From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH] KVM: SVM: fix NMI window after iret
Date: Tue, 18 Feb 2014 10:18:21 +0100
Message-ID: <5303255D.8000501@redhat.com>
References: <1389988362-15260-1-git-send-email-rkrcmar@redhat.com>
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Cc: kvm@vger.kernel.org, joro@8bytes.org, stable@vger.kernel.org
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Il 17/01/2014 20:52, Radim Kr=C4=8Dm=C3=A1=C5=99 ha scritto:
> We should open NMI window right after an iret, but SVM exits before i=
t.
> We wanted to single step using the trap flag and then open it.
> (or we could emulate the iret instead)
> We don't do it since commit 3842d135ff2 (likely), because the iret ex=
it
> handler does not request an event, so NMI window remains closed until
> the next exit.
>
> Fix this by making KVM_REQ_EVENT request in the iret handler.
>
> Signed-off-by: Radim Kr=C4=8Dm=C3=A1=C5=99 <rkrcmar@redhat.com>
> ---
>  (btw. kvm-unit-tests weren't executed on SVM since Nov 2010, at leas=
t)
>
>  arch/x86/kvm/svm.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index c7168a5..b5a735b 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -2829,6 +2829,7 @@ static int iret_interception(struct vcpu_svm *s=
vm)
>  	clr_intercept(svm, INTERCEPT_IRET);
>  	svm->vcpu.arch.hflags |=3D HF_IRET_MASK;
>  	svm->nmi_iret_rip =3D kvm_rip_read(&svm->vcpu);
> +	kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
>  	return 1;
>  }
>
>

Applying to kvm/queue, thanks.

Paolo