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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1343AC433FE for ; Tue, 5 Oct 2021 11:11:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7973610A5 for ; Tue, 5 Oct 2021 11:11:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234238AbhJELNc (ORCPT ); Tue, 5 Oct 2021 07:13:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:60206 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234295AbhJELNa (ORCPT ); Tue, 5 Oct 2021 07:13:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633432300; 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=eeArBAcS9Q84SLX+oAxukLYME3k/d29Rm/s+++jGKPE=; b=aP4eAenUkIHLEZ2Z6l0U25AbwG87RG7D+IV7FuWxnksjI9mQgTDaF9NMNKrujf8bzFhiw0 XPWmaY12ypT9ByQFxpqcLDqy/9QBKUpVxz10WKNK8QiddY+RrlcHXa8jZKRyy8PeYNMzpu Mm5Bg+PeH08yJicSA+UsoVX7RNgBYk8= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-88-L5BF3q9sNVClJC7D7LiDrw-1; Tue, 05 Oct 2021 07:11:38 -0400 X-MC-Unique: L5BF3q9sNVClJC7D7LiDrw-1 Received: by mail-ed1-f70.google.com with SMTP id d23-20020a50f697000000b003daf215e1efso5942353edn.23 for ; Tue, 05 Oct 2021 04:11:38 -0700 (PDT) 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=eeArBAcS9Q84SLX+oAxukLYME3k/d29Rm/s+++jGKPE=; b=jbJ3emPPcmwQMAfu1r6IFtnauJ6AA0yojTUJ/fJMBbbGNgaCPG+zd7JexIiFRfcUFr eMQhLMmM8TH7odjzpv4pN8/BS49hcFJfKiOwQeZaX/4uQD0G++UndjU/iUGodCPruONv BAdn0KjSfrP1TVNYBaSO+xdaJYEp7xBx5JZxrmEpc9RH5SBYYutl87U1l8122RTFyWIe e6TmRZHokOdzHedF91Yy5ghsnrG4AuXjOW10TG0iz8xCZDBW+4R9T65fiYBtWzcsgN2z mCtbwCn8lzniZTs+4YZlLPHvcCj6oWJFQZvByM/HWebbx1JTP+YrjshTnh7VcH/1qaMn DPnA== X-Gm-Message-State: AOAM5337y/14YeCJ5PpJ2ExeEqzl8wba6HuckBpt0xKWVI28On2vD5aH +FvxZfyg3GGVo8xrtnkBN1C/pqC5/X6UqLgnea6XLK80ejYGKzXvpJdfIgd9sPlLiaofvtD+YXt MjPRfodvHlbqqhNDh2sPJNzXz X-Received: by 2002:a17:906:81da:: with SMTP id e26mr23837035ejx.296.1633432297532; Tue, 05 Oct 2021 04:11:37 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxcsiNXEPQdBdUK3S2sCQgXB8aTeyms7C9ktkEXECdOiZs9AxXkmtcIiymlmiwW6qydZSPVfw== X-Received: by 2002:a17:906:81da:: with SMTP id e26mr23837003ejx.296.1633432297372; Tue, 05 Oct 2021 04:11:37 -0700 (PDT) Received: from redhat.com ([2.55.147.134]) by smtp.gmail.com with ESMTPSA id q6sm7451568ejm.106.2021.10.05.04.11.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Oct 2021 04:11:36 -0700 (PDT) Date: Tue, 5 Oct 2021 07:11:32 -0400 From: "Michael S. Tsirkin" To: Halil Pasic Cc: linux-s390@vger.kernel.org, markver@us.ibm.com, Christian Borntraeger , qemu-devel@nongnu.org, Jason Wang , Cornelia Huck , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Xie Yongji Subject: Re: [RFC PATCH 1/1] virtio: write back features before verify Message-ID: <20211005071128-mutt-send-email-mst@kernel.org> References: <20210930012049.3780865-1-pasic@linux.ibm.com> <20210930070444-mutt-send-email-mst@kernel.org> <20211001092125.64fef348.pasic@linux.ibm.com> <20211002055605-mutt-send-email-mst@kernel.org> <87bl452d90.fsf@redhat.com> <20211004090018-mutt-send-email-mst@kernel.org> <20211005092539.145c9cc4.pasic@linux.ibm.com> <20211005035014-mutt-send-email-mst@kernel.org> <20211005124634.2a774796.pasic@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211005124634.2a774796.pasic@linux.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 05, 2021 at 12:46:34PM +0200, Halil Pasic wrote: > On Tue, 5 Oct 2021 03:53:17 -0400 > "Michael S. Tsirkin" wrote: > > > > Wouldn't a call from transport code into virtio core > > > be more handy? What I have in mind is stuff like vhost-user and vdpa. My > > > understanding is, that for vhost setups where the config is outside qemu, > > > we probably need a new command that tells the vhost backend what > > > endiannes to use for config. I don't think we can use > > > VHOST_USER_SET_VRING_ENDIAN because that one is on a virtqueue basis > > > according to the doc. So for vhost-user and similar we would fire that > > > command and probably also set the filed, while for devices for which > > > control plane is handled by QEMU we would just set the field. > > > > > > Does that sound about right? > > > > I'm fine either way, but when would you invoke this? > > With my idea backends can check the field when get_config > > is invoked. > > > > As for using this in VHOST, can we maybe re-use SET_FEATURES? > > > > Kind of hacky but nice in that it will actually make existing backends > > work... > > Basically the equivalent of this patch, just on the vhost interface, > right? Could work I have to look into it :) yep