linux-kernel - Re: [PATCH v3] KVM: x86: do not go through vcpu in __get_kvmclock

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Message-ID: <20161116181337.GB20282@potion>
Date:   Wed, 16 Nov 2016 19:13:38 +0100
From:   Radim Krčmář <rkrcmar@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        mtosatti@...hat.com
Subject: Re: [PATCH v3] KVM: x86: do not go through vcpu in __get_kvmclock_ns

2016-11-16 18:31+0100, Paolo Bonzini:
> Going through the first VCPU is wrong if you follow a KVM_SET_CLOCK with
> a KVM_GET_CLOCK immediately after, without letting the VCPU run and
> call kvm_guest_time_update.
> 
> To fix this, compute the kvmclock value ourselves, using the master
> clock (tsc, nsec) pair as the base and the host CPU frequency as
> the scale.
> 
> Reported-by: Marcelo Tosatti <mtosatti@...hat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
> ---

Looks good, thanks!  Planned for 4.9-rc6.