CONFIG_VHOST (not configurable)

modulename: vhost.ko

configname: CONFIG_VHOST

Linux Kernel Configuration
└─>Device Drivers
└─>VHOST
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This option is selected by any driver which needs to access
the core of vhost.

source code:
drivers/vhost/vhost.c