RE: [PATCH net-next 19/19] mtty: Optionally support mtty alias

Parav Pandit
2019-11-08T15:31:43Z

> -----Original Message-----
> From: Cornelia Huck <cohuck@redhat.com>
> Sent: Friday, November 8, 2019 9:28 AM
> To: Parav Pandit <parav@mellanox.com>
> Cc: alex.williamson@redhat.com; davem@davemloft.net;
> kvm@vger.kernel.org; netdev@vger.kernel.org; Saeed Mahameed
> <saeedm@mellanox.com>; kwankhede@nvidia.com; leon@kernel.org; Jiri
> Pirko <jiri@mellanox.com>; linux-rdma@vger.kernel.org
> Subject: Re: [PATCH net-next 19/19] mtty: Optionally support mtty alias
>
> On Fri, 8 Nov 2019 15:10:42 +0000
> Parav Pandit <parav@mellanox.com> wrote:
>
> > > -----Original Message-----
> > > From: Cornelia Huck <cohuck@redhat.com>
> > > Sent: Friday, November 8, 2019 7:46 AM
> > > To: Parav Pandit <parav@mellanox.com>
> > > Cc: alex.williamson@redhat.com; davem@davemloft.net;
> > > kvm@vger.kernel.org; netdev@vger.kernel.org; Saeed Mahameed
> > > <saeedm@mellanox.com>; kwankhede@nvidia.com; leon@kernel.org; Jiri
> > > Pirko <jiri@mellanox.com>; linux-rdma@vger.kernel.org
> > > Subject: Re: [PATCH net-next 19/19] mtty: Optionally support mtty
> > > alias
> > >
> > > On Thu, 7 Nov 2019 10:08:34 -0600
> > > Parav Pandit <parav@mellanox.com> wrote:
> > >
> > > > Provide a module parameter to set alias length to optionally
> > > > generate mdev alias.
> > > >
> > > > Example to request mdev alias.
> > > > $ modprobe mtty alias_length=12
> > > >
> > > > Make use of mtty_alias() API when alias_length module parameter is
> set.
> > > >
> > > > Signed-off-by: Parav Pandit <parav@mellanox.com>
> > > > ---
> > > > samples/vfio-mdev/mtty.c | 13 +++++++++++++
> > > > 1 file changed, 13 insertions(+)
> > >
> > > If you already have code using the alias interface, you probably
> > > don't need to add it to the sample driver here. Especially as the
> > > alias looks kind of pointless here.
> >
> > It is pointless.
> > Alex point when we ran through the series in August, was, QA should be
> able to do cover coverage of mdev_core where there is mdev collision and
> mdev_create() can fail.
> > And QA should be able to set alias length to be short to 1 or 2 letters to
> trigger it.
> > Hence this patch was added.
>
> If we want this for testing purposes, that should be spelled out explicitly (the
> above had already dropped from my cache). Even better if we had
> something in actual test infrastructure.

What else purpose sample driver has other than getting reference on how to use API? :-)