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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C5F7FC04A6B for ; Wed, 8 May 2019 15:24:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 930A120989 for ; Wed, 8 May 2019 15:24:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AUf5kPx0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728507AbfEHPYh (ORCPT ); Wed, 8 May 2019 11:24:37 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:41159 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726979AbfEHPYf (ORCPT ); Wed, 8 May 2019 11:24:35 -0400 Received: by mail-pg1-f196.google.com with SMTP id z3so6564937pgp.8; Wed, 08 May 2019 08:24:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=b71hcILz1f2BsDF7VpHynv0OFLT/ZIfiSJGLjPU43yY=; b=AUf5kPx0Tmfu3xXyJgA+NOYA8dG6WANaUtWI+BufsQBfQ2oVwiWc3NkSKWq2sSR53J EcniU5rSGC7WcxZleI03Joe6Wu9kmpia8ytMp6iUg3OUctENSUmYzQ4+bARmMQ4oHNIU GvM5OxbqSKyo1KKjJdcZ7LL5yNydarv0FWAbARD4QbJF+Cs3HM5/iI0kE2qYH6uX5kYR A6C+RhBjdGEMUY/9FRo2KjsONnh5GxD74wV/W8AquKrVqUQ5ioR37TxKKRHjdnvW7xDb NaQ75XeKFniqNsPPmZDb6QyPTL/y81EuNqdHPdDO9vq3TTpKerQ9aFVtkmzBLSTN3NyV U6Yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=b71hcILz1f2BsDF7VpHynv0OFLT/ZIfiSJGLjPU43yY=; b=LKRnLfsC7DxXEky+yDqUFBpPUW6nrVPynzUpT6YAaogpB7YrrAw4CX/ihANmmSLMYn TkNZnoJM5/yk8UXk/dIrYzimw3MKToo99M/420qv7GIFZe20iUaCf2E0a9qAIwaUgota RmWQaJglCJwGi0PLexyGk2LD5kjYLGdntUBPFhRwilDehfZvhrb1HUKZUx1cBzHZh4lz xqQfYH408xb7WdoIpjiTqqnG2buH47l7C4S0n3nLpJxOsrBF9UdK49Dg8UGMA0Ydegls OPXSAA2RGCbBimd5uM5WIGrdETkHh8FpjhH2MKYSSTaVwQrLgJCMjmMS4ImMOnwu4Q++ f6FA== X-Gm-Message-State: APjAAAW0SCkbIQ3ybr/+mAw8eDs/werLaUwu5bbv1NnBM4aaGsjactFT O1d8dn/N4uiJBBUYyQ6tYZY= X-Google-Smtp-Source: APXvYqwaNB/l8fZn/OAcwwo7V+MGdmUdO5M7OwTJckAfjNpQsECLdUgVRBzyifZQdREoHhzjj6kojA== X-Received: by 2002:a63:9dc8:: with SMTP id i191mr46540197pgd.91.1557329074298; Wed, 08 May 2019 08:24:34 -0700 (PDT) Received: from localhost.localdomain ([104.238.181.70]) by smtp.gmail.com with ESMTPSA id o73sm7459360pfi.137.2019.05.08.08.24.28 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 08 May 2019 08:24:33 -0700 (PDT) From: Changbin Du To: corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de Cc: x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Changbin Du , Mauro Carvalho Chehab Subject: [PATCH v4 24/27] Documentation: x86: convert x86_64/5level-paging.txt to reST Date: Wed, 8 May 2019 23:21:38 +0800 Message-Id: <20190508152141.8740-25-changbin.du@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190508152141.8740-1-changbin.du@gmail.com> References: <20190508152141.8740-1-changbin.du@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This converts the plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du Reviewed-by: Mauro Carvalho Chehab --- .../{5level-paging.txt => 5level-paging.rst} | 16 +++++++++++----- Documentation/x86/x86_64/index.rst | 1 + 2 files changed, 12 insertions(+), 5 deletions(-) rename Documentation/x86/x86_64/{5level-paging.txt => 5level-paging.rst} (91%) diff --git a/Documentation/x86/x86_64/5level-paging.txt b/Documentation/x86/x86_64/5level-paging.rst similarity index 91% rename from Documentation/x86/x86_64/5level-paging.txt rename to Documentation/x86/x86_64/5level-paging.rst index 2432a5ef86d9..ab88a4514163 100644 --- a/Documentation/x86/x86_64/5level-paging.txt +++ b/Documentation/x86/x86_64/5level-paging.rst @@ -1,5 +1,11 @@ -== Overview == +.. SPDX-License-Identifier: GPL-2.0 +============== +5-level paging +============== + +Overview +======== Original x86-64 was limited by 4-level paing to 256 TiB of virtual address space and 64 TiB of physical address space. We are already bumping into this limit: some vendors offers servers with 64 TiB of memory today. @@ -16,16 +22,17 @@ QEMU 2.9 and later support 5-level paging. Virtual memory layout for 5-level paging is described in Documentation/x86/x86_64/mm.txt -== Enabling 5-level paging == +Enabling 5-level paging +======================= CONFIG_X86_5LEVEL=y enables the feature. Kernel with CONFIG_X86_5LEVEL=y still able to boot on 4-level hardware. In this case additional page table level -- p4d -- will be folded at runtime. -== User-space and large virtual address space == - +User-space and large virtual address space +========================================== On x86, 5-level paging enables 56-bit userspace virtual address space. Not all user space is ready to handle wide addresses. It's known that at least some JIT compilers use higher bits in pointers to encode their @@ -58,4 +65,3 @@ One important case we need to handle here is interaction with MPX. MPX (without MAWA extension) cannot handle addresses above 47-bit, so we need to make sure that MPX cannot be enabled we already have VMA above the boundary and forbid creating such VMAs once MPX is enabled. - diff --git a/Documentation/x86/x86_64/index.rst b/Documentation/x86/x86_64/index.rst index 4b65d29ef459..7b8c82151358 100644 --- a/Documentation/x86/x86_64/index.rst +++ b/Documentation/x86/x86_64/index.rst @@ -10,3 +10,4 @@ x86_64 Support boot-options uefi mm + 5level-paging -- 2.20.1