Re: [v3] PCI: Add an option to control probing of VFs before enabling SR-IOV

[Bodong Wang]

On 4/14/2017 10:37 AM, Bjorn Helgaas wrote:
> On Thu, Apr 13, 2017 at 01:51:40AM +0300, bodong@xxxxxxxxxxxx wrote:
> > From: Bodong Wang <bodong@xxxxxxxxxxxx>
> >
> > Sometimes it is not desirable to probe the virtual functions after
> > SRIOV is enabled. This can save host side resource usage by VF
> > instances which would be eventually probed to VMs.
> >
> > Add a new PCI sysfs interface "sriov_drivers_autoprobe" to control
> > that from the PF, all current callers still retain the same
> > functionality. To modify it, echo 0/n/N (disable probe) or 1/y/Y
> > (enable probe) to:
> >
> > /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_drivers_autoprobe
> >
> > Note that, the choice must be made before enabling VFs. The change
> > will not take effect if VFs are already enabled. Simply, one can set
> > sriov_numvfs to 0, choose whether to probe or not, and then resume
> > sriov_numvfs.
> >
> > Signed-off-by: Bodong Wang <bodong@xxxxxxxxxxxx>
> > Signed-off-by: Eli Cohen <eli@xxxxxxxxxxxx>
> > Reviewed-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> > Reviewed-by: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> Applied to pci/virtualization for v4.12, thanks, Bodong!
Thank you! Bjorn/Alex/Gavin.