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 39D29C7EE22 for ; Mon, 8 May 2023 18:12:46 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pw5Ks-0000vU-Cl; Mon, 08 May 2023 14:11:46 -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 1pw5Km-0000uY-Eg for qemu-devel@nongnu.org; Mon, 08 May 2023 14:11:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pw5Kk-0002eR-PM for qemu-devel@nongnu.org; Mon, 08 May 2023 14:11:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683569496; 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=rOVzPUBJ0Q+BKp+UL3hSIuQnYeoh2ItckY2JMbtMC00=; b=C9EdWzRIRV0d9d4dJ+EJcgDqcWMetfCgA8ZxvmwR2P+D6UfCv1z75Yc0GKHO1LJu689lOh MYkXZ1hQkPi02e9JR54aDZA6aWxS9WCpQlP2s2uQ4fFqUSqedcz7YHYSwFHRaiU9QqUfRk jPjJEg+duNwemobFpBi4htARv6UwKjA= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-668-PE10vANhP9agVM-mtVlalA-1; Mon, 08 May 2023 14:11:34 -0400 X-MC-Unique: PE10vANhP9agVM-mtVlalA-1 Received: by mail-qv1-f71.google.com with SMTP id 6a1803df08f44-61a66010dd7so23980236d6.3 for ; Mon, 08 May 2023 11:11:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683569494; x=1686161494; 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=rOVzPUBJ0Q+BKp+UL3hSIuQnYeoh2ItckY2JMbtMC00=; b=UKpdX6I+K8A2ir5wLHoicPuASp8QfQtITQOlw6BtdObOh4uBuUM5CmB+6Y7XMRtUT2 2fiV/5cf7W79yvt7utJVr2QnXMkyPNMb6XfCm1Bjp9K7K/muMr4x2JCU1EVv0Tpify8B wNLcfSzDVJNxfhEBNKSejGWnAYeGzrcG9frR1SYPFku+0ZUhshm2HBfmBZ/DsjooWU6w FN76TYJfkmMPiQ8D/bKbwqDTqbBgcsyFoj7WemwVXxrc2Gjygca9eR7XpvZhRVe+V9Z2 wPI1k4O51m7d/TG5fArHbrOuwJ51qzpDAttcHDI5bUHaUXtshU84lf5xFO+uoYaLnxlo hfPQ== X-Gm-Message-State: AC+VfDz3POCQJbG7svGZYGl0yOMqzZca+sSlWRIsFnsY1HeSCj0RPZgA b+5WpRZTrSSC9U6Dv4Maei6Dxb3EvNwR8pLUXWGajzWW47uDYqqkNl+L6dfeWoW8DreUHbhdO+g 5WnPEd3dNcSXxf4A= X-Received: by 2002:a05:6214:20e2:b0:61a:281b:9a5d with SMTP id 2-20020a05621420e200b0061a281b9a5dmr13724636qvk.5.1683569494306; Mon, 08 May 2023 11:11:34 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5teBtZhj3aQj66OlXwqgDuxvo+cuSzC/XDAv8zAScbWOY44nAAdl/Akgu3hXSdEZoSAlmW9g== X-Received: by 2002:a05:6214:20e2:b0:61a:281b:9a5d with SMTP id 2-20020a05621420e200b0061a281b9a5dmr13724611qvk.5.1683569494046; Mon, 08 May 2023 11:11:34 -0700 (PDT) Received: from redhat.com ([185.187.243.116]) by smtp.gmail.com with ESMTPSA id d14-20020a0cdb0e000000b0061b6d792ec2sm144536qvk.113.2023.05.08.11.11.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 May 2023 11:11:33 -0700 (PDT) Date: Mon, 8 May 2023 14:11:28 -0400 From: "Michael S. Tsirkin" To: Eugenio Perez Martin Cc: Xuan Zhuo , Jason Wang , Lei Yang , qemu-devel@nongnu.org Subject: Re: [PATCH] virtio-net: not enable vq reset feature unconditionally Message-ID: <20230508141103-mutt-send-email-mst@kernel.org> References: <20230504101447.389398-1-eperezma@redhat.com> <1683339216.3364966-2-xuanzhuo@linux.alibaba.com> <20230508062210-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Received-SPF: pass client-ip=170.10.133.124; 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 Mon, May 08, 2023 at 07:31:35PM +0200, Eugenio Perez Martin wrote: > On Mon, May 8, 2023 at 12:22 PM Michael S. Tsirkin wrote: > > > > On Mon, May 08, 2023 at 11:09:46AM +0200, Eugenio Perez Martin wrote: > > > On Sat, May 6, 2023 at 4:25 AM Xuan Zhuo wrote: > > > > > > > > On Thu, 4 May 2023 12:14:47 +0200, =?utf-8?q?Eugenio_P=C3=A9rez?= wrote: > > > > > The commit 93a97dc5200a ("virtio-net: enable vq reset feature") enables > > > > > unconditionally vq reset feature as long as the device is emulated. > > > > > This makes impossible to actually disable the feature, and it causes > > > > > migration problems from qemu version previous than 7.2. > > > > > > > > > > The entire final commit is unneeded as device system already enable or > > > > > disable the feature properly. > > > > > > > > > > This reverts commit 93a97dc5200a95e63b99cb625f20b7ae802ba413. > > > > > Fixes: 93a97dc5200a ("virtio-net: enable vq reset feature") > > > > > Signed-off-by: Eugenio Pérez > > > > > > > > > > --- > > > > > Tested by checking feature bit at /sys/devices/pci.../virtio0/features > > > > > enabling and disabling queue_reset virtio-net feature and vhost=on/off > > > > > on net device backend. > > > > > > > > Do you mean that this feature cannot be closed? > > > > > > > > I tried to close in the guest, it was successful. > > > > > > > > > > I'm not sure what you mean with close. If the device dataplane is > > > emulated in qemu (vhost=off), I'm not able to make the device not > > > offer it. > > > > > > > In addition, in this case, could you try to repair the problem instead of > > > > directly revert. > > > > > > > > > > I'm not following this. The revert is not to always disable the feature. > > > > > > By default, the feature is enabled. If cmdline states queue_reset=on, > > > the feature is enabled. That is true both before and after applying > > > this patch. > > > > > > However, in qemu master, queue_reset=off keeps enabling this feature > > > on the device. It happens that there is a commit explicitly doing > > > that, so I'm reverting it. > > > > > > Let me know if that makes sense to you. > > > > > > Thanks! > > > > > > question is this: > > > > DEFINE_PROP_BIT64("queue_reset", _state, _field, \ > > VIRTIO_F_RING_RESET, true) > > > > > > > > don't we need compat for 7.2 and back for this property? > > > > I think that part is already covered by commit 69e1c14aa222 ("virtio: > core: vq reset feature negotation support"). In that regard, maybe we > can simplify the patch message simply stating that queue_reset=off > does not work. > > Thanks! that compat for 7.1 and not 7.2 though? is that correct?