From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [Qemu-devel] KVM: Windows 64-bit troubles with user space irqchip Date: Wed, 02 Feb 2011 15:43:03 +0100 Message-ID: <4D496D77.2010405@siemens.com> References: <4D484A9B.9040604@siemens.com> <20110202115537.GE14984@redhat.com> <4D4946F7.1070702@siemens.com> <20110202123532.GF14984@redhat.com> <4D4952FA.8020300@siemens.com> <4D49569F.6060207@redhat.com> <4D496A8D.90000@siemens.com> <4D496BC5.10807@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , kvm , qemu-devel To: Avi Kivity Return-path: Received: from goliath.siemens.de ([192.35.17.28]:18408 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752922Ab1BBOnV (ORCPT ); Wed, 2 Feb 2011 09:43:21 -0500 In-Reply-To: <4D496BC5.10807@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2011-02-02 15:35, Avi Kivity wrote: > On 02/02/2011 04:30 PM, Jan Kiszka wrote: >> On 2011-02-02 14:05, Avi Kivity wrote: >>> On 02/02/2011 02:50 PM, Jan Kiszka wrote: >>>>>> >>>>> Opps, -smp 1. With -smp 2 it boot almost completely and then hangs. >>>> >>>> Ah, good (or not good). With Windows 2003 Server, I actually get a Blue >>>> Screen (Stop 0x000000b8). >>> >>> Userspace APIC is broken since it may run with an outdated cr8, does >>> reverting 27a4f7976d5 help? >> >> Can you elaborate on what is broken? The way hw/apic.c maintains the >> tpr? Would it make sense to compare this against the in-kernel model? Or >> do you mean something else? > > The problem, IIRC, was that we look up the TPR but it may already have > been changed by the running vcpu. Not 100% sure. > > If that is indeed the problem then the fix would be to process the APIC > in vcpu context (which is what the kernel does - we set a bit in the IRR > and all further processing is synchronous). You mean: user space changes the tpr value while the vcpu is in KVM_RUN, then we return from the kernel and overwrite the tpr in the apic with the vcpu's view, right? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=56707 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PkdvZ-0008MM-Eo for qemu-devel@nongnu.org; Wed, 02 Feb 2011 09:43:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PkdvI-0001Oa-EX for qemu-devel@nongnu.org; Wed, 02 Feb 2011 09:43:22 -0500 Received: from goliath.siemens.de ([192.35.17.28]:15847) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PkdvH-0001NE-PE for qemu-devel@nongnu.org; Wed, 02 Feb 2011 09:43:08 -0500 Message-ID: <4D496D77.2010405@siemens.com> Date: Wed, 02 Feb 2011 15:43:03 +0100 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Qemu-devel] KVM: Windows 64-bit troubles with user space irqchip References: <4D484A9B.9040604@siemens.com> <20110202115537.GE14984@redhat.com> <4D4946F7.1070702@siemens.com> <20110202123532.GF14984@redhat.com> <4D4952FA.8020300@siemens.com> <4D49569F.6060207@redhat.com> <4D496A8D.90000@siemens.com> <4D496BC5.10807@redhat.com> In-Reply-To: <4D496BC5.10807@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: kvm , Gleb Natapov , qemu-devel On 2011-02-02 15:35, Avi Kivity wrote: > On 02/02/2011 04:30 PM, Jan Kiszka wrote: >> On 2011-02-02 14:05, Avi Kivity wrote: >>> On 02/02/2011 02:50 PM, Jan Kiszka wrote: >>>>>> >>>>> Opps, -smp 1. With -smp 2 it boot almost completely and then hangs. >>>> >>>> Ah, good (or not good). With Windows 2003 Server, I actually get a Blue >>>> Screen (Stop 0x000000b8). >>> >>> Userspace APIC is broken since it may run with an outdated cr8, does >>> reverting 27a4f7976d5 help? >> >> Can you elaborate on what is broken? The way hw/apic.c maintains the >> tpr? Would it make sense to compare this against the in-kernel model? Or >> do you mean something else? > > The problem, IIRC, was that we look up the TPR but it may already have > been changed by the running vcpu. Not 100% sure. > > If that is indeed the problem then the fix would be to process the APIC > in vcpu context (which is what the kernel does - we set a bit in the IRR > and all further processing is synchronous). You mean: user space changes the tpr value while the vcpu is in KVM_RUN, then we return from the kernel and overwrite the tpr in the apic with the vcpu's view, right? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux