From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [Xen-devel] [PATCH v2 1/3] x86/boot: add acpi rsdp address to setup_header Date: Fri, 8 Dec 2017 09:35:16 +0100 Message-ID: <20171208083516.gc7buju6zucxnlnf@gmail.com> References: <20171207122821.30158-1-jgross@suse.com> <20171207122821.30158-2-jgross@suse.com> <20171208071653.mzyf3ct6n6h2x37r@gmail.com> <5A2A5B4C0200007800195CDC@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5A2A5B4C0200007800195CDC@prv-mh.provo.novell.com> Sender: linux-kernel-owner@vger.kernel.org To: Jan Beulich Cc: lenb@kernel.org, x86@kernel.org, tglx@linutronix.de, xen-devel@lists.xenproject.org, corbet@lwn.net, boris.ostrovsky@oracle.com, mingo@redhat.com, rjw@rjwysocki.net, Juergen Gross , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, Borislav Petkov , Matt Fleming , Ard Biesheuvel List-Id: linux-acpi@vger.kernel.org * Jan Beulich wrote: > >>> On 08.12.17 at 08:16, wrote: > > Also, a more fundamental question: why doesn't Xen use EFI to hand over > > hardware configuration details? > > Iirc the main purpose of the change here is to allow booting PVH > (guest or Dom0) with Grub2 in the middle. PVH, at least for the > time being, is something that gets away without any firmware > (and I'm pretty certain this is going to remain that way for Dom0). > ACPI tables are being built by the tool stack (guest) or hypervisor > (Dom0). Hence there simply isn't any EFI which could be used to > propagate such information. Ok, that's fair enough. If hpa (or someone else) doesn't object to the boot protocol extension this approach looks good to me in principle. Thanks, Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752845AbdLHIfb (ORCPT ); Fri, 8 Dec 2017 03:35:31 -0500 Received: from mail-wr0-f175.google.com ([209.85.128.175]:41940 "EHLO mail-wr0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752552AbdLHIfU (ORCPT ); Fri, 8 Dec 2017 03:35:20 -0500 X-Google-Smtp-Source: AGs4zMbq9+Xt3CKPMVZtq6gS5Dtzb8VslyyqfWPDOlM3QyvimT/f3GqO2eomJulqJ8CzmJs8YZMwzw== Date: Fri, 8 Dec 2017 09:35:16 +0100 From: Ingo Molnar To: Jan Beulich , "H. Peter Anvin" Cc: lenb@kernel.org, x86@kernel.org, tglx@linutronix.de, xen-devel@lists.xenproject.org, corbet@lwn.net, boris.ostrovsky@oracle.com, mingo@redhat.com, rjw@rjwysocki.net, Juergen Gross , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, Borislav Petkov , Matt Fleming , Ard Biesheuvel Subject: Re: [Xen-devel] [PATCH v2 1/3] x86/boot: add acpi rsdp address to setup_header Message-ID: <20171208083516.gc7buju6zucxnlnf@gmail.com> References: <20171207122821.30158-1-jgross@suse.com> <20171207122821.30158-2-jgross@suse.com> <20171208071653.mzyf3ct6n6h2x37r@gmail.com> <5A2A5B4C0200007800195CDC@prv-mh.provo.novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5A2A5B4C0200007800195CDC@prv-mh.provo.novell.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jan Beulich wrote: > >>> On 08.12.17 at 08:16, wrote: > > Also, a more fundamental question: why doesn't Xen use EFI to hand over > > hardware configuration details? > > Iirc the main purpose of the change here is to allow booting PVH > (guest or Dom0) with Grub2 in the middle. PVH, at least for the > time being, is something that gets away without any firmware > (and I'm pretty certain this is going to remain that way for Dom0). > ACPI tables are being built by the tool stack (guest) or hypervisor > (Dom0). Hence there simply isn't any EFI which could be used to > propagate such information. Ok, that's fair enough. If hpa (or someone else) doesn't object to the boot protocol extension this approach looks good to me in principle. Thanks, Ingo