From patchwork Thu Nov 28 01:40:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11265207 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1DC34109A for ; Thu, 28 Nov 2019 01:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06415216F4 for ; Thu, 28 Nov 2019 01:42:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727645AbfK1BkW (ORCPT ); Wed, 27 Nov 2019 20:40:22 -0500 Received: from mga02.intel.com ([134.134.136.20]:10961 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727628AbfK1BkW (ORCPT ); Wed, 27 Nov 2019 20:40:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Nov 2019 17:40:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,251,1571727600"; d="scan'208";a="221166479" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by orsmga002.jf.intel.com with ESMTP; 27 Nov 2019 17:40:19 -0800 From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org Cc: "H. Peter Anvin" , Peter Zijlstra , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Tony Luck , Tony W Wang-oc , Len Brown , Shuah Khan , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-edac@vger.kernel.org, linux-pm@vger.kernel.org, linux-kselftest@vger.kernel.org, Borislav Petkov , Jarkko Sakkinen Subject: [PATCH v4 05/19] x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked Date: Wed, 27 Nov 2019 17:40:02 -0800 Message-Id: <20191128014016.4389-6-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191128014016.4389-1-sean.j.christopherson@intel.com> References: <20191128014016.4389-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org WARN if the IA32_FEAT_CTL MSR is somehow left unlocked now that CPU initialization unconditionally locks the MSR. Signed-off-by: Sean Christopherson --- arch/x86/kernel/cpu/mce/intel.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c index c238518b84a2..5627b1091b85 100644 --- a/arch/x86/kernel/cpu/mce/intel.c +++ b/arch/x86/kernel/cpu/mce/intel.c @@ -116,14 +116,15 @@ static bool lmce_supported(void) /* * BIOS should indicate support for LMCE by setting bit 20 in * IA32_FEAT_CTL without which touching MCG_EXT_CTL will generate a #GP - * fault. + * fault. The MSR must also be locked for LMCE_ENABLED to take effect. + * WARN if the MSR isn't locked as init_ia32_feat_ctl() unconditionally + * locks the MSR in the event that it wasn't already locked by BIOS. */ rdmsrl(MSR_IA32_FEAT_CTL, tmp); - if ((tmp & (FEAT_CTL_LOCKED | FEAT_CTL_LMCE_ENABLED)) == - (FEAT_CTL_LOCKED | FEAT_CTL_LMCE_ENABLED)) - return true; + if (WARN_ON_ONCE(!(tmp & FEAT_CTL_LOCKED))) + return false; - return false; + return tmp & FEAT_CTL_LMCE_ENABLED; } bool mce_intel_cmci_poll(void)