[PATCH 19.11] net/mlx5: fix NIC egress flow mismatch in switchdev mode

[PATCH 19.11] net/mlx5: fix NIC egress flow mismatch in switchdev mode

[Jiawei Wang]

[ upstream commit 6d4f1066be6cd60a95f21ef07a16a3c3676c5cd9 ]

When E-Switch mode was enabled, the NIC egress flows was implicitly
appended with source vport to match on. If the metadata register C0
was used to maintain the source vport, it was initialized to zero
on packet steering engine entry, the flow could be hit only
if source vport was zero, the register C0 of the packet was not correct
to match in the TX side, this caused egress flow misses.

This patch:
 - removes the implicit source vport match for NIC egress flow.
 - rejects the NIC egress flows on the representor ports at validation.
 - allows the internal NIC egress flows containing the TX_QUEUE items in
   order to not impact hairpins.

Fixes: ce777b147bf8 ("net/mlx5: fix E-Switch flow without port item")

Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
Acked-by: Ori Kam <orika@nvidia.com>
---
 doc/guides/nics/mlx5.rst        |  2 ++
 drivers/net/mlx5/mlx5_flow_dv.c | 26 +++++++++++++++++++++-----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 546f0dd4c2..8f7b285271 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -241,6 +241,8 @@ Limitations
     from the reference "Clock Queue" completions,
     the scheduled send timestamps should not be specified with non-zero MSB.
 
+- The NIC egress flow rules on representor port are not supported.
+
 Statistics
 ----------
 
diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index dd62bbbbfb..f7e3d92045 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -4833,8 +4833,10 @@ flow_dv_validate(struct rte_eth_dev *dev, const struct rte_flow_attr *attr,
 				return ret;
 			last_item = MLX5_FLOW_ITEM_TAG;
 			break;
-		case MLX5_RTE_FLOW_ITEM_TYPE_TAG:
 		case MLX5_RTE_FLOW_ITEM_TYPE_TX_QUEUE:
+			last_item = MLX5_FLOW_ITEM_TX_QUEUE;
+			break;
+		case MLX5_RTE_FLOW_ITEM_TYPE_TAG:
 			break;
 		default:
 			return rte_flow_error_set(error, ENOTSUP,
@@ -5313,6 +5315,18 @@ flow_dv_validate(struct rte_eth_dev *dev, const struct rte_flow_attr *attr,
 					  NULL, "too many header modify"
 					  " actions to support");
 	}
+	/*
+	 * Validation the NIC Egress flow on representor, except implicit
+	 * hairpin default egress flow with TX_QUEUE item, other flows not
+	 * work due to metadata regC0 mismatch.
+	 */
+	if ((!attr->transfer && attr->egress) && priv->representor &&
+	    !(item_flags & MLX5_FLOW_ITEM_TX_QUEUE))
+		return rte_flow_error_set(error, EINVAL,
+					  RTE_FLOW_ERROR_TYPE_ITEM,
+					  NULL,
+					  "NIC egress rules on representors"
+					  " is not supported");
 	return 0;
 }
 
@@ -7891,12 +7905,14 @@ __flow_dv_translate(struct rte_eth_dev *dev,
 	/*
 	 * When E-Switch mode is enabled, we have two cases where we need to
 	 * set the source port manually.
-	 * The first one, is in case of Nic steering rule, and the second is
-	 * E-Switch rule where no port_id item was found. In both cases
-	 * the source port is set according the current port in use.
+	 * The first one, is in case of NIC ingress steering rule, and the
+	 * second is E-Switch rule where no port_id item was found.
+	 * In both cases the source port is set according the current port
+	 * in use.
 	 */
 	if (!(item_flags & MLX5_FLOW_ITEM_PORT_ID) &&
-	    (priv->representor || priv->master)) {
+	    (priv->representor || priv->master) &&
+	    !(attr->egress && !attr->transfer)) {
 		if (flow_dv_translate_item_port_id(dev, match_mask,
 						   match_value, NULL))
 			return -rte_errno;
-- 
2.18.1

Re: [PATCH 19.11] net/mlx5: fix NIC egress flow mismatch in switchdev mode

[Christian Ehrhardt]

On Sun, Mar 13, 2022 at 9:39 AM Jiawei Wang <jiaweiw@nvidia.com> wrote:
>
> [ upstream commit 6d4f1066be6cd60a95f21ef07a16a3c3676c5cd9 ]

