[dpdk-dev] [PATCH v2 2/3] net/mlx4: fix default RSS hash fields

[Adrien Mazarguil]

Using special types value -1 with mlx4_conv_rss_types() is supposed to
return a supported set of Verbs RSS hash fields, that is, priv->hw_rss_sup
unmodified.

Due to the way this function is written and because it is also used to
initially populate priv->hw_rss_sup however, this special value works
properly only once and fails with ENOTSUP errors afterward.

This problem can be seen when re-creating default flows (e.g. by entering
and leaving isolated mode).

Fixes: 024e87bef40b ("net/mlx4: restore UDP RSS by probing capabilities")
Cc: stable at dpdk.org

Signed-off-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
---
 drivers/net/mlx4/mlx4.c      | 15 +++++++--------
 drivers/net/mlx4/mlx4_flow.c | 13 ++++---------
 2 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index 3dd72dbf5..4e472fa1d 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -569,14 +569,13 @@ mlx4_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		if (!priv->hw_rss_sup) {
 			WARN("no RSS capabilities reported; disabling support"
 			     " for UDP RSS and inner VXLAN RSS");
-			/* Fake support for all possible RSS hash fields. */
-			priv->hw_rss_sup = ~UINT64_C(0);
-			priv->hw_rss_sup = mlx4_conv_rss_types(priv, -1);
-			/* Filter out known unsupported fields. */
-			priv->hw_rss_sup &=
-				~(uint64_t)(IBV_RX_HASH_SRC_PORT_UDP |
-					    IBV_RX_HASH_DST_PORT_UDP |
-					    IBV_RX_HASH_INNER);
+			priv->hw_rss_sup =
+				IBV_RX_HASH_SRC_IPV4 |
+				IBV_RX_HASH_DST_IPV4 |
+				IBV_RX_HASH_SRC_IPV6 |
+				IBV_RX_HASH_DST_IPV6 |
+				IBV_RX_HASH_SRC_PORT_TCP |
+				IBV_RX_HASH_DST_PORT_TCP;
 		}
 		DEBUG("supported RSS hash fields mask: %016" PRIx64,
 		      priv->hw_rss_sup);
diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
index e3d7aa8ef..bebad074e 100644
--- a/drivers/net/mlx4/mlx4_flow.c
+++ b/drivers/net/mlx4/mlx4_flow.c
@@ -125,20 +125,15 @@ mlx4_conv_rss_types(struct priv *priv, uint64_t types)
 	uint64_t conv = 0;
 	unsigned int i;
 
+	if (types == (uint64_t)-1)
+		return priv->hw_rss_sup;
 	for (i = 0; i != RTE_DIM(in); ++i)
 		if (types & in[i]) {
 			seen |= types & in[i];
 			conv |= out[i];
 		}
-	if ((conv & priv->hw_rss_sup) == conv) {
-		if (types == (uint64_t)-1) {
-			/* Include inner RSS by default if supported. */
-			conv |= priv->hw_rss_sup & IBV_RX_HASH_INNER;
-			return conv;
-		}
-		if (!(types & ~seen))
-			return conv;
-	}
+	if ((conv & priv->hw_rss_sup) == conv && !(types & ~seen))
+		return conv;
 	rte_errno = ENOTSUP;
 	return (uint64_t)-1;
 }
-- 
2.11.0