From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: How to reserve guest physical region for ACPI Date: Mon, 28 Dec 2015 10:39:04 +0800 Message-ID: <5680A0C8.6040505@linux.intel.com> References: <1449040860-19040-1-git-send-email-guangrong.xiao@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: gleb@kernel.org, mtosatti@redhat.com, stefanha@redhat.com, rth@twiddle.net, ehabkost@redhat.com, dan.j.williams@intel.com, kvm@vger.kernel.org, qemu-devel@nongnu.org To: pbonzini@redhat.com, imammedo@redhat.com, mst@redhat.com Return-path: Received: from mga02.intel.com ([134.134.136.20]:19989 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750844AbbL1Cps (ORCPT ); Sun, 27 Dec 2015 21:45:48 -0500 In-Reply-To: <1449040860-19040-1-git-send-email-guangrong.xiao@linux.intel.com> Sender: kvm-owner@vger.kernel.org List-ID: Hi Michael, Paolo, Now it is the time to return to the challenge that how to reserve guest physical region internally used by ACPI. Igor suggested that: | An alternative place to allocate reserve from could be high memory. | For pc we have "reserved-memory-end" which currently makes sure | that hotpluggable memory range isn't used by firmware (https://lists.nongnu.org/archive/html/qemu-devel/2015-11/msg00926.html) he also innovated a way to use 64-bit address in DSDT/SSDT.rev = 1: | when writing ASL one shall make sure that only XP supported | features are in global scope, which is evaluated when tables | are loaded and features of rev2 and higher are inside methods. | That way XP doesn't crash as far as it doesn't evaluate unsupported | opcode and one can guard those opcodes checking _REV object if neccesary. (https://lists.nongnu.org/archive/html/qemu-devel/2015-11/msg01010.html) Michael, Paolo, what do you think about these ideas? Thanks!