From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da3ui-0004vM-95 for qemu-devel@nongnu.org; Tue, 25 Jul 2017 13:46:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1da3uf-0003rm-NR for qemu-devel@nongnu.org; Tue, 25 Jul 2017 13:46:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39242) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1da3uf-0003re-Ho for qemu-devel@nongnu.org; Tue, 25 Jul 2017 13:46:29 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7FAD737EEC for ; Tue, 25 Jul 2017 17:46:28 +0000 (UTC) References: <20170725141041.1195-1-berrange@redhat.com> From: John Snow Message-ID: Date: Tue, 25 Jul 2017 13:46:23 -0400 MIME-Version: 1.0 In-Reply-To: <20170725141041.1195-1-berrange@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] qemu-options: document existance of versioned machine types List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" , qemu-devel@nongnu.org Cc: Paolo Bonzini On 07/25/2017 10:10 AM, Daniel P. Berrange wrote: > The -machine docs did not explain what the versioned machine > types are for, nor that they'll be maintained across > releases. > > Signed-off-by: Daniel P. Berrange > --- > qemu-options.hx | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/qemu-options.hx b/qemu-options.hx > index 746b5fa75d..9f6e2adfff 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -49,7 +49,20 @@ STEXI > @item -machine [type=]@var{name}[,prop=@var{value}[,...]] > @findex -machine > Select the emulated machine by @var{name}. Use @code{-machine help} to list > -available machines. Supported machine properties are: > +available machines. > + > +For architectures which aim to support live migration compatibility > +across releases, each release will introduce a new versioned machine > +type. For example, the 2.8.0 release introduced machine types > +``pc-i440fx-2.8'' and ``pc-q35-2.8'' for the x86_64/i686 architectures. > + > +To allow live migration of guests from QEMU version 2.8.0, to QEMU > +version 2.9.0, the 2.9.0 version must support the ``pc-i440fx-2.8'' > +and ``pc-q35-2.8'' machines too. To allow users live migrating VMs > +to skip multiple intermediate releases when upgrading, new releases > +of QEMU will support machine types from many previous versions. > + > +Supported machine properties are: > @table @option > @item accel=@var{accels1}[:@var{accels2}[:...]] > This is used to enable an accelerator. Depending on the target architecture, > Seems like an improvement to me, but do we have any formal policy on how long we support said machine types? The new wording prompts that question. Reviewed-by: John Snow