From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: KVM: x86: better fix for race between nmi injection and enabling nmi window Date: Wed, 30 Mar 2011 19:16:34 +0200 Message-ID: <4D936572.3060801@redhat.com> References: <20110330163028.GA27365@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm , Gleb Natapov To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:65110 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754785Ab1C3RQi (ORCPT ); Wed, 30 Mar 2011 13:16:38 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p2UHGbrb017121 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 30 Mar 2011 13:16:38 -0400 In-Reply-To: <20110330163028.GA27365@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: On 03/30/2011 06:30 PM, Marcelo Tosatti wrote: > Based on Gleb's idea, fix race between nmi injection and enabling > nmi window in a simpler way. > > Signed-off-by: Marcelo Tosatti > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index a6a129f..9a7cc1be 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -5152,6 +5152,7 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu) > static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > { > int r; > + int nmi_pending; > bool req_int_win = !irqchip_in_kernel(vcpu->kvm)&& > vcpu->run->request_interrupt_window; > > @@ -5195,11 +5196,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > if (unlikely(r)) > goto out; > > + nmi_pending = ACCESS_ONCE(vcpu->arch.nmi_pending); > + > if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { > inject_pending_event(vcpu); > > /* enable NMI/IRQ window open exits if needed */ > - if (vcpu->arch.nmi_pending) > + if (nmi_pending) > kvm_x86_ops->enable_nmi_window(vcpu); > else if (kvm_cpu_has_interrupt(vcpu) || req_int_win) > kvm_x86_ops->enable_irq_window(vcpu); > What about the check in inject_pending_events()? -- error compiling committee.c: too many arguments to function