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=-1.8 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 666F5C432C0 for ; Sun, 1 Dec 2019 16:40:56 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3188620718 for ; Sun, 1 Dec 2019 16:40:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ewfZ9rhF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3188620718 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52998 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ibSHH-0002Wu-5U for qemu-devel@archiver.kernel.org; Sun, 01 Dec 2019 11:40:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42227) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ibSGM-00021q-Ni for qemu-devel@nongnu.org; Sun, 01 Dec 2019 11:39:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ibSGL-0004nB-M2 for qemu-devel@nongnu.org; Sun, 01 Dec 2019 11:39:58 -0500 Received: from mail-io1-xd36.google.com ([2607:f8b0:4864:20::d36]:36826) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1ibSGL-0004mT-HD for qemu-devel@nongnu.org; Sun, 01 Dec 2019 11:39:57 -0500 Received: by mail-io1-xd36.google.com with SMTP id l17so11333389ioj.3 for ; Sun, 01 Dec 2019 08:39:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=nrzdauqQjl+Gtu4h2eEhHK1/fwKIUPO8zlYq2SyP7VU=; b=ewfZ9rhFb16403kL4WxpLnimNbUG0wY3issAExVqK4oYlk5emArVaen+d8V4glbP4D j79zQFiQqDjdtH+m3HqXclV7wgEVsDJ3WmXz+B6Ui9wr3wHE4WCO5boTDLCQSV7luMmg PfHyUFtngtYsV3R7I/y2yjx7OZaqwCNQjI+yRaBvHxqJJ0BIvDT5CD+6Xn1Jq+RLBpCp J7rPkdgMo66/vwFp0uyU60wwut9eI8vpH/oJ5jGcRQtx8IpsjQ/q6fr1hv+OEVi41eU4 PHtDcdrowVPLVCdOpyRvMaUJqNgSZKcSTZG1RQ4J8hskjKAgZO3T8LO4Rmnk0vd4DfCI cUGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=nrzdauqQjl+Gtu4h2eEhHK1/fwKIUPO8zlYq2SyP7VU=; b=fIsrqCLwogUDAvZTCGKpganM2mj1NnlTLRi464CCVsg7dr3ZcQnQz1fvkJ5SfGs4at OsU2gEIp4rcfD1qNUpBibYvSmyhegUDkyukjqYVl3F12VQXLMWoHqmvZPHbY0BFx5aXd 2mRpXCINIqws9TK5HUvG/tuJYHq9oz/cIA4kMA51NBusuyUmyw50UxargiilJGbM6bGf xIO8JQYGCE+/QDO4f3dKIvKF5zqoGtJU7ieNvT8eDvRrcyETW/JeZcPlN+ubnQWybPiT K2tRzAxkzdrZOUhahCgs/9dbcUbFD2INqh4lg1xz7qJUOCGKln/zOumV3BdQsikPyjIA zk/w== X-Gm-Message-State: APjAAAUqVdRod52W217cMooCmbtAo7oVGbszVLZyAW+REw/E23pTUuNL V/eVLxAdNXwHB+va8R/eqJk= X-Google-Smtp-Source: APXvYqzkylSQoi2vRq1vJFxYRl9Rz/plJFEp27CXda6upU9mu10SEPZ9DxmxSQWBQOOEjpdZIFouWA== X-Received: by 2002:a02:ac0a:: with SMTP id a10mr25083180jao.53.1575218396476; Sun, 01 Dec 2019 08:39:56 -0800 (PST) Received: from dahern-DO-MB.local ([2601:282:800:fd80:fd6b:fde:b20f:61ed]) by smtp.googlemail.com with ESMTPSA id 3sm2406097iow.71.2019.12.01.08.39.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 01 Dec 2019 08:39:55 -0800 (PST) Subject: Re: [RFC net-next 08/18] tun: run offloaded XDP program in Tx path To: Prashant Bhole , "David S . Miller" , "Michael S . Tsirkin" References: <20191126100744.5083-1-prashantbhole.linux@gmail.com> <20191126100744.5083-9-prashantbhole.linux@gmail.com> From: David Ahern Message-ID: Date: Sun, 1 Dec 2019 09:39:54 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191126100744.5083-9-prashantbhole.linux@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::d36 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Song Liu , Jakub Kicinski , Jesper Dangaard Brouer , Daniel Borkmann , netdev@vger.kernel.org, Jason Wang , John Fastabend , Alexei Starovoitov , qemu-devel@nongnu.org, kvm@vger.kernel.org, Yonghong Song , Andrii Nakryiko , Martin KaFai Lau Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 11/26/19 4:07 AM, Prashant Bhole wrote: > run offloaded XDP program as soon as packet is removed from the ptr > ring. Since this is XDP in Tx path, the traditional handling of > XDP actions XDP_TX/REDIRECT isn't valid. For this reason we call > do_xdp_generic_core instead of do_xdp_generic. do_xdp_generic_core > just runs the program and leaves the action handling to us. What happens if an offloaded program returns XDP_REDIRECT? Below you just drop the packet which is going to be a bad user experience. A better user experience is to detect XDP return codes a program uses, catch those that are not supported for this use case and fail the install of the program.