def block_device_mappings(vm_):
 return config.get_cloud_config_value('block_device_mappings', vm_, __opts__, search_global=True)

def block_device_mappings ( vm_ ) : return config . get_cloud_config_value ( 'block_device_mappings' , vm_ , __opts__ , search_global = True )
return the block device mapping: [{devicename: /dev/sdb .