CONFIG_KVM_MIPS_VZ is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
default or selected kernelversion does not have config value CONFIG_KVM_MIPS_VZ.
Result is shown for kernelversion 6.9.9

MIPS Virtualization (VZ) ASE

configname: CONFIG_KVM_MIPS_VZ

Virtualization mode
└─>MIPS Virtualization (VZ) ASE
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Use the MIPS Virtualization (VZ) ASE to virtualize guests. This
supports running unmodified guest kernels (with CONFIG_KVM_GUEST=n),
but requires hardware support.