I attempted to create a VM with GPU passthrough after enabling sys-gui VM. I set the VM’s guivm with qvm-prefs. The VM would then start but no windows would show. After deleting sys-gui and removing the VM’s guivm, it still will not show any windows. I could just create a new VM, but I need access to the data in the home folder and I’m not sure how to copy it out of there.
I think you need to logout and then select sys-gui instead of an Xfce session when logging in at the top right. It is also relatively easy to copy data from within a VM. You can right-click and select “Move to VM” or “Copy to VM” or you can run “qvm-move /path/to/folder” on the command line.