RE: [PATCH bpf v3 7/9] libeth, idpf: use truesize as XDP RxQ info frag_size
From: Loktionov, Aleksandr <hidden>
Date: 2026-02-17 15:06:18
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bpf, imx, intel-wired-lan, linux-kselftest, lkml
-----Original Message----- From: Zaremba, Larysa <redacted> Sent: Tuesday, February 17, 2026 2:25 PM To: bpf@vger.kernel.org Cc: Zaremba, Larysa <redacted>; Claudiu Manoil [off-list ref]; Vladimir Oltean [off-list ref]; Wei Fang [off-list ref]; Clark Wang [off-list ref]; Andrew Lunn [off-list ref]; David S. Miller [off-list ref]; Eric Dumazet [off-list ref]; Jakub Kicinski [off-list ref]; Paolo Abeni [off-list ref]; Nguyen, Anthony L [off-list ref]; Kitszel, Przemyslaw [off-list ref]; Alexei Starovoitov [off-list ref]; Daniel Borkmann [off-list ref]; Jesper Dangaard Brouer [off-list ref]; John Fastabend [off-list ref]; Stanislav Fomichev [off-list ref]; Andrii Nakryiko [off-list ref]; Martin KaFai Lau [off-list ref]; Eduard Zingerman [off-list ref]; Song Liu [off-list ref]; Yonghong Song [off-list ref]; KP Singh [off-list ref]; Hao Luo [off-list ref]; Jiri Olsa [off-list ref]; Simon Horman [off-list ref]; Shuah Khan [off-list ref]; Lobakin, Aleksander [off-list ref]; Fijalkowski, Maciej [off-list ref]; Bastien Curutchet (eBPF Foundation) [off-list ref]; Vyavahare, Tushar [off-list ref]; Jason Xing [off-list ref]; Ricardo B. Marlière [off-list ref]; Eelco Chaudron [off-list ref]; Lorenzo Bianconi [off-list ref]; Toke Hoiland-Jorgensen [off-list ref]; imx@lists.linux.dev; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; intel-wired- lan@lists.osuosl.org; linux-kselftest@vger.kernel.org; Loktionov, Aleksandr [off-list ref]; Dragos Tatulea [off-list ref] Subject: [PATCH bpf v3 7/9] libeth, idpf: use truesize as XDP RxQ info frag_size The only user of frag_size field in XDP RxQ info is bpf_xdp_frags_increase_tail(). It clearly expects whole buffer size instead of DMA write size. Different assumptions in idpf driver configuration lead to negative tailroom. To make it worse, buffer sizes are not actually uniform in idpf when splitq is enabled, as there are several buffer queues, so rxq-quoted
rx_buf_size is meaningless in this case.Use truesize of the first bufq in AF_XDP ZC, as there is only one. Disable growinf tail for regular splitq.
"growing" -> " growing" ? Otherwise fine Reviewed-by: Aleksandr Loktionov <redacted>
quoted hunk ↗ jump to hunk
Fixes: ac8a861f632e ("idpf: prepare structures to support XDP") Signed-off-by: Larysa Zaremba <redacted> --- drivers/net/ethernet/intel/idpf/xdp.c | 6 +++++- drivers/net/ethernet/intel/idpf/xsk.c | 1 + drivers/net/ethernet/intel/libeth/xsk.c | 1 + include/net/libeth/xsk.h | 3 +++ 4 files changed, 10 insertions(+), 1 deletion(-)diff --git a/drivers/net/ethernet/intel/idpf/xdp.cb/drivers/net/ethernet/intel/idpf/xdp.c index 958d16f87424..7d91f21174de 100644--- a/drivers/net/ethernet/intel/idpf/xdp.c +++ b/drivers/net/ethernet/intel/idpf/xdp.c@@ -46,11 +46,15 @@ static int __idpf_xdp_rxq_info_init(structidpf_rx_queue *rxq, void *arg) { const struct idpf_vport *vport = rxq->q_vector->vport; bool split = idpf_is_queue_model_split(vport->rxq_model); + u32 frag_size = 0; int err; + if (idpf_queue_has(XSK, rxq)) + frag_size = rxq->bufq_sets[0].bufq.truesize; + err = __xdp_rxq_info_reg(&rxq->xdp_rxq, vport->netdev, rxq-quoted
idx,rxq->q_vector->napi.napi_id, - rxq->rx_buf_size); + frag_size); if (err) return err;diff --git a/drivers/net/ethernet/intel/idpf/xsk.cb/drivers/net/ethernet/intel/idpf/xsk.c index fd2cc43ab43c..95a665cb2f33 100644--- a/drivers/net/ethernet/intel/idpf/xsk.c +++ b/drivers/net/ethernet/intel/idpf/xsk.c@@ -401,6 +401,7 @@ int idpf_xskfq_init(struct idpf_buf_queue *bufq) bufq->pending = fq.pending; bufq->thresh = fq.thresh; bufq->rx_buf_size = fq.buf_len; + bufq->truesize = fq.truesize; if (!idpf_xskfq_refill(bufq)) netdev_err(bufq->pool->netdev,diff --git a/drivers/net/ethernet/intel/libeth/xsk.cb/drivers/net/ethernet/intel/libeth/xsk.c index 846e902e31b6..4882951d5c9c 100644--- a/drivers/net/ethernet/intel/libeth/xsk.c +++ b/drivers/net/ethernet/intel/libeth/xsk.c@@ -167,6 +167,7 @@ int libeth_xskfq_create(struct libeth_xskfq *fq) fq->pending = fq->count; fq->thresh = libeth_xdp_queue_threshold(fq->count); fq->buf_len = xsk_pool_get_rx_frame_size(fq->pool); + fq->truesize = xsk_pool_get_rx_frag_step(fq->pool); return 0; }diff --git a/include/net/libeth/xsk.h b/include/net/libeth/xsk.h index481a7b28e6f2..82b5d21aae87 100644--- a/include/net/libeth/xsk.h +++ b/include/net/libeth/xsk.h@@ -597,6 +597,7 @@ __libeth_xsk_run_pass(struct libeth_xdp_buff *xdp, * @pending: current number of XSkFQEs to refill * @thresh: threshold below which the queue is refilled * @buf_len: HW-writeable length per each buffer + * @truesize: step between consecutive buffers, 0 if none exists * @nid: ID of the closest NUMA node with memory */ struct libeth_xskfq {@@ -614,6 +615,8 @@ struct libeth_xskfq { u32 thresh; u32 buf_len; + u32 truesize; + int nid; }; --2.52.0