On 05/09/2016 17:50, Mika Penttilä wrote: > While using the master clock among guests, when is it updated? Thought it had to be in > > pvclock_gtod_notify() but it only triggers update of : > > master_kernel_ns, master_cycle_now > > if clocksource changes away from TSC : > > if (gtod->clock.vclock_mode != VCLOCK_TSC && > atomic_read(&kvm_guest_has_master_clock) != 0) > queue_work(system_long_wq, &pvclock_gtod_work); > > And gtod work would set KVM_REQ_MASTERCLOCK_UPDATE if queued, which is not the case if always TSC. > > So kvm_guest_time_update() always uses same values is use_master_clock ? Yes, if the master clock is in use the kvmclock does _not_ adjust itself and, as a consequence, doesn't follow host NTP adjustments. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
