CONFIG_KVM_ARM_HOST is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

KVM host support for ARM cpus.

modulename: kvm.ko

and/or

banked-sr.ko

and/or

entry.ko

and/or

s2-setup.ko

and/or

hyp-entry.ko

and/or

fpsimd.ko

and/or

debug-sr.ko

and/or

switch.ko

and/or

vgic-v2-cpuif-proxy.ko

and/or

sysreg-sr.ko

and/or

cp15-sr.ko

and/or

tlb.ko

and/or

vfp.ko

configname: CONFIG_KVM_ARM_HOST

Linux Kernel Configuration
└─>Virtualization
└─>KVM host support for ARM cpus.
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Provides host support for ARM processors.

source code:
/arch/arm64/kvm/


is selected by
CONFIG_KVM_ARM_VGIC