I made my first VM in unRAID 6 and everything is working well except one thing. Most of the time I will be using teamviewer via WAN connection and Windows RDP via local LAN connection, but I would like to pass through my GPU for sitting at the VM itself as well. I am wondering if my card is just not compatible with KVM. Maybe that is why I am getting this message? It is an older card but i did pass it through in ESX 5.5 before. I have attached the message I am getting. The card is an AMD Radeon HD 2400 PRO/XT.

 

That message means that the device is in an IOMMU group with another device that is either bound to an in use driver such as your storage, Ethernet, or USB controller, or, assigned to another active VM.  By default, IOMMU groups devices that share a common pcie root port that doesn't have ACS features.

 

This isn't a KVM or GPU compatibility issue.  If you want to, you can turn on PCIE ACS Override on the VM Manager settings, but you should see the notes in the wiki about this being experimental, and Alex Williamson's blog post on the subject which is also linked in the wiki.