default or selected kernelversion does not have config value CONFIG_VFIO_MDEV_DEVICE.
Result is shown for kernelversion 6.9.9
VFIO driver for Mediated devices
modulename: vfio_mdev.ko
configname: CONFIG_VFIO_MDEV_DEVICE
Linux Kernel Configuration
└─>Device Drivers
└─>VFIO Non-Privileged userspace driver framework
└─>VFIO driver for Mediated devices
In linux kernel since version 3.10 (release Date: 2013-06-30)
VFIO based driver for Mediated devices.