Re: [dpdk-dev] kernel binding of devices + hotplug

[Alejandro Lucero <alejandro.lucero@netronome.com>]

I do not completely understand the discussion, but I think the disagreement
is due to how some devices interact with DPDK, at least Mellanox ones. I'm
saying that because we have a DPDK app which starts with no device at all
(--no-pci) and it relies on device plugging attach/detach for configuring
and removing ports once devices are bound to VFIO or UIO drivers. Maybe I'm
wrong, but I think because Mellanox cards do not use VFIO or UIO drivers
but some specific bound using verbs inside the PMD, leaving all this
binding to the system does not fit them.

If that is the case, although I agree with leaving the device binding to
the system, I think it would be fair to contemplate a dual approach for
legacy reasons, or to leave time for implementing a pseudo system driver
which Mellanox can use for having same functionality.

On Wed, Apr 18, 2018 at 7:54 PM, Flavio Leitner <fbl@redhat.com> wrote:

> On Wed, Apr 18, 2018 at 11:17:47AM -0700, Stephen Hemminger wrote:
> > On Wed, 18 Apr 2018 11:11:01 -0300
> > Flavio Leitner <fbl@redhat.com> wrote:
> >
> > > On Sun, Apr 15, 2018 at 01:48:36AM +0000, Stephen Hemminger wrote:
> > > > My vote is to work with udev and not try to replace it.
> > > >
> > > > Driverctl works well. Just not for bifurcated driver
> > >
> > > I second that.  We also have other system configs to care about like
> > > kernel parameters and hugepage configuration which I think follow the
> > > same idea that they are system wide configs and should not be managed
> > > by DPDK itself.
> >
> > Maybe teach driverctl (and udev) to handle bifurcated drivers.
>
> I don't know the challenges to tech driverctl to handle bifurcated
> drivers but I would agree that it should be our first place to look at.
>
> > Unfortunately, vendors are very fractured on how network devices are
> managed.
>
> You mean distros? hw vendors? all vendors? :)
>
> Perhaps if community focus on something, then they might follow at some
> point.
>
> --
> Flavio
>