> 8 9 /* Feature bits */ 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 */ 13 #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ 14 #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ 15 #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ 16 #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ 17 #define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ 18 19 struct virtio_blk_config { 20 /* The capacity (in 512-byte sectors). */ 21 __u64 capacity; 22 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 23 __u32 size_max; 24 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 25 __u32 seg_max; 26 /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */ 27 struct virtio_blk_geometry { 28 __u16 cylinders; 29 __u8 heads; 30 __u8 sectors; 31 } geometry; 32 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 33 __u32 blk_size; 34 } __attribute__((packed)); 35 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 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 54 /* Cache flush command */ 55 #define VIRTIO_BLK_T_FLUSH 4 56 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. */ 61 struct virtio_blk_outhdr { 62 /* VIRTIO_BLK_T* */ 63 __u32 type; 64 /* io priority. */ 65 __u32 ioprio; 66 /* Sector (ie. 512 byte offset) */ 67 __u64 sector; 68 }; 69 70 struct virtio_scsi_inhdr { 71 __u32 errors; 72 __u32 data_len; 73 __u32 sense_len; 74 __u32 residual; 75 }; 76 77 /* And this is the final byte of the write scatter-gather list. */ 78 #define VIRTIO_BLK_S_OK 0 79 #define VIRTIO_BLK_S_IOERR 1 80 #define VIRTIO_BLK_S_UNSUPP 2 81 #endif /* _LINUX_VIRTIO_BLK_H */ 82
