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

[David Hildenbrand <david@redhat.com>]

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

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