From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: qemu-kvm-1.1.0 crashing with kernel 3.5.0-rc6 Date: Thu, 26 Jul 2012 12:49:46 +0200 Message-ID: <501120CA.10704@siemens.com> References: <4FFAB92C.4030001@googlemail.com> <4FFD26B6.8000802@googlemail.com> <20120711071200.GG23898@redhat.com> <4FFD28B9.9040604@googlemail.com> <20120711072255.GH23898@redhat.com> <50031F85.6020908@googlemail.com> <5007FA1C.5080606@googlemail.com> <5007FAD6.2010407@redhat.com> <500850AD.8080504@googlemail.com> <50111369.6020209@googlemail.com> <50111566.5070202@redhat.com> <50111BFB.8080606@siemens.com> <50111FE5.8090801@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Chris Clayton , Gleb Natapov , "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from david.siemens.de ([192.35.17.14]:22652 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751962Ab2GZKtv (ORCPT ); Thu, 26 Jul 2012 06:49:51 -0400 In-Reply-To: <50111FE5.8090801@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2012-07-26 12:45, Avi Kivity wrote: > On 07/26/2012 01:29 PM, Jan Kiszka wrote: > >>> It looks like general memory corruption. Is this repeatable? What's >>> the guest uptime when it happens (i.e. is it immediate?) >>> >>> Jan, why are we calling cpu_set_apic_tpr() with kvm_irqchip_in_kernel? >> >> To sync the userspace state with what the kernel maintains. Will end up >> in kvm_apic_set_tpr which does precisely this. We always did, just the >> QOM modeling is new. > > We should move it to the general register synchronization code, there is > no reason to do this every exit (though the cost is likely minimal). The cost is, well, was close to nothing. But I'm not sure about that QOM type casting magic (and also it's locking requirements, long-term). However, if that is a problem, it's likely a much bigger one anyway. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux