It would also be interesting to know whether you could get networking
on qemu-sparc64 because recently I never managed to do that.
It seems the default machine is missing a network device, so no network by default, but that's easy to fix on the command-line: just add a network device.
I just installed the ISO image in qemu on a zvol using (here the nework device is of type 'pcnet'):
The bit in -net allows to do "ssh -p 10023 user@localhost" to connect to the VM once SSH is started. It's all bog-standard, slow, non-virtio devices, but it does the job.
Now I need to find a cd-r to burn, to try and install on my Ultra 1E if I can find the time. Probably won't be fast :-)