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=-6.9 required=3.0 tests=FROM_EXCESS_BASE64, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 186EFC43387 for ; Thu, 20 Dec 2018 20:06:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC5F321905 for ; Thu, 20 Dec 2018 20:06:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389563AbeLTUGg (ORCPT ); Thu, 20 Dec 2018 15:06:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43606 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387436AbeLTUGg (ORCPT ); Thu, 20 Dec 2018 15:06:36 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5D9E83F731; Thu, 20 Dec 2018 20:06:36 +0000 (UTC) Received: from flask (unknown [10.43.2.138]) by smtp.corp.redhat.com (Postfix) with SMTP id 98CAD5C1B2; Thu, 20 Dec 2018 20:06:31 +0000 (UTC) Received: by flask (sSMTP sendmail emulation); Thu, 20 Dec 2018 21:06:30 +0100 Date: Thu, 20 Dec 2018 21:06:30 +0100 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Vitaly Kuznetsov Cc: kvm@vger.kernel.org, Paolo Bonzini , linux-kernel@vger.kernel.org, Tom Lendacky , Joerg Roedel , x86@kernel.org Subject: Re: [PATCH] KVM: x86: svm: report MSR_IA32_MCG_EXT_CTL as unsupported Message-ID: <20181220200630.GC25497@flask> References: <20181219110613.24459-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181219110613.24459-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Thu, 20 Dec 2018 20:06:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2018-12-19 12:06+0100, Vitaly Kuznetsov: > AMD doesn't seem to implement MSR_IA32_MCG_EXT_CTL and svm code in kvm > knows nothing about it, however, this MSR is among emulated_msrs and > thus returned with KVM_GET_MSR_INDEX_LIST. The consequent KVM_GET_MSRS, > of course, fails. > > Report the MSR as unsupported to not confuse userspace. > > Signed-off-by: Vitaly Kuznetsov > --- > arch/x86/kvm/svm.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 2acb42b74a51..dfdf7d0b7f88 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -5845,6 +5845,13 @@ static bool svm_cpu_has_accelerated_tpr(void) > > static bool svm_has_emulated_msr(int index) > { > + switch (index) { > + case MSR_IA32_MCG_EXT_CTL: > + return false; > + default: > + break; Queued, thanks. Btw, I would prefer this without the default: break; as I don't think we'll ever add something there.