CONFIG_KERNEL_VIRTUAL_ADDRESS is not available for thedefaultarchitecture x86.
Result is shown for architecture xtensa

Kernel virtual address

configname: CONFIG_KERNEL_VIRTUAL_ADDRESS

Linux Kernel Configuration
└─>Platform options
└─>Kernel virtual address
In linux kernel since version 5.1 (release Date: 2019-05-05)  
This is the virtual address where the XIP kernel is mapped.
XIP kernel may be mapped into KSEG or KIO region, virtual address
provided here must match kernel load address provided in
KERNEL_LOAD_ADDRESS.