qemu/hw/virtio-blk.h
Michael S. Tsirkin 8172539d21 virtio: add features as qdev properties
Add feature bits as properties to virtio. This makes it possible to e.g. define
machine without indirect buffer support, which is required for 0.10
compatibility, or without hardware checksum support, which is required for 0.11
compatibility.  Since default values for optional features are now set by qdev,
get_features callback has been modified: it sets non-optional bits, and clears
bits not supported by host.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-11 13:40:59 -06:00

104 lines
2.9 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;
};
#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