[xdp-hints] Re: [PATCH bpf-next V1 4/5] igc: add XDP hints kfuncs for RX hash

["Song, Yoong Siang" <yoong.siang.song@intel.com>]

On Monday, April 17, 2023 10:57 PM, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
>This implements XDP hints kfunc for RX-hash (xmo_rx_hash).
>The HW rss hash type is handled via mapping table.
>
>This igc driver driver (default config) does L3 hashing for UDP packets (excludes

Repeated word: driver

>UDP src/dest ports in hash calc).  Meaning RSS hash type is
>L3 based.  Tested that the igc_rss_type_num for UDP is either
>IGC_RSS_TYPE_HASH_IPV4 or IGC_RSS_TYPE_HASH_IPV6.
>
>Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
>---
> drivers/net/ethernet/intel/igc/igc_main.c |   35
>+++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
>diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
>b/drivers/net/ethernet/intel/igc/igc_main.c
>index 862768d5d134..27f448d0ae94 100644
>--- a/drivers/net/ethernet/intel/igc/igc_main.c
>+++ b/drivers/net/ethernet/intel/igc/igc_main.c
>@@ -6507,8 +6507,43 @@ static int igc_xdp_rx_timestamp(const struct xdp_md
>*_ctx, u64 *timestamp)
> 	return -ENODATA;
> }
>
>+/* Mapping HW RSS Type to enum xdp_rss_hash_type */ enum
>+xdp_rss_hash_type igc_xdp_rss_type[IGC_RSS_TYPE_MAX_TABLE] = {

Since igc_xdp_rss_type is used in igc_main.c only, suggest to make it static.

Thanks & Regards
Siang

>+	[IGC_RSS_TYPE_NO_HASH]		= XDP_RSS_TYPE_L2,
>+	[IGC_RSS_TYPE_HASH_TCP_IPV4]	= XDP_RSS_TYPE_L4_IPV4_TCP,
>+	[IGC_RSS_TYPE_HASH_IPV4]	= XDP_RSS_TYPE_L3_IPV4,
>+	[IGC_RSS_TYPE_HASH_TCP_IPV6]	= XDP_RSS_TYPE_L4_IPV6_TCP,
>+	[IGC_RSS_TYPE_HASH_IPV6_EX]	= XDP_RSS_TYPE_L3_IPV6_EX,
>+	[IGC_RSS_TYPE_HASH_IPV6]	= XDP_RSS_TYPE_L3_IPV6,
>+	[IGC_RSS_TYPE_HASH_TCP_IPV6_EX] = XDP_RSS_TYPE_L4_IPV6_TCP_EX,
>+	[IGC_RSS_TYPE_HASH_UDP_IPV4]	= XDP_RSS_TYPE_L4_IPV4_UDP,
>+	[IGC_RSS_TYPE_HASH_UDP_IPV6]	= XDP_RSS_TYPE_L4_IPV6_UDP,
>+	[IGC_RSS_TYPE_HASH_UDP_IPV6_EX] = XDP_RSS_TYPE_L4_IPV6_UDP_EX,
>+	[10] = XDP_RSS_TYPE_NONE, /* RSS Type above 9 "Reserved" by HW  */
>+	[11] = XDP_RSS_TYPE_NONE, /* keep array sized for SW bit-mask   */
>+	[12] = XDP_RSS_TYPE_NONE, /* to handle future HW revisons       */
>+	[13] = XDP_RSS_TYPE_NONE,
>+	[14] = XDP_RSS_TYPE_NONE,
>+	[15] = XDP_RSS_TYPE_NONE,
>+};
>+
>+static int igc_xdp_rx_hash(const struct xdp_md *_ctx, u32 *hash,
>+			   enum xdp_rss_hash_type *rss_type) {
>+	const struct igc_xdp_buff *ctx = (void *)_ctx;
>+
>+	if (!(ctx->xdp.rxq->dev->features & NETIF_F_RXHASH))
>+		return -ENODATA;
>+
>+	*hash = le32_to_cpu(ctx->rx_desc->wb.lower.hi_dword.rss);
>+	*rss_type = igc_xdp_rss_type[igc_rss_type(ctx->rx_desc)];
>+
>+	return 0;
>+}
>+
> const struct xdp_metadata_ops igc_xdp_metadata_ops = {
> 	.xmo_rx_timestamp		= igc_xdp_rx_timestamp,
>+	.xmo_rx_hash			= igc_xdp_rx_hash,
> };
>
> /**
>