[dpdk-stable] [PATCH v3] net/mlx5: check the reg available for metadata action

[Viacheslav Ovsiienko <viacheslavo@nvidia.com>]

From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

If user don't set the dv_xmeta_en to 1 or 2,
in the flow_dv_convert_action_set_meta function:

- flow_dv_get_metadata_reg may return the REG_NONE,
  when MLX5_METADATA_FDB enabled for metadata set action.

- reg_to_field(REG_NONE) returns MLX5_MODI_OUT_NONE,
  that is invalid and rdma-core fails.

The rdma-core calltrace:
    dr_action_create_modify_action
    dr_actions_convert_modify_header
    dr_action_modify_sw_to_hw
    dr_action_modify_sw_to_hw_set
    dr_ste_get_modify_hdr_hw_field

Fixes: fcc8d2f716fd ("net/mlx5: extend flow metadata support")
Cc: stable@dpdk.org

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_dv.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index fa2e8f2..bee22f5 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -1217,6 +1217,7 @@ struct field_modify_info modify_tcp[] = {
 
 	if (reg < 0)
 		return reg;
+	MLX5_ASSERT(reg != REG_NON);
 	/*
 	 * In datapath code there is no endianness
 	 * coversions for perfromance reasons, all
@@ -1438,6 +1439,10 @@ struct field_modify_info modify_tcp[] = {
 		reg = flow_dv_get_metadata_reg(dev, attr, error);
 		if (reg < 0)
 			return reg;
+		if (reg == REG_NON)
+			return rte_flow_error_set(error, ENOTSUP,
+					RTE_FLOW_ERROR_TYPE_ITEM, item,
+					"unavalable extended metadata register");
 		if (reg == REG_B)
 			return rte_flow_error_set(error, ENOTSUP,
 					  RTE_FLOW_ERROR_TYPE_ITEM, item,
@@ -2446,6 +2451,10 @@ struct field_modify_info modify_tcp[] = {
 	reg = flow_dv_get_metadata_reg(dev, attr, error);
 	if (reg < 0)
 		return reg;
+	if (reg == REG_NON)
+		return rte_flow_error_set(error, ENOTSUP,
+					  RTE_FLOW_ERROR_TYPE_ACTION, action,
+					  "unavalable extended metadata register");
 	if (reg != REG_A && reg != REG_B) {
 		struct mlx5_priv *priv = dev->data->dev_private;
 
@@ -7471,6 +7480,7 @@ struct mlx5_hlist_entry *
 		reg = flow_dv_get_metadata_reg(dev, attr, NULL);
 		if (reg < 0)
 			return;
+		MLX5_ASSERT(reg != REG_NON);
 		/*
 		 * In datapath code there is no endianness
 		 * coversions for perfromance reasons, all
-- 
1.8.3.1