Re: [patch net-next v4 03/10] flow_offload: check for basic action hw stats type

[Jiri Pirko <jiri@resnulli.us>]

Mon, Mar 09, 2020 at 05:52:47PM CET, ecree@solarflare.com wrote:
>On 07/03/2020 11:40, Jiri Pirko wrote:
>> From: Jiri Pirko <jiri@mellanox.com>
>>
>> Introduce flow_action_basic_hw_stats_types_check() helper and use it
>> in drivers. That sanitizes the drivers which do not have support
>> for action HW stats types.
>>
>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>> ---
>> v3->v4:
>> - fixed entries iteration in check (s/0/i/)
>> - compare allowed type explicitly to 0 to avoid confusion
>> v2->v3:
>> - added flow_action_hw_stats_types_check() to pass allowed types
>> - "mixed" bool got remove, iterate entries in check
>> - added mlx5 checking instead of separate patches (will be changed by
>>   later patch to flow_action_hw_stats_types_check()
>> v1->v2:
>> - new patch
>> ---
>> <snip>
>> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
>> index 93d17f37e980..8b40f612a565 100644
>> --- a/include/net/flow_offload.h
>> +++ b/include/net/flow_offload.h
>> @@ -3,6 +3,7 @@
>>  
>>  #include <linux/kernel.h>
>>  #include <linux/list.h>
>> +#include <linux/netlink.h>
>>  #include <net/flow_dissector.h>
>>  #include <linux/rhashtable.h>
>>  
>> @@ -251,6 +252,66 @@ static inline bool flow_offload_has_one_action(const struct flow_action *action)
>>  	return action->num_entries == 1;
>>  }
>>  
>> +static inline bool
>> +flow_action_mixed_hw_stats_types_check(const struct flow_action *action,
>> +				       struct netlink_ext_ack *extack)
>> +{
>> +	const struct flow_action_entry *action_entry;
>> +	u8 uninitialized_var(last_hw_stats_type);
>> +	int i;
>> +
>> +	if (flow_offload_has_one_action(action))
>> +		return true;
>> +
>> +	for (i = 0; i < action->num_entries; i++) {
>Any reason you didn't use flow_action_for_each() here?

Nope. Will send a follow-up to change this.


>-ed
>
>> +		action_entry = &action->entries[i];
>> +		if (i && action_entry->hw_stats_type != last_hw_stats_type) {
>> +			NL_SET_ERR_MSG_MOD(extack, "Mixing HW stats types for actions is not supported");
>> +			return false;
>> +		}
>> +		last_hw_stats_type = action_entry->hw_stats_type;
>> +	}
>> +	return true;
>> +}
>> +
>> +static inline const struct flow_action_entry *
>> +flow_action_first_entry_get(const struct flow_action *action)
>> +{
>> +	WARN_ON(!flow_action_has_entries(action));
>> +	return &action->entries[0];
>> +}
>> +
>> +static inline bool
>> +flow_action_hw_stats_types_check(const struct flow_action *action,
>> +				 struct netlink_ext_ack *extack,
>> +				 u8 allowed_hw_stats_type)
>> +{
>> +	const struct flow_action_entry *action_entry;
>> +
>> +	if (!flow_action_has_entries(action))
>> +		return true;
>> +	if (!flow_action_mixed_hw_stats_types_check(action, extack))
>> +		return false;
>> +	action_entry = flow_action_first_entry_get(action);
>> +	if (allowed_hw_stats_type == 0 &&
>> +	    action_entry->hw_stats_type != FLOW_ACTION_HW_STATS_TYPE_ANY) {
>> +		NL_SET_ERR_MSG_MOD(extack, "Driver supports only default HW stats type \"any\"");
>> +		return false;
>> +	} else if (allowed_hw_stats_type != 0 &&
>> +		   action_entry->hw_stats_type != allowed_hw_stats_type) {
>> +		NL_SET_ERR_MSG_MOD(extack, "Driver does not support selected HW stats type");
>> +		return false;
>> +	}
>> +	return true;
>> +}
>> +
>> +static inline bool
>> +flow_action_basic_hw_stats_types_check(const struct flow_action *action,
>> +				       struct netlink_ext_ack *extack)
>> +{
>> +	return flow_action_hw_stats_types_check(action, extack, 0);
>> +}
>> +
>>  #define flow_action_for_each(__i, __act, __actions)			\
>>          for (__i = 0, __act = &(__actions)->entries[0]; __i < (__actions)->num_entries; __act = &(__actions)->entries[++__i])
>>  
>> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
>> index 79d9b4384d7b..fca9bfa8437e 100644
>> --- a/net/dsa/slave.c
>> +++ b/net/dsa/slave.c
>> @@ -865,6 +865,10 @@ static int dsa_slave_add_cls_matchall(struct net_device *dev,
>>  	if (!flow_offload_has_one_action(&cls->rule->action))
>>  		return err;
>>  
>> +	if (!flow_action_basic_hw_stats_types_check(&cls->rule->action,
>> +						    cls->common.extack))
>> +		return err;
>> +
>>  	act = &cls->rule->action.entries[0];
>>  
>>  	if (act->id == FLOW_ACTION_MIRRED && protocol == htons(ETH_P_ALL)) {
>