CONFIG_ARC_KVADDR_SIZE is not available for the default architecture x86.
Result is shown for architecture arc

Kernel Virtual Address Space size (MB)


Linux Kernel Configuration
└─> ARC Architecture Configuration
└─> Kernel Virtual Address Space size (MB)

The kernel address space is carved out of 256MB of translated address
space for catering to vmalloc, modules, pkmap, fixmap. This however may
not suffice vmalloc requirements of a 4K CPU EZChip system. So allow
this to be stretched to 512 MB (by extending into the reserved
kernel-user gutter)