On Wed, 29 Mar 2017 17:22:55 -0700, Sridhar Samudrala wrote:

Introduce switchdev_ops to PF and port netdevs to return the switch id via
SWITCHDEV_ATTR_ID_PORT_PARENT_ID attribute.
Also, ndo_get_phys_port_name() support is added to port netdevs to return
the port number.

...

+static int
+i40e_port_netdev_get_phys_port_name(struct net_device *dev, char *buf,
+				    size_t len)
+{
+	struct i40e_port_netdev_priv *priv = netdev_priv(dev);
+	struct i40e_vf *vf;
+	int ret;
+
+	switch (priv->type) {
+	case I40E_PORT_NETDEV_VF:
+		vf = (struct i40e_vf *)priv->f;
+		ret = snprintf(buf, len, "%d", vf->vf_id);
+		break;
+	case I40E_PORT_NETDEV_PF:
+		ret = snprintf(buf, len, "%d", I40E_MAIN_VSI_PORT_ID);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	if (ret >= len)
+		return -EOPNOTSUPP;
+
+	return 0;
+}

You are using only an integer here, which forces you to manually name
the netdev in patch 2, and that is what phys_port_name is supposed to
help avoid doing AFAIU.

We have naming rules in Documentation/networking/switchdev.txt for
switch ports suggested as pX for physical ports or pXsY for ports which
are broken out/split.  Could we establish similar suggestion for vf and
pf representors and document it? (note: we may need pf representors for
multi-host devices.)

IMHO naming representors pfr%d or vfr%d would make sense.  This way
actual VF and PF netdevs could be called pf%d and vf%d, and
udev/systemd will give all netdevs nice, meaningful names without any
custom rules.

Sorry for the bike shedding but I was hoping we could save some user
pain by establishing those rules (more or less) upfront.