def _find_vdi_refs(self, vm_ref, exclude_volumes=False):
        """Find and return the root and ephemeral vdi refs for a VM."""
        if not vm_ref:
            return {}

        vdi_refs = {}
        for vbd_ref in self._session.call_xenapi("VM.get_VBDs", vm_ref):
            vbd = self._session.call_xenapi("VBD.get_record", vbd_ref)
            if not exclude_volumes or 'osvol' not in vbd['other_config']:
                vdi_refs[vbd['userdevice']] = vbd['VDI']

        return vdi_refs
dataset/ETHPy150Open openstack/nova/nova/virt/xenapi/vmops.py/VMOps._find_vdi_refs/original