From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752638AbeDJIpU (ORCPT ); Tue, 10 Apr 2018 04:45:20 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:28561 "EHLO SMTP03.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751966AbeDJIpR (ORCPT ); Tue, 10 Apr 2018 04:45:17 -0400 X-IronPort-AV: E=Sophos;i="5.48,431,1517875200"; d="scan'208";a="51099963" Date: Tue, 10 Apr 2018 09:35:44 +0100 From: Wei Liu To: Boris Ostrovsky CC: , , , Wei Liu Subject: Re: [Xen-devel] [PATCH] xen/pvh: Indicate XENFEAT_linux_rsdp_unrestricted to Xen Message-ID: <20180410083544.q54rapngqie4ler3@citrix.com> References: <1523299904-18199-1-git-send-email-boris.ostrovsky@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1523299904-18199-1-git-send-email-boris.ostrovsky@oracle.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 09, 2018 at 02:51:44PM -0400, 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: Wei Liu