Re: [PATCH v2 0/2] s390x: support virtio-mem-pci

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jan 28, 2025 at 07:57:03PM +0100, David Hildenbrand wrote:
> This is based-on [1], which adds MSI-X support to virtio-balloon-pci,
> but can be applied independently.
> 
> Turns out it is fairly easy to get virtio-mem-pci running on s390x. We
> only have to add MSI-X support to virtio-mem-pci, and wire-up the
> (un)plugging in the machine.
> 
> Tried some simple stuff (hotplug/hotunplug/resize/reboot), and all seems
> to be working as expected.
> 
> The kernel in the VM needs both, CONFIG_VIRTIO_PCI and CONFIG_VIRTIO_MEM
> for it to work.
> 
> [1] https://lkml.kernel.org/r/20250115161425.246348-1-arbab@linux.ibm.com


Fails CI:

https://gitlab.com/mstredhat/qemu/-/jobs/9202574981


> v1 -> v2:
> * There are no transitional/non_transitional devices for virtio-mem
> * Spell out removal of "return;" in second patch
> 
> Cc: Eduardo Habkost <eduardo@habkost.net>
> Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Ilya Leoshkevich <iii@linux.ibm.com>
> Cc: Halil Pasic <pasic@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> Cc: Eric Farman <farman@linux.ibm.com>
> Cc: Thomas Huth <thuth@redhat.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Cornelia Huck <cohuck@redhat.com>
> Cc: Boris Fiuczynski <fiuczy@linux.ibm.com>
> Cc: Michal Privoznik <mprivozn@redhat.com>
> Cc: Mario Casquero <mcasquer@redhat.com>
> 
> David Hildenbrand (2):
>   virtio-mem-pci: Allow setting nvectors, so we can use MSI-X
>   s390x/s390-virtio-ccw: Support plugging PCI-based virtio memory
>     devices
> 
>  hw/core/machine.c          |  1 +
>  hw/s390x/s390-virtio-ccw.c | 20 ++++++++++++++------
>  hw/virtio/virtio-mem-pci.c | 12 ++++++++++++
>  3 files changed, 27 insertions(+), 6 deletions(-)
> 
> -- 
> 2.48.1