Re: [PATCH v4 07/10] KVM: x86: remove not used pvclock_gtod_copy

From: Marcelo Tosatti
Date: Fri Aug 11 2017 - 18:59:54 EST


On Thu, Aug 03, 2017 at 02:35:19PM +0200, Paolo Bonzini wrote:
> On 03/08/2017 01:21, Marcelo Tosatti wrote:
> >> - if (ka->use_master_clock ||
> >> - (gtod->clock.vclock_mode == VCLOCK_TSC && vcpus_matched))
> >> + if (ka->use_master_clock || vcpus_matched)
> >> kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
> > Don't drop this. The masterclock scheme requires TSC for proper functioning
> > (or an analysis why its supposed with different HPET+TSC, for example).
>
> I think testing gtod->clock.vclock_mode is just an optimization?
> kvm_get_time_and_clockread would return false anyway and masterclock
> would not be enabled.
>
> Paolo

Right.