Kernel & KVM switch

[Marius Kirschner]

I remember there used to some setting that you had to set if you wanted to
use a KVM switch, but for the live of me I can't find what it was.
Basically, with both my 4.9 and 5.1 boxes if I reboot any of them and they
are not selected on the switch then the keyboard won't work.  Since I do
most of the work via ssh it's not a big deal, but still, can somebody please
point me in the right direction?  Thanks,

---Marius