From: Simon Horman <[email protected]> Date: Thu, 31 Jul 2025 14:35:57 +0100
> On Wed, Jul 30, 2025 at 06:07:15PM +0200, Alexander Lobakin wrote: >> Use libeth XDP infra to support running XDP program on Rx polling. >> This includes all of the possible verdicts/actions. >> XDP Tx queues are cleaned only in "lazy" mode when there are less than >> 1/4 free descriptors left on the ring. libeth helper macros to define >> driver-specific XDP functions make sure the compiler could uninline >> them when needed. >> Use __LIBETH_WORD_ACCESS to parse descriptors more efficiently when >> applicable. It really gives some good boosts and code size reduction >> on x86_64. >> >> Co-developed-by: Michal Kubiak <[email protected]> >> Signed-off-by: Michal Kubiak <[email protected]> >> Signed-off-by: Alexander Lobakin <[email protected]> > > ... > >> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c >> b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > > ... > >> @@ -3127,14 +3125,12 @@ static bool idpf_rx_process_skb_fields(struct >> sk_buff *skb, >> return !__idpf_rx_process_skb_fields(rxq, skb, xdp->desc); >> } >> >> -static void >> -idpf_xdp_run_pass(struct libeth_xdp_buff *xdp, struct napi_struct *napi, >> - struct libeth_rq_napi_stats *ss, >> - const struct virtchnl2_rx_flex_desc_adv_nic_3 *desc) >> -{ >> - libeth_xdp_run_pass(xdp, NULL, napi, ss, desc, NULL, >> - idpf_rx_process_skb_fields); >> -} >> +LIBETH_XDP_DEFINE_START(); >> +LIBETH_XDP_DEFINE_RUN(static idpf_xdp_run_pass, idpf_xdp_run_prog, >> + idpf_xdp_tx_flush_bulk, idpf_rx_process_skb_fields); >> +LIBETH_XDP_DEFINE_FINALIZE(static idpf_xdp_finalize_rx, >> idpf_xdp_tx_flush_bulk, >> + idpf_xdp_tx_finalize); >> +LIBETH_XDP_DEFINE_END(); >> >> /** >> * idpf_rx_hsplit_wa - handle header buffer overflows and split errors >> @@ -3222,7 +3218,10 @@ static int idpf_rx_splitq_clean(struct idpf_rx_queue >> *rxq, int budget) >> struct libeth_rq_napi_stats rs = { }; >> u16 ntc = rxq->next_to_clean; >> LIBETH_XDP_ONSTACK_BUFF(xdp); >> + LIBETH_XDP_ONSTACK_BULK(bq); >> >> + libeth_xdp_tx_init_bulk(&bq, rxq->xdp_prog, rxq->xdp_rxq.dev, >> + rxq->xdpsqs, rxq->num_xdp_txq); >> libeth_xdp_init_buff(xdp, &rxq->xdp, &rxq->xdp_rxq); >> >> /* Process Rx packets bounded by budget */ >> @@ -3318,11 +3317,13 @@ static int idpf_rx_splitq_clean(struct idpf_rx_queue >> *rxq, int budget) >> if (!idpf_rx_splitq_is_eop(rx_desc) || unlikely(!xdp->data)) >> continue; >> >> - idpf_xdp_run_pass(xdp, rxq->napi, &rs, rx_desc); >> + idpf_xdp_run_pass(xdp, &bq, rxq->napi, &rs, rx_desc); >> } >> >> rxq->next_to_clean = ntc; >> + >> libeth_xdp_save_buff(&rxq->xdp, xdp); >> + idpf_xdp_finalize_rx(&bq); > > This will call __libeth_xdp_finalize_rx(), which calls rcu_read_unlock(). > But there doesn't seem to be a corresponding call to rcu_read_lock() > > Flagged by Sparse. It's false-positive, rcu_read_lock() is called in tx_init_bulk(). > >> >> u64_stats_update_begin(&rxq->stats_sync); >> u64_stats_add(&rxq->q_stats.packets, rs.packets); Thanks, Olek
