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,DKIM_SIGNED, DKIM_VALID,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 ADD53C433DF for ; Mon, 12 Oct 2020 15:35:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E1102087D for ; Mon, 12 Oct 2020 15:35:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PKk7kuvw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390173AbgJLPfF (ORCPT ); Mon, 12 Oct 2020 11:35:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388881AbgJLPfF (ORCPT ); Mon, 12 Oct 2020 11:35:05 -0400 Received: from mail-qv1-xf43.google.com (mail-qv1-xf43.google.com [IPv6:2607:f8b0:4864:20::f43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8F16C0613D0 for ; Mon, 12 Oct 2020 08:35:04 -0700 (PDT) Received: by mail-qv1-xf43.google.com with SMTP id b19so8550445qvm.6 for ; Mon, 12 Oct 2020 08:35:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=rZy2BE4vWe0WATq26ASIIAcpYFJbKzsyX+WqgN7Rz9o=; b=PKk7kuvwqT+rrvREsw9cIK4NHOIHIwLB+51FV9UANNJodmcbHP53c1OTu5IEbLdzEj cSTBXfCmtDQCvwxSuDVjH3ALTSbcFVPHCh422oN3PRfy6ExBxwn1xGnJr0tryEOMdJIU qdSh2tDcG8c5S4ubM8+6pR6QTS6AE3R0YiNjHycC4yQPwj96TvGf1HVFS8O2TaD9Jmel kwpw69GLNApN2F7/T2IcKhuipeDE6OeswPv8r1/H9fntFDRjpIZXkCgNwpvPGRugj3Mv mBOWWOxdqeLyNf/YNQR34tJVN7L3ZFPc5EdKOIOttT+KH+NYTPHm+9W9ohuyGE3ELxrN AwBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=rZy2BE4vWe0WATq26ASIIAcpYFJbKzsyX+WqgN7Rz9o=; b=WMmEEu7+SMRz+RKZ04W3oca4WeJYwU6NfvWs4TBgZgeUorXr19o26AV8jIHNgqAeyp Tv0nAWMOaywmfAth9brHhUhqe3XaPjGkjT3JbD9wKceK9lXC+j1UGKxepvLWI+dEGFFX Mxpw4YooaVNLfTXotWEgSx23jWCwwzV36DqK3Ap/6NJfz2qcneuoqTuZovizMuileW8c aSFODLbD2bNqlDByUa6VBKbRE2IX3iFLBti0kr47RvPjJY/p0DbcokWTsvARnsO80VVQ VwhUvqIecsjgZ9FKrRUUPcAVFw4PzU2o/XgNpdjNmWvOwfF/Rh+QThr27/VBY1qhoaRf 6EYg== X-Gm-Message-State: AOAM531+cuqyraTkiwNIxashpzENuk5Fxc4YEnVlJM2NuLO3wA+l5GIE 4pBGo9QuIQQV16JLL/geJNhzuCVRWV9BLA== X-Google-Smtp-Source: ABdhPJxv854oW7bKA8EGnpqpNlg1LXuCiUtIJDwMSF8OInFgxLViEEzeIiliBfbNYDDJavFTWghNqw== X-Received: by 2002:a05:6214:292:: with SMTP id l18mr16902164qvv.42.1602516904145; Mon, 12 Oct 2020 08:35:04 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id t3sm12697807qtq.24.2020.10.12.08.35.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Oct 2020 08:35:03 -0700 (PDT) Sender: Arvind Sankar From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Mon, 12 Oct 2020 11:35:01 -0400 To: "Kirill A. Shutemov" Cc: Arvind Sankar , 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: <20201012153501.GA559681@rani.riverdale.lan> References: <20201008191623.2881677-1-nivedita@alum.mit.edu> <20201010191110.4060905-1-nivedita@alum.mit.edu> <20201010192624.GA4062867@rani.riverdale.lan> <20201012140830.vrc25x2gwo7yo4kn@black.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201012140830.vrc25x2gwo7yo4kn@black.fi.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 12, 2020 at 05:08:30PM +0300, Kirill A. Shutemov wrote: > 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 Thanks! On QEMU, it does crash without this patch.