IOMMU group grayed out in system devices.

[Sam F]

I am having issues passing through 2 GPUs to a VM after swapping mobo and CPU. What does it mean when the IOMMU group is grayed out in system devices?

[itimpi]

If you are talking about group 14 in the screenshot then that is probably because that group cannot be passed through to a VM.   For pass-through to work you have to pass through every device in the group and that will not be viable for that group. 

[Sam F]

2 minutes ago, itimpi said:

If you are talking about group 14 in the screenshot then that is probably because that group cannot be passed through to a VM.   For pass-through to work you have to pass through every device in the group and that will not be viable for that group. 

Thank you for your reply!

Is there any way to resolve this issue?

[JonathanM]

For some motherboards, the various ACS override functions can help break up groups, but that's not a guaranteed solution. Moving physical cards to other slots may also be needed, and in some cases the motherboard is simply incapable of separating them, meaning a different motherboard would be required.

 

First try the various combinations of ACS overrides and see if you get any better results.