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/*
* Replication filter
*
* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
* Copyright (c) 2016 Intel Corporation
* Copyright (c) 2016 FUJITSU LIMITED
*
* Author:
* Changlong Xie <xiecl.fnst@cn.fujitsu.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef REPLICATION_H
#define REPLICATION_H
#include "qapi/qapi-types-block-core.h"
#include "qemu/module.h"
#include "qemu/queue.h"
typedef struct ReplicationOps ReplicationOps;
typedef struct ReplicationState ReplicationState;
/**
* SECTION:replication.h
* @title:Base Replication System
* @short_description: interfaces for handling replication
*
* The Replication Model provides a framework for handling Replication
*
* <example>
* <title>How to use replication interfaces</title>
* <programlisting>
* #include "replication.h"
*
* typedef struct BDRVReplicationState {
* ReplicationState *rs;
* } BDRVReplicationState;
*
* static void replication_start(ReplicationState *rs, ReplicationMode mode,
* Error **errp);
* static void replication_do_checkpoint(ReplicationState *rs, Error **errp);
* static void replication_get_error(ReplicationState *rs, Error **errp);
* static void replication_stop(ReplicationState *rs, bool failover,
* Error **errp);
*
* static ReplicationOps replication_ops = {
* .start = replication_start,
* .checkpoint = replication_do_checkpoint,
* .get_error = replication_get_error,
* .stop = replication_stop,
* }
*
* static int replication_open(BlockDriverState *bs, QDict *options,
* int flags, Error **errp)
* {
* BDRVReplicationState *s = bs->opaque;
* s->rs = replication_new(bs, &replication_ops);
* return 0;
* }
*
* static void replication_close(BlockDriverState *bs)
* {
* BDRVReplicationState *s = bs->opaque;
* replication_remove(s->rs);
* }
*
* BlockDriver bdrv_replication = {
* .format_name = "replication",
* .instance_size = sizeof(BDRVReplicationState),
*
* .bdrv_open = replication_open,
* .bdrv_close = replication_close,
* };
*
* static void bdrv_replication_init(void)
* {
* bdrv_register(&bdrv_replication);
* }
*
* block_init(bdrv_replication_init);
* </programlisting>
* </example>
*
* We create an example about how to use replication interfaces in above.
* Then in migration, we can use replication_(start/stop/do_checkpoint/
* get_error)_all to handle all replication operations.
*/
/**
* ReplicationState:
* @opaque: opaque pointer value passed to this ReplicationState
* @ops: replication operation of this ReplicationState
* @node: node that we will insert into @replication_states QLIST
*/
struct ReplicationState {
void *opaque;
ReplicationOps *ops;
QLIST_ENTRY(ReplicationState) node;
};
/**
* ReplicationOps:
* @start: callback to start replication
* @stop: callback to stop replication
* @checkpoint: callback to do checkpoint
* @get_error: callback to check if error occurred during replication
*/
struct ReplicationOps {
void (*start)(ReplicationState *rs, ReplicationMode mode, Error **errp);
void (*stop)(ReplicationState *rs, bool failover, Error **errp);
void (*checkpoint)(ReplicationState *rs, Error **errp);
void (*get_error)(ReplicationState *rs, Error **errp);
};
/**
* replication_new:
* @opaque: opaque pointer value passed to ReplicationState
* @ops: replication operation of the new relevant ReplicationState
*
* Called to create a new ReplicationState instance, and then insert it
* into @replication_states QLIST
*
* Returns: the new ReplicationState instance
*/
ReplicationState *replication_new(void *opaque, ReplicationOps *ops);
/**
* replication_remove:
* @rs: the ReplicationState instance to remove
*
* Called to remove a ReplicationState instance, and then delete it from
* @replication_states QLIST
*/
void replication_remove(ReplicationState *rs);
/**
* replication_start_all:
* @mode: replication mode that could be "primary" or "secondary"
* @errp: returns an error if this function fails
*
* Start replication, called in migration/checkpoint thread
*
* Note: the caller of the function MUST make sure vm stopped
*/
void replication_start_all(ReplicationMode mode, Error **errp);
/**
* replication_do_checkpoint_all:
* @errp: returns an error if this function fails
*
* This interface is called after all VM state is transferred to Secondary QEMU
*/
void replication_do_checkpoint_all(Error **errp);
/**
* replication_get_error_all:
* @errp: returns an error if this function fails
*
* This interface is called to check if error occurred during replication
*/
void replication_get_error_all(Error **errp);
/**
* replication_stop_all:
* @failover: boolean value that indicates if we need do failover or not
* @errp: returns an error if this function fails
*
* It is called on failover. The vm should be stopped before calling it, if you
* use this API to shutdown the guest, or other things except failover
*/
void replication_stop_all(bool failover, Error **errp);
#endif /* REPLICATION_H */
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