Key Locker is a CPU feature to minimize exposure of clear-text key material. An encoded form, called 'key handle', is referenced for data encryption or decryption instead of accessing the clear text key.
A wrapping key loaded in the CPU's software-inaccessible state is used to transform a user key into a key handle. It supports Advanced Encryption Standard (AES) cipher algorithm with new SIMD instruction set like its predecessor (AES-NI). So a new AES implementation will follow in the kernel's crypto library. Here add it to enumerate the hardware capability, but it will not be shown in /proc/cpuinfo as userspace usage is not supported. Make the feature depend on XMM2 as it comes with AES SIMD instructions. Add X86_FEATURE_KEYLOCKER to the disabled features mask. It will be enabled under a new config option. Signed-off-by: Chang S. Bae <[email protected]> Reviewed-by: Dan Williams <[email protected]> Cc: [email protected] Cc: [email protected] --- Changes from RFC v2: * Do not publish the feature flag to userspace. * Update the changelog. 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/uapi/asm/processor-flags.h | 2 ++ arch/x86/kernel/cpu/cpuid-deps.c | 1 + 4 files changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index d5b5f2ab87a0..e1964446bbe5 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -361,6 +361,7 @@ #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 8f28fafa98b3..75e1e87640d4 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 @@ -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_KEYLOCKER) #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..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 c881bcafba7d..abe7e04b27d9 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -78,6 +78,7 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_XFD, X86_FEATURE_XSAVES }, { X86_FEATURE_XFD, X86_FEATURE_XGETBV1 }, { X86_FEATURE_AMX_TILE, X86_FEATURE_XFD }, + { X86_FEATURE_KEYLOCKER, X86_FEATURE_XMM2 }, {} }; -- 2.17.1 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
