Anyway. Here's my status.

- I make a new VM in virt-manager. You're not allowed to give it a file. You're supposed to give it A DIRECTORY CONTAINING A FILE, and this creates a "pool", and then you select the file from the "pool". Whatever.

However, then you *MUST* select an "OS".

Redox actually does distribute a qemu-system-x86_64 invocation that bypasses virt-manager and launches Redox directly:

https://doc.redox-os.org/book/running-vm.html#:~:text=sdl_video_x11_dgamouse%3D0%20qemu-system-x86_64%20-d%20cpu_reset

It doesn't select an OS.

I guess I select "generic (not recommended)".