On 11/07/18 11:15, Woodhouse, David wrote:

On Wed, 2018-05-30 at 13:09 +0200, Juergen Gross wrote:

...

There is no need to set the same capabilities for each cpu individually. This can easily be done for all cpus when starting the kernel.

Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set cpu capabilities from xen_start_kernel()")

Signed-off-by: Juergen Gross jgross@suse.com Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com

That breaks PV guests because they get KAISER enabled — when kaiser_check_boottime_disable() runs, X86_FEATURE_XENPV isn't set.

Which kernel version are you talking about?

With upstream commit 60d3450167433f2d099ce2869dc52dd9e7dc9b29 which will be part of next stable-4.9 everything is fine.

Juergen