Created attachment 121441 [details]
Emulex OneConnect 10Gb NIC config space

From Alex's mail:

> Per the SR-IOV spec rev 1.1:

> 3.4.1.9 Header Type (Offset 0Eh)

> "... For VFs, this register must be RO Zero."

> Unfortunately some devices get this wrong, ex. Emulex OneConnect 10Gb
> NIC.  When they do it makes us handle ACS testing and therefore IOMMU
> groups as if they were actual multifunction devices and require ACS
> capabilities to make sure there's no peer-to-peer between functions.
> VFs are never traditional multifunction devices.

Note the Header Type at 0x0e in the attached config space dump:

09:04.0 Ethernet controller: Emulex Corporation OneConnect 10Gb NIC (be3) (rev 01)
...
00: ff ff ff ff 04 00 10 00 01 00 00 02 00 00 80 00

Header Type == 0x80; bit 7 is set, which indicates a multi-function device.