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: 1347633 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=b06NkbAj; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BWjBZ1Bbmz9sTW for ; Wed, 19 Aug 2020 19:28:22 +1000 (AEST) 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)