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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 4CC48C433E0 for ; Mon, 8 Jun 2020 13:01:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23C23206C3 for ; Mon, 8 Jun 2020 13:01:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FHU9qE2P" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729051AbgFHNBg (ORCPT ); Mon, 8 Jun 2020 09:01:36 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:46280 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728245AbgFHNBf (ORCPT ); Mon, 8 Jun 2020 09:01:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591621294; 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=N4tYRK/0WF4gJ3sPDYLn/EAB8Y9lZ28vccHh6mfdyZY=; b=FHU9qE2Puzlp93xauPxSTcir0dV3lMZwwsyK505r+8E8S4p0LRaKVuDwEnwTTSg23XexjC n4zsS5JvPJ0DNU0VsAT4gozOIPeW8nwiX4PjR57bLOOByTz2qpdxmH26HbHWWyYW3znZJj KZrDIy0/v0tnhYldHke9ZlxcmTrtzXc= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-415-14a6riF7Mo6X7YLJohSHdg-1; Mon, 08 Jun 2020 09:01:29 -0400 X-MC-Unique: 14a6riF7Mo6X7YLJohSHdg-1 Received: by mail-wr1-f72.google.com with SMTP id d6so7120882wrn.1 for ; Mon, 08 Jun 2020 06:01:29 -0700 (PDT) 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:references :mime-version:content-disposition:in-reply-to; bh=N4tYRK/0WF4gJ3sPDYLn/EAB8Y9lZ28vccHh6mfdyZY=; b=sYc3R1AvjxoQM0818MArTQZq/Ooaz4X44w6zXMv44lgo9fQTFnrCoIgn1P1bKmlRSw punz3HqrFj4MSE0q0V2RkTMfO57iw29ZMh2K4ZLWLiSgJslYO1uRriwU7fv4pqVeJK+E 5ThJ3XYQP77NsO3PGO9f/5d+W1JjwYkDPOPM+jdA6KVKer82Yu2AjfmgAwwWpR+L1XR/ kNk4HSHwmqN+P3ynnBTGDy7keFIAzqSF52etJEEtOZcEy1Un9z75rUyUJSV9ybPWM+Cg tNZjnKl++KYVoeWkGBMXgG3JzbqgULCpZVzc9dZBvfeaaP7zSShKKCZLMMOgRQyYJV03 6GiQ== X-Gm-Message-State: AOAM53294xaYELPRKWBABkfUTsDr92COltzZChXzvhlfSxRJ/65YUuGF sSwJX+gwCU01Fm8J0dpKnBoBe9wa1FIOKp29NP9o3ou4S4jAb2kDLImrQXTZnw6T0VLA21ID+5O 4ucN7V0pMaBXM X-Received: by 2002:adf:d851:: with SMTP id k17mr23165018wrl.30.1591621288297; Mon, 08 Jun 2020 06:01:28 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz+ZpeCIIHsXHsXp7F2is1vc7M7N6GxGrFprOEl+lRsTOD0+vtXz9a5XQCm3jC3ps0vzgeTJg== X-Received: by 2002:adf:d851:: with SMTP id k17mr23164991wrl.30.1591621288062; Mon, 08 Jun 2020 06:01:28 -0700 (PDT) Received: from redhat.com (bzq-109-64-41-91.red.bezeqint.net. [109.64.41.91]) by smtp.gmail.com with ESMTPSA id z25sm22048079wmf.10.2020.06.08.06.01.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Jun 2020 06:01:27 -0700 (PDT) Date: Mon, 8 Jun 2020 09:01:24 -0400 From: "Michael S. Tsirkin" To: Guennadi Liakhovetski Cc: kvm@vger.kernel.org, linux-remoteproc@vger.kernel.org, virtualization@lists.linux-foundation.org, sound-open-firmware@alsa-project.org, Pierre-Louis Bossart , Liam Girdwood , Jason Wang , Ohad Ben-Cohen , Bjorn Andersson , Mathieu Poirier Subject: Re: [PATCH v3 0/5] Add a vhost RPMsg API Message-ID: <20200608090010-mutt-send-email-mst@kernel.org> References: <20200527180541.5570-1-guennadi.liakhovetski@linux.intel.com> <20200604151917-mutt-send-email-mst@kernel.org> <20200605063435.GA32302@ubuntu> <20200608073715.GA10562@ubuntu> <20200608091100.GC10562@ubuntu> <20200608051358-mutt-send-email-mst@kernel.org> <20200608101526.GD10562@ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200608101526.GD10562@ubuntu> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Jun 08, 2020 at 12:15:27PM +0200, Guennadi Liakhovetski wrote: > On Mon, Jun 08, 2020 at 05:19:06AM -0400, Michael S. Tsirkin wrote: > > On Mon, Jun 08, 2020 at 11:11:00AM +0200, Guennadi Liakhovetski wrote: > > > Update: I looked through VirtIO 1.0 and 1.1 specs, data format their, > > > including byte order, is defined on a per-device type basis. RPMsg is > > > indeed included in the spec as device type 7, but that's the only > > > mention of it in both versions. It seems RPMsg over VirtIO isn't > > > standardised yet. > > > > Yes. And it would be very good to have some standartization before we > > keep adding things. For example without any spec if host code breaks > > with some guests, how do we know which side should be fixed? > > > > > Also it looks like newer interface definitions > > > specify using "guest native endianness" for Virtual Queue data. > > > > They really don't or shouldn't. That's limited to legacy chapters. > > Some definitions could have slipped through but it's not > > the norm. I just quickly looked through the 1.1 spec and could > > not find any instances that specify "guest native endianness" > > but feel free to point them out to me. > > Oh, there you go. No, sorry, my fault, it's the other way round: "guest > native" is for legacy and LE is for current / v1.0 and up. > > > > So > > > I think the same should be done for RPMsg instead of enforcing LE? > > > > That makes hardware implementations as well as any cross-endian > > hypervisors tricky. > > Yes, LE it is then. And we need to add some text to the spec. > > In theory there could be a backward compatibility issue - in case someone > was already using virtio_rpmsg_bus.c in BE mode, but I very much doubt > that... > > Thanks > Guennadi It's probably easiest to use virtio wrappers and then we don't need to worry about it. -- MST