I'm new to QEMU/KVM. I've created a new VM with the GUI (Virtual Machine Manager) and installed in it Kubuntu 14.04 (my host is Kubuntu 17.04). The quality of the display of the guest is very poor. Moreover, I can't switch to full screen, and the option "auto resize VM with window" is grayed out. The video model is QXL. What should I do to fix that?