CONFIG_TAP (not configurable)

modulename: tap.ko

configname: CONFIG_TAP

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>TAP
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This option is selected by any driver implementing tap user space
interface for a virtual interface to re-use core tap functionality.

source code: