From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: random crash in post_kvm_run() Date: Tue, 06 Jul 2010 10:46:45 +0300 Message-ID: <4C32DF65.4080206@redhat.com> References: <4C29E435.1040201@redhat.com> <4C2C7F9D.3010002@redhat.com> <4C2F10CA.6020907@redhat.com> <4C318CF6.9000601@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: BuraphaLinux Server Return-path: Received: from mx1.redhat.com ([209.132.183.28]:31575 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751109Ab0GFHqr (ORCPT ); Tue, 6 Jul 2010 03:46:47 -0400 In-Reply-To: <4C318CF6.9000601@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 07/05/2010 10:42 AM, Avi Kivity wrote: > Please don't top-post. > > On 07/03/2010 05:23 PM, BuraphaLinux Server wrote: >> Ok, I kept going like you said. Here is what it said: >> >> $git bisect good >> 44ea2b1758d88ad822e65b1c4c21ca6164494e27 is the first bad commit >> commit 44ea2b1758d88ad822e65b1c4c21ca6164494e27 >> Author: Avi Kivity >> Date: Sun Sep 6 15:55:37 2009 +0300 >> >> KVM: VMX: Move MSR_KERNEL_GS_BASE out of the vmx autoload msr area >> >> Currently MSR_KERNEL_GS_BASE is saved and restored as part of the >> guest/host msr reloading. Since we wish to lazy-restore all the >> other >> msrs, save and reload MSR_KERNEL_GS_BASE explicitly instead of >> using >> the common code. >> >> Signed-off-by: Avi Kivity > > That doesn't make any sense. This commit shouldn't affect anything in > user-kernel communications. > > Can you describe your environment? I'll try to reproduce it. > I was able to reproduce it, and the commit does make sense. The faulting instruction is 0x807182a mov %gs:0x14,%eax which is a stack guard fetch. It shouldn't ever fault - so it looks like %gs is corrupted, and indeed the commit plays with %gs. I'll investigate further. -- error compiling committee.c: too many arguments to function