[Qemu-devel] [PATCH COLO v3 04/14] 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                   | 40 ++++++++++++++++++++++++++++++++++++++++
 include/block/block.h     |  5 +++++
 include/block/block_int.h | 11 +++++++++++
 qapi/block.json           | 16 ++++++++++++++++
 4 files changed, 72 insertions(+)

diff --git a/block.c b/block.c
index f2f8ae7..82e139b 100644
--- a/block.c
+++ b/block.c
@@ -6229,3 +6229,43 @@ BlockAcctStats *bdrv_get_stats(BlockDriverState *bs)
 {
     return &bs->stats;
 }
+
+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, "this feature or command is not currently supported");
+    }
+}
+
+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, "this feature or command is not currently supported");
+    }
+}
+
+void bdrv_stop_replication(BlockDriverState *bs, Error **errp)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_stop_replication) {
+        drv->bdrv_stop_replication(bs, errp);
+    } else if (bs->file) {
+        bdrv_stop_replication(bs->file, errp);
+    } else {
+        error_setg(errp, "this feature or command is not currently supported");
+    }
+}
diff --git a/include/block/block.h b/include/block/block.h
index 4c57d63..2f8f361 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -569,4 +569,9 @@ void bdrv_flush_io_queue(BlockDriverState *bs);
 
 BlockAcctStats *bdrv_get_stats(BlockDriverState *bs);
 
+void bdrv_start_replication(BlockDriverState *bs, ReplicationMode mode,
+                            Error **errp);
+void bdrv_do_checkpoint(BlockDriverState *bs, Error **errp);
+void bdrv_stop_replication(BlockDriverState *bs, Error **errp);
+
 #endif
diff --git a/include/block/block_int.h b/include/block/block_int.h
index dccb092..b15d5b8 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -290,6 +290,17 @@ struct BlockDriver {
      */
     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 
+
+    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.
+     */
+    void (*bdrv_stop_replication)(BlockDriverState *bs, Error **errp);
+
     QLIST_ENTRY(BlockDriver) list;
 };
 
diff --git a/qapi/block.json b/qapi/block.json
index e313465..7884cc6 100644
--- a/qapi/block.json
+++ b/qapi/block.json
@@ -40,6 +40,22 @@
   'data': ['auto', 'none', 'lba', 'large', 'rechs']}
 
 ##
+# @COLOMode
+#
+# An enumeration of replication modes.
+#
+# @unprotected: COLO 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' : ['unprotected', 'primary', 'secondary']}
+
+##
 # @BlockdevSnapshotInternal
 #
 # @device: the name of the device to generate the snapshot from
-- 
2.1.0