default or selected kernelversion does not have config value CONFIG_HAVE_KVM_EVENTFD.
Result is shown for kernelversion 6.9.9

CONFIG_HAVE_KVM_EVENTFD (not configurable)

configname: CONFIG_HAVE_KVM_EVENTFD

Linux Kernel Configuration
└─>HAVE_KVM_EVENTFD
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
selects
CONFIG_EVENTFD

is depended by
CONFIG_KVM