From patchwork Tue Jun 15 16:45:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12322405 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=-21.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 53B60C48BDF for ; Tue, 15 Jun 2021 16:45:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 305376191A for ; Tue, 15 Jun 2021 16:45:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230316AbhFOQro (ORCPT ); Tue, 15 Jun 2021 12:47:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229976AbhFOQrn (ORCPT ); Tue, 15 Jun 2021 12:47:43 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3542CC061574 for ; Tue, 15 Jun 2021 09:45:39 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id j190-20020a253cc70000b029054c72781aa2so19534807yba.9 for ; Tue, 15 Jun 2021 09:45:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:message-id:mime-version:subject:from:to:cc; bh=6HZGdFlUWM4LdlL5+cotm9rGAhlwZSYKVNXCJc52TBE=; b=j9bMtMZ1Zel3jGQWMxvx1581g0LAM3fjKvw5SnIg00Xsbe8bVn93dunrjWw2rMq4Cq 54LEK/RU6P5miLuqCTjGED3cKTaOFH6cujbzfx5TG8ZdK8oHbwmlDEREd9SMOpC/9U1d EGizH6qQAYuM4z0uv5FOWe6aus8noEzFaeqk+3QO+BsiC8Y3lJ6HZxTwTlcvCYA7eEdF +LQERTO2dF7s5x2EXYjOH3mKHZEWEWch1/IfYT0WbqRXWSJiIgKct4XSNjdcklUbml7y u9ZGazlneZshx1D54e8I5se/YmQtztExmgR7VN/TmGVF/I8mSqpQPROmqkxS+6V/xxoS GV8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:message-id:mime-version:subject :from:to:cc; bh=6HZGdFlUWM4LdlL5+cotm9rGAhlwZSYKVNXCJc52TBE=; b=cQz5kyOUXAHxR5FJzMilrHETOlryKwzjTl8Ds4l2AeYPcV9hUr4aec9+LZm2nFK9VG j9s0OrDcijRDOPOaPmcIcUV28vLpsk3yFfA5q3SAPTymcn7PivlVobtWXHM2NASKgTEn +r86anHqmepQqmIs0LWh/RTbTjJtigKyQIN4mtKhPyb6jCKFgiKNtiFhw6zirl5M35lr NZp+ZD5NcrCtm70MITA6NQMcmt1MXxKWSp4u0w4O+Oem70gLsSA39Z2bxOAw201570vm HBooHHVCatqfLTo9FF+0TxanCibyP8ABRjhQKGlCUgHIqAtw1YTB9RCqNDtUI/pAFOt/ jkvw== X-Gm-Message-State: AOAM531hWQD1diPo4w9NOA1brt22JdI9DG18XzzMPW7VaUJB+SkV3SRk PsXIRSmN9O8/dy6LU7BahCPMEado5yg= X-Google-Smtp-Source: ABdhPJwijPv+0zQjSxRmkTTlgNWU/8MzeoSZ7RLtDFw5X8sp1a318M/0ZuE7ovu43XIh5DcZM4x+lJGK6bI= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:13fc:a8bd:9d6b:e5]) (user=seanjc job=sendgmr) by 2002:a25:ec12:: with SMTP id j18mr45215ybh.267.1623775538389; Tue, 15 Jun 2021 09:45:38 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 15 Jun 2021 09:45:31 -0700 Message-Id: <20210615164535.2146172-1-seanjc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.32.0.272.g935e593368-goog Subject: [PATCH 0/4] KVM: x86: Require EFER.NX support unless EPT is on From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org KVM has silently required EFER.NX support for shadow paging for well over a year, and for NPT for roughly the same amount of time. Attempting to run any VM with shadow paging on a system without NX support will fail due to invalid state, while enabling nx_huge_pages with NPT and no NX will explode due to setting a reserved bit in the page tables. I really, really wanted to require NX across the board, because the lack of bug reports for the shadow paging change strongly suggests no one is running KVM on a CPU that truly doesn't have NX. But, Intel CPUs let firmware disable NX via MISC_ENABLES, so it's plausible that there are users running KVM with EPT and no NX. Sean Christopherson (4): KVM: VMX: Refuse to load kvm_intel if EPT and NX are disabled KVM: SVM: Refuse to load kvm_amd if NX support is not available KVM: x86: WARN and reject loading KVM if NX is supported but not enabled KVM: x86: Simplify logic to handle lack of host NX support arch/x86/kvm/cpuid.c | 13 +++++-------- arch/x86/kvm/svm/svm.c | 13 ++++++++++--- arch/x86/kvm/vmx/vmx.c | 6 ++++++ arch/x86/kvm/x86.c | 3 +++ 4 files changed, 24 insertions(+), 11 deletions(-)