Thank you - applied to 19.11 stable

> When E-Switch mode was enabled, the NIC egress flows was implicitly
> appended with source vport to match on. If the metadata register C0
> was used to maintain the source vport, it was initialized to zero
> on packet steering engine entry, the flow could be hit only
> if source vport was zero, the register C0 of the packet was not correct
> to match in the TX side, this caused egress flow misses.
>
> This patch:
>  - removes the implicit source vport match for NIC egress flow.
>  - rejects the NIC egress flows on the representor ports at validation.
>  - allows the internal NIC egress flows containing the TX_QUEUE items in
>    order to not impact hairpins.
>
> Fixes: ce777b147bf8 ("net/mlx5: fix E-Switch flow without port item")
>
> Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> Acked-by: Ori Kam <orika@nvidia.com>
> ---
>  doc/guides/nics/mlx5.rst        |  2 ++
>  drivers/net/mlx5/mlx5_flow_dv.c | 26 +++++++++++++++++++++-----
>  2 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
> index 546f0dd4c2..8f7b285271 100644
> --- a/doc/guides/nics/mlx5.rst
> +++ b/doc/guides/nics/mlx5.rst
> @@ -241,6 +241,8 @@ Limitations
>      from the reference "Clock Queue" completions,
>      the scheduled send timestamps should not be specified with non-zero MSB.
>
> +- The NIC egress flow rules on representor port are not supported.
> +
>  Statistics
>  ----------
>
> diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
> index dd62bbbbfb..f7e3d92045 100644
> --- a/drivers/net/mlx5/mlx5_flow_dv.c
> +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> @@ -4833,8 +4833,10 @@ flow_dv_validate(struct rte_eth_dev *dev, const struct rte_flow_attr *attr,
>                                 return ret;
>                         last_item = MLX5_FLOW_ITEM_TAG;
>                         break;
> -               case MLX5_RTE_FLOW_ITEM_TYPE_TAG:
>                 case MLX5_RTE_FLOW_ITEM_TYPE_TX_QUEUE:
> +                       last_item = MLX5_FLOW_ITEM_TX_QUEUE;
> +                       break;
> +               case MLX5_RTE_FLOW_ITEM_TYPE_TAG:
>                         break;
>                 default:
>                         return rte_flow_error_set(error, ENOTSUP,
> @@ -5313,6 +5315,18 @@ flow_dv_validate(struct rte_eth_dev *dev, const struct rte_flow_attr *attr,
>                                           NULL, "too many header modify"
>                                           " actions to support");
>         }
> +       /*
> +        * Validation the NIC Egress flow on representor, except implicit
> +        * hairpin default egress flow with TX_QUEUE item, other flows not
> +        * work due to metadata regC0 mismatch.
> +        */
> +       if ((!attr->transfer && attr->egress) && priv->representor &&
> +           !(item_flags & MLX5_FLOW_ITEM_TX_QUEUE))
> +               return rte_flow_error_set(error, EINVAL,
> +                                         RTE_FLOW_ERROR_TYPE_ITEM,
> +                                         NULL,
> +                                         "NIC egress rules on representors"
> +                                         " is not supported");
>         return 0;
>  }
>
> @@ -7891,12 +7905,14 @@ __flow_dv_translate(struct rte_eth_dev *dev,
>         /*
>          * When E-Switch mode is enabled, we have two cases where we need to
>          * set the source port manually.
> -        * The first one, is in case of Nic steering rule, and the second is
> -        * E-Switch rule where no port_id item was found. In both cases
> -        * the source port is set according the current port in use.
> +        * The first one, is in case of NIC ingress steering rule, and the
> +        * second is E-Switch rule where no port_id item was found.
> +        * In both cases the source port is set according the current port
> +        * in use.
>          */
>         if (!(item_flags & MLX5_FLOW_ITEM_PORT_ID) &&
> -           (priv->representor || priv->master)) {
> +           (priv->representor || priv->master) &&
> +           !(attr->egress && !attr->transfer)) {
>                 if (flow_dv_translate_item_port_id(dev, match_mask,
>                                                    match_value, NULL))
>                         return -rte_errno;
> --
> 2.18.1
>


-- 
Christian Ehrhardt
Staff Engineer, Ubuntu Server
Canonical Ltd