It looks like my IPMI implementation always emulates a USB keyboard on the virtual console. The real keyboards are PS/2 and I can't change that because it runs on a wire physically passing a /real/ firewall, e. g. a constructive element of the building designed to confine a possible fire in the server room. It's close to prohibitively expensive to install another (USB) cable through that and I didn't think about it when I orderd power, VGA and PS/2 cables to be routed through the firewall.
Can I have ddb input multiplexed from both PS/2 and USB?