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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,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 C7AFFC433FF for ; Fri, 9 Aug 2019 00:05:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95F7A208C4 for ; Fri, 9 Aug 2019 00:05:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="CwvrFR0o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404533AbfHIAFR (ORCPT ); Thu, 8 Aug 2019 20:05:17 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:32992 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733258AbfHIAFQ (ORCPT ); Thu, 8 Aug 2019 20:05:16 -0400 Received: by mail-qt1-f195.google.com with SMTP id v38so1761741qtb.0 for ; Thu, 08 Aug 2019 17:05:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=eMbvkJMMhKVoLdAFucGO2xR/SA34OH5l6Gu6lVMIR7U=; b=CwvrFR0on7zstKP9Y3NJqU8QU4jCWc2ggN8bYirEiSk8qRGADjaxByhPr8NVVxo0Qu /c8gK91UpzBrsU5QshTPwcMRWIs93BZqUm1ZF7mGgYYLP1n1VFEbk8FvihwzcmPULmhF HeaKL5pR6gAdjhtu+nw8Ff2OBwGMFnKyiBwFpE5PLqJhZgmJxjJYUvfm4olYZo/WxjH/ nLjd+X9Nqmj1Yht13H4fyzM0YAEGjPi6AUsR5KQ6tKJLUXcM39eNo1GthogGAQ6KOx0w vSVwhk2iQx6CGR2AZC79acnPcPcjaCU3Vnefun+Ve5GeDiPhrOJCVJ4ZEsubzk0AQIAC DLGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=eMbvkJMMhKVoLdAFucGO2xR/SA34OH5l6Gu6lVMIR7U=; b=dnbNvCZz8+XycoXOMLmhol0OuwyIMmog1u0awdgNDn7AewSVSQY2SrnV/Z/QZDoCyi mz/qKTLKMYqje5Vf7nJp0fDx/errca07bMTxKtptDENCgtjwdEQLLA4B64mamrMBr+2k 5NvvqJJ4GSDdNDxYxGAvULHdXq/HO8HCZ1TLptPriC177UPnKLpZEStT1Vjd8n2zqkfo UnJOyq74R34ddIuvNWdjlwbpXcreIFO8CGC8vrTgcNTULiA5fHBf0Qq7jwEt75wo+xLX Xm2MKdG+dgoZc2xVYjNKHC+vrZ2+U84tvhe9prbS/jv0x1F6GtZM9zVmqR81KS/zTVV9 382Q== X-Gm-Message-State: APjAAAVAZoAF59I39NJdjp++kvgcpKtRea6wBQbrqc7JJrxWhjA1YsXU BPJUZbTxIvNb0s/mSqlIyJG7NQ== X-Google-Smtp-Source: APXvYqzqUxyxCPIKqh4D/S3W6yFAx0r/OSLty4LcwBDCAVZor66kQACwwgYdrsxGu6A9I15oMFfKNg== X-Received: by 2002:ac8:72d1:: with SMTP id o17mr8713168qtp.212.1565309115539; Thu, 08 Aug 2019 17:05:15 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id 18sm43622992qkh.77.2019.08.08.17.05.14 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 08 Aug 2019 17:05:15 -0700 (PDT) Date: Thu, 8 Aug 2019 17:05:11 -0700 From: Jakub Kicinski To: Y Song Cc: Maciej Fijalkowski , "Daniel T. Lee" , Daniel Borkmann , Alexei Starovoitov , netdev Subject: Re: [v3,2/4] tools: bpftool: add net detach command to detach XDP on interface Message-ID: <20190808170511.08bc93fc@cakuba.netronome.com> In-Reply-To: References: <20190807022509.4214-1-danieltimlee@gmail.com> <20190807022509.4214-3-danieltimlee@gmail.com> <20190807203041.000020a8@gmail.com> <20190807223807.00002740@gmail.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 8 Aug 2019 12:52:11 -0700, Y Song wrote: > > Ah ok. In this scenario if driver has a native xdp support we would be invoking > > its ndo_bpf even if there's no prog currently attached and it wouldn't return > > error value. > > > > Looking at dev_xdp_uninstall, setting driver's prog to NULL is being done only > > when prog is attached. Maybe we should consider querying the driver in > > dev_change_xdp_fd regardless of passed fd value? E.g. don't query only when > > prog >= 0. > > > > I don't recall whether this was brought up previously. > > Thanks for explanation. I think return an error is better in > such error cases. Otherwise, people mistakenly write wrong > device name and they may think xdp is detached and it is > actually not. > > But this probably should not prevent > this patch as it is more like a kernel issue. Agreed, we'd probably need a flag here, similar to IF_NOEXIST to keep backward compat.