From patchwork Wed Aug 19 09:28:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Bianconi X-Patchwork-Id: 262267 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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=no 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 C4EECC433DF for ; Wed, 19 Aug 2020 09:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BCF420639 for ; Wed, 19 Aug 2020 09:28:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597829301; bh=uCS77yLkqSqHmXUtzwGVl98ooeyqgf/ZLwCgUzgk/xo=; h=Date:From:To:Cc:Subject:List-ID:From; b=nFwq9XQgGJ/UFBjU0G9S6bNEwz54aCkHwEFsBramlkIVhCfHucI4anpdxSQhFKHcs 1czHULAhxrefpCwRk8+5/Z7ijVYJafju0/nRml7ifD1jTz4Bux9gX89VskkdADAfrp gpgaGmSb4wnx50DBW0ErYMN+/XQylwP7xLpl3AX8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726835AbgHSJ2U (ORCPT ); Wed, 19 Aug 2020 05:28:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:38404 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727098AbgHSJ2Q (ORCPT ); Wed, 19 Aug 2020 05:28:16 -0400 Received: from localhost (unknown [151.48.139.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC9EE20786; Wed, 19 Aug 2020 09:28:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597829296; bh=uCS77yLkqSqHmXUtzwGVl98ooeyqgf/ZLwCgUzgk/xo=; h=Date:From:To:Cc:Subject:From; b=b06NkbAjLDXEVHnTv1mMSQKNIJNOR4IR0jYDMXWvE3CPYR3CrM8zQ4Tls6NZkrBGg S+lKphZxDtYXqQDS/0A/HSB0nMKXVl9AoSHI/Nw0OsRkOw9UvNrgFe5JhDnSwXWFKy Le3P2HqZ7adeuT/p4lxms1PlmVGCXedXIV3CIiTo= Date: Wed, 19 Aug 2020 11:28:11 +0200 From: Lorenzo Bianconi To: andriin@fb.com Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, Jesper Dangaard Brouer , David Miller , ast@kernel.org Subject: xdp generic default option Message-ID: <20200819092811.GA2420@lore-desk> MIME-Version: 1.0 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Andrii, working on xdp multi-buff I figured out now xdp generic is the default choice if not specified by userspace. In particular after commit 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device"), running the command below, XDP will run in generic mode even if the underlay driver support XDP in native mode: $ip link set dev eth0 xdp obj prog.o $ip link show dev eth0 2: eth0: mtu 1500 xdpgeneric qdisc mq state UP mode DEFAULT group default qlen 1024 link/ether f0:ad:4e:09:6b:57 brd ff:ff:ff:ff:ff:ff prog/xdp id 1 tag 3b185187f1855c4c jited Is it better to use xdpdrv as default choice if not specified by userspace? doing something like: Regards, Lorenzo diff --git a/net/core/dev.c b/net/core/dev.c index a00aa737ce29..1f85880ee412 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -8747,9 +8747,9 @@ static enum bpf_xdp_mode dev_xdp_mode(u32 flags) { if (flags & XDP_FLAGS_HW_MODE) return XDP_MODE_HW; - if (flags & XDP_FLAGS_DRV_MODE) - return XDP_MODE_DRV; - return XDP_MODE_SKB; + if (flags & XDP_FLAGS_SKB_MODE) + return XDP_MODE_SKB; + return XDP_MODE_DRV; } static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)