From patchwork Fri Nov 6 23:29:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 11888429 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 4FA1716C1 for ; Fri, 6 Nov 2020 23:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 378A52087E for ; Fri, 6 Nov 2020 23:30:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729271AbgKFX3i (ORCPT ); Fri, 6 Nov 2020 18:29:38 -0500 Received: from mga11.intel.com ([192.55.52.93]:33110 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728270AbgKFX3i (ORCPT ); Fri, 6 Nov 2020 18:29:38 -0500 IronPort-SDR: 3VLyvhvDiNTVAXyPdpnx72z1LGlQFa9PnZDpMhB5Yzh5YHXwnNIKrDoYBZK3OrnHxPHTahq9o8 zmSNHVP0fgvA== X-IronPort-AV: E=McAfee;i="6000,8403,9797"; a="166102931" X-IronPort-AV: E=Sophos;i="5.77,457,1596524400"; d="scan'208";a="166102931" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Nov 2020 15:29:37 -0800 IronPort-SDR: k4byyvrseYAeoBugGywJ+QOjnx9bAxJF6P0x70TOG2wyk/Qhysfn8ADhVz292RTBJTIDkyng9d GrFVwhEgV3Mw== X-IronPort-AV: E=Sophos;i="5.77,457,1596524400"; d="scan'208";a="307352972" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Nov 2020 15:29:37 -0800 From: ira.weiny@intel.com To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra , Dave Hansen Cc: Fenghua Yu , Ira Weiny , x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , linux-doc@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Dan Williams , Greg KH Subject: [PATCH V3 09/10] x86/pks: Enable Protection Keys Supervisor (PKS) Date: Fri, 6 Nov 2020 15:29:07 -0800 Message-Id: <20201106232908.364581-10-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 In-Reply-To: <20201106232908.364581-1-ira.weiny@intel.com> References: <20201106232908.364581-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Fenghua Yu Protection Keys for Supervisor pages (PKS) enables fast, hardware thread specific, manipulation of permission restrictions on supervisor page mappings. It uses the same mechanism of Protection Keys as those on User mappings but applies that mechanism to supervisor mappings using a supervisor specific MSR. Kernel users can thus defines 'domains' of page mappings which have an extra level of protection beyond those specified in the supervisor page table entries. Enable PKS on supported CPUS. Co-developed-by: Ira Weiny Signed-off-by: Ira Weiny Signed-off-by: Fenghua Yu --- Changes from V2 From Thomas: Make this patch last so PKS is not enabled until all the PKS mechanisms are in place. Specifically: 1) Modify setup_pks() to call write_pkrs() to properly set up the initial value when enabled. 2) Split this patch into two. 1) a precursor patch with the required defines/config options and 2) this patch which actually enables feature on CPUs which support it. Changes since RFC V3 Per Dave Hansen Update comment Add X86_FEATURE_PKS to disabled-features.h Rebase based on latest TIP tree --- arch/x86/include/asm/disabled-features.h | 6 +++++- arch/x86/kernel/cpu/common.c | 15 +++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 164587177152..82540f0c5b6c 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -44,7 +44,11 @@ # define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE & 31)) #endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */ -#define DISABLE_PKS (1<<(X86_FEATURE_PKS & 31)) +#ifdef CONFIG_ARCH_HAS_SUPERVISOR_PKEYS +# define DISABLE_PKS 0 +#else +# define DISABLE_PKS (1<<(X86_FEATURE_PKS & 31)) +#endif #ifdef CONFIG_X86_5LEVEL # define DISABLE_LA57 0 diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 35ad8480c464..f8929a557d72 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -58,6 +58,7 @@ #include #include #include +#include #include "cpu.h" @@ -1494,6 +1495,19 @@ static void validate_apic_and_package_id(struct cpuinfo_x86 *c) #endif } +/* + * PKS is independent of PKU and either or both may be supported on a CPU. + * Configure PKS if the CPU supports the feature. + */ +static void setup_pks(void) +{ + if (!cpu_feature_enabled(X86_FEATURE_PKS)) + return; + + write_pkrs(INIT_PKRS_VALUE); + cr4_set_bits(X86_CR4_PKS); +} + /* * This does the hard work of actually picking apart the CPU stuff... */ @@ -1591,6 +1605,7 @@ static void identify_cpu(struct cpuinfo_x86 *c) x86_init_rdrand(c); setup_pku(c); + setup_pks(); /* * Clear/Set all flags overridden by options, need do it