ACK[B/C] / NACK[D]: [SRU][Disco][Cosmic][Bionic][Patch 0/1] Fixes for 1818854

[Seth Forshee]

On Mon, Mar 25, 2019 at 04:36:49PM +0100, frank.heimes at canonical.com wrote:
> Buglink: https://bugs.launchpad.net/bugs/1818854
> 
> SRU Justification:
> 
> [Impact]
> 
> * The vfio-ap driver will create a matrix device in sysfs without a subsystem link.
> 
> * This causes failures in libudev that might also lead to libvirt errors.
> 
> * A fix is upstream in master branch for kernel 5.1
> 
> [Fix]
> 
> * 36360658eb5a6cf04bb9f2704d1e4ce54037ec99 3636065 "s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem"
> 
> [Test Case]
> 
> * An s390x machine with at least one CryptoExpress card,
>   where at least one AP and one 'Domain' is assigned to a particular LPAR.
> 
> * Now running virsh nodedev-list before (and later after) construction the matrix device should expose the issue.
> 
> * For details about how to setup a vfio-ap matrix device see: http://kvmonz.blogspot.com/2018/12/qemu-v31-released.html
>   (see 2nd bullet: virtio-ap)
> 
> [Regression Potential] 
> 
> * The regression potential can be considered as low since it only affects the s390x platform
> 
> * and there it only affects the usage of AP (CryptoExpress) cards and it's driver/module
> 
> * and again only affects the recently introduced virtual IO function of AP (vfio-ap).
> 
> [Other Info]
> 
> * It was already briefly discussed here:
>   https://www.redhat.com/archives/libvir-list/2019-February/msg00837.html
>   as well as reviewed and pushed.
> 
> * Commit 3636065 from v5.1-rc1
> 
> * This affects ccw cards and their vf only, NOT vf of PCI/PCIe cards!
> 
> * * For details on virtio-ap/vfio-ap see bullet #2 here: http://kvmonz.blogspot.com/2018/12/qemu-v31-released.html

This patch is in upstream stable updates, so therefore it also meets the
SRU criteria for Ubuntu. For B/C:

Acked-by: Seth Forshee <seth.forshee at canonical.com>

Disco already got this from upstream stable, so not needed there.