Re: [PATCH v2 03/24] net/nfp: add the flow APIs of nfp PMD

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 10/10/2022 7:08 AM, Chaoyong He wrote:
> Add the flow validate/create/query/destroy/flush API of nfp PMD.
> 
> The flow create API construct a control cmsg and send it to
> firmware, then add this flow  to the hash table.
> 
> The flow query API get flow stats from the flow_priv structure.
> Note there exist an rte_spin_lock to prevent the update and query
> action occur at the same time.
> 
> The flow destroy API construct a control cmsg and send it to
> firmware, then adelete this flow from the hash table.
> 
> The flow flush API just iterate the flows in hash table and
> call the flow destroy API.
> 
> Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>

<...>

> +static void
> +nfp_flow_stats_get(struct rte_eth_dev *dev,
> +		struct rte_flow *nfp_flow,
> +		void *data)
> +{
> +	uint32_t ctx_id;
> +	struct rte_flow *flow;
> +	struct nfp_flow_priv *priv;
> +	struct nfp_fl_stats *stats;
> +	struct rte_flow_query_count *query;
> +
> +	priv = nfp_flow_dev_to_priv(dev);
> +	flow = nfp_flow_table_search(priv, nfp_flow);
> +	if (flow == NULL) {
> +		PMD_DRV_LOG(ERR, "Can not find statistics for this flow.");
> +		return;
> +	}
> +
> +	query = (struct rte_flow_query_count *)data;
> +	ctx_id = rte_be_to_cpu_32(nfp_flow->payload.meta->host_ctx_id);
> +	stats = &priv->stats[ctx_id];
> +
> +	rte_spinlock_lock(&priv->stats_lock);
> +	if (stats->pkts && stats->bytes) {

Is it guaranteed that 'query' ("void *data") is zeroed out when it is 
provided by application?

> +		query->hits = stats->pkts;
> +		query->bytes = stats->bytes;
> +		query->hits_set = 1;
> +		query->bytes_set = 1;
> +		stats->pkts = 0;
> +		stats->bytes = 0;

need to check 'reset' field of action to decide reset or not.

<...>

> @@ -75,6 +101,7 @@ struct nfp_fl_stats {
>   
>   struct nfp_flow_priv {
>   	uint32_t hash_seed; /**< Hash seed for hash tables in this structure. */
> +	uint64_t flower_version; /**< Flow version, always increase. */

Is this version to keep unique value per flow configuration? If so as 
far as I can see '.validate' is updating this value, is this expected?

Also who suppose to use this value?