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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 0575CCDB482 for ; Fri, 13 Oct 2023 14:17:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qrIyg-0007k5-Nb; Fri, 13 Oct 2023 10:17:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qrIyf-0007jg-Fx for qemu-devel@nongnu.org; Fri, 13 Oct 2023 10:17:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qrIyd-0005ax-JH for qemu-devel@nongnu.org; Fri, 13 Oct 2023 10:17:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697206638; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D59iuCO7qZpWcZ+CoZHjatLd3jwhkzM8DwTkYAXXCW0=; b=fopozZaNOh/ODquHJfmnnMmKAm1hDHpiBQYM/JWk6u6pZshixgI5UGC7wBq1d46rlBdp5B llzE3eNenW78FSroPPCySRCDtZ0P91EZxjEpQxbaen8X4OasTa+mEAJzqSWOb3jdUzwdPZ 5v2OedoBJyp+ad1C7HJBZpDX9Rf+UEE= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-445-9MtCOp17Mt2Vz55nonwrVQ-1; Fri, 13 Oct 2023 10:17:17 -0400 X-MC-Unique: 9MtCOp17Mt2Vz55nonwrVQ-1 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-3f5df65fa35so14824075e9.3 for ; Fri, 13 Oct 2023 07:17:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697206635; x=1697811435; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=D59iuCO7qZpWcZ+CoZHjatLd3jwhkzM8DwTkYAXXCW0=; b=dxMvJgyLM4mHMQ4CYxO5G32kD9Nm447c3VHxRINssh9z7SHQTiYi8tP8/0NAvA49kE KWfIsKOOrCFvNRiodalm0PZNpq60M+WkVc6cnB6H705vHwr9m7krPAQg+QVAcahC6FYm c5yA/0oU2F0JYl5477kBE99hAJLg1USOxoNnISoec6MI32r1bCkBRSvqO7ZsXuNhLi9g //4onvttOPmvVEJWJCAUHuuS+4fOPK5ka3XgFSfcSoRa/pFFAFCD17YTl6ma38fSau5t 3hnirmMSzKArFQNMDTQLeiaR7lIogMjQ/2s406C26WdQLbokjPfiHzI+HZRG5YWHMsW2 RQWA== X-Gm-Message-State: AOJu0Yxl2yjLYJmusS8hoYN4jlHkbzIQkNyCOVEaB0Uq+Od3CdcakiNR JHwC+6NdvoV1VmcwEHzsnekWiBlOX3y6JNsyiVBnkq/nkyFR5LwUeSa6CWpACvoO/M6/ilKIlwN rtLanC3IVJVwJB14wb6Ud+wmXJw== X-Received: by 2002:a05:600c:5103:b0:406:8498:3d3a with SMTP id o3-20020a05600c510300b0040684983d3amr23333612wms.14.1697206635388; Fri, 13 Oct 2023 07:17:15 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGbvQXbQvrFF9w9DyxHGYIjh+8V2Uag8EotWijiogb2KOt2pkErRqEK6EmbacSp1afEVqkSag== X-Received: by 2002:a05:600c:5103:b0:406:8498:3d3a with SMTP id o3-20020a05600c510300b0040684983d3amr23333593wms.14.1697206635023; Fri, 13 Oct 2023 07:17:15 -0700 (PDT) Received: from redhat.com ([2a02:14f:175:cf7d:d542:c2ef:a65c:aaad]) by smtp.gmail.com with ESMTPSA id fk14-20020a05600c0cce00b004077227bcdesm245937wmb.26.2023.10.13.07.17.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Oct 2023 07:17:14 -0700 (PDT) Date: Fri, 13 Oct 2023 10:17:10 -0400 From: "Michael S. Tsirkin" To: Akihiko Odaki Cc: Jason Wang , qemu-devel@nongnu.org, Yuri Benditovich , Andrew Melnychenko Subject: Re: [PATCH v3 01/11] tap: Remove tap_probe_vnet_hdr_len() Message-ID: <20231013101508-mutt-send-email-mst@kernel.org> References: <20231011153944.39572-1-akihiko.odaki@daynix.com> <20231011153944.39572-2-akihiko.odaki@daynix.com> <74139826-7e06-48c0-bb1c-0b5bf708c808@daynix.com> <12412f11-4395-460f-9523-930ad9270188@daynix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <12412f11-4395-460f-9523-930ad9270188@daynix.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Oct 13, 2023 at 02:26:03PM +0900, Akihiko Odaki wrote: > On 2023/10/13 14:00, Jason Wang wrote: > > On Fri, Oct 13, 2023 at 12:14 PM Akihiko Odaki wrote: > > > > > > On 2023/10/13 10:38, Jason Wang wrote: > > > > On Wed, Oct 11, 2023 at 11:40 PM Akihiko Odaki wrote: > > > > > > > > > > It was necessary since an Linux older than 2.6.35 may implement the > > > > > virtio-net header but may not allow to change its length. Remove it > > > > > since such an old Linux is no longer supported. > > > > > > > > Where can I see this agreement? > > > > > > docs/about/build-platforms.rst says: > > > > The project aims to support the most recent major version at all times > > > > for up to five years after its initial release. Support for the > > > > previous major version will be dropped 2 years after the new major > > > > version is released or when the vendor itself drops support, whichever > > > > comes first. In this context, third-party efforts to extend the > > > > lifetime of a distro are not considered, even when they are endorsed > > > > by the vendor (eg. Debian LTS); the same is true of repositories that > > > > contain packages backported from later releases (e.g. Debian > > > > backports). Within each major release, only the most recent minor > > > > release is considered. > > > > > > > > For the purposes of identifying supported software versions available > > > > on Linux, the project will look at CentOS, Debian, Fedora, openSUSE, > > > > RHEL, SLES and Ubuntu LTS. Other distros will be assumed to ship > > > > similar software versions. > > > > Well it also says: > > > > """ > > If a platform is not listed here, it does not imply that QEMU won't > > work. If an unlisted platform has comparable software versions to a > > listed platform, there is every expectation that it will work. > > """ > > > > A lot of downstream have customized build scripts. > > Still Linux versions older than 2.6.35 do not look like "comparable software > versions to a listed platform" in my opinion. This is fine - I would be ok to replace support with an error message and failure. Not checking that a capability is supported however isn't a good idea. And once we do - do we still gain anything by not working around that? > > And is something similar to such removal that has been done for other > > subsystems? > > With commit c42e77a90d ("qemu/osdep: Remove fallback for > MAP_FIXED_NOREPLACE"), I remove the support for glibc older than 2.28. Linux > 2.6.35 is even older.