CONFIG_KVM_AMD_SEV is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

AMD Secure Encrypted Virtualization (SEV) support

modulename: sev.ko

configname: CONFIG_KVM_AMD_SEV

Linux Kernel Configuration
└─>Virtualization
└─>AMD Secure Encrypted Virtualization (SEV) support
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Provides support for launching Encrypted VMs (SEV) and Encrypted VMs
with Encrypted State (SEV-ES) on AMD processors.