ixgbe: fix vf lookup

commit a4b08329 upstream.

Recent addition of code to find already allocated VFs failed to take
account that systems with 2 or more multi-port SR-IOV capable controllers
might have already enabled VFs.  Make sure that the VFs the function is
finding are actually subordinate to the particular instance of the adapter
that is looking for them and not subordinate to some device that has
previously enabled SR-IOV.

This bug exists in 3.2 stable as well as 3.3 release candidates.
Reported-by: David Ahern <daahern@cisco.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Robert E Garrett <robertX.e.garrett@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c

@@ -67,7 +67,8 @@ static int ixgbe_find_enabled_vfs(struct ixgbe_adapter *adapter)
 	vf_devfn = pdev->devfn + 0x80;
 	pvfdev = pci_get_device(IXGBE_INTEL_VENDOR_ID, device_id, NULL);
 	while (pvfdev) {
-		if (pvfdev->devfn == vf_devfn)
+		if (pvfdev->devfn == vf_devfn &&
+		    (pvfdev->bus->number >= pdev->bus->number))
 			vfs_found++;
 		vf_devfn += 2;
 		pvfdev = pci_get_device(IXGBE_INTEL_VENDOR_ID,