[porker]

Though from the research I did, unless you're running a Type 1 hypervisor vt-d is not necessary (or usable). Type 2 hypervisors will use vt-x only.

[wtallis]

What are your sources for that? VirtualBox seems to fall under "type 2", but supports PCI passthrough using VT-d on linux hosts.

[porker]

About 10 hours of crawling through forums, VMWare documentation and a couple of conversations with people about ESXi. So all of it pretty unreliable ;)

I'd love to see sources/evidence to the contrary.

[venomsnake]

IOMMU is needed for VGA and PCI passtrough in general.

[comex]

VT-d is still useful without any hypervisor, to guard against DMA attacks by malicious connected devices.