linux-kernel - Re: [PATCH] KVM: apic: short-circuit kvm_apic_accept_pic

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Message-ID: <87sgkafmcu.fsf@vitty.brq.redhat.com>
Date:   Mon, 20 Jan 2020 11:33:53 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     linmiaohe <linmiaohe@...wei.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org, x86@...nel.org,
        pbonzini@...hat.com, rkrcmar@...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: apic: short-circuit kvm_apic_accept_pic_intr() when pic intr is accepted

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

> From: Miaohe Lin <linmiaohe@...wei.com>
>
> Short-circuit kvm_apic_accept_pic_intr() when pic intr is accepted, there
> is no need to proceed further. Also remove unnecessary var r.
>
> Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
> ---
>  arch/x86/kvm/lapic.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 679692b55f6d..502c7b0d8fdb 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -2370,14 +2370,13 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
>  int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
>  {
>  	u32 lvt0 = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LVT0);
> -	int r = 0;
>  
>  	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
> -		r = 1;
> +		return 1;
>  	if ((lvt0 & APIC_LVT_MASKED) == 0 &&
>  	    GET_APIC_DELIVERY_MODE(lvt0) == APIC_MODE_EXTINT)
> -		r = 1;
> -	return r;
> +		return 1;
> +	return 0;
>  }
>  
>  void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu)

My eyes would've appreciated a blank line after each "return 1;" but you
patch makes the code a bit nicer anyway, thanks.

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

-- 
Vitaly