Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759960AbcDMKZP (ORCPT ); Wed, 13 Apr 2016 06:25:15 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:43125 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759713AbcDMKZN (ORCPT ); Wed, 13 Apr 2016 06:25:13 -0400 X-IronPort-AV: E=Sophos;i="5.24,479,1454976000"; d="scan'208";a="353431220" Date: Wed, 13 Apr 2016 12:25:03 +0200 From: Roger Pau =?iso-8859-1?Q?Monn=E9?= To: "Luis R. Rodriguez" CC: George Dunlap , Matt Fleming , Michael Chang , Julien Grall , Jan Beulich , "H. Peter Anvin" , Daniel Kiper , "the arch/x86 maintainers" , =?utf-8?Q?Vojt=C4=9Bch_Pavl=C3=ADk?= , Gary Lin , xen-devel , Jeffrey Cheung , "Charles Arndol" , Stefano Stabellini , Jim Fehlig , joeyli , Borislav Petkov , Boris Ostrovsky , Juergen Gross , Andrew Cooper , Linux Kernel Mailing List , Andy Lutomirski , "David Vrabel" , Takashi Iwai , , , Julien Grall Subject: Re: [Xen-devel] HVMLite / PVHv2 - using x86 EFI boot entry Message-ID: <20160413102156.b4qwhwbqvnnpmxgw@mac> References: <20160406024027.GX1990@wotan.suse.de> <20160407185148.GL1990@wotan.suse.de> <5707BD2E.20204@citrix.com> <20160408215854.GU1990@wotan.suse.de> <20160412221225.GN1990@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20160412221225.GN1990@wotan.suse.de> User-Agent: Mutt/1.6.0-neo (2016-04-07) X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1118 Lines: 24 On Wed, Apr 13, 2016 at 12:12:25AM +0200, Luis R. Rodriguez wrote: [...] > Also, x86 does have a history of short DT use. Just pointing that its there as > an option as well. I'll Cc you on some thread about that. I don't see how this is relevant to the conversation that's going on: How many x86 hardware provide DT? I bet this is 0%. How many OSes can boot on x86 using DT? Linux maybe, certainly FreeBSD, Windows or OpenBSD won't be able to boot at all when provided a DT on x86. Is Xen going to craft a DT for x86 based on ACPI? No, because it can't parse the DSDT or other dynamic tables that contain the information about the devices in the system. I would also like to point out that DT or not DT is not really the problem here, the issue that George was trying to point out is that on x86 there's some legacy hardware that's considered to be always there, so it's presence is not signaled by ACPI, and HVMlite is _not_ emulating this hardware. It doesn't matter if the hardware description comes from ACPI or DT, this hardware is considered to be always present on PC compatible hardware. Roger.