CONFIG_KVM_BOOK3S_HV_P8_TIMING is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

Detailed timing for hypervisor real-mode code (for POWER8)


Linux Kernel Configuration
└─>Detailed timing for hypervisor real-mode code (for POWER8)
In linux kernel since version 6 (release Date: 2022-10-02)  
Calculate time taken for each vcpu in the real-mode guest entry,
exit, and interrupt handling code, plus time spent in the guest
and in nap mode due to idle (cede) while other threads are still
in the guest. The total, minimum and maximum times in nanoseconds
together with the number of executions are reported in debugfs in
kvm/vm#/vcpu#/timings. The overhead is of the order of 30 - 40
ns per exit on POWER8.

If unsure, say N.