CONFIG_KVM_BOOK3S_HV_POSSIBLE is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

CONFIG_KVM_BOOK3S_HV_POSSIBLE (not configurable)

configname: CONFIG_KVM_BOOK3S_HV_POSSIBLE

Linux Kernel Configuration
└─>Virtualization
└─>KVM_BOOK3S_HV_POSSIBLE
In linux kernel since version 3.13 (release Date: 2014-01-19)  

is selected by
CONFIG_PPC_UV

is depended by
CONFIG_KVM_BOOK3S_64_HV