thx for your help, dcsapak.
gpu passthrough on windows 7 is running on proxmox-ve: 5.3-1, qemu-server: 5.0-43 and
-device vfio-pci,host=1a:00.0,multifunction=on,x-vga=on,bus=pcie.0,addr=0x10.0 -device vfio-pci,host=1a:00.1,bus=pcie.0,addr=0x10.1
is there a bug id for
?