diff mbox series

[v3,14/22] net/ena: indicate Rx RSS hash presence

Message ID 20210506142526.28245-15-mk@semihalf.com (mailing list archive)
State Changes Requested, archived
Delegated to: Ferruh Yigit
Headers
Series net/ena: update ENA PMD to v2.3.0 |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Michal Krawczyk May 6, 2021, 2:25 p.m. UTC 
  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>
---
 drivers/net/ena/ena_ethdev.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Ferruh Yigit May 7, 2021, 4:47 p.m. UTC | #1 
On 5/6/2021 3:25 PM, 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>
> ---
>  drivers/net/ena/ena_ethdev.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
> index 6092288239..5d107775f4 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;
> +	}

The driver should announce the 'DEV_RX_OFFLOAD_RSS_HASH' offload capability
first, and should set 'PKT_RX_RSS_HASH' only if application requests the
'DEV_RX_OFFLOAD_RSS_HASH'.


Normally this is an optimization to not always update the 'mbuf->hash.rss' but
wait for explicit request from application for it.

But there is no practical performance gain for some PMDs and they enable it even
user does not ask for it [1] (of course if RSS is enabled), if this is same for
'ena' you can do the same.

[1]
https://git.dpdk.org/dpdk/tree/drivers/net/ixgbe/ixgbe_ethdev.c?h=v21.05-rc2#n2384

> +
>  	mbuf->ol_flags = ol_flags;
>  	mbuf->packet_type = packet_type;
>  }
> @@ -2245,8 +2252,6 @@ 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;
>  	}
>
Michal Krawczyk May 9, 2021, 2:20 p.m. UTC | #2 
pt., 7 maj 2021 o 18:47 Ferruh Yigit <ferruh.yigit@intel.com> napisał(a):
>
> On 5/6/2021 3:25 PM, 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>
> > ---
> >  drivers/net/ena/ena_ethdev.c | 9 +++++++--
> >  1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
> > index 6092288239..5d107775f4 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;
> > +     }
>
> The driver should announce the 'DEV_RX_OFFLOAD_RSS_HASH' offload capability
> first, and should set 'PKT_RX_RSS_HASH' only if application requests the
> 'DEV_RX_OFFLOAD_RSS_HASH'.
>
>
> Normally this is an optimization to not always update the 'mbuf->hash.rss' but
> wait for explicit request from application for it.
>
> But there is no practical performance gain for some PMDs and they enable it even
> user does not ask for it [1] (of course if RSS is enabled), if this is same for
> 'ena' you can do the same.
>

Thanks for the reference - ENA should do the same, I will change that in v4.

> [1]
> https://git.dpdk.org/dpdk/tree/drivers/net/ixgbe/ixgbe_ethdev.c?h=v21.05-rc2#n2384
>
> > +
> >       mbuf->ol_flags = ol_flags;
> >       mbuf->packet_type = packet_type;
> >  }
> > @@ -2245,8 +2252,6 @@ 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;
> >       }
> >
>
diff mbox series

Patch

diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index 6092288239..5d107775f4 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;
 }
@@ -2245,8 +2252,6 @@  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;
 	}