Yeah it is assumed that a Malta should always have a GIC and no one got around to fix this in qemu yet.
I can only improve on the patch to do
if (!ipidomain && nr_cpu_ids == 1)
Which is more generic way to do it. I think a WARN_ON () would still be useful as SMP without ipis will not work really.
I can send a proper patch if Ralf is OK with that.
I got the console output from qemu by the way. I didn't use your script though.