From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: xenstored crashes with SIGSEGV Date: Thu, 18 Dec 2014 10:51:43 +0000 Message-ID: <1418899903.11882.19.camel@citrix.com> References: <546461A2.2070908@univention.de> <1415869951.31613.26.camel@citrix.com> <548B1472.5080302@univention.de> <1418401932.16425.34.camel@citrix.com> <548B1BA8.3090504@univention.de> <1418403387.16425.38.camel@citrix.com> <548B23FA.6070108@univention.de> <1418407116.16425.53.camel@citrix.com> <1418649458.16425.108.camel@citrix.com> <548EEDF5.20808@univention.de> <1418655014.16425.138.camel@citrix.com> <1418665524.16425.171.camel@citrix.com> <548F60BF.4020901@univention.de> <1418726712.16425.213.camel@citrix.com> <1418727970.16425.217.camel@citrix.com> <1418732635.16425.221.camel@citrix.com> <1418897867.11882.11.camel@citrix.com> <5492BF510200007800050889@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5492BF510200007800050889@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: George Dunlap , Philipp Hahn , Ian Jackson , Xen-devel@lists.xen.org, DavidVrabel , Frediano Ziglio List-Id: xen-devel@lists.xenproject.org On Thu, 2014-12-18 at 10:49 +0000, Jan Beulich wrote: > >>> On 18.12.14 at 11:17, wrote: > > On Tue, 2014-12-16 at 16:13 +0000, Frediano Ziglio wrote: > >> Do we have a bug in Xen that affect SSE instructions (possibly already > >> fixed after Philipp version) ? > > > > I've had a niggling feeling of Deja Vu over this which I'd been putting > > down to an old Xen on ARM bug in the area of FPU register switching. > > > > But it seems at some point (possibly even still) there was a similar > > issue with pvops kernels on x86, see: > > http://bugs.xenproject.org/xen/bug/40 > > > > Philipp, what kernel are you guys using? > > > > CCing Jan and the x86 kernel guys (and George since he registered the > > bug). I'm not seeing anything in the kernel logs which looks like a fix > > (there's some PVH related cr0 frobbing, but I don't think that's it). > > I just went through the thread again and didn't find where kernel/ > hypervisor logs were posted. I don't think they were yet -- until recently it seemed like a xenstored bug. Philipp, can you post them now? Also the patch linked to by David seems like a good thing to try if you are indeed running a kernel which is susceptible to this issue. > You mentioning PVH made me want to take a look - said FPU related bug > would be exposed only by PV kernels. It's (almost certainly) not a PVH issue, I was saying that the patch which touched PVH probably isn't relevant to this particular issue. Ian.