CONFIG_KVM_S390_UCONTROL is not available for thedefaultarchitecture x86.
Result is shown for architecture s390

Userspace controlled virtual machines

configname: CONFIG_KVM_S390_UCONTROL

Linux Kernel Configuration
└─>Userspace controlled virtual machines
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Allow CAP_SYS_ADMIN users to create KVM virtual machines that are
controlled by userspace.

If unsure, say N.