1 /* SPDX-License-Identifier: BSD-3-Clause */ 2 /* 3 * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> 4 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com> 5 * 6 * From Linux kernel include/uapi/linux/virtio_blk.h 7 */ 8 9 #ifndef _LINUX_VIRTIO_BLK_H 10 #define _LINUX_VIRTIO_BLK_H 11 12 /* Feature bits */ 13 #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ 14 #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */ 15 #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ 16 #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ 17 #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available */ 18 #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ 19 #define VIRTIO_BLK_F_MQ 12 /* Support more than one vq */ 20 21 /* Legacy feature bits */ 22 #ifndef VIRTIO_BLK_NO_LEGACY 23 #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ 24 #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ 25 #define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */ 26 #define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ 27 #ifndef __KERNEL__ 28 /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH */ 29 #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH 30 #endif 31 #endif /* !VIRTIO_BLK_NO_LEGACY */ 32 33 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 34 35 struct __packed virtio_blk_config { 36 /* The capacity (in 512-byte sectors) */ 37 __u64 capacity; 38 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 39 __u32 size_max; 40 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 41 __u32 seg_max; 42 /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 43 struct virtio_blk_geometry { 44 __u16 cylinders; 45 __u8 heads; 46 __u8 sectors; 47 } geometry; 48 49 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 50 __u32 blk_size; 51 52 /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ 53 /* exponent for physical block per logical block */ 54 __u8 physical_block_exp; 55 /* alignment offset in logical blocks */ 56 __u8 alignment_offset; 57 /* minimum I/O size without performance penalty in logical blocks */ 58 __u16 min_io_size; 59 /* optimal sustained I/O size in logical blocks */ 60 __u32 opt_io_size; 61 62 /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 63 __u8 wce; 64 __u8 unused; 65 66 /* number of vqs, only available when VIRTIO_BLK_F_MQ is set */ 67 __u16 num_queues; 68 }; 69 70 /* 71 * Command types 72 * 73 * Usage is a bit tricky as some bits are used as flags and some are not. 74 * 75 * Rules: 76 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 77 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 78 * and may not be combined with any of the other flags. 79 */ 80 81 /* These two define direction */ 82 #define VIRTIO_BLK_T_IN 0 83 #define VIRTIO_BLK_T_OUT 1 84 85 #ifndef VIRTIO_BLK_NO_LEGACY 86 /* This bit says it's a scsi command, not an actual read or write */ 87 #define VIRTIO_BLK_T_SCSI_CMD 2 88 #endif /* VIRTIO_BLK_NO_LEGACY */ 89 90 /* Cache flush command */ 91 #define VIRTIO_BLK_T_FLUSH 4 92 93 /* Get device ID command */ 94 #define VIRTIO_BLK_T_GET_ID 8 95 96 #ifndef VIRTIO_BLK_NO_LEGACY 97 /* Barrier before this op */ 98 #define VIRTIO_BLK_T_BARRIER 0x80000000 99 #endif /* !VIRTIO_BLK_NO_LEGACY */ 100 101 /* 102 * This comes first in the read scatter-gather list. 103 * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, 104 * this is the first element of the read scatter-gather list. 105 */ 106 struct virtio_blk_outhdr { 107 /* VIRTIO_BLK_T* */ 108 __virtio32 type; 109 /* io priority */ 110 __virtio32 ioprio; 111 /* Sector (ie. 512 byte offset) */ 112 __virtio64 sector; 113 }; 114 115 #ifndef VIRTIO_BLK_NO_LEGACY 116 struct virtio_scsi_inhdr { 117 __virtio32 errors; 118 __virtio32 data_len; 119 __virtio32 sense_len; 120 __virtio32 residual; 121 }; 122 #endif /* !VIRTIO_BLK_NO_LEGACY */ 123 124 /* And this is the final byte of the write scatter-gather list */ 125 #define VIRTIO_BLK_S_OK 0 126 #define VIRTIO_BLK_S_IOERR 1 127 #define VIRTIO_BLK_S_UNSUPP 2 128 129 #endif /* _LINUX_VIRTIO_BLK_H */ 130