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,URIBL_BLOCKED,USER_AGENT_GIT 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 18472C00454 for ; Wed, 11 Dec 2019 15:09:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DFBAE2173E for ; Wed, 11 Dec 2019 15:09:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576076990; bh=TQTDf8uMGZaMCrhwqddDGr70A0eN8FQyvw+Bojojpcs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HrM2lRO6GexmV44xtKaZxih07E1D6fQsl+ql4oBrMHjIzAZyokOykAPBieNWn0mCn XgDQBJ+QE81vw9NM002MpTdKxdvvIDvtnJqjktfrS0Jr+Uiob4/hZchlxZPUc/KXrf 3kwnV8zNiXJbn5DMTein9TrxzFdbDNHJMr0NSyME= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730663AbfLKPJt (ORCPT ); Wed, 11 Dec 2019 10:09:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:57858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730177AbfLKPJp (ORCPT ); Wed, 11 Dec 2019 10:09:45 -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 7064D22B48; Wed, 11 Dec 2019 15:09:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576076984; bh=TQTDf8uMGZaMCrhwqddDGr70A0eN8FQyvw+Bojojpcs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LrmO6YumTuEx2NXR3BkfdgSBej2yGRq2jOvphU39TrYUV8Blvd48Jpv9P8g5Pfgj5 0R3wK4AS5YWS5Hg/e3gNx7VDtiUqeDxaHphfyh0efDsi36OzGgaYOehWC7qAbhB1YK E6RXOBBSXVBJ2VurDAbIEv9w1ZVLBeQq/VZ77HrI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Mattson , Paolo Bonzini Subject: [PATCH 5.4 65/92] KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES Date: Wed, 11 Dec 2019 16:05:56 +0100 Message-Id: <20191211150252.913746294@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191211150221.977775294@linuxfoundation.org> References: <20191211150221.977775294@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1328,12 +1328,18 @@ static u64 kvm_get_arch_capabilities(voi * 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; } +EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities); static int kvm_get_msr_feature(struct kvm_msr_entry *msr) {