From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v4 07/10] KVM: x86: remove not used pvclock_gtod_copy Date: Fri, 11 Aug 2017 19:59:12 -0300 Message-ID: <20170811225909.GA3676@amt.cnet> References: <1501684690-211093-1-git-send-email-dplotnikov@virtuozzo.com> <1501684690-211093-8-git-send-email-dplotnikov@virtuozzo.com> <20170802232131.GA20388@amt.cnet> <5b46dad3-a81f-e908-70e5-e7a0f29318d1@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Denis Plotnikov , rkrcmar@redhat.com, kvm@vger.kernel.org, john.stultz@linaro.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, x86@kernel.org, rkagan@virtuozzo.com, den@virtuozzo.com To: Paolo Bonzini Return-path: Content-Disposition: inline In-Reply-To: <5b46dad3-a81f-e908-70e5-e7a0f29318d1@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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.