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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E10A6ECAAA1 for ; Fri, 9 Sep 2022 11:13:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229881AbiIILNw (ORCPT ); Fri, 9 Sep 2022 07:13:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229647AbiIILNv (ORCPT ); Fri, 9 Sep 2022 07:13:51 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E8C0AA369; Fri, 9 Sep 2022 04:13:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1662722028; x=1694258028; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=JbCdULcpLNTKeyruG9enleFdW1gpzUig7Itvs4b5dVc=; b=INsG+aeUFP0VRrFgtvRzDzvrqWY8chU4Mnk26lLnpf2S52nT4wy9WYbE Ta+epC9pJh7zKxulnZzFkoDwzhJj89whGrnqM4xFtjC7yiJvpNJYE16Vy qFpScU0pt/lWi7EMacfFwBhk9xl97BePkhtT+44ojIWSibn7t/+PA5FZR r/c3rtz0FVIML6i8SbwaOGn8G2C6z00riQv0pPQvsgg+q5dRYPd3HiDZS UHFxrV8MsVDNxriaWBqqaYi5uuQOxxD8MKHLOwrqoNEoq44UpcTi50R6Z xOuRzXEMzfJDLoHtFnM5h44hzegBBKjL8N4oIPto/6K3kltw7Wwkk5vbs A==; X-IronPort-AV: E=McAfee;i="6500,9779,10464"; a="298255036" X-IronPort-AV: E=Sophos;i="5.93,303,1654585200"; d="scan'208";a="298255036" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2022 04:13:43 -0700 X-IronPort-AV: E=Sophos;i="5.93,303,1654585200"; d="scan'208";a="790781551" Received: from lmongeax-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.212.106.181]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2022 04:13:39 -0700 From: Kai Huang To: linux-sgx@vger.kernel.org Cc: dave.hansen@linux.intel.com, seanjc@google.com, jarkko@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] x86/intel: Clear SGX feature bit if both SGX driver and KVM SGX are not enabled Date: Fri, 9 Sep 2022 23:13:31 +1200 Message-Id: <20220909111331.558936-1-kai.huang@intel.com> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Currently on platform which has SGX enabled, if CONFIG_X86_SGX is not enabled, the X86_FEATURE_SGX bit is not cleared in init_ia32_feat_ctl(). This results in /proc/cpuinfo still showing "sgx" feature when the kernel doesn't support SGX at all, which is not desired. Clear SGX feature bit if both SGX driver and KVM SGX are not enabled in init_ia32_feat_ctl(). Signed-off-by: Kai Huang --- Hi Dave, Sean, Jarkko, Could you help to review? Tested on SGX (BIOS) enabled machine with CONFIG_X86_SGX unset. This patch is generated on latest tip/master, but it applies to tip/x86/sgx cleanly as well. v1 -> v2: - Move the check down after checking X86_FEATURE_VMX which may set enable_sgx_kvm to false. - Slightly improve changelog. - Change "Clear SGX bit" to "Clear SGX feature bit" in patch title. --- arch/x86/kernel/cpu/feat_ctl.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c index 993697e71854..79d18caebff1 100644 --- a/arch/x86/kernel/cpu/feat_ctl.c +++ b/arch/x86/kernel/cpu/feat_ctl.c @@ -200,6 +200,19 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) enable_sgx_kvm = 0; } + /* + * By reaching here, it is certain that: + * - CPU supports SGX. + * - SGX is enabled by BIOS. + * + * However if both SGX driver and KVM SGX are not enabled, just + * need to clear SGX feature bit. + */ + if (!enable_sgx_driver && !enable_sgx_kvm) { + clear_cpu_cap(c, X86_FEATURE_SGX); + return; + } + if (!(msr & FEAT_CTL_SGX_LC_ENABLED) && enable_sgx_driver) { if (!enable_sgx_kvm) { pr_err_once("SGX Launch Control is locked. Disable SGX.\n"); base-commit: b8b09110cf290fdab4006b717da7a776ffb0cb73 -- 2.37.1