Test was failing in case of coldplug + nondisk combination due missin…

…g property definiton.

For not hotplug will now start the VM in case of disk only if the disk attachment was successful. in case of other test_devices the VM should start

libvirt/tests/src/svirt/selinux/selinux_seclabel_per_device.py

@@ -46,6 +46,7 @@ def attach_device(vm, test_device, dev_dict):
     :param vm: VM instance
     :param test_device: the device type, e.g. disk
     :param dev_dict: the device definition
+    :return: CmdResult object    
     """
 
     dev_obj = libvirt_vmxml.create_vm_device_by_type(test_device, dev_dict)
@@ -78,6 +79,7 @@ def run(test, params, env):
     dev_dict, seclabel_attr = get_dev_dict(test_device, params)
     test.log.debug("The device setting will be updated to %s.", dev_dict)
     try:
+        res = None
         if test_scenario != "hot_plug":
             test.log.info("TEST_STEP: Start VM with per-device dac setting.")
             try:
@@ -89,7 +91,9 @@ def run(test, params, env):
                 if not status_error:
                     test.fail(details)
             test.log.debug("VM XML: %s.", VMXML.new_from_inactive_dumpxml(vm_name))
-            if res.exit_status == 0:
+            # res is None in case of non disk device and the VM should be started
+            # in case of disk, the VM should be started only in successful attach.
+            if res is None or res.exit_status == 0:
                 res = virsh.start(vm.name)
         else:
             test.log.info("TEST_STEP: Hot plug a device with dac setting.")