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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 EA02BC433E1 for ; Wed, 19 Aug 2020 22:09:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC4D32078D for ; Wed, 19 Aug 2020 22:09:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KEYsVedF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727125AbgHSWJU (ORCPT ); Wed, 19 Aug 2020 18:09:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726209AbgHSWJS (ORCPT ); Wed, 19 Aug 2020 18:09:18 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCD57C061383 for ; Wed, 19 Aug 2020 15:09:16 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id a65so20327633otc.8 for ; Wed, 19 Aug 2020 15:09:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=P2aZms47v6extSBzv//sF/AtrAyAelQrYrDctYBpr04=; b=KEYsVedFdZOQOSKvm37iFMygyWYKzyeKVhW7GTGsl2VQmKBUg/hkZq15rfVRQfC5eu dUtnTcGVi3clYiP8Mj5/69CXlvkgXFTYDkUlcWkoQ9qBcKDdXnK7v5CcO25kpXzKE5xS UoFKnLSkqfQ+sQDk6RybtzVcijHxCY5agHtf1D0MUFmQi8DMQy/bw26109HhW7KpI7KN F0tQYmHfj9dQhoyiwlrrYHPfIlB78enPqA7h59oq5DS6DdzqdUwcmXqOjNqtzotEtrrQ vgk5zbQjOqe3nwzXchl3hOB6/KvfHZuUlrSKoIgZyzXCwG73zgJnYCtd14yyyX7tvkYG /gXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=P2aZms47v6extSBzv//sF/AtrAyAelQrYrDctYBpr04=; b=mMHEEbUK8+2ry4mxc4L/WRCmZ4H3i19O8akeK5Airwggim4TJj7DqRIOGO8JN3HKHA QiQvBRglZC/8cp5gjZUZLrVETYANBxTJd11V7vmzas9P+yYvuGXPckkR9tV2oFPUtoZo a/C8rP8L66iZue8SuWYR+eKKXfPYUhuxwDK6riEq2AaZZVTD709ByObZLjKXXtHfEdoo d2u3DUHQYNYB7yYiijPZP4/SykodA0E9uU4WfhpGHy3sf6ovvBQ49VQBMcZOLC9IEZca DUDq1pKBBjUbzsKvl7j+yqdragyTZVwQSIhHCmIbk936fJV5SSjRo1Dt9yisrL5CE+df prhQ== X-Gm-Message-State: AOAM533ZXykl7IRIgsixgqZ7VgpsNgs4oFzcQfCfPqt22ybiwjjyQFJa ta/83bCroWhlSJF6z+Wj5oOauUCIxv+jus1b2YH/Kg== X-Google-Smtp-Source: ABdhPJzt1m4Jk/Vfsw/369PYrT54BgnJK9X0NCnwn7bI4EEVd9vbywxvaU0LIHS+rgWiI+SfMc+IIrkD07Q745+LHBc= X-Received: by 2002:a9d:ae9:: with SMTP id 96mr18674otq.241.1597874955900; Wed, 19 Aug 2020 15:09:15 -0700 (PDT) MIME-Version: 1.0 References: <20200803211423.29398-1-graf@amazon.com> In-Reply-To: From: Jim Mattson Date: Wed, 19 Aug 2020 15:09:04 -0700 Message-ID: Subject: Re: [PATCH v4 0/3] Allow user space to restrict and augment MSR emulation To: "Graf (AWS), Alexander" Cc: Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Joerg Roedel , "Raslan, KarimAllah" , Aaron Lewis , kvm list , "linux-doc@vger.kernel.org" , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 19, 2020 at 2:46 PM Graf (AWS), Alexander wrote: > Special MSRs like EFER also irritate me a bit. We can't really trap on them - most code paths just know they're handled in kernel. Maybe I'll add some sanity checks as well... Why can't we intercept EFER?