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SubjectRe: [PATCH] KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
On Wed, Jan 15, 2014 at 06:08:11PM +0100, Paolo Bonzini wrote:
> After the previous patch from Marcelo, the comment before this write
> became obsolete. In fact, the write is unnecessary. The calls to
> kvm_write_tsc ultimately result in a master clock update as soon as
> all TSCs agree and the master clock is re-enabled. This master
> clock update will rewrite tsc_timestamp.
>
> So, together with the comment, delete the dead write too.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/x86.c | 2 --
> 1 files changed, 0 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 842abd3..0fbdced 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1278,8 +1278,6 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
> kvm->arch.last_tsc_write = data;
> kvm->arch.last_tsc_khz = vcpu->arch.virtual_tsc_khz;
>
> - /* Reset of TSC must disable overshoot protection below */
> - vcpu->arch.hv_clock.tsc_timestamp = 0;
> vcpu->arch.last_guest_tsc = data;
>
> /* Keep track of which generation this VCPU has synchronized to */
> --
> 1.7.1

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>



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