From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH -v2] QEMU-KVM: MCE: Relay UCR MCE to guest Date: Mon, 14 Sep 2009 08:10:29 +0300 Message-ID: <4AADD045.1090909@redhat.com> References: <1252463282.5212.44.camel@yhuang-dev.sh.intel.com> <4AA79A31.9070600@redhat.com> <1252550406.5212.133.camel@yhuang-dev.sh.intel.com> <20090910093539.GB19428@basil.fritz.box> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Huang Ying , Anthony Liguori , "kvm@vger.kernel.org" To: Andi Kleen Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33944 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbZINFKg (ORCPT ); Mon, 14 Sep 2009 01:10:36 -0400 In-Reply-To: <20090910093539.GB19428@basil.fritz.box> Sender: kvm-owner@vger.kernel.org List-ID: On 09/10/2009 12:35 PM, Andi Kleen wrote: >>> (also, I if we can't handle guest-mode SIGBUS I think it would be nice >>> to raise it again so the process terminates due to the SIGBUS). >>> >> For SIGBUS we can not relay to guest as MCE, we can either abort or >> reset SIGBUS to SIGDFL and re-raise it. Both are OK for me. You prefer >> the latter one? >> > I think a suitable error message and exit would be better than a plain > signal kill. It shouldn't look like qemu crashed due to a software > bug. Ideally a error message in a way that it can be parsed by libvirt etc. > and reported in a suitable way. > libvirt etc. can/should wait() for qemu to terminate abnormally and report the reason why. However it doesn't seem there is a way to get extended signal information from wait(), so it looks like internal handling by qemu is better. > However qemu getting killed itself is very unlikely, it doesn't > have much memory foot print compared to the guest and other data. > So this should be a very rare condition. > (I get SIGBUS quite often running qemu from nfs and compiling a new one, however that's a really different use case) -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.