Hi,
Also I'd suggest to add a sysbus -> s390-virtio bus bridge device, so your bus gets properly hooked up in the device tree. Have a look at the (quite simple) "isabus-bridge" device in isa-bus.c, which is used with 'qemu -M isapc'. You'll see the s390-virtio bus and all virtio devices attached to it in 'info qtree' then.Uh, ok :o. Is that really important?
Quite a few things depend on it. I think creating disks via '-device virtio-blk-s390' will not work without that ...
cheers, Gerd