Changlong Xie | 190b9a8 | 2016-07-27 15:01:49 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Replication filter |
| 3 | * |
| 4 | * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. |
| 5 | * Copyright (c) 2016 Intel Corporation |
| 6 | * Copyright (c) 2016 FUJITSU LIMITED |
| 7 | * |
| 8 | * Author: |
| 9 | * Changlong Xie <xiecl.fnst@cn.fujitsu.com> |
| 10 | * |
| 11 | * This work is licensed under the terms of the GNU GPL, version 2 or later. |
| 12 | * See the COPYING file in the top-level directory. |
| 13 | */ |
| 14 | |
| 15 | #ifndef REPLICATION_H |
| 16 | #define REPLICATION_H |
| 17 | |
Markus Armbruster | 9af2398 | 2018-02-11 10:36:01 +0100 | [diff] [blame] | 18 | #include "qapi/qapi-types-block-core.h" |
Markus Armbruster | 0b8fa32 | 2019-05-23 16:35:07 +0200 | [diff] [blame] | 19 | #include "qemu/module.h" |
Changlong Xie | 190b9a8 | 2016-07-27 15:01:49 +0800 | [diff] [blame] | 20 | #include "qemu/queue.h" |
| 21 | |
| 22 | typedef struct ReplicationOps ReplicationOps; |
| 23 | typedef struct ReplicationState ReplicationState; |
| 24 | |
| 25 | /** |
| 26 | * SECTION:replication.h |
| 27 | * @title:Base Replication System |
| 28 | * @short_description: interfaces for handling replication |
| 29 | * |
| 30 | * The Replication Model provides a framework for handling Replication |
| 31 | * |
| 32 | * <example> |
| 33 | * <title>How to use replication interfaces</title> |
| 34 | * <programlisting> |
| 35 | * #include "replication.h" |
| 36 | * |
| 37 | * typedef struct BDRVReplicationState { |
| 38 | * ReplicationState *rs; |
| 39 | * } BDRVReplicationState; |
| 40 | * |
| 41 | * static void replication_start(ReplicationState *rs, ReplicationMode mode, |
| 42 | * Error **errp); |
| 43 | * static void replication_do_checkpoint(ReplicationState *rs, Error **errp); |
| 44 | * static void replication_get_error(ReplicationState *rs, Error **errp); |
| 45 | * static void replication_stop(ReplicationState *rs, bool failover, |
| 46 | * Error **errp); |
| 47 | * |
| 48 | * static ReplicationOps replication_ops = { |
| 49 | * .start = replication_start, |
| 50 | * .checkpoint = replication_do_checkpoint, |
| 51 | * .get_error = replication_get_error, |
| 52 | * .stop = replication_stop, |
| 53 | * } |
| 54 | * |
| 55 | * static int replication_open(BlockDriverState *bs, QDict *options, |
| 56 | * int flags, Error **errp) |
| 57 | * { |
| 58 | * BDRVReplicationState *s = bs->opaque; |
| 59 | * s->rs = replication_new(bs, &replication_ops); |
| 60 | * return 0; |
| 61 | * } |
| 62 | * |
| 63 | * static void replication_close(BlockDriverState *bs) |
| 64 | * { |
| 65 | * BDRVReplicationState *s = bs->opaque; |
| 66 | * replication_remove(s->rs); |
| 67 | * } |
| 68 | * |
| 69 | * BlockDriver bdrv_replication = { |
| 70 | * .format_name = "replication", |
Changlong Xie | 190b9a8 | 2016-07-27 15:01:49 +0800 | [diff] [blame] | 71 | * .instance_size = sizeof(BDRVReplicationState), |
| 72 | * |
| 73 | * .bdrv_open = replication_open, |
| 74 | * .bdrv_close = replication_close, |
| 75 | * }; |
| 76 | * |
| 77 | * static void bdrv_replication_init(void) |
| 78 | * { |
| 79 | * bdrv_register(&bdrv_replication); |
| 80 | * } |
| 81 | * |
| 82 | * block_init(bdrv_replication_init); |
| 83 | * </programlisting> |
| 84 | * </example> |
| 85 | * |
| 86 | * We create an example about how to use replication interfaces in above. |
| 87 | * Then in migration, we can use replication_(start/stop/do_checkpoint/ |
