default or selected kernelversion does not have config value CONFIG_VIRTIO_DEBUG.
Result is shown for kernelversion 6.9.8

Debug facilities

modulename: virtio_debug.ko


Linux Kernel Configuration
└─>Device Drivers
└─>Virtio drivers
└─>Debug facilities
In linux kernel since version 4.19.318 (release Date: 2024-07-18)  
Enable this to expose debug facilities over debugfs.
This allows to debug features, to see what features the device
advertises and to set filter for features used by driver.

If unsure, say N.

source code: