On Thu, Jan 9, 2014 at 11:25 AM, Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > On Thu, 2014-01-09 at 11:08 -0700, Bjorn Helgaas wrote: >> On Thu, Jan 9, 2014 at 8:36 AM, Alex Williamson >> <alex.williamson@xxxxxxxxxx> wrote: >> > 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, so simply clear this >> > bit before we get any further into setup. >> >> This seems reasonable. Do you have "lspci -vvxxxx" output for this >> device? I'd like to save it for future reference. > > Sure, here's a VF: > > 09:04.0 Ethernet controller: Emulex Corporation OneConnect 10Gb NIC (be3) (rev 01) > Subsystem: Emulex Corporation Device e722 Thanks! I put this in https://bugzilla.kernel.org/show_bug.cgi?id=68431, and I'll add a reference to the changelog. But I wonder if we can make this slightly more generic by doing something like this in pci_setup_device(): dev->multifunction = (PCI_FUNC(dev->devfn) == 0) && (hdr_type & 0x80); That's basically what lspci does in pci_generic_scan_bus(), and section 3.2.2.3.4 of the PCI 3.0 spec sort of implies that we should only look at the bit 7 of the header type for function 0: If a single function device is detected (i.e., bit 7 in the Header Type register of function 0 is 0), no more functions for that Device Number will be checked. If a multi-function device is detected (i.e., bit 7 in the Header Type register of function 0 is 1), then all remaining Function Numbers will be checked. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
