commit 4301b95af7f554700de8e69ecf3f3bb3148b1d44
Author: Jim Fehlig <jfehlig@novell.com>
Date:   Thu Jan 13 12:52:23 2011 -0700

    [v2] qemu: Retry JSON monitor cont cmd on MigrationExpected error
    
    When restoring a saved qemu instance via JSON monitor, the vm is
    left in a paused state.  Turns out the 'cont' cmd was failing with
    "MigrationExpected" error class and "An incoming migration is
    expected before this command can be executed" error description
    due to migration (restore) not yet complete.
    
    Detect if 'cont' cmd fails with "MigrationExpecte" error class and
    retry 'cont' cmd.
    
    V2: Fix potential double-free noted by Laine Stump

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 2e159c7..ca06e7e 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -702,13 +702,29 @@ qemuMonitorJSONStartCPUs(qemuMonitorPtr mon,
     int ret;
     virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("cont", NULL);
     virJSONValuePtr reply = NULL;
+    int i = 0, timeout = 3;
     if (!cmd)
         return -1;
 
-    ret = qemuMonitorJSONCommand(mon, cmd, &reply);
+    do {
+        ret = qemuMonitorJSONCommand(mon, cmd, &reply);
 
-    if (ret == 0)
-        ret = qemuMonitorJSONCheckError(cmd, reply);
+        if (ret != 0)
+            break;
+
+        /* If no error, we're done */
+        if ((ret = qemuMonitorJSONCheckError(cmd, reply)) == 0)
+            break;
+
+        /* If error class is not MigrationExpected, we're done.
+         * Otherwise try 'cont' cmd again */
+        if (!qemuMonitorJSONHasError(reply, "MigrationExpected"))
+            break;
+
+        virJSONValueFree(reply);
+        reply = NULL;
+        usleep(250000);
+    } while (++i <= timeout);
 
     virJSONValueFree(cmd);
     virJSONValueFree(reply);