[RFC PATCH v2 01/11] x86/cpufeature: Enumerate Key Locker feature
From: Chang S. Bae <hidden>
Date: 2021-05-14 20:20:45
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Intel's Key Locker is a new security feature providing a mechanism to protect data encryption keys when processing the Advanced Encryption Standard (AES) algorithm. The feature accompanies new AES instructions as a successor to Intel's AES New Instructions (AES-NI). It also follows AES-NI's other feature dependency. Here add it to enumerate the hardware capability, shown as 'keylocker' in /proc/cpuinfo. Define the feature-specific CPUID leaf and bits for the feature enablement. Add X86_FEATURE_KEYLOCKER to the disabled features mask for the use of compile-time configuration. Signed-off-by: Chang S. Bae <redacted> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org --- Changes from RFC v1: * Updated the changelog. --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/disabled-features.h | 8 +++++++- arch/x86/include/asm/keylocker.h | 18 ++++++++++++++++++ arch/x86/include/uapi/asm/processor-flags.h | 2 ++ arch/x86/kernel/cpu/cpuid-deps.c | 1 + 5 files changed, 29 insertions(+), 1 deletion(-) create mode 100644 arch/x86/include/asm/keylocker.h
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index ac37830ae941..578cf3fe7182 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h@@ -359,6 +359,7 @@ #define X86_FEATURE_AVX512_VPOPCNTDQ (16*32+14) /* POPCNT for vectors of DW/QW */ #define X86_FEATURE_LA57 (16*32+16) /* 5-level page tables */ #define X86_FEATURE_RDPID (16*32+22) /* RDPID instruction */ +#define X86_FEATURE_KEYLOCKER (16*32+23) /* Key Locker */ #define X86_FEATURE_BUS_LOCK_DETECT (16*32+24) /* Bus Lock detect */ #define X86_FEATURE_CLDEMOTE (16*32+25) /* CLDEMOTE instruction */ #define X86_FEATURE_MOVDIRI (16*32+27) /* MOVDIRI instruction */
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index b7dd944dc867..96acda147a50 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_X86_KEYLOCKER +# define DISABLE_KEYLOCKER 0 +#else +# define DISABLE_KEYLOCKER (1<<(X86_FEATURE_KEYLOCKER & 31)) +#endif /* CONFIG_X86_KEYLOCKER */ + #ifdef CONFIG_X86_5LEVEL # define DISABLE_LA57 0 #else
@@ -88,7 +94,7 @@ #define DISABLED_MASK14 0 #define DISABLED_MASK15 0 #define DISABLED_MASK16 (DISABLE_PKU|DISABLE_OSPKE|DISABLE_LA57|DISABLE_UMIP| \ - DISABLE_ENQCMD) + DISABLE_ENQCMD|DISABLE_KEYLOCKER) #define DISABLED_MASK17 0 #define DISABLED_MASK18 0 #define DISABLED_MASK19 0
diff --git a/arch/x86/include/asm/keylocker.h b/arch/x86/include/asm/keylocker.h
new file mode 100644
index 000000000000..0597d6b1cd05
--- /dev/null
+++ b/arch/x86/include/asm/keylocker.h@@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _ASM_KEYLOCKER_H +#define _ASM_KEYLOCKER_H + +#ifndef __ASSEMBLY__ + +#include <linux/bits.h> + +#define KEYLOCKER_CPUID 0x019 +#define KEYLOCKER_CPUID_EAX_SUPERVISOR BIT(0) +#define KEYLOCKER_CPUID_EBX_AESKLE BIT(0) +#define KEYLOCKER_CPUID_EBX_WIDE BIT(2) +#define KEYLOCKER_CPUID_EBX_BACKUP BIT(4) +#define KEYLOCKER_CPUID_ECX_RAND BIT(1) + +#endif /*__ASSEMBLY__ */ +#endif /* _ASM_KEYLOCKER_H */
diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
index bcba3c643e63..b958a95a0908 100644
--- a/arch/x86/include/uapi/asm/processor-flags.h
+++ b/arch/x86/include/uapi/asm/processor-flags.h@@ -124,6 +124,8 @@ #define X86_CR4_PCIDE _BITUL(X86_CR4_PCIDE_BIT) #define X86_CR4_OSXSAVE_BIT 18 /* enable xsave and xrestore */ #define X86_CR4_OSXSAVE _BITUL(X86_CR4_OSXSAVE_BIT) +#define X86_CR4_KEYLOCKER_BIT 19 /* enable Key Locker */ +#define X86_CR4_KEYLOCKER _BITUL(X86_CR4_KEYLOCKER_BIT) #define X86_CR4_SMEP_BIT 20 /* enable SMEP support */ #define X86_CR4_SMEP _BITUL(X86_CR4_SMEP_BIT) #define X86_CR4_SMAP_BIT 21 /* enable SMAP support */
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index defda61f372d..ce2020b9ff4d 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c@@ -75,6 +75,7 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_SGX_LC, X86_FEATURE_SGX }, { X86_FEATURE_SGX1, X86_FEATURE_SGX }, { X86_FEATURE_SGX2, X86_FEATURE_SGX1 }, + { X86_FEATURE_KEYLOCKER, X86_FEATURE_XMM2 }, {} };
--
2.17.1