Torification of host traffic using Non-Qubes-Whonix is unsupported.
We have something related that may help to develop this.
For Whonix VirtualBox we have instructions on how to ssh into Whonix-Workstation from the host through Whonix-Gateway, i.e. host -> Whonix-Gateway -> Whonix-Workstation.
I don’t think we have this documented for Whonix KVM.
As per Free Support Principle, I suggest to create a non-Whonix, plain Debian KVM VM first. Then figure out how to connect from the host to a port inside that Debian VM. Then have second plain Debian (non-Whonix) VM connected through an isolated network (similar to the Whonix configuration) to the first Debian VM. Once that all was figured out, you may be capable to add Whonix into the mix. Adding Whonix into the mix from start would make all of this a lot more difficult since you would have multiple sources of issues (not just figuring out how to do this in the first place but also how to do this while not having Whonix stream isolation and Whonix firewall getting into the way).