IB/mlx5: Add multicast flow steering support for underlay QP

In order to add multicast flow steering support, there is need
to block the attaching of mcg flow for underlay QP, recognize
multicast IB_FLOW_SPEC_IPV4 based on its IP and enable
creating/destroying flow for IB layer.
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/main.c

@@ -2102,21 +2102,32 @@ static int parse_flow_attr(struct mlx5_core_dev *mdev, u32 *match_c,
  */
 static bool flow_is_multicast_only(struct ib_flow_attr *ib_attr)
 {
-	struct ib_flow_spec_eth *eth_spec;
+	union ib_flow_spec *flow_spec;
 
 	if (ib_attr->type != IB_FLOW_ATTR_NORMAL ||
-	    ib_attr->size < sizeof(struct ib_flow_attr) +
-	    sizeof(struct ib_flow_spec_eth) ||
 	    ib_attr->num_of_specs < 1)
 		return false;
 
-	eth_spec = (struct ib_flow_spec_eth *)(ib_attr + 1);
-	if (eth_spec->type != IB_FLOW_SPEC_ETH ||
-	    eth_spec->size != sizeof(*eth_spec))
+	flow_spec = (union ib_flow_spec *)(ib_attr + 1);
+	if (flow_spec->type == IB_FLOW_SPEC_IPV4) {
+		struct ib_flow_spec_ipv4 *ipv4_spec;
+
+		ipv4_spec = (struct ib_flow_spec_ipv4 *)flow_spec;
+		if (ipv4_is_multicast(ipv4_spec->val.dst_ip))
+			return true;
+
 		return false;
+	}
+
+	if (flow_spec->type == IB_FLOW_SPEC_ETH) {
+		struct ib_flow_spec_eth *eth_spec;
 
+		eth_spec = (struct ib_flow_spec_eth *)flow_spec;
 		return is_multicast_ether_addr(eth_spec->mask.dst_mac) &&
 		       is_multicast_ether_addr(eth_spec->val.dst_mac);
+	}
+
+	return false;
 }
 
 static bool is_valid_ethertype(struct mlx5_core_dev *mdev,
@@ -2594,8 +2605,14 @@ static struct ib_flow *mlx5_ib_create_flow(struct ib_qp *qp,
 static int mlx5_ib_mcg_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 {
 	struct mlx5_ib_dev *dev = to_mdev(ibqp->device);
+	struct mlx5_ib_qp *mqp = to_mqp(ibqp);
 	int err;
 
+	if (mqp->flags & MLX5_IB_QP_UNDERLAY) {
+		mlx5_ib_dbg(dev, "Attaching a multi cast group to underlay QP is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
 	err = mlx5_core_attach_mcg(dev->mdev, gid, ibqp->qp_num);
 	if (err)
 		mlx5_ib_warn(dev, "failed attaching QPN 0x%x, MGID %pI6\n",
@@ -3941,18 +3958,20 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 			(1ull << IB_USER_VERBS_CMD_CLOSE_XRCD);
 	}
 
-	if (mlx5_ib_port_link_layer(&dev->ib_dev, 1) ==
-	    IB_LINK_LAYER_ETHERNET) {
 	dev->ib_dev.create_flow	= mlx5_ib_create_flow;
 	dev->ib_dev.destroy_flow = mlx5_ib_destroy_flow;
+	dev->ib_dev.uverbs_ex_cmd_mask |=
+			(1ull << IB_USER_VERBS_EX_CMD_CREATE_FLOW) |
+			(1ull << IB_USER_VERBS_EX_CMD_DESTROY_FLOW);
+
+	if (mlx5_ib_port_link_layer(&dev->ib_dev, 1) ==
+	    IB_LINK_LAYER_ETHERNET) {
 		dev->ib_dev.create_wq	 = mlx5_ib_create_wq;
 		dev->ib_dev.modify_wq	 = mlx5_ib_modify_wq;
 		dev->ib_dev.destroy_wq	 = mlx5_ib_destroy_wq;
 		dev->ib_dev.create_rwq_ind_table = mlx5_ib_create_rwq_ind_table;
 		dev->ib_dev.destroy_rwq_ind_table = mlx5_ib_destroy_rwq_ind_table;
 		dev->ib_dev.uverbs_ex_cmd_mask |=
-			(1ull << IB_USER_VERBS_EX_CMD_CREATE_FLOW) |
-			(1ull << IB_USER_VERBS_EX_CMD_DESTROY_FLOW) |
 			(1ull << IB_USER_VERBS_EX_CMD_CREATE_WQ) |
 			(1ull << IB_USER_VERBS_EX_CMD_MODIFY_WQ) |
 			(1ull << IB_USER_VERBS_EX_CMD_DESTROY_WQ) |