[Qemu-devel] [PATCH 11/16] Add new block driver interfaces to control block replication

[Wen Congyang <wency@cn.fujitsu.com>]

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
 block.c                   | 43 +++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h     |  5 +++++
 include/block/block_int.h | 14 ++++++++++++++
 qapi/block-core.json      | 15 +++++++++++++++
 4 files changed, 77 insertions(+)

diff --git a/block.c b/block.c
index 5119e1e..c7670d2 100644
--- a/block.c
+++ b/block.c
@@ -4390,3 +4390,46 @@ void bdrv_del_child(BlockDriverState *bs, BlockDriverState *child_bs,
 
     bs->drv->bdrv_del_child(bs, child_bs, errp);
 }
+
+void bdrv_start_replication(BlockDriverState *bs, ReplicationMode mode,
+                            Error **errp)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_start_replication) {
+        drv->bdrv_start_replication(bs, mode, errp);
+    } else if (bs->file) {
+        bdrv_start_replication(bs->file, mode, errp);
+    } else {
+        error_setg(errp, "The BDS %s doesn't support starting block"
+                   " replication", bs->filename);
+    }
+}
+
+void bdrv_do_checkpoint(BlockDriverState *bs, Error **errp)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_do_checkpoint) {
+        drv->bdrv_do_checkpoint(bs, errp);
+    } else if (bs->file) {
+        bdrv_do_checkpoint(bs->file, errp);
+    } else {
+        error_setg(errp, "The BDS %s doesn't support block checkpoint",
+                   bs->filename);
+    }
+}
+
+void bdrv_stop_replication(BlockDriverState *bs, bool failover, Error **errp)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_stop_replication) {
+        drv->bdrv_stop_replication(bs, failover, errp);
+    } else if (bs->file) {
+        bdrv_stop_replication(bs->file, failover, errp);
+    } else {
+        error_setg(errp, "The BDS %s doesn't support stopping block"
+                   " replication", bs->filename);
+    }
+}
diff --git a/include/block/block.h b/include/block/block.h
index 98c8509..192a066 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -626,4 +626,9 @@ void bdrv_add_child(BlockDriverState *bs, QDict *options, Error **errp);
 void bdrv_del_child(BlockDriverState *bs, BlockDriverState *child,
                     Error **errp);
 
+void bdrv_start_replication(BlockDriverState *bs, ReplicationMode mode,
+                            Error **errp);
+void bdrv_do_checkpoint(BlockDriverState *bs, Error **errp);
+void bdrv_stop_replication(BlockDriverState *bs, bool failover, Error **errp);
+
 #endif
diff --git a/include/block/block_int.h b/include/block/block_int.h
index b6f2905..1c2d310 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -293,6 +293,20 @@ struct BlockDriver {
     void (*bdrv_del_child)(BlockDriverState *bs, BlockDriverState *child,
                            Error **errp);
 
+    void (*bdrv_start_replication)(BlockDriverState *bs, ReplicationMode mode,
+                                   Error **errp);
+    /* Drop Disk buffer when doing checkpoint. */
+    void (*bdrv_do_checkpoint)(BlockDriverState *bs, Error **errp);
+    /*
+     * After failover, we should flush Disk buffer into secondary disk
+     * and stop block replication.
+     *
+     * If the guest is shutdown, we should drop Disk buffer and stop
+     * block representation.
+     */
+    void (*bdrv_stop_replication)(BlockDriverState *bs, bool failover,
+                                  Error **errp);
+
     QLIST_ENTRY(BlockDriver) list;
 };
 
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 24099ef..96f0530 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1810,6 +1810,21 @@
   'data': { '*export': 'str' } }
 
 ##
+# @ReplicationMode
+#
+# An enumeration of replication modes.
+#
+# @unprotected: Replication is not started or after failover.
+#
+# @primary: Primary mode, the vm's state will be sent to secondary QEMU.
+#
+# @secondary: Secondary mode, receive the vm's state from primary QEMU.
+#
+# Since: 2.4
+##
+{ 'enum' : 'ReplicationMode', 'data' : [ 'primary', 'secondary' ] }
+
+##
 # @BlockdevOptions
 #
 # Options for creating a block device.
-- 
2.4.3