I tried this config:
args: -device vfio-pci,host=00:02.0,addr=0x02,x-vga=on,x-igd-opregion=on
agent: 1
bootdisk: scsi0
cores: 4
#hostpci0: 00:02.0,x-vga=1,romfile=undefined,rombar=0
ide2: QNAP:iso/linuxmint-19-cinnamon-64bit-v2.iso,media=cdrom
machine: pc-i440fx-2.2
memory: 2048
name: MintVM...