Hi Kaizer,
I agree to ww2m1911a1. I don’t use the virt-manager play, I pass through my Graphics Card (Sapphire RX 560) to the VM and also a second mouse and keyboard as sugessted in the HowTo from ycnrg.org https://forum.level1techs.com/clicks/track?url=https%3A%2F%2Fycnrg.org%2Fvga-passthrough-with-ovmf-vfio%2F&post_id=2134254&topic_id=120055
I will buy a KVM Switch (Keyboard Video Mouse…) soon to switch my input peripherals in a simple way.
If you have some Performance Issues try my findings about IO (virtual) Devices that I posted here: Ubuntu 17.04 -- VFIO PCIe Passthrough & Kernel Update (4.14-rc1) - #14 by Marf at the end of my reply.