Re: [PATCH] KVM: x86: Pending interrupt may be delivered after INIT

[Gleb Natapov <gleb@kernel.org>]

On Mon, Jun 30, 2014 at 11:35:27AM +0300, Nadav Amit wrote:
> We encountered a scenario in which after an INIT is delivered, a pending
> interrupt is delivered, although it was sent before the INIT.  As the SDM
> states in section 10.4.7.1, the ISR and the IRR should be cleared after INIT as
> KVM does.  This also means that pending interrupts should be cleared.  This
> patch clears upon reset (and INIT) the pending interrupts; and at the same
> occassion clears the pending exceptions, since they may cause a similar issue.
> 
> Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
> ---
>  arch/x86/kvm/x86.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index f32a025..863ac07 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6835,6 +6835,8 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu)
>  	atomic_set(&vcpu->arch.nmi_queued, 0);
>  	vcpu->arch.nmi_pending = 0;
>  	vcpu->arch.nmi_injected = false;
> +	vcpu->arch.interrupt.pending = false;
> +	vcpu->arch.exception.pending = false;
kvm_clear_interrupt_queue(vcpu);
kvm_clear_exception_queue(vcpu);

>  
>  	memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
>  	vcpu->arch.dr6 = DR6_FIXED_1;
> -- 
> 1.9.1
> 

--
			Gleb.