From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15696C433E7 for ; Tue, 13 Oct 2020 15:47:35 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8CC16251F0 for ; Tue, 13 Oct 2020 15:47:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="ILzzLaIV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8CC16251F0 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.6301.16789 (Exim 4.92) (envelope-from ) id 1kSMWC-0001FL-0t; Tue, 13 Oct 2020 15:47:16 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 6301.16789; Tue, 13 Oct 2020 15:47:15 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kSMWB-0001FE-U6; Tue, 13 Oct 2020 15:47:15 +0000 Received: by outflank-mailman (input) for mailman id 6301; Tue, 13 Oct 2020 15:47:15 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kSMWA-0001F7-Vp for xen-devel@lists.xenproject.org; Tue, 13 Oct 2020 15:47:15 +0000 Received: from esa6.hc3370-68.iphmx.com (unknown [216.71.155.175]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id df3c3e0b-9d39-4f9a-8199-bafa4d4ad748; Tue, 13 Oct 2020 15:47:13 +0000 (UTC) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kSMWA-0001F7-Vp for xen-devel@lists.xenproject.org; Tue, 13 Oct 2020 15:47:15 +0000 X-Inumbo-ID: df3c3e0b-9d39-4f9a-8199-bafa4d4ad748 Received: from esa6.hc3370-68.iphmx.com (unknown [216.71.155.175]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id df3c3e0b-9d39-4f9a-8199-bafa4d4ad748; Tue, 13 Oct 2020 15:47:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1602604033; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=qPWmkc2ZFeFYf0b2dKh9DRNp0gTWx0DBaI4WjaMTVxw=; b=ILzzLaIV0uZY/hOZQ2hC3r+YiNr/hoZjHq3u4AJAi66RK/gKTLwrJtdT 7xOhjxdDHcqgY2HRS0NHPfObYJzvnXwcJtMQeuP8U51lKFpC5l7pHvipE LZWuGlkKkajYkqphbUv4DgOyj1AlR4NQi3gbvujfdCfJnZ01w0nHmvLK9 A=; Authentication-Results: esa6.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: 3e/y38pEDJMjCMfqTS0H0DHusp9IeEG24VUZjC0eniMrNLV744okFu+MwTwxhh6oGtINSogFDH gNaYfdD5m4KMmkZchp0RddtevJSkd0TLoEK51VBrxOerfB/dNeIvdco8tBIe7jUbcW1cC5bYru cmb5oJKSXbKXtMg1+tWDeQXWUhOd1aBQy5YcU+ISp1vykcgfGpwVOd0TnleZkgTjYa9DU6zg75 4fdTSGfT9ruU0GAGAC/rbkGq/ngg9s5nEyZ7ddUrIyzYUfD/iKvALkdrjvkaGOgpqaVeoAhzud b+k= X-SBRS: 2.5 X-MesageID: 29158354 X-Ironport-Server: esa6.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.77,371,1596513600"; d="scan'208";a="29158354" Subject: Re: [PATCH] hvmloader: flip "ACPI data" to ACPI NVS type for ACPI table region To: Jan Beulich CC: , , , , References: <1602586216-27371-1-git-send-email-igor.druzhinin@citrix.com> <56bea9a9-2509-cc39-a6fd-fb7db3e54d71@suse.com> <83f567a1-35f3-a227-830b-a59b53217f3b@citrix.com> From: Igor Druzhinin Message-ID: Date: Tue, 13 Oct 2020 16:47:10 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit On 13/10/2020 16:35, Jan Beulich wrote: > On 13.10.2020 14:59, Igor Druzhinin wrote: >> On 13/10/2020 13:51, Jan Beulich wrote: >>> As a consequence I think we will also want to adjust Xen itself to >>> automatically disable ACPI when it ends up consuming E801 data. Or >>> alternatively we should consider dropping all E801-related code (as >>> being inapplicable to 64-bit systems). >> >> I'm not following here. What Xen has to do with E801? It's a SeaBIOS implemented >> call that happened to be used by QEMU option ROM. We cannot drop it from there >> as it's part of BIOS spec. > > Any ACPI aware OS has to use E820 (and nothing else). Hence our > own use of E801 should either be dropped, or lead to the > disabling of ACPI. Otherwise real firmware using logic similar > to SeaBIOS'es (but hopefully properly accounting for holes) > could make us use ACPI table space as normal RAM. It's not us using it - it's a boot loader from QEMU in a form of option ROM that works in 16bit pre-OS environment which is not OS and relies on e801 BIOS call. I'm sure any ACPI aware OS does indeed use E820 but the problem here is not an OS. The option ROM is loaded using fw_cfg from QEMU so it's not our code. Technically it's one foreign code (QEMU boot loader) talking to another foreign code (SeaBIOS) which provides information based on E820 that we gave them. So I'm afraid decision to dynamically disable ACPI (whatever you mean by this) cannot be made by sole usage of this call by a pre-OS boot loader. Igor