[PATCH net-next 16/16] idpf: add XDP RSS hash hint

Alexander Lobakin
2025-03-05T16:23:23Z

Add &xdp_metadata_ops with a callback to get RSS hash hint from the
descriptor. Declare the splitq 32-byte descriptor as 4 u64s to parse
them more efficiently when possible.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
drivers/net/ethernet/intel/idpf/xdp.h | 64 +++++++++++++++++++++++++++
drivers/net/ethernet/intel/idpf/xdp.c | 28 +++++++++++-
2 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/idpf/xdp.h b/drivers/net/ethernet/intel/idpf/xdp.h
index a2ac1b2f334f..52783a5c8e0f 100644
--- a/drivers/net/ethernet/intel/idpf/xdp.h
+++ b/drivers/net/ethernet/intel/idpf/xdp.h
@@ -107,6 +107,70 @@ static inline void idpf_xdp_tx_finalize(void *_xdpq, bool sent, bool flush)
libeth_xdpsq_unlock(&xdpq->xdp_lock);
}

+struct idpf_xdp_rx_desc {
+ aligned_u64 qw0;
+#define IDPF_XDP_RX_BUFQ BIT_ULL(47)
+#define IDPF_XDP_RX_GEN BIT_ULL(46)
+#define IDPF_XDP_RX_LEN GENMASK_ULL(45, 32)
+#define IDPF_XDP_RX_PT GENMASK_ULL(25, 16)
+
+ aligned_u64 qw1;
+#define IDPF_XDP_RX_BUF GENMASK_ULL(47, 32)
+#define IDPF_XDP_RX_EOP BIT_ULL(1)
+
+ aligned_u64 qw2;
+#define IDPF_XDP_RX_HASH GENMASK_ULL(31, 0)
+
+ aligned_u64 qw3;
+} __aligned(4 * sizeof(u64));
+static_assert(sizeof(struct idpf_xdp_rx_desc) ==
+ sizeof(struct virtchnl2_rx_flex_desc_adv_nic_3));
+
+#define idpf_xdp_rx_bufq(desc) !!((desc)->qw0 & IDPF_XDP_RX_BUFQ)
+#define idpf_xdp_rx_gen(desc) !!((desc)->qw0 & IDPF_XDP_RX_GEN)
+#define idpf_xdp_rx_len(desc) FIELD_GET(IDPF_XDP_RX_LEN, (desc)->qw0)
+#define idpf_xdp_rx_pt(desc) FIELD_GET(IDPF_XDP_RX_PT, (desc)->qw0)
+#define idpf_xdp_rx_buf(desc) FIELD_GET(IDPF_XDP_RX_BUF, (desc)->qw1)
+#define idpf_xdp_rx_eop(desc) !!((desc)->qw1 & IDPF_XDP_RX_EOP)
+#define idpf_xdp_rx_hash(desc) FIELD_GET(IDPF_XDP_RX_HASH, (desc)->qw2)
+
+static inline void
+idpf_xdp_get_qw0(struct idpf_xdp_rx_desc *desc,
+ const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+ desc->qw0 = ((const typeof(desc))rxd)->qw0;
+#else
+ desc->qw0 = ((u64)le16_to_cpu(rxd->pktlen_gen_bufq_id) << 32) |
+ ((u64)le16_to_cpu(rxd->ptype_err_fflags0) << 16);
+#endif
+}
+
+static inline void
+idpf_xdp_get_qw1(struct idpf_xdp_rx_desc *desc,
+ const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+ desc->qw1 = ((const typeof(desc))rxd)->qw1;
+#else
+ desc->qw1 = ((u64)le16_to_cpu(rxd->buf_id) << 32) |
+ rxd->status_err0_qw1;
+#endif
+}
+
+static inline void
+idpf_xdp_get_qw2(struct idpf_xdp_rx_desc *desc,
+ const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+ desc->qw2 = ((const typeof(desc))rxd)->qw2;
+#else
+ desc->qw2 = ((u64)rxd->hash3 << 24) |
+ ((u64)rxd->ff2_mirrid_hash2.hash2 << 16) |
+ le16_to_cpu(rxd->hash1);
+#endif
+}
+
void idpf_xdp_set_features(const struct idpf_vport *vport);

int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp);
diff --git a/drivers/net/ethernet/intel/idpf/xdp.c b/drivers/net/ethernet/intel/idpf/xdp.c
index 1834f217a07f..b0b4b785bf8e 100644
--- a/drivers/net/ethernet/intel/idpf/xdp.c
+++ b/drivers/net/ethernet/intel/idpf/xdp.c
@@ -386,12 +386,38 @@ int idpf_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
idpf_xdp_tx_finalize);
}

+static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
+ enum xdp_rss_hash_type *rss_type)
+{
+ const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
+ const struct idpf_rx_queue *rxq;
+ struct idpf_xdp_rx_desc desc;
+ struct libeth_rx_pt pt;
+
+ rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
+
+ idpf_xdp_get_qw0(&desc, xdp->desc);
+
+ pt = rxq->rx_ptype_lkup[idpf_xdp_rx_pt(&desc)];
+ if (!libeth_rx_pt_has_hash(rxq->xdp_rxq.dev, pt))
+ return -ENODATA;
+
+ idpf_xdp_get_qw2(&desc, xdp->desc);
+
+ return libeth_xdpmo_rx_hash(hash, rss_type, idpf_xdp_rx_hash(&desc),
+ pt);
+}
+
+static const struct xdp_metadata_ops idpf_xdpmo = {
+ .xmo_rx_hash = idpf_xdpmo_rx_hash,
+};
+
void idpf_xdp_set_features(const struct idpf_vport *vport)
{
if (!idpf_is_queue_model_split(vport->rxq_model))
return;

- libeth_xdp_set_features_noredir(vport->netdev);
+ libeth_xdp_set_features_noredir(vport->netdev, &idpf_xdpmo);
}

/**
--
2.48.1