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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 57644C04E53 for ; Wed, 15 May 2019 11:11:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2AA2720862 for ; Wed, 15 May 2019 11:11:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557918709; bh=MImSsXvWpLoPg86zZhy9nBvmMuJY3uBgGLoSEpjiewo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CJmM/BUFfsbfh5BAB6gs6RL8T49mBaS4ygZB3SObJCSQAjV3gaVJqEOxlQQAkKlHn DpfjSPyQhtTkGiG4Vonmm93CaR15Yo1q/tWX6j0cZxF2reKCbqPnmS596DuwJ+ztv5 65b04GTgfLMrOew0HS4aR2yptpp6VjD5vFIUcjjc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729632AbfEOLLq (ORCPT ); Wed, 15 May 2019 07:11:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:46388 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729414AbfEOLLl (ORCPT ); Wed, 15 May 2019 07:11:41 -0400 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 4FB8B2084F; Wed, 15 May 2019 11:11:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557918700; bh=MImSsXvWpLoPg86zZhy9nBvmMuJY3uBgGLoSEpjiewo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nKQbjYPYcVQA/zdt239AkmF2wayhffzSipSeA1gQzrdGBILJVPpeV/P+3NbafrIWj hhtdyO/bn2ab5f6oWoaEfKBcut2aiJeYINZF4Iv20FHwsjBvNK+KhlQoQgOFBkdXgh hmpPq7DtvamFtlOEbaK/dCpuNdd3X8NFenmpH/qw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andi Kleen , Thomas Gleixner , Borislav Petkov , Frederic Weisbecker , Jon Masters , Ben Hutchings Subject: [PATCH 4.4 232/266] x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests Date: Wed, 15 May 2019 12:55:39 +0200 Message-Id: <20190515090730.851971386@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090722.696531131@linuxfoundation.org> References: <20190515090722.696531131@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: Andi Kleen commit 6c4dbbd14730c43f4ed808a9c42ca41625925c22 upstream. X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode provides the mechanism to invoke a flush of various exploitable CPU buffers by invoking the VERW instruction. Hand it through to guests so they can adjust their mitigations. This also requires corresponding qemu changes, which are available separately. [ tglx: Massaged changelog ] Signed-off-by: Andi Kleen Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Reviewed-by: Greg Kroah-Hartman Reviewed-by: Frederic Weisbecker Reviewed-by: Jon Masters Tested-by: Jon Masters [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/cpuid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -366,7 +366,7 @@ static inline int __do_cpuid_ent(struct /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = F(SPEC_CTRL) | F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | - F(INTEL_STIBP); + F(INTEL_STIBP) | F(MD_CLEAR); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu();