From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C26DC433DF for ; Thu, 20 Aug 2020 19:43:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04C71208C7 for ; Thu, 20 Aug 2020 19:43:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728087AbgHTTn6 (ORCPT ); Thu, 20 Aug 2020 15:43:58 -0400 Received: from mga18.intel.com ([134.134.136.126]:6047 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726887AbgHTTn5 (ORCPT ); Thu, 20 Aug 2020 15:43:57 -0400 IronPort-SDR: aBGCAlJBhlOuy5RL3yoMj+v5DCipkv/Ryk5/AFVFJhtDL2cPt0tBh1L3OO/KHxvWnc00Oalm3Z jfoYSSXqA4Bw== X-IronPort-AV: E=McAfee;i="6000,8403,9718"; a="143028629" X-IronPort-AV: E=Sophos;i="5.76,334,1592895600"; d="scan'208";a="143028629" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2020 12:43:57 -0700 IronPort-SDR: vaSHAulyVGUhgZbbR9H3VHNWNcCnAlBmNCoF1EoiTknxQG0NWWwwkRafNVKpjMH0KITA69CEFW Fg0Re2GVZaRQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,334,1592895600"; d="scan'208";a="321003880" Received: from ranger.igk.intel.com ([10.102.21.164]) by fmsmga004.fm.intel.com with ESMTP; 20 Aug 2020 12:43:54 -0700 Date: Thu, 20 Aug 2020 21:38:14 +0200 From: Maciej Fijalkowski To: Lorenzo Bianconi Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net, lorenzo.bianconi@redhat.com, brouer@redhat.com, echaudro@redhat.com, sameehj@amazon.com, kuba@kernel.org Subject: Re: [PATCH net-next 3/6] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Message-ID: <20200820193814.GB12291@ranger.igk.intel.com> References: <08f8656e906ff69bd30915a6a37a01d5f0422194.1597842004.git.lorenzo@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <08f8656e906ff69bd30915a6a37a01d5f0422194.1597842004.git.lorenzo@kernel.org> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Aug 19, 2020 at 03:13:48PM +0200, Lorenzo Bianconi wrote: > Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and > XDP remote drivers if this is a "non-linear" XDP buffer > > Signed-off-by: Lorenzo Bianconi > --- > drivers/net/ethernet/marvell/mvneta.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c > index 832bbb8b05c8..36a3defa63fa 100644 > --- a/drivers/net/ethernet/marvell/mvneta.c > +++ b/drivers/net/ethernet/marvell/mvneta.c > @@ -2170,11 +2170,14 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, > struct bpf_prog *prog, struct xdp_buff *xdp, > u32 frame_sz, struct mvneta_stats *stats) > { > + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); > unsigned int len, data_len, sync; > u32 ret, act; > > len = xdp->data_end - xdp->data_hard_start - pp->rx_offset_correction; > data_len = xdp->data_end - xdp->data; > + > + xdp->mb = !!sinfo->nr_frags; But this set is not utilizing it from BPF side in any way. Personally I would like to see this as a part of work where BPF program would actually be taught how to rely on xdp->mb. Especially after John's comment in other patch. > act = bpf_prog_run_xdp(prog, xdp); > > /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */ > -- > 2.26.2 >