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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 82A5EC433E7 for ; Mon, 12 Oct 2020 14:08:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50A7920776 for ; Mon, 12 Oct 2020 14:08:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730162AbgJLOIq (ORCPT ); Mon, 12 Oct 2020 10:08:46 -0400 Received: from mga05.intel.com ([192.55.52.43]:56827 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731799AbgJLOIe (ORCPT ); Mon, 12 Oct 2020 10:08:34 -0400 IronPort-SDR: YkfdJNv7f51CxYKqkUq4TDfpBFt7HnIZdcW6RBy9hOIjWS1Y2vyW0r40vr0pGpZV+rbK7pgqgO 3SEju5/lnwyg== X-IronPort-AV: E=McAfee;i="6000,8403,9771"; a="250439094" X-IronPort-AV: E=Sophos;i="5.77,366,1596524400"; d="scan'208";a="250439094" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Oct 2020 07:08:33 -0700 IronPort-SDR: wbAGRGWAXQa1ibfUea/jP7QJf6mUAd5tHGdH8L/hm79dKaKdKhvacleFkl0isuM7S5/3jrGBr8 cTM3t7JAxeEA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,366,1596524400"; d="scan'208";a="356628626" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga007.jf.intel.com with ESMTP; 12 Oct 2020 07:08:31 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 0A663150; Mon, 12 Oct 2020 17:08:30 +0300 (EEST) Date: Mon, 12 Oct 2020 17:08:30 +0300 From: "Kirill A. Shutemov" To: Arvind Sankar Cc: x86@kernel.org, Joerg Roedel , Borislav Petkov , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/boot/64: Initialize 5-level paging variables earlier Message-ID: <20201012140830.vrc25x2gwo7yo4kn@black.fi.intel.com> References: <20201008191623.2881677-1-nivedita@alum.mit.edu> <20201010191110.4060905-1-nivedita@alum.mit.edu> <20201010192624.GA4062867@rani.riverdale.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201010192624.GA4062867@rani.riverdale.lan> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 10, 2020 at 03:26:24PM -0400, Arvind Sankar wrote: > On Sat, Oct 10, 2020 at 03:11:10PM -0400, Arvind Sankar wrote: > > Commit > > ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table") > > started using a new set of pagetables even without KASLR. > > > > After that commit, initialize_identity_maps() is called before the > > 5-level paging variables are setup in choose_random_location(), which > > will not work if 5-level paging is actually enabled. > > Note that I don't have hardware that supports 5-level paging, so this > is not actually tested with 5-level, but based on code inspection, it > shouldn't work. qemu supports it. -cpu "qemu64,+la57" -- Kirill A. Shutemov