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

Edward Cree
2020-03-09T16:53:02Z

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?
-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)) {