migration: Truncate state file in xen-save-devices-state

When running the xen-save-devices-state QMP command, if the filename
already exists it will be truncated before dumping the devices' state
into it.

Signed-off-by: Dov Murik <dovmurik@linux.vnet.ibm.com>
Message-Id: <20200921094830.114028-1-dovmurik@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

diff --git a/migration/savevm.c b/migration/savevm.c
index ee21e981ba2ce07695d1481616d3713f59b06286..34e4b710521bc7206d700fa944f43c0bab5f8a63 100644 (file)
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2803,7 +2803,8 @@ void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live,
     vm_stop(RUN_STATE_SAVE_VM);
     global_state_store_running();
 
-    ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT, 0660, errp);
+    ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT | O_TRUNC,
+                                    0660, errp);
     if (!ioc) {
         goto the_end;
     }