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Subject: Re: [PATCH v4 07/10] KVM: x86: remove not used pvclock_gtod_copy
To: Marcelo Tosatti <mtosatti@redhat.com>,
        Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: 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
References: <1501684690-211093-1-git-send-email-dplotnikov@virtuozzo.com>
 <1501684690-211093-8-git-send-email-dplotnikov@virtuozzo.com>
 <20170802232131.GA20388@amt.cnet>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <5b46dad3-a81f-e908-70e5-e7a0f29318d1@redhat.com>
Date: Thu, 3 Aug 2017 14:35:19 +0200
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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