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 62795C433FE for ; Thu, 30 Sep 2021 09:17:30 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id CDCC16140F for ; Thu, 30 Sep 2021 09:17:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org CDCC16140F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:33340 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mVsC0-0001YH-H9 for qemu-devel@archiver.kernel.org; Thu, 30 Sep 2021 05:17:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59450) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVsBG-0000sN-C8 for qemu-devel@nongnu.org; Thu, 30 Sep 2021 05:16:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:29862) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVsBC-0003iU-AR for qemu-devel@nongnu.org; Thu, 30 Sep 2021 05:16:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632993395; 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=bU6iTf9NKjMwaTTohBE4uLjKrjvIH62Ik2WPu2ZKE/g=; b=XX3h/K/La+bYHBCgGVEnTYTTRCSXSwaYoAs0oAv34YCu4B6dq/k41dHfsfIiLYcvbSkP4x s767eFRstFKspS72jWI7MQ+seCVoy4tHG6/hGUBozK+5/qDbGqR+EbOjkngWbCvPvhE2HI 9eY3aPjjD+pldyHCipYS8Gdo4XMnpzM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-11-eTnwj0nMOxG_MHItN8RbQA-1; Thu, 30 Sep 2021 05:16:27 -0400 X-MC-Unique: eTnwj0nMOxG_MHItN8RbQA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 179298143FF for ; Thu, 30 Sep 2021 09:16:27 +0000 (UTC) Received: from localhost (unknown [10.39.194.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 49CB35C23A; Thu, 30 Sep 2021 09:16:21 +0000 (UTC) Date: Thu, 30 Sep 2021 10:16:20 +0100 From: "Richard W.M. Jones" To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Subject: Re: [PATCH 0/1] vmx: Fix mapping Message-ID: <20210930091620.GX3361@redhat.com> References: <20210929092044.GE3361@redhat.com> <20210929095719.GH3361@redhat.com> <20210929103400.GJ3361@redhat.com> <20210930073348.GL7596@redhat.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=rjones@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=rjones@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: libvir-list@redhat.com, Michal Privoznik , lersek@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Sep 30, 2021 at 09:47:01AM +0100, Daniel P. Berrangé wrote: > On Thu, Sep 30, 2021 at 08:33:48AM +0100, Richard W.M. Jones wrote: > > I propose we deprecate the guid parameter in: > > > > -device vmgenid,guid=8987940a-0951-2cc5-e815-10634ff550b9,id=vmgenid0 > > > > Instead it will be replaced by bytes= which will simply write > > the bytes, in the order they appear, into guest memory with no > > attempt to interpret or byte-swap. Something like: > > > > -device vmgenid,bytes=112233445566778899aabbccddeeff00,id=vmgenid0 > > > > (guid although deprecated will need to be kept around for a while, > > along with its weird byte-swapping behaviour). > > > > We will then have a plain and simple method to emulate the behaviour > > of other hypervisors. We will look at exactly what bytes they write > > to guest memory and copy that behaviour when v2v converting from those > > hypervisors. > > From the libvirt POV, I'm not expecting anything in QEMU to change > in this respect. If guid is replaced by a new attribute taking data > in a different way, then libvirt will have to remap itself, so that > existing usage in libvirt keeps working the same way as it did with > guid. Essentially from libvirt's POV, it is simply a documentation > issue to specify how the libvirt XML representation translates to > the guest visible representation, and ensure that all libvirt drivers > implement it the same way. The QEMU genid support arrived first so > that set the standard for how libvirt will represent it, that all > further libvirt hypervisor drivers need to match. I was going to suggest something like: aa-bb-cc.. or aabbcc.. with the type defaulting to guid for backwards compatibility. Does libvirt XML have any other fields were you're passing essentially small snippets of binary data? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org