qemu/include/hw/virtio/vhost-user-blk.h
Changpeng Liu 00343e4b54 vhost-user-blk: introduce a new vhost-user-blk host device
This commit introduces a new vhost-user device for block, it uses a
chardev to connect with the backend, same with Qemu virito-blk device,
Guest OS still uses the virtio-blk frontend driver.

To use it, start QEMU with command line like this:

qemu-system-x86_64 \
    -chardev socket,id=char0,path=/path/vhost.socket \
    -device vhost-user-blk-pci,chardev=char0,num-queues=2, \
            bootindex=2... \

Users can use different parameters for `num-queues` and `bootindex`.

Different with exist Qemu virtio-blk host device, it makes more easy
for users to implement their own I/O processing logic, such as all
user space I/O stack against hardware block device. It uses the new
vhost messages(VHOST_USER_GET_CONFIG) to get block virtio config
information from backend process.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-18 21:52:37 +02:00

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995 B
C

/*
* vhost-user-blk host device
* Copyright(C) 2017 Intel Corporation.
*
* Authors:
* Changpeng Liu <changpeng.liu@intel.com>
*
* Based on vhost-scsi.h, Copyright IBM, Corp. 2011
*
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#ifndef VHOST_USER_BLK_H
#define VHOST_USER_BLK_H
#include "standard-headers/linux/virtio_blk.h"
#include "qemu-common.h"
#include "hw/qdev.h"
#include "hw/block/block.h"
#include "chardev/char-fe.h"
#include "hw/virtio/vhost.h"
#define TYPE_VHOST_USER_BLK "vhost-user-blk"
#define VHOST_USER_BLK(obj) \
OBJECT_CHECK(VHostUserBlk, (obj), TYPE_VHOST_USER_BLK)
typedef struct VHostUserBlk {
VirtIODevice parent_obj;
CharBackend chardev;
int32_t bootindex;
struct virtio_blk_config blkcfg;
uint16_t num_queues;
uint32_t queue_size;
uint32_t config_wce;
uint32_t config_ro;
struct vhost_dev dev;
} VHostUserBlk;
#endif