1 files changed, 41 insertions, 0 deletions
diff --git a/migration/colo-failover.c b/migration/colo-failover.c
index e31fc10..6cca039 100644
--- a/migration/colo-failover.c
+++ b/migration/colo-failover.c
@@ -15,22 +15,63 @@
 #include "migration/failover.h"
 #include "qmp-commands.h"
 #include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
+#include "trace.h"
 
 static QEMUBH *failover_bh;
+static FailoverStatus failover_state;
 
 static void colo_failover_bh(void *opaque)
 {
+    int old_state;
+
     qemu_bh_delete(failover_bh);
     failover_bh = NULL;
+
+    old_state = failover_set_state(FAILOVER_STATUS_REQUIRE,
+                                   FAILOVER_STATUS_ACTIVE);
+    if (old_state != FAILOVER_STATUS_REQUIRE) {
+        error_report("Unknown error for failover, old_state = %s",
+                    FailoverStatus_lookup[old_state]);
+        return;
+    }
+
     /* TODO: Do failover work */
 }
 
 void failover_request_active(Error **errp)
 {
+   if (failover_set_state(FAILOVER_STATUS_NONE,
+        FAILOVER_STATUS_REQUIRE) != FAILOVER_STATUS_NONE) {
+        error_setg(errp, "COLO failover is already actived");
+        return;
+    }
     failover_bh = qemu_bh_new(colo_failover_bh, NULL);
     qemu_bh_schedule(failover_bh);
 }
 
+void failover_init_state(void)
+{
+    failover_state = FAILOVER_STATUS_NONE;
+}
+
+FailoverStatus failover_set_state(FailoverStatus old_state,
+                    FailoverStatus new_state)
+{
+    FailoverStatus old;
+
+    old = atomic_cmpxchg(&failover_state, old_state, new_state);
+    if (old == old_state) {
+        trace_colo_failover_set_state(FailoverStatus_lookup[new_state]);
+    }
+    return old;
+}
+
+FailoverStatus failover_get_state(void)
+{
+    return atomic_read(&failover_state);
+}
+
 void qmp_x_colo_lost_heartbeat(Error **errp)
 {
     if (get_colo_mode() == COLO_MODE_UNKNOWN) {