linux-kernel - Re: [PATCH] KVM: VMX: remove duplicated segment cache clear

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Message-ID: <87eevtf9xz.fsf@vitty.brq.redhat.com>
Date:   Tue, 21 Jan 2020 10:14:16 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Miaohe Lin <linmiaohe@...wei.com>
Cc:     linmiaohe@...wei.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, x86@...nel.org, pbonzini@...hat.com,
        sean.j.christopherson@...el.com, wanpengli@...cent.com,
        jmattson@...gle.com, joro@...tes.org, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, hpa@...or.com
Subject: Re: [PATCH] KVM: VMX: remove duplicated segment cache clear

Miaohe Lin <linmiaohe@...wei.com> writes:

> vmx_set_segment() clears segment cache unconditionally, so we should not
> clear it again by calling vmx_segment_cache_clear().
>
> Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
> ---
>  arch/x86/kvm/vmx/vmx.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index b5a0c2e05825..b32236e6b513 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2688,8 +2688,6 @@ static void enter_pmode(struct kvm_vcpu *vcpu)
>  
>  	vmx->rmode.vm86_active = 0;
>  
> -	vmx_segment_cache_clear(vmx);
> -
>  	vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR);
>  
>  	flags = vmcs_readl(GUEST_RFLAGS);

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>

-- 
Vitaly