Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753771AbcDNKN6 (ORCPT ); Thu, 14 Apr 2016 06:13:58 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:20251 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752967AbcDNKNz (ORCPT ); Thu, 14 Apr 2016 06:13:55 -0400 X-IronPort-AV: E=Sophos;i="5.24,484,1454976000"; d="scan'208";a="353681446" Subject: Re: [Xen-devel] HVMLite / PVHv2 - using x86 EFI boot entry To: "Luis R. Rodriguez" , Konrad Rzeszutek Wilk References: <20160406024027.GX1990@wotan.suse.de> <20160407185148.GL1990@wotan.suse.de> <5707BD2E.20204@citrix.com> <20160408215854.GU1990@wotan.suse.de> <20160413095428.5mcbrimvc6vxffcw@mac> <20160413185010.GX1990@wotan.suse.de> <20160413190226.GB7501@char.us.oracle.com> <20160413191408.GA1990@wotan.suse.de> CC: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Matt Fleming , , Michael Chang , Linux Kernel Mailing List , Jim Fehlig , Jan Beulich , "H. Peter Anvin" , Daniel Kiper , "the arch/x86 maintainers" , Takashi Iwai , =?UTF-8?Q?Vojt=c4=9bch_Pavl=c3=adk?= , Gary Lin , xen-devel , Jeffrey Cheung , Juergen Gross , Stefano Stabellini , Julien Grall , joeyli , Borislav Petkov , Boris Ostrovsky , Charles Arndol , "Andrew Cooper" , Julien Grall , "Andy Lutomirski" , David Vrabel , From: George Dunlap Message-ID: <570F6D5D.60700@citrix.com> Date: Thu, 14 Apr 2016 11:13:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:38.0) Gecko/20100101 Icedove/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160413191408.GA1990@wotan.suse.de> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2029 Lines: 43 On 13/04/16 20:14, Luis R. Rodriguez wrote: > On Wed, Apr 13, 2016 at 03:02:26PM -0400, Konrad Rzeszutek Wilk wrote: >> On Wed, Apr 13, 2016 at 08:50:10PM +0200, Luis R. Rodriguez wrote: >>> On Wed, Apr 13, 2016 at 11:54:29AM +0200, Roger Pau Monn? wrote: >>>> On Fri, Apr 08, 2016 at 11:58:54PM +0200, Luis R. Rodriguez wrote: >>>>> OK thanks for the clarification -- still no custom entries for Xen! >>>>> We should strive for that, at the very least. >>>>> >>>>> You do have a point about the legacy stuff. There are two options there: >>>>> >>>>> * Fold legacy support under HVMLite -- which seems to be what we >>>>> currently want to do (we should evaluate the implications and >>>>> requirements here for that); or >>>> >>>> I'm not following here. What does it mean to fold legacy support under >>>> HVMlite? HVMlite doesn't have any legacy hardware, and that's the issue when >>>> it comes to using native Linux entry points. Linux might expect some legacy >>>> PC hardware to be always present, which is not true for HVMlite. >>>> >>>> Could you please clarify this point? >>> >>> It seems there is a confusion on terms used. By folding legacy support under >>> HVMLite I meant folding legacy PV path (classic PV with PV interfaces) under >>> HVMlite. >> >> Ewww. > > Probably a confusion again on terms, by the above I meant to say what you seem > to be indicating below, which is to keep old PV guest support with PV interfaces > using a new shiny entry. > > Or are we really going to nuke full support for old PV guests ? Just to be clear: In this case "support for old PV guests" really means, "Support for running new versions of Linux in PV mode on old (non-HVMLite-capable) hypervisors". And yes, that is the plan: in 5 years' time, if you're still running Xen 4.6, to run a Linux 5.17* guest you'll have to run it in HVM mode, and you won't be able to use it as a dom0. (Xen 6.1 will still support Linux 4.5 running in PV mode, however.) -George * Making up version numbers here, obviously