pt., 7 maj 2021 o 18:47 Ferruh Yigit <ferruh.yi...@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: sta...@dpdk.org
> >
> > Signed-off-by: Michal Krawczyk <m...@semihalf.com>
> > Reviewed-by: Igor Chauskin <igo...@amazon.com>
> > Reviewed-by: Amit Bernstein <amitb...@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;
> > }
> >
>
