PS/2 keyboard emulation in QEMU vs. SCO 5 guest

[Frantisek Rysanek]

Dear fellow tinkerers,

as an academic exercise (will need to tackle licensing if this turns 
out technically feasible) I'm teasing an image of SCO OpenServer 
5.0.6 in a QEMU+KVM VM (QEMU 5.2 on Debian 11).

The disk image is effectively a backup copy of an old SCO-based PC 
box that is starting to have HW issues, and the existing software 
cannot be reinstalled and it would make sense to move the software = 
OS + apps "en bloc" into a VM.

On ancient bare metal, the disk boots just fine, I can log in and 
everything works.

When I connect that same disk to a QEMU VM, OpenServer does detect 
the emulated IDE disk controller, does detect the system disk and 
rattles its heads a little, and then the VGA console asks for booting 
into the single-user runlevel (requiring a root password), or a 
CTRL+D to continue booting normally.

The trouble is, that in the VM, at this point the keyboard no longer 
responds. The NumLock LED on the keyboard is responsive, probably 
owing to the host OS (Debian) that keeps living. But, I cannot enter 
a root password or try a CTRL+D.

In the initial "laundry list of hardware detected", the OpenServer 
does report a PS/2 keyboard controller at ISA at a standard address.
But, when the request for CTRL+D appears, the OpenServer in a VM no 
longer responds to my keyboard.

I'm a fan of QEMU - owing to its large set of configurable options.
Interestingly to me, I haven't found a single option related to the 
PS/2 KB controller hardware... probablly because there's nothing to 
tweak about it. Any suggestions what else could help?

Frank