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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 094E1C433DF for ; Wed, 17 Jun 2020 22:53:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D238C21534 for ; Wed, 17 Jun 2020 22:53:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gzQGj00u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726848AbgFQWxC (ORCPT ); Wed, 17 Jun 2020 18:53:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726758AbgFQWxC (ORCPT ); Wed, 17 Jun 2020 18:53:02 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBEB8C06174E for ; Wed, 17 Jun 2020 15:53:01 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id x207so1858690pfc.5 for ; Wed, 17 Jun 2020 15:53:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=jDsiGpHlHt3A6TlGq6foih1kuiL4GlYeWIrZSOkZpxY=; b=gzQGj00ueXc2W/kOiGPOcTIAbJbr/M/MLdgqTtuhg5grPOrTu3BaxWlh8qOcwEYPtj qe03kbeetPJMdpKWXdSYw0Ln/fx9cMl6bRF4zZ6alGlnV6HRhnHB+trO2CH/K2qV/gpS 3NB8IJAhQw/Nvs7O7OFXgO56j6elETkFG+H0kzbZRn0JJ8Ojl3tyJLYdU8fjrsBMwGug PKlkZtp0fFdkyBfsIHsCui78044VbKGgQrlzz8hC3KW/Rjw7DeF/XFuLkcpIzzy610eT mGfCtn90i5IVz76mMYs+ZX9N8SbKCwhS6p1zBzFzWMY12QRrZ21+X78Sjh6+b6G40Onk 6D/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=jDsiGpHlHt3A6TlGq6foih1kuiL4GlYeWIrZSOkZpxY=; b=cwy2ArR8S9Dronub+7fkc9HQD5COjTWYEqeDEaTmz25cC0eFWdMzGmrbrk8/NKBRyZ 9wRQKXGg824II+ekOlwMjZnBv3OpgkhyvtYvGhlDMcrj5ZUyNpfAA5ZQeTFOGUHWcj0u DVPP34fBW1VlTkENCcmW0SnF6IJz8LvI3MeNhq06g2Ldrr3xWwKtCBRRDjBX0wiwp//9 EwQr1Ou9MOpshf0HX4I3MDpx47Ijr2Kw7yRy3QsrFQsdFLJMFLOsVfSc7b7JoAtq64cp jTDMHSWW27Enb+by3wtHtE0IeE7H6qtjIuJDljhOGbiZA3t6mI0gD/1h7yt1uKpElJz8 d9/A== X-Gm-Message-State: AOAM530nt37/D6J8EoPdly1DPvNyc2MLjCa7gI/Zi5cPV357Erfp0qel gMDEwc3EhH8R3AEdqog07jhx4WkyMfA= X-Google-Smtp-Source: ABdhPJx8Qbf49zWcMX8/NXw0QB3RvDxyw4NaaPU5k5Ty2ssb3CbYBVNbXy4fzd/ZWZlzMfKdx8wrmQ== X-Received: by 2002:a63:1718:: with SMTP id x24mr916736pgl.72.1592434381286; Wed, 17 Jun 2020 15:53:01 -0700 (PDT) Received: from ?IPv6:2601:647:4700:9b2:1c36:bfc:73ae:1f3? ([2601:647:4700:9b2:1c36:bfc:73ae:1f3]) by smtp.gmail.com with ESMTPSA id p19sm821798pff.116.2020.06.17.15.52.59 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Jun 2020 15:53:00 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.80.23.2.2\)) Subject: Re: [kvm-unit-tests PATCH] x86: Add control register pinning tests From: Nadav Amit In-Reply-To: <20200617224606.27954-1-john.s.andersen@intel.com> Date: Wed, 17 Jun 2020 15:52:59 -0700 Cc: corbet@lwn.net, Paolo Bonzini , Thomas Gleixner , mingo , bp , hpa@zytor.com, shuah@kernel.org, sean.j.christopherson@intel.com, rick.p.edgecombe@intel.com, kvm@vger.kernel.org, kernel-hardening@lists.openwall.com Content-Transfer-Encoding: quoted-printable Message-Id: References: <20200617224606.27954-1-john.s.andersen@intel.com> To: John Andersen X-Mailer: Apple Mail (2.3608.80.23.2.2) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org > On Jun 17, 2020, at 3:46 PM, John Andersen = wrote: >=20 > Paravirutalized control register pinning adds MSRs guests can use to > discover which bits in CR0/4 they may pin, and MSRs for activating > pinning for any of those bits. >=20 [ sni[ > +static void vmx_cr_pin_test_guest(void) > +{ > + unsigned long i, cr0, cr4; > + > + /* Step 1. Skip feature detection to skip handling VMX_CPUID */ > + /* nop */ I do not quite get this comment. Why do you skip checking whether the feature is enabled? What happens if KVM/bare-metal/other-hypervisor that runs this test does not support this feature?