From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [RFC] hv_netvsc: automatically name slave VF network device
Date: Tue, 19 Dec 2017 15:44:05 -0800
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        <e2fa7512-7c49-b756-f239-8bf52bc70d65@intel.com>
        <20171219145017.78b60959@xeon-e3>
        <20171219152057.1e19a0bc@cakuba.netronome.com>
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Cc: "Samudrala, Sridhar" <sridhar.samudrala@intel.com>,
        netdev@vger.kernel.org, Stephen Hemminger <sthemmin@microsoft.com>
To: Jakub Kicinski <jakub.kicinski@netronome.com>
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On Tue, 19 Dec 2017 15:20:57 -0800
Jakub Kicinski <jakub.kicinski@netronome.com> wrote:

> On Tue, 19 Dec 2017 14:50:17 -0800, Stephen Hemminger wrote:
> > On Tue, 19 Dec 2017 14:44:37 -0800
> > "Samudrala, Sridhar" <sridhar.samudrala@intel.com> wrote:
> >  =20
> > >  -static void __netvsc_vf_setup(struct net_device *ndev,   =20
> > > > -			      struct net_device *vf_netdev)
> > > > -{
> > > > -	int ret;
> > > > +	/* set the name of VF device based on upper device name */
> > > > +	snprintf(vf_name, IFNAMSIZ, "%s_vf", ndev->name);
> > > > +	ret =3D dev_change_name(vf_netdev, vf_name);
> > > > +	if (ret !=3D 0)
> > > > +		netdev_warn(vf_netdev,
> > > > +			    "can not rename device: (%d)\n", ret);     =20
> > >=20
> > > It is possible that upper device name can change after this call.=C2=
=A0 I=20
> > > noticed this
> > > when i tried this approach with virtio_net.
> > >=20
> > > Also, what should happen if the upper device is unloaded? Should we r=
ename
> > > the VF name?   =20
> >=20
> > Yes upper device can change name. So sure, netdevice could trap that
> > in callback (it already has notifier) and rename VF. Will add that in V=
2.
> >=20
> > If upper device is unloaded then it is already decoupled from the VF.
> > There is no good value to change it back to. The orignal name probably
> > has been reused by then. =20
>=20
> Both of those issues would be solved by just exposing phys_port_name
> from the VF driver, and letting systemd do its thing independent of=20
> magic bonds.
>=20
> Reluctance to do driver work aside :/

The port name for Mellanox driver is already set in the driver as a numeric=
 value.
It indicates which port is used.
This won't work.