From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54894) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da0Xy-0003LC-33 for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:10:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1da0Xu-0002ny-ST for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:10:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53506) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1da0Xu-0002nF-LY for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:10:46 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 920E2FBA4 for ; Tue, 25 Jul 2017 14:10:45 +0000 (UTC) From: "Daniel P. Berrange" Date: Tue, 25 Jul 2017 15:10:41 +0100 Message-Id: <20170725141041.1195-1-berrange@redhat.com> Subject: [Qemu-devel] [PATCH] qemu-options: document existance of versioned machine types List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , "Daniel P. Berrange" 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, -- 2.13.3