libeth_xdpmo_rx_hash(9)

📦 version 7.3.1, in nixpkgs unstable

💖 libeth_xdpmo_rx_hash(9) — a Kernel API Manual moment 💖

okay bestie, this page lives in the Kernel API Manual section and honestly it's giving "small function, big responsibility" ✨

🌸 NAME 🌸

libeth_xdpmo_rx_hash — converts a &libeth_rx_pt into an XDP RSS hash metadata. that's it, that's the whole gig, and she ate 💅

🦋 SYNOPSIS 🦋

int libeth_xdpmo_rx_hash (u32 *hash , enum xdp_rss_hash_type *rss_type ,
u32 val , struct libeth_rx_pt pt );

look at her. four args. zero chill. 🔥

🎀 ARGUMENTS 🎀

  • hash — a pointer to the variable where the hash gets written. she's not returning it, she's placing it, main character energy fr 💫
  • rss_type — a pointer to the variable where the hash type gets written. yes, another pointer. yes, you have to keep track. you got this 🫶
  • val — the hash value straight out of the HW descriptor. raw. unprocessed. iconic 💀
  • pt — the libeth parsed packet type. the libeth parsed one, not just any packet type, iykyk 👑

⭐ DESCRIPTION ⭐

so here's the vibe: this function handles the zeroed / not-available hash situation and converts the libeth parsed packet type into the corresponding XDP RSS hash type. lowkey the whole point of her existence 💖

she's meant to be called at the end of the xdp_metadata_ops idpf_xdpmo::xmo_rx_hash implementation. like, last. the finale. the closing number 🎬

⚠️ important caveat bestie, do not skip this: if your driver doesn't use a constant packet type lookup table but instead generates it at runtime, it must call libeth_rx_pt_gen_hash_type(pt) to generate the XDP RSS hash type for each packet type. no cap, it's a must, not a maybe 🙈

🌈 RETURN 🌈

  • 0 on success — slay ✨
  • -ENODATA when the hash is not available — she's just not there, and that's valid 😭

👑 SEE ALSO 👑

Kernel file ./include/net/libeth/xdp.h, plus the whole friend group:

struct libeth_xdp_buff(9), __LIBETH_XDP_ONSTACK_BUFF(9), LIBETH_XDP_ONSTACK_BUFF(9), libeth_xdpsq_num(9), libeth_xdpsq_shared(9), libeth_xdpsq_id(9), libeth_xdpsq_get(9), libeth_xdpsq_put(9), libeth_xdpsq_lock(9), libeth_xdpsq_unlock(9), libeth_xdpsq_deinit_timer(9), libeth_xdpsq_queue_timer(9), libeth_xdpsq_run_timer(9), enum (anonymous)(9), enum (anonymous)(9), struct libeth_xdp_tx_frame(9), struct libeth_xdp_tx_bulk(9), LIBETH_XDP_ONSTACK_BULK(9), struct libeth_xdpsq(9), struct libeth_xdp_tx_desc(9), libeth_xdp_ptr_to_priv(9), libeth_xdp_priv_to_ptr(9), libeth_xdp_tx_xmit_bulk(9), libeth_xdp_tx_queue_head(9), libeth_xdp_tx_queue_frag(9), libeth_xdp_tx_queue_bulk(9), libeth_xdp_tx_fill_stats(9), libeth_xdp_tx_fill_buf(9), __libeth_xdp_tx_flush_bulk(9), libeth_xdp_tx_flush_bulk(9), libeth_xdp_xmit_init_bulk(9), libeth_xdp_xmit_frame_dma(9), libeth_xdp_xmit_queue_head(9), libeth_xdp_xmit_queue_frag(9), libeth_xdp_xmit_queue_bulk(9), libeth_xdp_xmit_fill_buf(9), libeth_xdp_xmit_flush_bulk(9), __libeth_xdp_xmit_do_bulk(9), libeth_xdp_xmit_do_bulk(9), libeth_xdp_tx_init_bulk(9), libeth_xdp_init_buff(9), libeth_xdp_save_buff(9), libeth_xdp_return_stash(9), libeth_xdp_return_buff(9), libeth_xdp_prepare_buff(9), libeth_xdp_process_buff(9), libeth_xdp_buff_stats_frags(9), __libeth_xdp_run_prog(9), __libeth_xdp_run_flush(9), libeth_xdp_run_prog(9), __libeth_xdp_run_pass(9), libeth_xdp_run_pass(9), libeth_xdp_finalize_rx(9), LIBETH_XDP_DEFINE_TIMER(9), LIBETH_XDP_DEFINE_FLUSH_TX(9), LIBETH_XDP_DEFINE_FLUSH_XMIT(9), LIBETH_XDP_DEFINE_RUN_PROG(9), LIBETH_XDP_DEFINE_RUN_PASS(9), LIBETH_XDP_DEFINE_RUN(9), LIBETH_XDP_DEFINE_FINALIZE(9), libeth_xdp_buff_to_rq(9), __libeth_xdp_complete_tx(9), libeth_xdp_set_features(9), libeth_xdp_set_features_noredir(9)

and that's the page, bestie 🧚💜 she ships from ./include/net/libeth and her version date is October 2026 — go be normal about it 🍓

📦 where this page comes from