George myglc2 Clemmer <myglc2@gmail.com> writes:

> It appears that there are 3 ways to reach a QEMU VM desktop on headless
> GuixSD servers: X11, spice, and maybe VNC. Is that right?
>
> Can anyone comment on which has the best performance.

Spice was designed to be a better protocol than VNC for accessing
virtual machine consoles.  I haven't done any benchmarks though.

It requires a rather involved QEMU command line[0]:

 [qemu] -spice addr=127.0.0.1,port=3001,disable-ticketing -soundhw hda \
        -device virtio-serial -chardev spicevmc,id=vdagent,debug=0,name=vdagent \
        -device virtserialport,chardev=vdagent,name=com.redhat.spice.0 \

Then you can use virt-viewer or "spicy" from spice-gtk along with SSH
forwarding to access 127.0.0.1:3001 on the remote machine.  Setting up
encryption or authentication requires a few more arguments if you want
to expose this on a network-facing interface directly.

[0] https://www.spice-space.org/spice-user-manual.html