Hey, > I have a big problem (still the same) with my Win10 guest. > Linux use is own Nvidia graphic card (Gtx960) and the Guest a Nvidia Gtx970. > I use Debian Jessie with Qemu 2.5, libvirt 1.0.1 and virt-manager 1.4.0 What CPU and motherboard? Could you list the IOMMU-groups your host and gues GPU are in? Cheers!