Re: [PATCH v3] target/s390x/kvm: Enable adapter interruption suppression again

[Matthew Rosato]

On 1/20/20 8:24 AM, Thomas Huth wrote:
> The AIS feature has been disabled late in the v2.10 development cycle since
> there were some issues with migration (see commit 3f2d07b3b01ea61126b -
> "s390x/ais: for 2.10 stable: disable ais facility"). We originally wanted
> to enable it again for newer machine types, but apparently we forgot to do
> this so far. Let's do it for the new s390-ccw-virtio-5.0 machine now.
>
> While at it, also add a more verbose comment why we need the *_allowed()
> wrappers in s390-virtio-ccw.c.
>
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946
> Reviewed-by: David Hildenbrand <address@hidden>
> Signed-off-by: Thomas Huth <address@hidden>
> ---

Took it for a spin with vfio-pci.  With this patch applied, I see the 
appropriate change reflected in guest /proc/cpuinfo.  I did some tracing 
and see the expected behavior changes (ex: hits in host 
kvm_s390_injrect_airq that show suppression occurring).  Data transfer 
tests worked fine.  Also sanity-tested that ais=off behaves as expected.

Looks good to me.