| 88 | * get_error)_all to handle all replication operations. |
| 89 | */ |
| 90 | |
| 91 | /** |
| 92 | * ReplicationState: |
| 93 | * @opaque: opaque pointer value passed to this ReplicationState |
| 94 | * @ops: replication operation of this ReplicationState |
| 95 | * @node: node that we will insert into @replication_states QLIST |
| 96 | */ |
| 97 | struct ReplicationState { |
| 98 | void *opaque; |
| 99 | ReplicationOps *ops; |
| 100 | QLIST_ENTRY(ReplicationState) node; |
| 101 | }; |
| 102 | |
| 103 | /** |
| 104 | * ReplicationOps: |
| 105 | * @start: callback to start replication |
| 106 | * @stop: callback to stop replication |
| 107 | * @checkpoint: callback to do checkpoint |
| 108 | * @get_error: callback to check if error occurred during replication |
| 109 | */ |
| 110 | struct ReplicationOps { |
| 111 | void (*start)(ReplicationState *rs, ReplicationMode mode, Error **errp); |
| 112 | void (*stop)(ReplicationState *rs, bool failover, Error **errp); |
| 113 | void (*checkpoint)(ReplicationState *rs, Error **errp); |
| 114 | void (*get_error)(ReplicationState *rs, Error **errp); |
| 115 | }; |
| 116 | |
| 117 | /** |
| 118 | * replication_new: |
| 119 | * @opaque: opaque pointer value passed to ReplicationState |
| 120 | * @ops: replication operation of the new relevant ReplicationState |
| 121 | * |
| 122 | * Called to create a new ReplicationState instance, and then insert it |
| 123 | * into @replication_states QLIST |
| 124 | * |
| 125 | * Returns: the new ReplicationState instance |
| 126 | */ |
| 127 | ReplicationState *replication_new(void *opaque, ReplicationOps *ops); |
| 128 | |
| 129 | /** |
| 130 | * replication_remove: |
| 131 | * @rs: the ReplicationState instance to remove |
| 132 | * |
| 133 | * Called to remove a ReplicationState instance, and then delete it from |
| 134 | * @replication_states QLIST |
| 135 | */ |
| 136 | void replication_remove(ReplicationState *rs); |
| 137 | |
| 138 | /** |
| 139 | * replication_start_all: |
| 140 | * @mode: replication mode that could be "primary" or "secondary" |
| 141 | * @errp: returns an error if this function fails |
| 142 | * |
| 143 | * Start replication, called in migration/checkpoint thread |
| 144 | * |
| 145 | * Note: the caller of the function MUST make sure vm stopped |
| 146 | */ |
| 147 | void replication_start_all(ReplicationMode mode, Error **errp); |
| 148 | |
| 149 | /** |
| 150 | * replication_do_checkpoint_all: |
| 151 | * @errp: returns an error if this function fails |
| 152 | * |
| 153 | * This interface is called after all VM state is transferred to Secondary QEMU |
| 154 | */ |
| 155 | void replication_do_checkpoint_all(Error **errp); |
| 156 | |
| 157 | /** |
| 158 | * replication_get_error_all: |
| 159 | * @errp: returns an error if this function fails |
| 160 | * |
| 161 | * This interface is called to check if error occurred during replication |
| 162 | */ |
| 163 | void replication_get_error_all(Error **errp); |
| 164 | |
| 165 | /** |
| 166 | * replication_stop_all: |
| 167 | * @failover: boolean value that indicates if we need do failover or not |
| 168 | * @errp: returns an error if this function fails |
| 169 | * |
| 170 | * It is called on failover. The vm should be stopped before calling it, if you |
| 171 | * use this API to shutdown the guest, or other things except failover |
| 172 | */ |
| 173 | void replication_stop_all(bool failover, Error **errp); |
| 174 | |
| 175 | #endif /* REPLICATION_H */ |