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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 BC027C433E0 for ; Mon, 8 Jun 2020 11:16:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F2702072F for ; Mon, 8 Jun 2020 11:16:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729532AbgFHLQn (ORCPT ); Mon, 8 Jun 2020 07:16:43 -0400 Received: from mga07.intel.com ([134.134.136.100]:17355 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729371AbgFHLQm (ORCPT ); Mon, 8 Jun 2020 07:16:42 -0400 IronPort-SDR: rpZr5W3iBMzAwoth/g9/KtgFcfqya2pIC9fN7f1xSNnE6woowbTWpa+9bcOdkrQc8infoDNCHU 4YZDyT9g8Icw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2020 04:16:42 -0700 IronPort-SDR: dl0qMu7dTDv+wwShs4f6FCGDv2URJOMFnCoSpWPuwosIAU8FdJ3hB6cg3IQtAVv53P8j+CQP/X 1sto+gbPjG1Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,487,1583222400"; d="scan'208";a="288442494" Received: from gliakhov-mobl2.ger.corp.intel.com (HELO ubuntu) ([10.249.46.212]) by orsmga002.jf.intel.com with ESMTP; 08 Jun 2020 04:16:39 -0700 Date: Mon, 8 Jun 2020 13:16:38 +0200 From: Guennadi Liakhovetski To: "Michael S. Tsirkin" 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: <20200608111637.GE10562@ubuntu> 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> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Jun 08, 2020 at 12:15:26PM +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. I found the protocol and the message format definition: https://github.com/OpenAMP/open-amp/wiki/RPMsg-Messaging-Protocol#transport-layer---rpmsg Don't know what the best way for referencing it in the VirtIO standard would be: just a link to the source or a quote. Thanks Guennadi