[CentOS] CentOS 7.4 fails to boot as Xen PV guest: resurfaces (now also) with centosplus kernel 693.11.6.el7

Mon Jan 8 12:46:31 UTC 2018
Johnny Hughes <johnny at centos.org>

On 01/08/2018 12:38 AM, Akemi Yagi wrote:
> On Sun, Jan 7, 2018 at 12:07 PM, David Groep <davidg at nikhef.nl> wrote:
>> Dear all,
>> Maybe I'm the only one - so before filing it as a bug: it appears that
>> the latest set of kernel patches in 3.10.0-693.11.6.el7 makes issue
>> 0013763 "CentOS 7.4 kernel (3.10.0-693*) fails to boot as Xen PV guest"
>> re-surface *also* with the CentOS PLUS kernel. But maybe in a
>> different way ...
>> Thanks to the (great!) quick work on making the plus kernel available
>> (in #14330, thanks for that!) I was able to test the following
>> combinations:
>> - 3.10.0-693.11.6.el7.centos.plus works fine on XenServer 7 HVM guests
>> - 3.10.0-693.11.1.el7.centos.plus works fine on XenServer 7 XenPV guests
>> - 3.10.0-693.11.6.el7.centos.plus crashes on boot for XS7 XenPV guests
>>   immediately after the boot stage where the PS/2 drivers are loaded
>> Crashing does not depend on the amount of VM memory or #cores/sockets.
>> Also, the tell-tale "mm/vmalloc.c" failure output is no longer present.
>> The system 'just' crashes (with the kernel log lines as below) around the
>> time of the i8042 controller probing.
>> Obviously the stock upstream 3.10.0-693.11.6.el7 crashes as well for
>> XS7 XenPV guests, but that was to be expected as per 0013763.
>> It crashes in the same way, around the time of the i8042 probes.
>> Can anyone (maybe bill_mcgonigle?) reproduce the issue?
>> Did the KPTI patches break the XenPV fixes in CentOS Plus per 13763?
>> Or is this a new XenPV issue?
> ​You may want to be watching the centos-virt mailing list. Xen-related
> issues are discussed there.
> This thread:
>> https://lists.centos.org/pipermail/centos-virt/2018-January/005716.html
> ​has a response from Johnny Hughes with a possible solution.

And specifically, this message has links to the 4.9.75 x86_64 kernel
that will boot and run as a Xen PV kernel:


Also, the latest Xen Dom0 kernel 4.9.75 kernel will also boot a DomU Xen
PV.  That kernel is still in testing, and also requires the latest
linux-firmware rpms:




(And your xen version ... xen-44/, xen-46/, xen-48/)

Those kernels should be signed released to the main Xen repo sometime
this week.

And as someone has mentioned in another thread (Phil Perry), please read
Greg K-H's (the Kernel.org LTS maintainer, he is in charge of the 4.9.x
LTS tree that we use for the above kernels):


Johnny Hughes

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