migration: Add 'pre-switchover' and 'device' statuses

Add two statuses for use when the 'pause-before-switchover'
capability is enabled.

'pre-switchover' is the state that we wait in for management
to allow us to continue.
'device' is the state we enter while serialising the devices
after management gives us the OK.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

migration/migration.c

@@ -526,6 +526,8 @@ static bool migration_is_setup_or_active(int state)
     case MIGRATION_STATUS_ACTIVE:
     case MIGRATION_STATUS_POSTCOPY_ACTIVE:
     case MIGRATION_STATUS_SETUP:
+    case MIGRATION_STATUS_PRE_SWITCHOVER:
+    case MIGRATION_STATUS_DEVICE:
         return true;
 
     default:
@@ -600,6 +602,8 @@ MigrationInfo *qmp_query_migrate(Error **errp)
     case MIGRATION_STATUS_ACTIVE:
     case MIGRATION_STATUS_CANCELLING:
     case MIGRATION_STATUS_POSTCOPY_ACTIVE:
+    case MIGRATION_STATUS_PRE_SWITCHOVER:
+    case MIGRATION_STATUS_DEVICE:
          /* TODO add some postcopy stats */
         info->has_status = true;
         info->has_total_time = true;
@@ -1189,6 +1193,8 @@ bool migration_is_idle(void)
     case MIGRATION_STATUS_ACTIVE:
     case MIGRATION_STATUS_POSTCOPY_ACTIVE:
     case MIGRATION_STATUS_COLO:
+    case MIGRATION_STATUS_PRE_SWITCHOVER:
+    case MIGRATION_STATUS_DEVICE:
         return false;
     case MIGRATION_STATUS__MAX:
         g_assert_not_reached();

qapi/migration.json

@@ -96,12 +96,18 @@
 # @colo: VM is in the process of fault tolerance, VM can not get into this
 #        state unless colo capability is enabled for migration. (since 2.8)
 #
+# @pre-switchover: Paused before device serialisation. (since 2.11)
+#
+# @device: During device serialisation when pause-before-switchover is enabled
+#        (since 2.11)
+#
 # Since: 2.3
 #
 ##
 { 'enum': 'MigrationStatus',
   'data': [ 'none', 'setup', 'cancelling', 'cancelled',
-            'active', 'postcopy-active', 'completed', 'failed', 'colo' ] }
+            'active', 'postcopy-active', 'completed', 'failed', 'colo',
+            'pre-switchover', 'device' ] }
 
 ##
 # @MigrationInfo: