On 4 Jan 2018, at 17:57, Andy Smith <andy(a)bitfolk.com> wrote:
I haven't had chance to personally check this out
but apparently the
latest CentOS 7 kernel package doesn't boot under Xen PV:
https://bugs.centos.org/view.php?id=13763
This may be highly relevant to you because an update was just pushed
out for the KPTI feature (to help mitigate Spectre/Meltdown etc in
Linux).
As mentioned in that bug report, there are patches to fix this but
they haven't yet been applied to the main CentOS kernel package.
In the mean time you can use the kernel package from the CentOSPlus
repository which does have this fix and the KPTI one.
https://wiki.centos.org/AdditionalResources/Repositories/CentOSPlus
All of this was researched by a customer having the problem today
and it resolved it for them.
This was fine until CentOS updated the CentOSPlus kernel overnight. Now the updated one
fails to boot in exactly the same way as the standard CentOS kernel. This must be some
change they have made to mitigate the CPU vulnerabilities.
I think we’ll have to stay on the standard kernel version 3.10.0-693.11.1 until more
information is available.
Cheers,
Mike