DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E3059DB2E3
Date: Fri, 11 Aug 2017 19:59:12 -0300
From: Marcelo Tosatti <mtosatti@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>, 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
Subject: Re: [PATCH v4 07/10] KVM: x86: remove not used pvclock_gtod_copy
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
Content-Disposition: inline
In-Reply-To: <5b46dad3-a81f-e908-70e5-e7a0f29318d1@redhat.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 666
Lines: 17

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.