[Qemu-devel] [PATCH V6 1/2] Add a new qmp command to start/stop replication

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

We can call this qmp command to start/stop replication outside of qemu.
Like Xen colo need this function.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wencongyang@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

---
 docs/qmp-commands.txt | 18 ++++++++++++++++++
 migration/colo.c      | 23 +++++++++++++++++++++++
 qapi-schema.json      | 19 +++++++++++++++++++
 3 files changed, 60 insertions(+)

diff --git a/docs/qmp-commands.txt b/docs/qmp-commands.txt
index abf210a..d182147 100644
--- a/docs/qmp-commands.txt
+++ b/docs/qmp-commands.txt
@@ -432,6 +432,24 @@ Example:
      "arguments": { "enable": true } }
 <- { "return": {} }
 
+xen-set-replication
+-------------------
+
+Enable or disable replication.
+
+Arguments:
+
+- "enable": Enable it or disable it.
+- "primary": True for primary or false for secondary.
+- "failover": Enable failover when stopping replication, but cannot be
+              specified if 'enable' is true (optional, default false).
+
+Example:
+
+-> { "execute": "xen-set-replication",
+     "arguments": {"enable": true, "primary": false} }
+<- { "return": {} }
+
 migrate
 -------
 
diff --git a/migration/colo.c b/migration/colo.c
index 93c85c5..6fc2ade 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -19,6 +19,8 @@
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "migration/failover.h"
+#include "replication.h"
+#include "qmp-commands.h"
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
@@ -104,6 +106,27 @@ void colo_do_failover(MigrationState *s)
     }
 }
 
+void qmp_xen_set_replication(bool enable, bool primary,
+                             bool has_failover, bool failover,
+                             Error **errp)
+{
+    ReplicationMode mode = primary ?
+                           REPLICATION_MODE_PRIMARY :
+                           REPLICATION_MODE_SECONDARY;
+
+    if (has_failover && enable) {
+        error_setg(errp, "Parameter 'failover' is only for"
+                   " stopping replication");
+        return;
+    }
+
+    if (enable) {
+        replication_start_all(mode, errp);
+    } else {
+        replication_stop_all(failover, failover ? NULL : errp);
+    }
+}
+
 static void colo_send_message(QEMUFile *f, COLOMessage msg,
                               Error **errp)
 {
diff --git a/qapi-schema.json b/qapi-schema.json
index f3e9bfc..78802f4 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4676,6 +4676,25 @@
 { 'command': 'xen-load-devices-state', 'data': {'filename': 'str'} }
 
 ##
+# @xen-set-replication
+#
+# Enable or disable replication.
+#
+# @enable: true to enable, false to disable.
+#
+# @primary: true for primary or false for secondary.
+#
+# @failover: #optional true to do failover, false to stop. but cannot be
+#            specified if 'enable' is true. default value is false.
+#
+# Returns: nothing.
+#
+# Since: 2.9
+##
+{ 'command': 'xen-set-replication',
+  'data': { 'enable': 'bool', 'primary': 'bool', '*failover' : 'bool' } }
+
+##
 # @GICCapability:
 #
 # The struct describes capability for a specific GIC (Generic
-- 
2.7.4