Re: [dpdk-dev] [PATCH v4 13/19] net/ena: indicate Rx RSS hash presence

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

On 5/11/2021 7:45 AM, Michal Krawczyk wrote:
> To make it possible to the app to determine if the hash was calculated
> for the packet or not, the PKT_RX_RSS_HASH should be set in the mbuf's
> ol_flags.
> 
> As the PMD wasn't setting that, the application couldn't check if there
> is a hash in a proper way.
> 
> The hash is valid only if it's UDP or TCP and the IP packet wasn't
> fragmented.
> 
> Fixes: e5df9f33db00 ("net/ena: fix passing RSS hash to mbuf")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Michal Krawczyk <mk@semihalf.com>
> Reviewed-by: Igor Chauskin <igorch@amazon.com>
> Reviewed-by: Amit Bernstein <amitbern@amazon.com>
> ---
> v4:
> * Add release notes.
> * Always announce DEV_RX_OFFLOAD_RSS_HASH if RSS is enabled.
> 
>  doc/guides/rel_notes/release_21_05.rst |  1 +
>  drivers/net/ena/ena_ethdev.c           | 12 ++++++++++--
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/doc/guides/rel_notes/release_21_05.rst b/doc/guides/rel_notes/release_21_05.rst
> index 755d5fcd32..389a7a05ac 100644
> --- a/doc/guides/rel_notes/release_21_05.rst
> +++ b/doc/guides/rel_notes/release_21_05.rst
> @@ -210,6 +210,7 @@ New Features
>    * Changed memcpy mapping to the dpdk-optimized version.
>    * Updated ena_com (HAL) to the latest version.
>    * Fixed bugs when requesting large LLQ headers using the devargs.
> +  * Added indication of the RSS hash presence in the mbuf.
>  
>  * **Added support of multiple data-units in cryptodev API.**
>  
> diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
> index 6092288239..9a43ab50fe 100644
> --- a/drivers/net/ena/ena_ethdev.c
> +++ b/drivers/net/ena/ena_ethdev.c
> @@ -51,6 +51,8 @@
>  
>  #define ENA_MIN_RING_DESC	128
>  
> +#define ENA_PTYPE_HAS_HASH	(RTE_PTYPE_L4_TCP | RTE_PTYPE_L4_UDP)
> +
>  enum ethtool_stringset {
>  	ETH_SS_TEST             = 0,
>  	ETH_SS_STATS,
> @@ -314,6 +316,11 @@ static inline void ena_rx_mbuf_prepare(struct rte_mbuf *mbuf,
>  		else
>  			ol_flags |= PKT_RX_L4_CKSUM_GOOD;
>  
> +	if (likely((packet_type & ENA_PTYPE_HAS_HASH) && !ena_rx_ctx->frag)) {
> +		ol_flags |= PKT_RX_RSS_HASH;
> +		mbuf->hash.rss = ena_rx_ctx->hash;
> +	}
> +
>  	mbuf->ol_flags = ol_flags;
>  	mbuf->packet_type = packet_type;
>  }
> @@ -1960,6 +1967,9 @@ static int ena_dev_configure(struct rte_eth_dev *dev)
>  
>  	adapter->state = ENA_ADAPTER_STATE_CONFIG;
>  
> +	if (dev->data->dev_conf.rxmode.mq_mode & ETH_MQ_RX_RSS_FLAG)
> +		dev->data->dev_conf.rxmode.offloads |= DEV_RX_OFFLOAD_RSS_HASH;
> +

Also need to advertise this offload in 'dev_info->rx_offload_capa'.

>  	adapter->tx_selected_offloads = dev->data->dev_conf.txmode.offloads;
>  	adapter->rx_selected_offloads = dev->data->dev_conf.rxmode.offloads;
>  	return 0;
> @@ -2245,8 +2255,6 @@ static uint16_t eth_ena_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
>  			++rx_ring->rx_stats.bad_csum;
>  		}
>  
> -		mbuf->hash.rss = ena_rx_ctx.hash;
> -
>  		rx_pkts[completed] = mbuf;
>  		rx_ring->rx_stats.bytes += mbuf->pkt_len;
>  	}
>