qemu-system-ppc: no keyboard after savevm/loadvm

Here the steps to reproduce:

1. qemu-img create -f qcow2 test.qcow2 100M
2. qemu-system-ppc -m 1024 -hda test.qcow2
3. change to the console via Ctrl-Alt-2 and save a snapshot: "savevm test"
4. quit
5. start again and go to the console
6. load the snapshot via "loadvm test"
7. change back to the guest display (Ctrl-Alt-1)
8. try to type something => no keyboard
9. the same via console, e.g. "sendkey 1" has no effect

I tried the following branches from git:
master, stable-1.0, stable-0.15 
=> all behave the same