From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752099AbeDJFcr (ORCPT ); Tue, 10 Apr 2018 01:32:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:58291 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751851AbeDJFcr (ORCPT ); Tue, 10 Apr 2018 01:32:47 -0400 Subject: Re: [PATCH] xen/pvh: Indicate XENFEAT_linux_rsdp_unrestricted to Xen To: Boris Ostrovsky , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org References: <1523299904-18199-1-git-send-email-boris.ostrovsky@oracle.com> From: Juergen Gross Message-ID: Date: Tue, 10 Apr 2018 07:32:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <1523299904-18199-1-git-send-email-boris.ostrovsky@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/04/18 20:51, Boris Ostrovsky wrote: > Pre-4.17 kernels ignored start_info's rsdp_paddr pointer and instead > relied on finding RSDP in standard location in BIOS RO memory. This > has worked since that's where Xen used to place it. > > However, with recent Xen change (commit 4a5733771e6f ("libxl: put RSDP > for PVH guest near 4GB")) it prefers to keep RSDP at a "non-standard" > address. Even though as of commit b17d9d1df3c3 ("x86/xen: Add pvh > specific rsdp address retrieval function") Linux is able to find RSDP, > for back-compatibility reasons we need to indicate to Xen that we can > handle this, an we do so by setting XENFEAT_linux_rsdp_unrestricted > flag in ELF notes. > > (Also take this opportunity and sync features.h header file with Xen) > > Signed-off-by: Boris Ostrovsky Reviewed-by: Juergen Gross Juergen