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/* SPDX-License-Identifier: BSD-3-Clause */
/*
* Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*
* From Linux kernel include/uapi/linux/virtio_blk.h
*/
#ifndef _LINUX_VIRTIO_BLK_H
#define _LINUX_VIRTIO_BLK_H
/* Feature bits */
#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
#define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */
#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available */
#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */
#define VIRTIO_BLK_F_MQ 12 /* Support more than one vq */
/* Legacy feature bits */
#ifndef VIRTIO_BLK_NO_LEGACY
#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
#define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */
#define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */
#ifndef __KERNEL__
/* Old (deprecated) name for VIRTIO_BLK_F_FLUSH */
#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH
#endif
#endif /* !VIRTIO_BLK_NO_LEGACY */
#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */
struct __packed virtio_blk_config {
/* The capacity (in 512-byte sectors) */
__u64 capacity;
/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
__u32 size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
__u32 seg_max;
/* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
struct virtio_blk_geometry {
__u16 cylinders;
__u8 heads;
__u8 sectors;
} geometry;
/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
__u32 blk_size;
/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */
/* exponent for physical block per logical block */
__u8 physical_block_exp;
/* alignment offset in logical blocks */
__u8 alignment_offset;
/* minimum I/O size without performance penalty in logical blocks */
__u16 min_io_size;
/* optimal sustained I/O size in logical blocks */
__u32 opt_io_size;
/* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
__u8 wce;
__u8 unused;
/* number of vqs, only available when VIRTIO_BLK_F_MQ is set */
__u16 num_queues;
};
/*
* Command types
*
* Usage is a bit tricky as some bits are used as flags and some are not.
*
* Rules:
* VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
* VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
* and may not be combined with any of the other flags.
*/
/* These two define direction */
#define VIRTIO_BLK_T_IN 0
#define VIRTIO_BLK_T_OUT 1
#ifndef VIRTIO_BLK_NO_LEGACY
/* This bit says it's a scsi command, not an actual read or write */
#define VIRTIO_BLK_T_SCSI_CMD 2
#endif /* VIRTIO_BLK_NO_LEGACY */
/* Cache flush command */
#define VIRTIO_BLK_T_FLUSH 4
/* Get device ID command */
#define VIRTIO_BLK_T_GET_ID 8
#ifndef VIRTIO_BLK_NO_LEGACY
/* Barrier before this op */
#define VIRTIO_BLK_T_BARRIER 0x80000000
#endif /* !VIRTIO_BLK_NO_LEGACY */
/*
* This comes first in the read scatter-gather list.
* For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,
* this is the first element of the read scatter-gather list.
*/
struct virtio_blk_outhdr {
/* VIRTIO_BLK_T* */
__virtio32 type;
/* io priority */
__virtio32 ioprio;
/* Sector (ie. 512 byte offset) */
__virtio64 sector;
};
#ifndef VIRTIO_BLK_NO_LEGACY
struct virtio_scsi_inhdr {
__virtio32 errors;
__virtio32 data_len;
__virtio32 sense_len;
__virtio32 residual;
};
#endif /* !VIRTIO_BLK_NO_LEGACY */
/* And this is the final byte of the write scatter-gather list */
#define VIRTIO_BLK_S_OK 0
#define VIRTIO_BLK_S_IOERR 1
#define VIRTIO_BLK_S_UNSUPP 2
#endif /* _LINUX_VIRTIO_BLK_H */
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