From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=36401 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pke4c-0002HW-4T for qemu-devel@nongnu.org; Wed, 02 Feb 2011 09:53:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Pke4I-0007iV-GM for qemu-devel@nongnu.org; Wed, 02 Feb 2011 09:52:43 -0500 Received: from david.siemens.de ([192.35.17.14]:22278) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Pke4I-0007gR-6N for qemu-devel@nongnu.org; Wed, 02 Feb 2011 09:52:26 -0500 Message-ID: <4D496FA6.8070301@siemens.com> Date: Wed, 02 Feb 2011 15:52:22 +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> <4D496D77.2010405@siemens.com> In-Reply-To: <4D496D77.2010405@siemens.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 15:43, Jan Kiszka wrote: > 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 Userspace APIC is broken since it may run with an outdated cr8, does 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? Hmm, probably rather that there is a discrepancy between tpr and irr. The latter is changed asynchronously /wrt to the vcpu, the former /wrt the user space device model. Run apic_set_irq on the vcpu? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux