[PATCH] net/mlx5: fix GRE item matching

[Alexander Kozyrev]

GRE protocol type is implicitly set in the matching translation in case
an application doesn't specify any type explicitly in a flow rule.
It is extracted from the inner header type, but this type may be absent.
In this case, GRE item matching is broken. Check if we have the inner
header type before setting it to allow matching on all GRE packets.

Fixes: be26e81bfc1c ("net/mlx5: fix GRE protocol type translation")
Cc: stable at dpdk.org

Signed-off-by: Alexander Kozyrev <akozyrev at nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_dv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 9d4bd0560c..7bb092ea9f 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -8823,8 +8823,9 @@ flow_dv_translate_item_gre(void *matcher, void *key,
 	protocol_v = rte_be_to_cpu_16(gre_v->protocol);
 	if (!protocol_m) {
 		/* Force next protocol to prevent matchers duplication */
-		protocol_m = 0xFFFF;
 		protocol_v = mlx5_translate_tunnel_etypes(pattern_flags);
+		if (protocol_v)
+			protocol_m = 0xFFFF;
 	}
 	MLX5_SET(fte_match_set_misc, misc_m, gre_protocol, protocol_m);
 	MLX5_SET(fte_match_set_misc, misc_v, gre_protocol,
-- 
2.18.2