undefine.patch

diff --git a/virttest/libvirt_vm.py b/virttest/libvirt_vm.py
index e17e30c..42e66da 100644
--- a/virttest/libvirt_vm.py
+++ b/virttest/libvirt_vm.py
@@ -277,6 +277,7 @@ class VM(virt_vm.BaseVM):
 
             virsh.dumpxml(self.name, extra=extra,
                           to_file=xml_file, uri=self.connect_uri)
+            utils.run("sed -i '/<nvram>.*<\/nvram>/d' %s" % xml_file)
             return xml_file
         except Exception, detail:
             if os.path.exists(xml_file):
diff --git a/virttest/libvirt_xml/vm_xml.py b/virttest/libvirt_xml/vm_xml.py
index 1a77bc2..76f2c14 100644
--- a/virttest/libvirt_xml/vm_xml.py
+++ b/virttest/libvirt_xml/vm_xml.py
@@ -528,6 +528,8 @@ class VMXML(VMXMLBase):
         vmxml = VMXML(virsh_instance=virsh_instance)
         vmxml['xml'] = virsh_instance.dumpxml(vm_name,
                                               extra=options).stdout.strip()
+        vmxml.xmltreefile.remove_by_xpath('/os/nvram', remove_all=True)
+        vmxml.xmltreefile.write()
         return vmxml
 
     @staticmethod
diff --git a/virttest/virsh.py b/virttest/virsh.py
index 70dc302..5c8a3f5 100644
--- a/virttest/virsh.py
+++ b/virttest/virsh.py
@@ -1310,7 +1310,7 @@ def undefine(name, options=None, **dargs):
     :param dargs: standardized virsh function API keywords
     :return: CmdResult object
     """
-    cmd = "undefine %s" % name
+    cmd = "undefine %s --nvram" % name
     if options is not None:
         cmd += " %s" % options