SirPumpkin

While this seems to work fairly well, only caveat is that usually vm hangs at boot when starting 2nd or especially 3rd or 4th time. After full unraid reboot it always works..

Ok I tried with another PCI-E card (network card), Linux VM and xen-pciback.hide= method. Same problem. When I start the VM the rounded arrows go round some time before VM actually starts, and the passthrough device isn't there Edit. Whoa, I tried to passthrough internal USB3 gen1 controllers which are managed by CPU and it actually worked! (Mb: Gigabyte Aorus M and CPU 2200G). Yippee!

I am having similar problem. I am trying to attach PCI USB3 Controller (Transcend PDU3) to Windows VM. I enabled ACS Override multifunction to get it to its own IOMMU group. Which one would be better to use btw multifunction or downstream,multifunction (both) ? I also added the vfio-pci.ids= to the unraid configuration and the USB controller appears correctly in PCI Devices in VM settings. The problem is the VM startup is slooow and VM doesn't recognize it after it finally is up. Is this incompatible card with unraid or is it something else ? This can't have multiple controller onboard because it is just 2 port card, right?!