PCI/IOV: Add pci-pf-stub driver for PFs that only enable VFs

Some SR-IOV PF devices provide no functionality other than acting as a
means of enabling VFs.  For these devices, we want to enable the VFs and
assign them to guest virtual machines, but there's no need to have a driver
for the PF itself.

Add a new pci-pf-stub driver to claim those PF devices and provide the
generic VF enable functionality.  An administrator can use the sysfs
"sriov_numvfs" file to enable VFs, then assign them to guests.

For now I only have one example ID provided by Amazon in terms of devices
that require this functionality.  The general idea is that in the future we
will see other devices added as vendors come up with devices where the PF
is more or less just a lightweight shim used to allocate VFs.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index cc608fc55334..411c12287dda 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -2552,6 +2552,8 @@
 #define PCI_VENDOR_ID_CIRCUITCO		0x1cc8
 #define PCI_SUBSYSTEM_ID_CIRCUITCO_MINNOWBOARD	0x0001
 
+#define PCI_VENDOR_ID_AMAZON		0x1d0f
+
 #define PCI_VENDOR_ID_TEKRAM		0x1de1
 #define PCI_DEVICE_ID_TEKRAM_DC290	0xdc29