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 1CD5EC433EF for ; Thu, 9 Dec 2021 17:56:06 +0000 (UTC) Received: from localhost ([::1]:56144 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mvNeH-0004WH-4X for qemu-devel@archiver.kernel.org; Thu, 09 Dec 2021 12:56:05 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57124) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mvNd3-00038O-Nd for qemu-devel@nongnu.org; Thu, 09 Dec 2021 12:54:50 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:25441) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mvNct-0001i6-W7 for qemu-devel@nongnu.org; Thu, 09 Dec 2021 12:54:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1639072478; 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: in-reply-to:in-reply-to:references:references; bh=7QFXA2Wvcqku9f8sx5e5vLHbXIC9rbIvqCiwyowtrDA=; b=Hgl01ZjyDWi4ltVbgFw9Q/GLUC7RRX04UEZaX3BPCf8eUfvB8BxWAqg0D9lNZjfUzM9ams zSaoLH8W9jmRZAd2xP4EtK+z07KGsrTuSFEZuu4ENB8ebC4QoJ72nUynPtuKNasxdsTpFz Qrir4kwyK4wRP5kkRPdFrgWtPWQOb0E= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-415-it6dQIYeOwmS3vRQNfiSTg-1; Thu, 09 Dec 2021 12:54:37 -0500 X-MC-Unique: it6dQIYeOwmS3vRQNfiSTg-1 Received: by mail-wr1-f69.google.com with SMTP id h13-20020adfa4cd000000b001883fd029e8so1659533wrb.11 for ; Thu, 09 Dec 2021 09:54:36 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=7QFXA2Wvcqku9f8sx5e5vLHbXIC9rbIvqCiwyowtrDA=; b=mTBKWWusCbFCcYq2v/hQ67F7B9T/BpBpSszrH8Q0VeZ+v3m2anfLbSJyuESkKSUgY1 7zVIfAJlt35j1ZBs5k6Re3+7nQdevPzBOQ6sqkEpykcmyxRdMuF0cUiDuhNjHPnH9lkG 2eINEP9b2qsaCbq9+1nLrSKfn98XvlEk0jaX71RKcbZTdSL7a5HhPcjql2omwGqjz0Q7 eyg7qRNKTc/KcTXXIEVjJZa2pM4ALSoY2vi0Z/4urK5E2gyx7E20R4raVga8aooJ9CoD JpLc5SxDxv/sz+W3M8OreLKpzFsHPSFIP4OUsYgy1maDegKnE0eIi6JAvFz1hxwspmHi Op6g== X-Gm-Message-State: AOAM531F2vt2lVqG5r+yi9lo67r+btCUq5lkVauAB9i2hiA9pwufUums MCW+sufSOoepANtoe+K/94oQ5WsVwxNNT1vO551qPRF0GU/CoSZw32AoXk/vo3tz4kRMNSyjZRn WH+r9M069PzGzP8c= X-Received: by 2002:a05:600c:3505:: with SMTP id h5mr9132115wmq.22.1639072476049; Thu, 09 Dec 2021 09:54:36 -0800 (PST) X-Google-Smtp-Source: ABdhPJwnCxVxM9C0ckSGLyuO9FTPQivI6XoWYlUZ2dd5anUbCHvmCdmiITVTqR5BAaZ76ZtJTHa1Mw== X-Received: by 2002:a05:600c:3505:: with SMTP id h5mr9132079wmq.22.1639072475828; Thu, 09 Dec 2021 09:54:35 -0800 (PST) Received: from redhat.com ([2.55.18.120]) by smtp.gmail.com with ESMTPSA id f7sm463213wri.74.2021.12.09.09.54.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Dec 2021 09:54:35 -0800 (PST) Date: Thu, 9 Dec 2021 12:54:30 -0500 From: "Michael S. Tsirkin" To: Halil Pasic Subject: Re: [RFC PATCH v2 0/5] virtio: early detect 'modern' virtio Message-ID: <20211209125419-mutt-send-email-mst@kernel.org> References: <20211112145749.618157-1-pasic@linux.ibm.com> <20211208135456-mutt-send-email-mst@kernel.org> <20211209142925.0decf425.pasic@linux.ibm.com> MIME-Version: 1.0 In-Reply-To: <20211209142925.0decf425.pasic@linux.ibm.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mst@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.618, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: , Cc: Thomas Huth , David Hildenbrand , Cornelia Huck , Richard Henderson , qemu-devel@nongnu.org, Christian Borntraeger , qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Dec 09, 2021 at 02:29:25PM +0100, Halil Pasic wrote: > On Wed, 8 Dec 2021 13:56:19 -0500 > "Michael S. Tsirkin" wrote: > > > On Fri, Nov 12, 2021 at 03:57:44PM +0100, Halil Pasic wrote: > > > This is an early RFC for a transport specific early detecton of > > > modern virtio, which is most relevant for transitional devices on big > > > endian platforms, when drivers access the config space before > > > FEATURES_OK is set. > > > > > > The most important part that is missing here is fixing all the problems > > > that arise in the situation described in the previous paragraph, when > > > the config is managed by a vhost device (and thus outside QEMU. This > > > series tackles this problem only for virtio_net+vhost as an example. If > > > this approach is deemed good, we need to do something very similar for > > > every single affected device. > > > > > > This series was only lightly tested. The vhost stuff is entirely > > > untested, unfortunately I don't have a working setup where this > > > handling would be needed (because the config space is handled in the > > > device). DPDK is not supported on s390x so at the moment I can't test > > > DPDK based setups. > > > > So this looks sane to me. Cornelia requested some name tweaks and we > > need to add vhost-user things and more devices, but otherwise we are > > good. > > Thanks for your feedback! There were several points where I could > not reach agreement with Cornelia. From your response I recon that: > > 1) I should rename virtio_force_modern() to virtio_indicate_modern() > (per maintainer request). > 2) Keep the call to virtio_set_features()? > > Is that right? > > Regards, > Halil that's my take, yes. -- MST