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

[Bodong Wang <bodong@mellanox.com>]

On 4/14/2017 10:37 AM, Bjorn Helgaas wrote:
> On Thu, Apr 13, 2017 at 01:51:40AM +0300, bodong@mellanox.com wrote:
>> From: Bodong Wang <bodong@mellanox.com>
>>
>> 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@mellanox.com>
>> Signed-off-by: Eli Cohen <eli@mellanox.com>
>> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
>> Reviewed-by: Bjorn Helgaas <helgaas@kernel.org>
> Applied to pci/virtualization for v4.12, thanks, Bodong!
Thank you! Bjorn/Alex/Gavin.