[RFC PATCH v2 01/11] x86/cpufeature: Enumerate Key Locker feature
From: Chang S. Bae
Date: Fri May 14 2021 - 16:20:45 EST
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 <chang.seok.bae@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
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