> -----Original Message-----
> From: Jakub Kicinski <k...@kernel.org>
> Sent: Wednesday, July 15, 2020 02:24
> To: Wang, Haiyue <haiyue.w...@intel.com>
> Cc: Nguyen, Anthony L <anthony.l.ngu...@intel.com>; da...@davemloft.net;
> netdev@vger.kernel.org;
> nhor...@redhat.com; sassm...@redhat.com; Kirsher, Jeffrey T
> <jeffrey.t.kirs...@intel.com>; Lu, Nannan
> <nannan...@intel.com>; Bowers, AndrewX <andrewx.bow...@intel.com>
> Subject: Re: [net-next 1/5] ice: add the virtchnl handler for AdminQ command
>
> On Tue, 14 Jul 2020 01:29:40 +0000 Wang, Haiyue wrote:
> > > On Mon, 13 Jul 2020 10:43:16 -0700 Tony Nguyen wrote:
> > > > From: Haiyue Wang <haiyue.w...@intel.com>
> > > >
> > > > The DCF (Device Config Function) is a named trust VF (always with ID 0,
> > > > single entity per PF port) that can act as a sole controlling entity to
> > > > exercise advance functionality such as adding switch rules for the rest
> > > > of VFs.
> > >
> > > But why? This looks like a bifurcated driver to me.
> >
> > Yes, like bifurcated about flow control. This expands Intel AVF virtual
> > channel
> > commands, so that VF can talk to hardware indirectly, which is under
> > control of
> > PF. Then VF can set up the flow control for other VFs. This enrich current
> > PF's
> > Flow Director filter for PF itself only by ethtool.
>
> Could you say a little more about the application and motivation for
> this?
>
Sure, I will try to describe the whole story.
> We are talking about a single control domain here, correct?
Correct.
As you know, with the help of vfio-pci kernel module, we can write the user
space
driver for PCI devices, like DPDK. ;-)
We have
1). user space iavf framework:
http://git.dpdk.org/dpdk/tree/drivers/common/iavf
2). user space iavf driver:
http://git.dpdk.org/dpdk/tree/drivers/net/iavf
3). user space ice driver with no SR-IOV support:
http://git.dpdk.org/dpdk/tree/drivers/net/ice
Nowadays, the concept of control path and data path separation is popular, we
tried
to design a software defined control path by the above software portfolio, and
the
scenario is described in:
http://doc.dpdk.org/guides/nics/ice.html 23.4.3. Device Config Function
(DCF)
With the patch in user space ice driver:
http://git.dpdk.org/dpdk/commit/?id=c5dccda9f2ae6ecc716892c233a0dadc94e013da
and this patch set in ice kernel driver, we can now promote the VF from iAVF
(data
path we called) to DCF (control path) for each PF device.
