mlxsw: spectrum_router: Demote tunnels on VRF migration

The mlxsw driver currently doesn't offload GRE tunnels if they have the
same local address and use the same underlay VRF. When such a situation
arises, the tunnels in conflict are demoted to slow path.

However, the current code only verifies this condition on tunnel
creation and tunnel change, not when a tunnel is moved to a different
VRF. When the tunnel has no bound device, underlay and overlay are the
same. Thus moving a tunnel moves the underlay as well, and that can
cause local address conflict.

So modify mlxsw_sp_netdevice_ipip_ol_vrf_event() to check if there are
any conflicting tunnels, and demote them if yes.

Fixes: af64171 ("mlxsw: spectrum_router: Onload conflicting tunnels")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -1449,9 +1449,27 @@ static int mlxsw_sp_netdevice_ipip_ol_vrf_event(struct mlxsw_sp *mlxsw_sp,
 {
 	struct mlxsw_sp_ipip_entry *ipip_entry =
 		mlxsw_sp_ipip_entry_find_by_ol_dev(mlxsw_sp, ol_dev);
+	enum mlxsw_sp_l3proto ul_proto;
+	union mlxsw_sp_l3addr saddr;
+	u32 ul_tb_id;
 
 	if (!ipip_entry)
 		return 0;
+
+	/* For flat configuration cases, moving overlay to a different VRF might
+	 * cause local address conflict, and the conflicting tunnels need to be
+	 * demoted.
+	 */
+	ul_tb_id = mlxsw_sp_ipip_dev_ul_tb_id(ol_dev);
+	ul_proto = mlxsw_sp->router->ipip_ops_arr[ipip_entry->ipipt]->ul_proto;
+	saddr = mlxsw_sp_ipip_netdev_saddr(ul_proto, ol_dev);
+	if (mlxsw_sp_ipip_demote_tunnel_by_saddr(mlxsw_sp, ul_proto,
+						 saddr, ul_tb_id,
+						 ipip_entry)) {
+		mlxsw_sp_ipip_entry_demote_tunnel(mlxsw_sp, ipip_entry);
+		return 0;
+	}
+
 	return __mlxsw_sp_ipip_entry_update_tunnel(mlxsw_sp, ipip_entry,
 						   true, false, false, extack);
 }