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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 E822AC2B9F4 for ; Mon, 28 Jun 2021 10:59:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1EB361463 for ; Mon, 28 Jun 2021 10:59:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232745AbhF1LCF (ORCPT ); Mon, 28 Jun 2021 07:02:05 -0400 Received: from mga02.intel.com ([134.134.136.20]:21666 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232786AbhF1LCE (ORCPT ); Mon, 28 Jun 2021 07:02:04 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10028"; a="195081205" X-IronPort-AV: E=Sophos;i="5.83,305,1616482800"; d="scan'208";a="195081205" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2021 03:59:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,305,1616482800"; d="scan'208";a="407692251" Received: from ranger.igk.intel.com ([10.102.21.164]) by orsmga006.jf.intel.com with ESMTP; 28 Jun 2021 03:59:34 -0700 Date: Mon, 28 Jun 2021 12:47:21 +0200 From: Maciej Fijalkowski To: Xuan Zhuo Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, Jesse Brandeburg , Tony Nguyen , "David S. Miller" , Jakub Kicinski , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Jeff Kirsher , Krzysztof Kazimierczak , Ong Boon Leong , intel-wired-lan@lists.osuosl.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH net v2] xdp, net: fix for construct skb by xdp inside xsk zc rx Message-ID: <20210628104721.GA57589@ranger.igk.intel.com> References: <20210617145534.101458-1-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210617145534.101458-1-xuanzhuo@linux.alibaba.com> User-Agent: Mutt/1.12.1 (2019-06-15) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, Jun 17, 2021 at 10:55:34PM +0800, Xuan Zhuo wrote: > When each driver supports xsk rx, if the received buff returns XDP_PASS > after run xdp prog, it must construct skb based on xdp. This patch > extracts this logic into a public function xdp_construct_skb(). > > There is a bug in the original logic. When constructing skb, we should > copy the meta information to skb and then use __skb_pull() to correct > the data. Thanks for fixing the bug on Intel drivers, Xuan. However, together with Magnus we feel that include/net/xdp.h is not a correct place for introducing xdp_construct_skb. If mlx side could use it, then probably include/net/xdp_sock_drv.h is a better fit for that. Once again, CCing Maxim. Maxim, any chances that mlx driver could be aligned in a way that we could have a common function for creating skb on ZC path? Otherwise, maybe we should think about introducing the Intel-specific common header in tree? > > Fixes: 0a714186d3c0f ("i40e: add AF_XDP zero-copy Rx support") > Fixes: 2d4238f556972 ("ice: Add support for AF_XDP") > Fixes: bba2556efad66 ("net: stmmac: Enable RX via AF_XDP zero-copy") > Fixes: d0bcacd0a1309 ("ixgbe: add AF_XDP zero-copy Rx support") > Signed-off-by: Xuan Zhuo > --- > drivers/net/ethernet/intel/i40e/i40e_xsk.c | 16 +--------- > drivers/net/ethernet/intel/ice/ice_xsk.c | 12 +------- > drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 12 +------- > .../net/ethernet/stmicro/stmmac/stmmac_main.c | 23 +------------- > include/net/xdp.h | 30 +++++++++++++++++++ > 5 files changed, 34 insertions(+), 59 deletions(-) > > diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c > index 68f177a86403..81b0f44eedda 100644 > --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c > +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c > @@ -246,23 +246,9 @@ bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count) > static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring, > struct xdp_buff *xdp) > { > - unsigned int metasize = xdp->data - xdp->data_meta; > - unsigned int datasize = xdp->data_end - xdp->data; > struct sk_buff *skb; > > - /* allocate a skb to store the frags */ > - skb = __napi_alloc_skb(&rx_ring->q_vector->napi, > - xdp->data_end - xdp->data_hard_start, > - GFP_ATOMIC | __GFP_NOWARN); > - if (unlikely(!skb)) > - goto out; > - > - skb_reserve(skb, xdp->data - xdp->data_hard_start); > - memcpy(__skb_put(skb, datasize), xdp->data, datasize); > - if (metasize) > - skb_metadata_set(skb, metasize); > - > -out: > + skb = xdp_construct_skb(xdp, &rx_ring->q_vector->napi); > xsk_buff_free(xdp); > return skb; > } > diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c > index a1f89ea3c2bd..f95e1adcebda 100644 > --- a/drivers/net/ethernet/intel/ice/ice_xsk.c > +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c > @@ -430,22 +430,12 @@ static void ice_bump_ntc(struct ice_ring *rx_ring) > static struct sk_buff * > ice_construct_skb_zc(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf) > { > - unsigned int metasize = rx_buf->xdp->data - rx_buf->xdp->data_meta; > - unsigned int datasize = rx_buf->xdp->data_end - rx_buf->xdp->data; > - unsigned int datasize_hard = rx_buf->xdp->data_end - > - rx_buf->xdp->data_hard_start; > struct sk_buff *skb; > > - skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize_hard, > - GFP_ATOMIC | __GFP_NOWARN); > + skb = xdp_construct_skb(rx_buf->xdp, &rx_ring->q_vector->napi); > if (unlikely(!skb)) > return NULL; > > - skb_reserve(skb, rx_buf->xdp->data - rx_buf->xdp->data_hard_start); > - memcpy(__skb_put(skb, datasize), rx_buf->xdp->data, datasize); > - if (metasize) > - skb_metadata_set(skb, metasize); > - > xsk_buff_free(rx_buf->xdp); > rx_buf->xdp = NULL; > return skb; > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > index f72d2978263b..123945832c96 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c > @@ -203,22 +203,12 @@ bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count) > static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring, > struct ixgbe_rx_buffer *bi) > { > - unsigned int metasize = bi->xdp->data - bi->xdp->data_meta; > - unsigned int datasize = bi->xdp->data_end - bi->xdp->data; > struct sk_buff *skb; > > - /* allocate a skb to store the frags */ > - skb = __napi_alloc_skb(&rx_ring->q_vector->napi, > - bi->xdp->data_end - bi->xdp->data_hard_start, > - GFP_ATOMIC | __GFP_NOWARN); > + skb = xdp_construct_skb(bi->xdp, &rx_ring->q_vector->napi); > if (unlikely(!skb)) > return NULL; > > - skb_reserve(skb, bi->xdp->data - bi->xdp->data_hard_start); > - memcpy(__skb_put(skb, datasize), bi->xdp->data, datasize); > - if (metasize) > - skb_metadata_set(skb, metasize); > - > xsk_buff_free(bi->xdp); > bi->xdp = NULL; > return skb; > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index c87202cbd3d6..143ac1edb876 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -4729,27 +4729,6 @@ static void stmmac_finalize_xdp_rx(struct stmmac_priv *priv, > xdp_do_flush(); > } > > -static struct sk_buff *stmmac_construct_skb_zc(struct stmmac_channel *ch, > - struct xdp_buff *xdp) > -{ > - unsigned int metasize = xdp->data - xdp->data_meta; > - unsigned int datasize = xdp->data_end - xdp->data; > - struct sk_buff *skb; > - > - skb = __napi_alloc_skb(&ch->rxtx_napi, > - xdp->data_end - xdp->data_hard_start, > - GFP_ATOMIC | __GFP_NOWARN); > - if (unlikely(!skb)) > - return NULL; > - > - skb_reserve(skb, xdp->data - xdp->data_hard_start); > - memcpy(__skb_put(skb, datasize), xdp->data, datasize); > - if (metasize) > - skb_metadata_set(skb, metasize); > - > - return skb; > -} > - > static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue, > struct dma_desc *p, struct dma_desc *np, > struct xdp_buff *xdp) > @@ -4761,7 +4740,7 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue, > struct sk_buff *skb; > u32 hash; > > - skb = stmmac_construct_skb_zc(ch, xdp); > + skb = xdp_construct_skb(xdp, &ch->rxtx_napi); > if (!skb) { > priv->dev->stats.rx_dropped++; > return; > diff --git a/include/net/xdp.h b/include/net/xdp.h > index a5bc214a49d9..561e21eaf718 100644 > --- a/include/net/xdp.h > +++ b/include/net/xdp.h > @@ -95,6 +95,36 @@ xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start, > xdp->data_meta = meta_valid ? data : data + 1; > } > > +static __always_inline struct sk_buff * > +xdp_construct_skb(struct xdp_buff *xdp, struct napi_struct *napi) > +{ > + unsigned int metasize; > + unsigned int datasize; > + unsigned int headroom; > + struct sk_buff *skb; > + unsigned int len; > + > + /* this include metasize */ > + datasize = xdp->data_end - xdp->data_meta; > + metasize = xdp->data - xdp->data_meta; > + headroom = xdp->data_meta - xdp->data_hard_start; > + len = xdp->data_end - xdp->data_hard_start; > + > + /* allocate a skb to store the frags */ > + skb = __napi_alloc_skb(napi, len, GFP_ATOMIC | __GFP_NOWARN); > + if (unlikely(!skb)) > + return NULL; > + > + skb_reserve(skb, headroom); > + memcpy(__skb_put(skb, datasize), xdp->data_meta, datasize); > + if (metasize) { > + __skb_pull(skb, metasize); > + skb_metadata_set(skb, metasize); > + } > + > + return skb; > +} > + > /* Reserve memory area at end-of data area. > * > * This macro reserves tailroom in the XDP buffer by limiting the > -- > 2.31.0 >