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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AFF00C2D0D1 for ; Thu, 19 Dec 2019 19:04:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CF35206D8 for ; Thu, 19 Dec 2019 19:04:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576782299; bh=iJSZqTbyRA+cNrTUI1i9sJNbprEpHV78xyk1cGnBK9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KxWGIBvkti+/hZVjxtZVLRu9Jl+WVB/WWMiG3PPXZrMbjZLiJMzKeSWJYqa4wdocu sTQY2tLBrt957et88k9hJyZWOm/77Z6Gf5za25PFQn0023NQgw0EG4T760mrS8++qS AliSVSKNnQHtSWKGw8Nok5CLk6mpGYqd5xlql2Gw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729354AbfLSSqi (ORCPT ); Thu, 19 Dec 2019 13:46:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:39360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729095AbfLSSqh (ORCPT ); Thu, 19 Dec 2019 13:46:37 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 90A92222C2; Thu, 19 Dec 2019 18:46:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781197; bh=iJSZqTbyRA+cNrTUI1i9sJNbprEpHV78xyk1cGnBK9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xtwmm7uOpX6AfTf7Zj/qPKf9yBt11Z/eL54jc/0usoWLvAbDmvqTWw5t0jiWYMS5l ma7/Jd0UWHfGy3Ysx+nlgvl8YIN1agGcc6lI3YenaiisRBGWaQiFkIzb3+uu6EWiIf vIF7OQek2vb//wAiM2XpMntADrKi+1jjwx94AvWs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Mattson , Paolo Bonzini Subject: [PATCH 4.9 085/199] KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES Date: Thu, 19 Dec 2019 19:32:47 +0100 Message-Id: <20191219183219.652680024@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191219183214.629503389@linuxfoundation.org> References: <20191219183214.629503389@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Bonzini commit cbbaa2727aa3ae9e0a844803da7cef7fd3b94f2b upstream. KVM does not implement MSR_IA32_TSX_CTRL, so it must not be presented to the guests. It is also confusing to have !ARCH_CAP_TSX_CTRL_MSR && !RTM && ARCH_CAP_TAA_NO: lack of MSR_IA32_TSX_CTRL suggests TSX was not hidden (it actually was), yet the value says that TSX is not vulnerable to microarchitectural data sampling. Fix both. Cc: stable@vger.kernel.org Tested-by: Jim Mattson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1075,10 +1075,15 @@ u64 kvm_get_arch_capabilities(void) * If TSX is disabled on the system, guests are also mitigated against * TAA and clear CPU buffer mitigation is not required for guests. */ - if (boot_cpu_has_bug(X86_BUG_TAA) && boot_cpu_has(X86_FEATURE_RTM) && - (data & ARCH_CAP_TSX_CTRL_MSR)) + if (!boot_cpu_has(X86_FEATURE_RTM)) + data &= ~ARCH_CAP_TAA_NO; + else if (!boot_cpu_has_bug(X86_BUG_TAA)) + data |= ARCH_CAP_TAA_NO; + else if (data & ARCH_CAP_TSX_CTRL_MSR) data &= ~ARCH_CAP_MDS_NO; + /* KVM does not emulate MSR_IA32_TSX_CTRL. */ + data &= ~ARCH_CAP_TSX_CTRL_MSR; return data; }