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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 2A53CC2BC61 for ; Tue, 30 Oct 2018 19:23:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE1FF2080A for ; Tue, 30 Oct 2018 19:23:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EE1FF2080A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728289AbeJaESa (ORCPT ); Wed, 31 Oct 2018 00:18:30 -0400 Received: from mga11.intel.com ([192.55.52.93]:23880 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728040AbeJaERZ (ORCPT ); Wed, 31 Oct 2018 00:17:25 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Oct 2018 12:22:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,445,1534834800"; d="scan'208";a="103876756" Received: from skl-02.jf.intel.com ([10.54.74.62]) by fmsmga001.fm.intel.com with ESMTP; 30 Oct 2018 12:22:40 -0700 From: Tim Chen To: Jiri Kosina , Thomas Gleixner Cc: Tim Chen , Tom Lendacky , Ingo Molnar , Peter Zijlstra , Josh Poimboeuf , Andrea Arcangeli , David Woodhouse , Andi Kleen , Dave Hansen , Casey Schaufler , Asit Mallick , Arjan van de Ven , Jon Masters , Waiman Long , linux-kernel@vger.kernel.org, x86@kernel.org Subject: [Patch v4 07/18] x86/smt: Convert cpu_smt_control check to cpu_smt_enabled static key Date: Tue, 30 Oct 2018 11:49:14 -0700 Message-Id: <55b8a35095d778d257c7b22d86e45eace6905ae5.1540923609.git.tim.c.chen@linux.intel.com> X-Mailer: git-send-email 2.9.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Change the SMT code paths check from using cpu_smt_control to cpu_smt_enabled static key. This saves a branching check. Signed-off-by: Tim Chen --- arch/x86/kernel/cpu/bugs.c | 2 +- arch/x86/kvm/vmx.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index eb07ab6..32d962e 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -355,7 +355,7 @@ void arch_smt_update(void) mutex_lock(&spec_ctrl_mutex); mask = x86_spec_ctrl_base; - if (cpu_smt_control == CPU_SMT_ENABLED) + if (static_branch_likely(&cpu_smt_enabled)) mask |= SPEC_CTRL_STIBP; else mask &= ~SPEC_CTRL_STIBP; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 533a327..8ec0ea3 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -11072,7 +11072,7 @@ static int vmx_vm_init(struct kvm *kvm) * Warn upon starting the first VM in a potentially * insecure environment. */ - if (cpu_smt_control == CPU_SMT_ENABLED) + if (static_branch_likely(&cpu_smt_enabled)) pr_warn_once(L1TF_MSG_SMT); if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_NEVER) pr_warn_once(L1TF_MSG_L1D); -- 2.9.4