CONFIG_VIRTUALIZATION is not available for the selected architecture x86.
Result is shown for architecture s390

KVM

configname: CONFIG_VIRTUALIZATION

Linux Kernel Configuration
└─>KVM
In linux kernel since version 2.6.24 (release Date: 2008-01-24)
Say Y here to get to see options for using your Linux host to run other
operating systems inside virtual machines (guests).
This option alone does not add any kernel code.

If you say N, all options in this submenu will be skipped and disabled.
is selected by
CONFIG_KVM_INTEL_TDX