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=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 1524FC43603 for ; Mon, 16 Dec 2019 17:56:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE84521775 for ; Mon, 16 Dec 2019 17:56:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576518991; bh=twlSvSLJpbpIjcmSMCIchDBYbKZAHazciYiLj5xREQw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gWUSUdsuHbtQ8BZTJHOQ8aH7wcwd+nXfdBZzQZgYnzPb3bDeR8xJ5eoq5usTHIypz /BSvwyskKpb0QM2Rcl3oY13uvVWrltfwdN6WfxaedZ5FsWQPCTaWL/3AXluwuOYCXZ BldOinW4U/E0hpUlRBD6b3K1u1jjw1iIOESKtnTw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728228AbfLPR4a (ORCPT ); Mon, 16 Dec 2019 12:56:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:54684 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728221AbfLPR43 (ORCPT ); Mon, 16 Dec 2019 12:56:29 -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 0DA4521739; Mon, 16 Dec 2019 17:56:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576518988; bh=twlSvSLJpbpIjcmSMCIchDBYbKZAHazciYiLj5xREQw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FcwBvpn2q1RNvSzdsjD/phqzwOoMsf3jC51z1iPymfyY0ncot3fCR8T8gvqyiI7cN SnClW8pUm+N7+DPv3rDRT25/VsWPiuMmbyquXixeIuWHUyyZAU+e/79KHB4I6wGrOs GYzAo4Uo89fTnjkfTE85D/7/u+Kj1qbJgg/Wdkrg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Mattson , Paolo Bonzini Subject: [PATCH 4.14 142/267] KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES Date: Mon, 16 Dec 2019 18:47:48 +0100 Message-Id: <20191216174910.260734464@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216174848.701533383@linuxfoundation.org> References: <20191216174848.701533383@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 | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1113,10 +1113,15 @@ 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; }