Re: [PATCH 1/4] KVM: x86: ignore APICv if LAPIC is not enabled

Maxim Levitsky
2021-11-30T07:50:45Z

On Mon, 2021-11-22 at 19:43 -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>
> ---
> 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))) {
Reviewed-by: Maxim Levitsky <mlevitk@redhat.com>

Best regards,
Maxim Levitsky