Date:   Mon, 29 Nov 2021 23:32:38 +0000
From:   David Matlack <dmatlack@google.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        seanjc@google.com, stable@vger.kernel.org
Subject: Re: [PATCH 1/4] KVM: x86: ignore APICv if LAPIC is not enabled
Message-ID: <YaVjFlTjpoD6XyP3@google.com>
References: <20211123004311.2954158-1-pbonzini@redhat.com>
 <20211123004311.2954158-2-pbonzini@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20211123004311.2954158-2-pbonzini@redhat.com>
Precedence: bulk

On Mon, Nov 22, 2021 at 07:43:08PM -0500, Paolo Bonzini wrote:
> Synchronize the condition for the two calls to kvm_x86_sync_pir_to_irr.
> The one in the reenter-guest fast path invoked the callback
> unconditionally even if LAPIC is disabled.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: David Matlack <dmatlack@google.com>

> ---
>  arch/x86/kvm/x86.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 5a403d92833f..441f4769173e 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -9849,7 +9849,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>  		if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST))
>  			break;
>  
> -		if (vcpu->arch.apicv_active)
> +		if (kvm_lapic_enabled(vcpu) && vcpu->arch.apicv_active)
>  			static_call(kvm_x86_sync_pir_to_irr)(vcpu);
>  
>  		if (unlikely(kvm_vcpu_exit_request(vcpu))) {
> -- 
> 2.27.0
> 
>