Re: [dpdk-dev] [dpdk-stable] [PATCH v3 14/22] net/ena: indicate Rx RSS hash presence
From: Ferruh Yigit <hidden>
Date: 2021-05-07 16:47:39
On 5/6/2021 3:25 PM, Michal Krawczyk wrote:
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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 <redacted> Reviewed-by: Igor Chauskin <redacted> Reviewed-by: Amit Bernstein <redacted> --- 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
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+ 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; }