Re: SR-IOV function passthrough to a PV domU

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, Jun 15, 2010 at 03:15:35PM -0600, Chris Reeves wrote:
> I'm trying to pass through an SR-IOV virtual function to a PV domU.
> The pci passthrough seems to work, but the virtual function never shows
> up on the pci bus of the domU.  All I see is a message stating:
> [  342.002602] pcifront pci-0: Rescanning PCI Frontend Bus 0000:00
> 
> I'm using kernel 2.6.31.12-0.1-xen from OpenSUSE on the dom0 and domU
> and Xen 4.0.  I've recompiled with the CONFIG_XEN_PCIDEV_FE_DEBUG option
> set, but I don't get any additional output when attaching the device.
> 
> Is it possible to use pci passthrough with SR-IOV virtual functions to a
> PV domU?

Yes. But your Dom0 kernel MUST be the updated PV-OPS version. You need
to get the latest pv-ops kernel. Details at:
http://wiki.xensource.com/xenwiki/XenParavirtOps

> 
> I noticed in this thread:
> http://lists.xensource.com/archives/html/xen-devel/2010-03/msg00082.html
> That someone mentioned a specific SR-IOV pcifront driver.
> Does anyone know where this driver may be available?

In the PV-OPS tree.
> 
> For what it's worth, I've also tried kernel 2.6.34 with the xen patches
> from http://code.google.com/p/gentoo-xen-kernel/downloads/list and I get
> the same results.

Yeah, no surprise. They don't have the fixes for Xen PCIBack working
with SR-IOV hardware.