From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH] KVM: VMX: blocked-by-sti must not defer NMI injections Date: Tue, 11 May 2010 15:16:46 +0200 Message-ID: <4BE958BE.9020503@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm , Gleb Natapov To: Avi Kivity , Marcelo Tosatti Return-path: Received: from thoth.sbs.de ([192.35.17.2]:20521 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756740Ab0EKNRr (ORCPT ); Tue, 11 May 2010 09:17:47 -0400 Sender: kvm-owner@vger.kernel.org List-ID: As the processor may not consider GUEST_INTR_STATE_STI as a reason for blocking NMI, it could return immediately with EXIT_REASON_NMI_WINDOW when we asked for it. But as we consider this state as NMI-blocking, we can run into an endless loop. Resolve this by allowing NMI injection if just GUEST_INTR_STATE_STI is active (originally suggested by Gleb). Intel confirmed that this is safe, the processor will never complain about NMI injection in this state. Signed-off-by: Jan Kiszka KVM-Stable-Tag --- arch/x86/kvm/vmx.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 777e00d..fa3959b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2824,8 +2824,7 @@ static int vmx_nmi_allowed(struct kvm_vcpu *vcpu) return 0; return !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & - (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS | - GUEST_INTR_STATE_NMI)); + (GUEST_INTR_STATE_MOV_SS | GUEST_INTR_STATE_NMI)); } static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu)