From patchwork Fri May 14 20:15:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Chang S. Bae" X-Patchwork-Id: 439030 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AB42AC4360C for ; Fri, 14 May 2021 20:20:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DB6361460 for ; Fri, 14 May 2021 20:20:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233459AbhENUV4 (ORCPT ); Fri, 14 May 2021 16:21:56 -0400 Received: from mga14.intel.com ([192.55.52.115]:16070 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233008AbhENUVw (ORCPT ); Fri, 14 May 2021 16:21:52 -0400 IronPort-SDR: bWO3tqoUDaz1abDlLVzJ4Na2+9UCw0eKHuNElZj3diDTMlfs8MfLFduT5kB8dYjUqSquPjtAjh 2W4f//8Cse8w== X-IronPort-AV: E=McAfee;i="6200,9189,9984"; a="199921592" X-IronPort-AV: E=Sophos;i="5.82,300,1613462400"; d="scan'208";a="199921592" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 May 2021 13:20:37 -0700 IronPort-SDR: PENpovH2k+3B1gl75FEYU68QMWaA7N8r8mm1bAC8cweXNONJq1/xuiTfwhrloOeEexext0cqWC E6q6+7iTKxyg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,300,1613462400"; d="scan'208";a="438147177" Received: from chang-linux-3.sc.intel.com ([172.25.66.175]) by orsmga008.jf.intel.com with ESMTP; 14 May 2021 13:20:36 -0700 From: "Chang S. Bae" To: tglx@linutronix.de, mingo@kernel.org, bp@suse.de, luto@kernel.org, x86@kernel.org, herbert@gondor.apana.org.au Cc: dan.j.williams@intel.com, dave.hansen@intel.com, ravi.v.shankar@intel.com, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, chang.seok.bae@intel.com, linux-doc@vger.kernel.org Subject: [RFC PATCH v2 06/11] x86/cpu: Add a config option and a chicken bit for Key Locker Date: Fri, 14 May 2021 13:15:03 -0700 Message-Id: <20210514201508.27967-7-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210514201508.27967-1-chang.seok.bae@intel.com> References: <20210514201508.27967-1-chang.seok.bae@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Add a kernel config option to enable the feature (disabled by default) at compile-time. Also, add a new command-line parameter -- 'nokeylocker' to disable the feature at boot-time. Signed-off-by: Chang S. Bae Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- Documentation/admin-guide/kernel-parameters.txt | 2 ++ arch/x86/Kconfig | 14 ++++++++++++++ arch/x86/kernel/cpu/common.c | 16 ++++++++++++++++ 3 files changed, 32 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..d0afe36c1802 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3284,6 +3284,8 @@ nohugevmalloc [PPC] Disable kernel huge vmalloc mappings. + nokeylocker [X86] Disables Key Locker hardware feature. + nosmt [KNL,S390] Disable symmetric multithreading (SMT). Equivalent to smt=1. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0045e1b44190..de8eeb705ed8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1885,6 +1885,20 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS If unsure, say y. +config X86_KEYLOCKER + prompt "Key Locker" + def_bool n + depends on CPU_SUP_INTEL + help + Key Locker is a new security feature to protect data encryption + keys for the Advanced Encryption Standard (AES) algorithm. + + When enabled, every CPU has a unique internal key to wrap AES + keys in an encoded format. The internal key is not accessible + to software once loaded. + + If unsure, say y. + choice prompt "TSX enable mode" depends on CPU_SUP_INTEL diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 2e64371acb81..c655cce30c2b 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -353,6 +353,22 @@ static __always_inline void setup_umip(struct cpuinfo_x86 *c) /* These bits should not change their value after CPU init is finished. */ static const unsigned long cr4_pinned_mask = X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | X86_CR4_FSGSBASE; + +static __init int x86_nokeylocker_setup(char *arg) +{ + /* Expect an exact match without trailing characters. */ + if (strlen(arg)) + return 0; + + if (!cpu_feature_enabled(X86_FEATURE_KEYLOCKER)) + return 1; + + setup_clear_cpu_cap(X86_FEATURE_KEYLOCKER); + pr_info("x86/keylocker: Disabled by kernel command line.\n"); + return 1; +} +__setup("nokeylocker", x86_nokeylocker_setup); + static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning); static unsigned long cr4_pinned_bits __ro_after_init;