Commit 75d92289 authored by Larysa Zaremba's avatar Larysa Zaremba Committed by Jakub Kicinski
Browse files

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->rx_buf_size
is meaningless in this case.

Use truesize of the first bufq in AF_XDP ZC, as there is only one. Disable
growing tail for regular splitq.

Fixes: ac8a861f ("idpf: prepare structures to support XDP")
Reviewed-by: default avatarAleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: default avatarLarysa Zaremba <larysa.zaremba@intel.com>
Link: https://patch.msgid.link/20260305111253.2317394-8-larysa.zaremba@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c69d22c6

drivers/net/ethernet/intel/idpf/xdp.c

+5 −1
Original line number Diff line number Diff line
@@ -47,12 +47,16 @@ static int __idpf_xdp_rxq_info_init(struct idpf_rx_queue *rxq, void *arg) 
{

	const struct idpf_vport *vport = rxq->q_vector->vport;

	const struct idpf_q_vec_rsrc *rsrc;

	u32 frag_size = 0;

	bool split;

	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->idx,

				 rxq->q_vector->napi.napi_id,

				 rxq->rx_buf_size);

				 frag_size);

	if (err)

		return err;

drivers/net/ethernet/intel/idpf/xsk.c

+1 −0
Original line number Diff line number Diff line
@@ -403,6 +403,7 @@ 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,

drivers/net/ethernet/intel/libeth/xsk.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

}

include/net/libeth/xsk.h

+3 −0
Original line number Diff line number Diff line
@@ -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;

};