'Takes a key/value pair and adds it to the xenstore parameter
record for the given vm instance. If the key exists in xenstore,
it is overwritten'

def _add_to_param_xenstore(self, vm_ref, key, val):

    self._remove_from_param_xenstore(vm_ref, key)
    self._session.call_xenapi('VM.add_to_xenstore_data', vm_ref, key, val)
