[v1,0/2] s390x: support virtio-mem-pci

Message

David Hildenbrand Jan. 27, 2025, 2:28 p.m. UTC

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/[e-mail]

Cc: Eduardo Habkost <[e-mail]>
Cc: Marcel Apfelbaum <[e-mail]>
Cc: Richard Henderson <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: Ilya Leoshkevich <[e-mail]>
Cc: Halil Pasic <[e-mail]>
Cc: Christian Borntraeger <[e-mail]>
Cc: Eric Farman <[e-mail]>
Cc: Thomas Huth <[e-mail]>
Cc: "Michael S. Tsirkin" <[e-mail]>
Cc: Cornelia Huck <[e-mail]>
Cc: Boris Fiuczynski <[e-mail]>
Cc: Michal Privoznik <[e-mail]>

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          |  3 +++
 hw/s390x/s390-virtio-ccw.c | 20 ++++++++++++++------
 hw/virtio/virtio-mem-pci.c | 12 ++++++++++++
 3 files changed, 29 insertions(+), 6 deletions(-)