linux-kernel - Re: [PATCH] KVM: SVM: remove unnecessary check on INIT intercept

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Message-ID: <74218ad22f227bb62e7bc52397426545eb1c995d.camel@redhat.com>
Date:   Sun, 21 Aug 2022 11:27:23 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Subject: Re: [PATCH] KVM: SVM: remove unnecessary check on INIT intercept

On Fri, 2022-08-19 at 12:56 -0400, Paolo Bonzini wrote:
> Since svm_check_nested_events() is now handling INIT signals, there is
> no need to latch it until the VMEXIT is injected.  The only condition
> under which INIT signals are latched is GIF=0.
> 
> Suggested-by: Maxim Levitsky <mlevitsk@...hat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
> ---
>  arch/x86/kvm/svm/svm.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index f3813dbacb9f..26a348389ece 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -4697,15 +4697,7 @@ static bool svm_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
>  {
>         struct vcpu_svm *svm = to_svm(vcpu);
>  
> -       /*
> -        * TODO: Last condition latch INIT signals on vCPU when
> -        * vCPU is in guest-mode and vmcb12 defines intercept on INIT.
> -        * To properly emulate the INIT intercept,
> -        * svm_check_nested_events() should call nested_svm_vmexit()
> -        * if an INIT signal is pending.
> -        */
> -       return !gif_set(svm) ||
> -                  (vmcb_is_intercept(&svm->vmcb->control, INTERCEPT_INIT));
> +       return !gif_set(svm);
>  }
>  
>  static void svm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)

Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>

Best regards,
	Maxim Levitsky