mirror of
https://github.com/qemu/qemu.git
synced 2024-11-28 22:33:36 +08:00
aa659be3dc
Add a new VIRTIO_BLK_F_WCACHE feature to virtio-blk to indicate that we have a volatile write cache that needs controlled flushing. Implement a VIRTIO_BLK_T_FLUSH operation to flush it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
96 lines
2.6 KiB
C
96 lines
2.6 KiB
C
/*
|
|
* 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 */
|
|
#define VIRTIO_BLK_F_WCACHE 9 /* write cache enabled */
|
|
|
|
#define VIRTIO_BLK_ID_LEN 256 /* length of identify u16 array */
|
|
#define VIRTIO_BLK_ID_SN 10 /* start of char * serial# */
|
|
#define VIRTIO_BLK_ID_SN_BYTES 20 /* length in bytes of serial# */
|
|
|
|
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 */
|
|
uint16_t identify[VIRTIO_BLK_ID_LEN];
|
|
} __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;
|
|
};
|
|
|
|
#endif
|