RE: [PATCH] hv_netvsc:Register VF in netvsc_probe if NET_DEVICE_REGISTER missed

[Dexuan Cui]

> From: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Sent: Wednesday, January 31, 2024 8:46 AM
>  [...]
> > From: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
> > Sent: Wednesday, January 31, 2024 2:54 AM
> > > [...]
> > > > +		netvsc_prepare_bonding(vf_netdev);
> > > > +		netvsc_register_vf(vf_netdev, VF_REG_IN_PROBE);
> > > > +		__netvsc_vf_setup(net, vf_netdev);
> > >
> > > add a "break;' ?
> > With MANA devices and multiport support there, the individual ports are
> > also net_devices.
> > Wouldn't this be needed for such scenario(where we have multiple mana
> > port net devices) to
> > register them all?
> 
> Each device has separate probe() call, so only one VF will match in one
> netvsc_probe().
> 
> netvsc_prepare_bonding() &  netvsc_register_vf() have
> get_netvsc_byslot(vf_netdev), but __netvsc_vf_setup() doesn't have. So,
> in case of multi-Vfs, this code will run "this" netvsc NIC with multiple VFs by
> __netvsc_vf_setup() which isn't correct.
> 
> You need to add the following lines before
> netvsc_prepare_bonding(vf_netdev)
> in netvsc_probe() to skip non-matching VFs:
> 
> if (net != get_netvsc_byslot(vf_netdev))
> 	continue;

Haiyang is correct.
I think it's still good to add a "break;", e.g. my understanding is something
like the below (this is untested):

+static struct net_device *get_matching_netvsc_dev(net_device *event_ndev)
+{
+       /* Skip NetVSC interfaces */
+       if (event_ndev->netdev_ops == &device_ops)
+               return NULL;
+
+       /* Avoid non-Ethernet type devices */
+       if (event_ndev->type != ARPHRD_ETHER)
+               return NULL;
+
+       /* Avoid Vlan dev with same MAC registering as VF */
+       if (is_vlan_dev(event_ndev))
+               return NULL;
+
+       /* Avoid Bonding master dev with same MAC registering as VF */
+       if (netif_is_bond_master(event_ndev))
+               return NULL;
+
+       return get_netvsc_byslot(event_ndev);
+}

+	for_each_netdev(dev_net(net), vf_netdev) {
+ 		if (get_matching_netvsc_dev(event_dev) != net)
+			continue;
+
+		netvsc_prepare_bonding(vf_netdev);
+		netvsc_register_vf(vf_netdev, VF_REG_IN_PROBE);
+		__netvsc_vf_setup(net, vf_netdev);
+
+		break;
+	}

We can also use get_matching_netvsc_dev() in netvsc_netdev_event().

BTW, please add a space between "hv_netvsc:" and "Register" in the Subject.