net/mlx4_en: Handle unassigned VF MAC address correctly

When a VF sense they didn't get MAC address, use random one. This will
address the case of administrator not assigning MAC to the VF through
the PF OS APIs and keep udev happy.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

@@ -2119,6 +2119,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	struct mlx4_en_priv *priv;
 	int i;
 	int err;
+	u64 mac_u64;
 
 	dev = alloc_etherdev_mqs(sizeof(struct mlx4_en_priv),
 				 MAX_TX_RINGS, MAX_RX_RINGS);
@@ -2192,11 +2193,18 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	dev->addr_len = ETH_ALEN;
 	mlx4_en_u64_to_mac(dev->dev_addr, mdev->dev->caps.def_mac[priv->port]);
 	if (!is_valid_ether_addr(dev->dev_addr)) {
+		if (mlx4_is_slave(priv->mdev->dev)) {
+			eth_hw_addr_random(dev);
+			en_warn(priv, "Assigned random MAC address %pM\n", dev->dev_addr);
+			mac_u64 = mlx4_en_mac_to_u64(dev->dev_addr);
+			mdev->dev->caps.def_mac[priv->port] = mac_u64;
+		} else {
 			en_err(priv, "Port: %d, invalid mac burned: %pM, quiting\n",
 			       priv->port, dev->dev_addr);
 			err = -EINVAL;
 			goto out;
 		}
+	}
 
 	memcpy(priv->prev_mac, dev->dev_addr, sizeof(priv->prev_mac));