From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: VMX: Fix race between pending IRQ and NMI Date: Sat, 22 Nov 2008 14:25:20 +0200 Message-ID: <4927FA30.5020900@redhat.com> References: <491858C8.2040401@siemens.com> <49201213.1080305@redhat.com> <49203513.2080800@web.de> <4920392F.9020303@redhat.com> <49203EAF.3000800@web.de> <49244F20.3030803@redhat.com> <49248514.9020605@redhat.com> <49256649.6060801@siemens.com> <49256D38.4090908@redhat.com> <492687BE.9030307@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Jan Kiszka , kvm-devel , "Xu, Jiajun" , "Yang, Sheng" To: Jan Kiszka Return-path: Received: from mx2.redhat.com ([66.187.237.31]:35602 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757417AbYKVMZa (ORCPT ); Sat, 22 Nov 2008 07:25:30 -0500 In-Reply-To: <492687BE.9030307@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: Jan Kiszka wrote: >> But I think I see a bigger issue - if we inject an regular interrupt >> while another is pending, then we will encounter this problem. Looks >> like we have to enable the interrupt window after injecting an interrupt >> if there are still pending interrupts. >> > > Yeah, probably. I'm just wondering now if we can set > exit-on-interrupt-window while the vcpu state is interruptible (ie. > _before_ the injection). There is some entry check like this for NMIs, > but maybe no for interrupts. Need to check. > Turns out it's not necessary, since the guest eoi will cause an exit and allow the code to request an interrupt window. I've added an apic test program so we can track these issues (user/test/x86/apic.c). -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.