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,URIBL_BLOCKED,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 79553C4741F for ; Mon, 9 Nov 2020 22:36:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2369520679 for ; Mon, 9 Nov 2020 22:36:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DQepMCFh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730387AbgKIWgo (ORCPT ); Mon, 9 Nov 2020 17:36:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729785AbgKIWgn (ORCPT ); Mon, 9 Nov 2020 17:36:43 -0500 Received: from mail-oi1-x22b.google.com (mail-oi1-x22b.google.com [IPv6:2607:f8b0:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE559C0613CF for ; Mon, 9 Nov 2020 14:36:41 -0800 (PST) Received: by mail-oi1-x22b.google.com with SMTP id d9so12045540oib.3 for ; Mon, 09 Nov 2020 14:36:41 -0800 (PST) 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=CTh6EHdj/sEjVeEM7tTLdCGN17vFXhY30SLk5/K9tus=; b=DQepMCFhAe7e5wzfvOjHy+zSRqIgqviiVN86ZTuq+EjTL/Mjqv1OpUP/DhwbvqVXWt 76jrPoQJBhQiAsIMEsumWsQ69zJmoKfDn+XzeIQbC7V9v/kcPPAOCAGzHdulH9SG77xX kA2zleK1xZmj/sADDwAzXXUeIL1Ht0tEFFO/RhzwcEs2ySi+sL23LWKiHjUJctMTcfZV zQf0bfsCwCfeP3brkU25GS2wehLX6WX52wLpctCDKAlLTgBX0yL0HpnPv9yZ94uvaqYy 6a4TcSqhRT4gixWuZ4PA86TEB6/POnXjx8nx0X+PAfNhDQm071OPu9Iwx3qzuNL3G8jh 9HlA== 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=CTh6EHdj/sEjVeEM7tTLdCGN17vFXhY30SLk5/K9tus=; b=J6WIsdEWD0h55Ow1D0nN7wWAznzHphhNxaqMP0vlzDumXJaOqxpdiUrTXXsTcYIrMY I34XUKfHygbcwdPl7EJzrFv6JvBvpMYPdl05eIWXQhnsSAL9w+mrrZCayr0b8zmalmv/ F/ZpEJpt61+C5i94h2INtdA7AhKHuY0h3YmvsKvVs7vHRygkMM77e/+DJICc2n8nrf34 QUIwVnRBiIHtwN8Votx2khsO+RLd12AcsVefWoxhsqPKOKMIwz7Gyt45Wqv2CpvbCStv 0dx+CoW9JZddRgW3pPFVL3wHBJqRkswe1vTJ8MUAZdeIv4msyq11FngDT1fz0shb9mbG MY8g== X-Gm-Message-State: AOAM531bO0Q+2GFHdmcg/FUpmrTFWRsSV8r9CaiAkscR8u2qeNhjGTHc 8wYDfXK6+njSYFE0fMICI6ps8baaEWx3+y2eKKSmphMxbaQ= X-Google-Smtp-Source: ABdhPJyGsZp34bN65P+ZviA1hv7Uw0zaa+Kw38+E6oue4vDWjH3T/+uur8iehxwmbCi7dDf59M+lS1szSQhCxNuYQeo= X-Received: by 2002:a54:4082:: with SMTP id i2mr969744oii.28.1604961400870; Mon, 09 Nov 2020 14:36:40 -0800 (PST) MIME-Version: 1.0 References: <20201030190807.GA13884@agluck-desk2.amr.corp.intel.com> <160431588828.397.16468104725047768957.tip-bot2@tip-bot2> <3f863634cd75824907e8ccf8164548c2ef036f20.camel@redhat.com> In-Reply-To: From: Jim Mattson Date: Mon, 9 Nov 2020 14:36:29 -0800 Message-ID: Subject: Re: [tip: ras/core] x86/mce: Enable additional error logging on certain Intel CPUs To: "Luck, Tony" Cc: Qian Cai , "linux-kernel@vger.kernel.org" , "linux-tip-commits@vger.kernel.org" , Boris Petkov , Borislav Petkov , x86 , Paolo Bonzini , "kvm@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 9, 2020 at 2:09 PM Luck, Tony wrote: > > What does KVM do with model specific MSRs? "Model specific model-specific registers?" :-) KVM only implements a small subset of MSRs. By default, any access to the rest raises #GP. > Looks like you let the guest believe it was running on one of Sandy Bridge, Ivy Bridge, Haswell (Xeon). > > So, the core MCE code tried to enable extended error reporting. > > If there is a mode to have KVM let the guest think that it read/wrote MSR 0x17F, > but actually, doesn't do it ... that would seem to be a reasonable thing to do here. There is an 'ignore_msrs' module parameter, to sink writes and return zero on reads for unknown MSRs, but I don't think it's commonly used. I thought Linux had long ago gone the route of turning rdmsr/wrmsr into rdmsr_safe/wrmsr_safe, so that the guest would ignore the #GPs on writes and return zero to the caller for #GPs on reads.