From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: HVM domains crash after upgrade from XEN 4.5.1 to 4.5.2 Date: Mon, 16 Nov 2015 10:02:21 +0000 Message-ID: <5649A9AD.9060809@citrix.com> References: <5643E68C.8090406@web2web.at> <564499B002000078000B43EE@prv-mh.provo.novell.com> <56448D9B.4090007@citrix.com> <5644A248.1060505@web2web.at> <5644C1CD.3020202@citrix.com> <56451A2B.9090706@web2web.at> <56459E5F02000078000B4944@prv-mh.provo.novell.com> <5645B6BC.6030603@citrix.com> <56467D44.5040205@web2web.at> <56479A6B.6080102@citrix.com> <5647CE57.50209@web2web.at> <5648A0F2.9000302@citrix.com> <564925B7.4090801@web2web.at> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6060419785209556437==" Return-path: In-Reply-To: <564925B7.4090801@web2web.at> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Atom2 Cc: Jan Beulich , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org --===============6060419785209556437== Content-Type: multipart/alternative; boundary="------------080904030504040708060207" --------------080904030504040708060207 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit On 16/11/15 00:39, Atom2 wrote: > Am 15.11.15 um 16:12 schrieb Andrew Cooper: > [big snip] >> Great - so confirms the issue as a SeaBIOS interaction issue, rather >> than a hypervisor regression. >> >> As I said before, I am still certain that a guest should not be able >> to get itself into the crashing state (short of a hardware errata), >> so I still suspect that there is a latent hypervisor emulation bug >> which has been tickled by the SeaBIOS update. >> >> Would you please mind running the bad HVMLoader on Xen 4.5.2 with >> hvm_debug=0xc3f ? I am still hoping that that will shed some light on >> SeaBIOS actions just leading up to the crash. > Hi Andrew, > Please see the attached two files. One is the dmesg from booting the > system. This looks pretty normal in my view. The other is the output > of "xl dmesg" which is most likely what you were after. It's probably > worth noting that the "traps.c" output between lines 259 and 314 and > again between lines 346 and 353 seem to be xen-4.5.2 specific and > don't show up under xen-4.5.1, but that may not be of any relevance > for the SeaBIOS issue we are experiencing. Though I'd still be > interested to know whether that's anything for me to worry about ... Sorry, but you need to be using a debug build of Xen. The internals of hvm_debug are not compiled in a regular build. I am also only interested in `xl dmesg`. There will be lots of log lines prefixed with [HVM:$DOMID.$VCPUID]. >> >> Are you able to experiment with newer versions of Xen? It would be >> interesting to see whether the issue is still present in Xen 4.6 > Currently xen-4.6 is not stable in gentoo and I try to stick to stable > packages as much as possible. But in case the above does not help you > any further, I am happy to give this a try as well. Would this just be > a straightforward test to see whether it works at all or would you > require debug symbols as well? That's ok. It is unlikely that this issue has been fixed since, so I suspect that it is still present. ~Andrew --------------080904030504040708060207 Content-Type: text/html; charset="utf-8" Content-Length: 3063 Content-Transfer-Encoding: quoted-printable
On 16/11/15 00:39, Atom2 wrote:
Am 15.11.15 um 16:12 schrieb Andrew Cooper:
[big snip]
Great - so confirms the issue as a SeaBIOS interaction issue, rather than a hypervisor regression.

As I said before, I am still certain that a guest should not be able to get itself into the crashing state (short of a hardware errata), so I still suspect that there is a latent hypervisor emulation bug which has been tickled by the SeaBIOS update.

Would you please mind running the bad HVMLoader on Xen 4.5.2 with hvm_debug=3D0xc3f =3F I am still hoping that that will shed some light on SeaBIOS actions just leading up to the crash.
Hi Andrew,
Please see the attached two files. One is the dmesg from booting the system. This looks pretty normal in my view. The other is the output of "xl dmesg" which is most likely what you were after. It's probably worth noting that the "traps.c" output between lines 259 and 314 and again between lines 346 and 353 seem to be xen-4.5.2 specific and don't show up under xen-4.5.1, but that may not be of any relevance for the SeaBIOS issue we are experiencing. Though I'd still be interested to know whether that's anything for me to worry about ...

Sorry, but you need to be using a debug build of Xen.=C2=A0 The internals of hvm_debug are not compiled in a regular build.

I am also only interested in `xl dmesg`.=C2=A0 There will be lots of log lines prefixed with [HVM:$DOMID.$VCPUID].


Are you able to experiment with newer versions of Xen=3F=C2=A0 It would be interesting to see whether the issue is still present in Xen 4.6
Currently xen-4.6 is not stable in gentoo and I try to stick to stable packages as much as possible. But in case the above does not help you any further, I am happy to give this a try as well. Would this just be a straightforward test to see whether it works at all or would you require debug symbols as well=3F

That's ok.=C2=A0 It is unlikely that this issue has been fixed since, so I suspect that it is still present.

~Andrew --------------080904030504040708060207-- --===============6060419785209556437== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============6060419785209556437==--