From 190b9a8b559385b733677224277f9050a0cf76f4 Mon Sep 17 00:00:00 2001 From: Changlong Xie Date: Wed, 27 Jul 2016 15:01:49 +0800 Subject: replication: Introduce new APIs to do replication operation This commit introduces six replication interfaces(for block, network etc). Firstly we can use replication_(new/remove) to create/destroy replication instances, then in migration we can use replication_(start/stop/do_checkpoint /get_error)_all to handle all replication operations. More detail please refer to replication.h Signed-off-by: Wen Congyang Signed-off-by: Changlong Xie Signed-off-by: Wang WeiWei Signed-off-by: zhanghailiang Signed-off-by: Gonglei Message-id: 1469602913-20979-9-git-send-email-xiecl.fnst@cn.fujitsu.com Signed-off-by: Stefan Hajnoczi --- replication.h | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 replication.h (limited to 'replication.h') diff --git a/replication.h b/replication.h new file mode 100644 index 0000000000..ece6ca6133 --- /dev/null +++ b/replication.h @@ -0,0 +1,174 @@ +/* + * Replication filter + * + * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. + * Copyright (c) 2016 Intel Corporation + * Copyright (c) 2016 FUJITSU LIMITED + * + * Author: + * Changlong Xie + * + * 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 "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 + * + * + * How to use replication interfaces + * + * #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", + * .protocol_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); + * + * + * + * 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 */ -- cgit v1.2.1