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/*

 * Virtio Block Device

 *

 * Copyright IBM, Corp. 2007

 *

 * Authors:

 *  Anthony Liguori   <aliguori@us.ibm.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 *

 */

#ifndef _QEMU_VIRTIO_BLK_H

#define _QEMU_VIRTIO_BLK_H

#include "virtio.h"

#include "block.h"

/* from Linux's linux/virtio_blk.h */

/* The ID for virtio_block */

#define VIRTIO_ID_BLOCK 2

/* Feature bits */

#define VIRTIO_BLK_F_BARRIER    0       /* Does host support barriers? */

#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       /* Indicates support of legacy geometry */

#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_SCSI       7       /* Supports scsi command passthru */

/* #define VIRTIO_BLK_F_IDENTIFY   8       ATA IDENTIFY supported, DEPRECATED */

#define VIRTIO_BLK_F_WCACHE     9       /* write cache enabled */

struct virtio_blk_config

{

    uint64_t capacity;

    uint32_t size_max;

    uint32_t seg_max;

    uint16_t cylinders;

    uint8_t heads;

    uint8_t sectors;

    uint32_t _blk_size;    /* structure pad, currently unused */

} __attribute__((packed));

/* These two define direction. */

#define VIRTIO_BLK_T_IN         0

#define VIRTIO_BLK_T_OUT        1

/* This bit says it's a scsi command, not an actual read or write. */

#define VIRTIO_BLK_T_SCSI_CMD   2

/* Flush the volatile write cache */

#define VIRTIO_BLK_T_FLUSH      4

/* Barrier before this op. */

#define VIRTIO_BLK_T_BARRIER    0x80000000

/* This is the first element of the read scatter-gather list. */

struct virtio_blk_outhdr

{

    /* VIRTIO_BLK_T* */

    uint32_t type;

    /* io priority. */

    uint32_t ioprio;

    /* Sector (ie. 512 byte offset) */

    uint64_t sector;

};

#define VIRTIO_BLK_S_OK         0

#define VIRTIO_BLK_S_IOERR      1

#define VIRTIO_BLK_S_UNSUPP     2

/* This is the last element of the write scatter-gather list */

struct virtio_blk_inhdr

{

    unsigned char status;

};

/* SCSI pass-through header */

struct virtio_scsi_inhdr

{

    uint32_t errors;

    uint32_t data_len;

    uint32_t sense_len;

    uint32_t residual;

};

#ifdef __linux__

#define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \

        DEFINE_VIRTIO_COMMON_FEATURES(_state, _field), \

        DEFINE_PROP_BIT("scsi", _state, _field, VIRTIO_BLK_F_SCSI, true)

#else

#define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \

        DEFINE_VIRTIO_COMMON_FEATURES(_state, _field)

#endif

#endif