From patchwork Fri Jul 17 07:20:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 11669319 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 5C67B618 for ; Fri, 17 Jul 2020 07:22:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D2642080D for ; Fri, 17 Jul 2020 07:22:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728022AbgGQHVF (ORCPT ); Fri, 17 Jul 2020 03:21:05 -0400 Received: from mga06.intel.com ([134.134.136.31]:63230 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726250AbgGQHVD (ORCPT ); Fri, 17 Jul 2020 03:21:03 -0400 IronPort-SDR: TK+Ls29bvEJ9NK3xzTywA54xIJUCWvfJlxMBLMPYVfNypdUmrobYarKysjNdKwXAQU4muyhmiA RQZILJTkgtcQ== X-IronPort-AV: E=McAfee;i="6000,8403,9684"; a="211088495" X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="211088495" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2020 00:21:02 -0700 IronPort-SDR: 9TZYXuwZbrDnScxB5w1nio0NSrgEKQWVrml8Z0Vouo/2sHHo7seDbZhh7uxEap0kelUd5xM7mt 7m4oE9c/5TCA== X-IronPort-AV: E=Sophos;i="5.75,362,1589266800"; d="scan'208";a="269468907" 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; 17 Jul 2020 00:21:02 -0700 From: ira.weiny@intel.com To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Cc: Fenghua Yu , Ira Weiny , x86@kernel.org, Dave Hansen , Dan Williams , Vishal Verma , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH RFC V2 03/17] x86/pks: Enable Protection Keys Supervisor (PKS) Date: Fri, 17 Jul 2020 00:20:42 -0700 Message-Id: <20200717072056.73134-4-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 In-Reply-To: <20200717072056.73134-1-ira.weiny@intel.com> References: <20200717072056.73134-1-ira.weiny@intel.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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. Define ARCH_HAS_SUPERVISOR_PKEYS to distinguish this functionality from the existing ARCH_HAS_PKEYS and then enable PKS when configured and indicated by the CPU instance. While not strictly necessary in this patch, ARCH_HAS_SUPERVISOR_PKEYS separates this functionality through the patch series so it is introduced here. Co-developed-by: Ira Weiny Signed-off-by: Ira Weiny Signed-off-by: Fenghua Yu --- arch/x86/Kconfig | 1 + arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/uapi/asm/processor-flags.h | 2 ++ arch/x86/kernel/cpu/common.c | 15 +++++++++++++++ mm/Kconfig | 2 ++ 5 files changed, 21 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 883da0abf779..c3ecbed2cfa0 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1872,6 +1872,7 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) select ARCH_USES_HIGH_VMA_FLAGS select ARCH_HAS_PKEYS + select ARCH_HAS_SUPERVISOR_PKEYS help Memory Protection Keys provides a mechanism for enforcing page-based protections, but without requiring modification of the diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 02dabc9e77b0..a832ed8820c0 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -351,6 +351,7 @@ #define X86_FEATURE_CLDEMOTE (16*32+25) /* CLDEMOTE instruction */ #define X86_FEATURE_MOVDIRI (16*32+27) /* MOVDIRI instruction */ #define X86_FEATURE_MOVDIR64B (16*32+28) /* MOVDIR64B instruction */ +#define X86_FEATURE_PKS (16*32+31) /* Protection Keys for Supervisor pages */ /* AMD-defined CPU features, CPUID level 0x80000007 (EBX), word 17 */ #define X86_FEATURE_OVERFLOW_RECOV (17*32+ 0) /* MCA overflow recovery support */ diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h index bcba3c643e63..191c574b2390 100644 --- a/arch/x86/include/uapi/asm/processor-flags.h +++ b/arch/x86/include/uapi/asm/processor-flags.h @@ -130,6 +130,8 @@ #define X86_CR4_SMAP _BITUL(X86_CR4_SMAP_BIT) #define X86_CR4_PKE_BIT 22 /* enable Protection Keys support */ #define X86_CR4_PKE _BITUL(X86_CR4_PKE_BIT) +#define X86_CR4_PKS_BIT 24 /* enable Protection Keys for Supervisor */ +#define X86_CR4_PKS _BITUL(X86_CR4_PKS_BIT) /* * x86-64 Task Priority Register, CR8 diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 95c090a45b4b..f34bcefeda42 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1430,6 +1430,20 @@ 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 (!IS_ENABLED(CONFIG_ARCH_HAS_SUPERVISOR_PKEYS)) + return; + if (!cpu_feature_enabled(X86_FEATURE_PKS)) + return; + + cr4_set_bits(X86_CR4_PKS); +} + /* * This does the hard work of actually picking apart the CPU stuff... */ @@ -1521,6 +1535,7 @@ 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 diff --git a/mm/Kconfig b/mm/Kconfig index f2104cc0d35c..e541d2c0dcac 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -826,6 +826,8 @@ config ARCH_USES_HIGH_VMA_FLAGS bool config ARCH_HAS_PKEYS bool +config ARCH_HAS_SUPERVISOR_PKEYS + bool config PERCPU_STATS bool "Collect percpu memory statistics"