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From: ira.weiny@intel.com
To: Dave Hansen <dave.hansen@linux.intel.com>,
	Dan Williams <dan.j.williams@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	nvdimm@lists.linux.dev, linux-mm@kvack.org
Subject: [PATCH V7 04/18] x86/pks: Add PKS defines and Kconfig options
Date: Tue,  3 Aug 2021 21:32:17 -0700	[thread overview]
Message-ID: <20210804043231.2655537-5-ira.weiny@intel.com> (raw)
In-Reply-To: <20210804043231.2655537-1-ira.weiny@intel.com>

From: Ira Weiny <ira.weiny@intel.com>

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.

Define the PKS CPU feature bits.

Add the Kconfig ARCH_HAS_SUPERVISOR_PKEYS to indicate to kernel
consumers that an architecture supports pkeys.

Introduce ARCH_ENABLE_SUPERVISOR_PKEYS to allow architectures to avoid
PKS code unless a kernel consumers is configured.

ARCH_ENABLE_SUPERVISOR_PKEYS remains off until the first kernel use case
sets it.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/x86/Kconfig                            | 1 +
 arch/x86/include/asm/cpufeatures.h          | 1 +
 arch/x86/include/asm/disabled-features.h    | 8 +++++++-
 arch/x86/include/uapi/asm/processor-flags.h | 2 ++
 mm/Kconfig                                  | 4 ++++
 5 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 49270655e827..d0a7d19aa245 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1837,6 +1837,7 @@ 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 d0ce5cfd3ac1..80c357f638fd 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -365,6 +365,7 @@
 #define X86_FEATURE_MOVDIR64B		(16*32+28) /* MOVDIR64B instruction */
 #define X86_FEATURE_ENQCMD		(16*32+29) /* ENQCMD and ENQCMDS instructions */
 #define X86_FEATURE_SGX_LC		(16*32+30) /* Software Guard Extensions Launch Control */
+#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/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 8f28fafa98b3..66fdad8f3941 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -44,6 +44,12 @@
 # define DISABLE_OSPKE		(1<<(X86_FEATURE_OSPKE & 31))
 #endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
 
+#ifdef CONFIG_ARCH_ENABLE_SUPERVISOR_PKEYS
+# define DISABLE_PKS		0
+#else
+# define DISABLE_PKS		(1<<(X86_FEATURE_PKS & 31))
+#endif
+
 #ifdef CONFIG_X86_5LEVEL
 # define DISABLE_LA57	0
 #else
@@ -85,7 +91,7 @@
 #define DISABLED_MASK14	0
 #define DISABLED_MASK15	0
 #define DISABLED_MASK16	(DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP| \
-			 DISABLE_ENQCMD)
+			 DISABLE_ENQCMD|DISABLE_PKS)
 #define DISABLED_MASK17	0
 #define DISABLED_MASK18	0
 #define DISABLED_MASK19	0
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/mm/Kconfig b/mm/Kconfig
index 40a9bfcd5062..e0d29c655ade 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -818,6 +818,10 @@ config ARCH_USES_HIGH_VMA_FLAGS
 	bool
 config ARCH_HAS_PKEYS
 	bool
+config ARCH_HAS_SUPERVISOR_PKEYS
+	bool
+config ARCH_ENABLE_SUPERVISOR_PKEYS
+	bool
 
 config PERCPU_STATS
 	bool "Collect percpu memory statistics"
-- 
2.28.0.rc0.12.gb6a658bd00c9


  parent reply	other threads:[~2021-08-04  4:32 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04  4:32 [PATCH V7 00/18] PKS/PMEM: Add Stray Write Protection ira.weiny
2021-08-04  4:32 ` [PATCH V7 01/18] x86/pkeys: Create pkeys_common.h ira.weiny
2021-08-04  4:32 ` [PATCH V7 02/18] x86/fpu: Refactor arch_set_user_pkey_access() ira.weiny
2021-08-04  4:32 ` [PATCH V7 03/18] x86/pks: Add additional PKEY helper macros ira.weiny
2021-08-04  4:32 ` ira.weiny [this message]
2021-08-04  4:32 ` [PATCH V7 05/18] x86/pks: Add PKS setup code ira.weiny
2021-08-04  4:32 ` [PATCH V7 06/18] x86/fault: Adjust WARN_ON for PKey fault ira.weiny
2021-08-04  4:32 ` [PATCH V7 07/18] x86/pks: Preserve the PKRS MSR on context switch ira.weiny
2021-08-04  4:32 ` [PATCH V7 08/18] x86/entry: Preserve PKRS MSR across exceptions ira.weiny
2021-08-04  4:32 ` [PATCH V7 09/18] x86/pks: Add PKS kernel API ira.weiny
2021-08-04  4:32 ` [PATCH V7 10/18] x86/pks: Introduce pks_abandon_protections() ira.weiny
2021-08-04  4:32 ` [PATCH V7 11/18] x86/pks: Add PKS Test code ira.weiny
2021-08-04  4:32 ` [PATCH V7 12/18] x86/pks: Add PKS fault callbacks ira.weiny
2021-08-11 21:18   ` Edgecombe, Rick P
2021-08-17  3:21     ` Ira Weiny
2021-08-04  4:32 ` [PATCH V7 13/18] memremap_pages: Add access protection via supervisor Protection Keys (PKS) ira.weiny
2021-08-04  4:32 ` [PATCH V7 14/18] memremap_pages: Add memremap.pks_fault_mode ira.weiny
2021-08-04  4:57   ` Randy Dunlap
2021-08-07 19:32     ` Ira Weiny
2021-08-11 19:01   ` Edgecombe, Rick P
2021-08-17  3:12     ` Ira Weiny
2021-08-04  4:32 ` [PATCH V7 15/18] kmap: Add stray access protection for devmap pages ira.weiny
2021-08-04  4:32 ` [PATCH V7 16/18] dax: Stray access protection for dax_direct_access() ira.weiny
2021-08-04  4:32 ` [PATCH V7 17/18] nvdimm/pmem: Enable stray access protection ira.weiny
2021-08-04  4:32 ` [PATCH V7 18/18] devdax: " ira.weiny

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