Re: [PATCH net-next v2] net/mlx5e: Add mlx5e_flower_parse_meta support

[Roi Dayan <roid@mellanox.com>]

On 2020-01-07 11:16 AM, wenxu@ucloud.cn wrote:
> From: wenxu <wenxu@ucloud.cn>
> 
> In the flowtables offload all the devices in the flowtables
> share the same flow_block. An offload rule will be installed on
> all the devices. This scenario is not correct.
> 
> It is no problem if there are only two devices in the flowtable,
> The rule with ingress and egress on the same device can be reject
> by driver.
> 
> But more than two devices in the flowtable will install the wrong
> rules on hardware.
> 
> For example:
> Three devices in a offload flowtables: dev_a, dev_b, dev_c
> 
> A rule ingress from dev_a and egress to dev_b:
> The rule will install on device dev_a.
> The rule will try to install on dev_b but failed for ingress
> and egress on the same device.
> The rule will install on dev_c. This is not correct.
> 
> The flowtables offload avoid this case through restricting the ingress dev
> with FLOW_DISSECTOR_KEY_META as following patch.
> http://patchwork.ozlabs.org/patch/1218109/
> 
> So the mlx5e driver also should support the FLOW_DISSECTOR_KEY_META parse.
> 
> Signed-off-by: wenxu <wenxu@ucloud.cn>
> ---
> v2: remap the patch description
> 
>  drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 39 +++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> index 9b32a9c..33d1ce5 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> @@ -1805,6 +1805,40 @@ static void *get_match_headers_value(u32 flags,
>  			     outer_headers);
>  }
>  
> +static int mlx5e_flower_parse_meta(struct net_device *filter_dev,
> +				   struct flow_cls_offload *f)
> +{
> +	struct flow_rule *rule = flow_cls_offload_flow_rule(f);
> +	struct netlink_ext_ack *extack = f->common.extack;
> +	struct net_device *ingress_dev;
> +	struct flow_match_meta match;
> +
> +	if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_META))
> +		return 0;
> +
> +	flow_rule_match_meta(rule, &match);
> +	if (match.mask->ingress_ifindex != 0xFFFFFFFF) {
> +		NL_SET_ERR_MSG_MOD(extack, "Unsupported ingress ifindex mask");
> +		return -EINVAL;
> +	}
> +
> +	ingress_dev = __dev_get_by_index(dev_net(filter_dev),
> +					 match.key->ingress_ifindex);
> +	if (!ingress_dev) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Can't find the ingress port to match on");
> +		return -EINVAL;
> +	}
> +
> +	if (ingress_dev != filter_dev) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Can't match on the ingress filter port");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static int __parse_cls_flower(struct mlx5e_priv *priv,
>  			      struct mlx5_flow_spec *spec,
>  			      struct flow_cls_offload *f,
> @@ -1825,6 +1859,7 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
>  	u16 addr_type = 0;
>  	u8 ip_proto = 0;
>  	u8 *match_level;
> +	int err;
>  
>  	match_level = outer_match_level;
>  
> @@ -1868,6 +1903,10 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
>  						    spec);
>  	}
>  
> +	err = mlx5e_flower_parse_meta(filter_dev, f);
> +	if (err)
> +		return err;
> +
>  	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_BASIC)) {
>  		struct flow_match_basic match;
>  
> 

Acked-by: Roi Dayan <roid@mellanox.com>