Re: [dpdk-dev] [PATCH v3 2/4] nfp-uio: new uio driver for netronome nfp6000 card

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

Wow!

This is just what we (likely) need.

We could have that support in our BSP but this is something yet to be
approved. Setting  per VF pci bus master and pci mask should also be added
to BSP.

Current PMD submitted would need nfp_uio by now for LSC interrupt support.
As I said, this is not critical so NFP devices could be used with that
limitation. My concern is tests without using nfp_uio have not been done,
just some minor work for proof of concept.

I understand interest for not having another UIO driver does exist. We
could maintain an external nfp_uio by now till either we get rid of it or
we definitely find out it is really needed. any chance to accept nfp_uio by
now?

Thanks

On Wed, Oct 21, 2015 at 4:25 PM, Thomas Monjalon <thomas.monjalon@6wind.com>
wrote:

> 2015-10-21 15:39, Alejandro Lucero:
> > On Wed, Oct 21, 2015 at 6:24 AM, David Marchand <
> david.marchand@6wind.com>
> > wrote:
> > > Please, can you elaborate on the need for (yet another) uio driver,
> rather
> > > than make igb_uio work with your hardware ?
> [...]
> > I have been looking at the possibility of getting rid of nfp_uio. The
> fact
> > is our PMD can work without it, both for the PF and VF (not the PMD
> version
> > already submitted but one under development).  The PF support requires
> not
> > using UIO at all, because the device is attached to the BSP driver. The
> > only problem with this approach is we do not have support for interrupts,
> > what is not critical (I can see other PMDs not having support for Link
> > Status Changes) but we do not like it as programs can register callbacks
> > for these interrupts which would not work at all.
> >
> > Interrupt support could be implemented in the BSP, doing the same UIO or
> > VFIO do, but this will require (minor) changes to DPDK for having another
> > intr_handle (not UIO, not VFIO). I do not know if other PMDs could also
> > make use of such a change but I guess that would help to accept those
> > changes.
>
> We are going to have an external handler (used for mlx5):
>         http://dpdk.org/ml/archives/dev/2015-October/024678.html
> Problem solved :)
>
> Is it possible to rework your PMD without nfp-uio?
>
> Thanks
>