Thanks for the suggestion, however if I try to separate out the function then I get a code 10 error and device cannot start. Ultimately, I'm wondering why Windows is grouping the gpu hdmi audio bus and controller as an external Acer "graphics dock" when no such thing exists in the system. <div class="gmail_quote">On Apr 23, 2016 6:54 PM, "Karsten Mettke" <<a href="mailto:k.mettke@d4net.de">k.mettke@d4net.de</a>> wrote: <blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Maybe i should clarify. I meant passing them seperate into own Slots in the guest. This way you can ommit multifunction=on. Which Made it working for me. <div class="quoted-text"> Gesendet von meinem BlackBerry 10-Smartphone. Originalnachricht Von: Muted Bytes Gesendet: Sonntag, 24. April 2016 04:47 An: vfio-users Betreff: [vfio-users] GPU HDMI audio passthrough weird behavior? </div><div class="elided-text">Hi all, Has anyone experienced weird behavior when assigning HDMI function of GPU along with the GPU itself in Windows guest? In my case, I have: 02:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Pitcairn XT [Radeon HD 7870 GHz Edition] [1002:6818] 02:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Cape Verde/Pitcairn HDMI Audio [Radeon HD 7700/7800 Series] [1002:aab0] and pass these through using -device vfio-pci,host=02:00.0,addr=00.0,multifunction=on \ -device vfio-pci,host=02:00.1,addr=00.1 \ however, in the guest the 1002:aab0 HDMI Audio shows up under system devices as a "High Definition Audio Bus" rather than an HDMI device/controller, and what shows up as the "AMD High Definition Audio Device" itself is something which is 1002:aa01. Where does this 1002:aa01 come from? Is this correct that 1002:aab0 device at 02:00.1 is the "bus"? As a result of this behavior, a completely different device as "Acer DynaVivid Graphics Dock" is showing up on my system as a result of the "High Definition Audio Bus" after installing AMD drivers. None of my devices are Acer, and certainly nothing should be a graphics dock? Regards, MB </div><div class="elided-text">_______________________________________________ vfio-users mailing list <a href="mailto:vfio-users@redhat.com">vfio-users@redhat.com</a> <a href="https://www.redhat.com/mailman/listinfo/vfio-users" rel="noreferrer" target="_blank">https://www.redhat.com/mailman/listinfo/vfio-users</a> </div></blockquote></div>