RE: [PATCH] pci/sriov: Add an option to probe VFs or not before enabling SR-IOV

From: Eli Cohen
Date: Tue Mar 21 2017 - 10:35:03 EST


> If we want to talk about the ABI, I would suggest drawing from existing ABIs. We already have
> drivers_autoprobe as part of the standard sysfs ABI, so if we want a binary switch, then
>sriov_drivers_autoprobe might be a logical choice. If you're concerned about this mythical overhead of > binding to one driver then another, then why not draw from the driver_override interface to allow the
> user to specify the driver to bind to, perhaps sriov_driver_override. Then if the user wants to bind all
> the devices to vfio-pci, they can do so easily. I still fail to see that probing some fixed number of the VFs
> and leaving the rest unprobed has any practical value and I imagine bugs coming in because users are
> confused why some of their VFs behave differently than others. Thanks,

I agree with Alex - the interface should better be binary - either probe VFs or not. The rest can be done with binding/unbinding VFs as necessary. The main goal is to refrain from automatically initializing virtual functions at the hypervisor if they were initially instantiated to assign then to guests.