Add support for Secure Memory Encryption (SME). This initial support provides a Kconfig entry to build the SME support into the kernel and defines the memory encryption mask that will be used in subsequent patches to mark pages as encrypted. Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> --- arch/x86/Kconfig | 9 +++++++++ arch/x86/include/asm/mem_encrypt.h | 30 ++++++++++++++++++++++++++++++ arch/x86/mm/Makefile | 1 + arch/x86/mm/mem_encrypt.c | 21 +++++++++++++++++++++ include/linux/mem_encrypt.h | 30 ++++++++++++++++++++++++++++++ 5 files changed, 91 insertions(+) create mode 100644 arch/x86/include/asm/mem_encrypt.h create mode 100644 arch/x86/mm/mem_encrypt.c create mode 100644 include/linux/mem_encrypt.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9b2d50a..cc57bc0 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1368,6 +1368,15 @@ config X86_DIRECT_GBPAGES supports them), so don't confuse the user by printing that we have them enabled. +config AMD_MEM_ENCRYPT + bool "AMD Secure Memory Encryption support" + depends on X86_64 && CPU_SUP_AMD + ---help--- + Say yes to enable the encryption of system memory. This requires + an AMD processor that supports Secure Memory Encryption (SME). + The encryption of system memory is disabled by default but can be + enabled with the mem_encrypt=on command line option. + # Common NUMA Features config NUMA bool "Numa Memory Allocation and Scheduler Support" diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h new file mode 100644 index 0000000..a105796 --- /dev/null +++ b/arch/x86/include/asm/mem_encrypt.h @@ -0,0 +1,30 @@ +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2016 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lendacky@xxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __X86_MEM_ENCRYPT_H__ +#define __X86_MEM_ENCRYPT_H__ + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_AMD_MEM_ENCRYPT + +extern unsigned long sme_me_mask; + +#else /* !CONFIG_AMD_MEM_ENCRYPT */ + +#define sme_me_mask 0UL + +#endif /* CONFIG_AMD_MEM_ENCRYPT */ + +#endif /* __ASSEMBLY__ */ + +#endif /* __X86_MEM_ENCRYPT_H__ */ diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 96d2b84..44d4d21 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -39,3 +39,4 @@ obj-$(CONFIG_X86_INTEL_MPX) += mpx.o obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) += pkeys.o obj-$(CONFIG_RANDOMIZE_MEMORY) += kaslr.o +obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c new file mode 100644 index 0000000..1ed75a4 --- /dev/null +++ b/arch/x86/mm/mem_encrypt.c @@ -0,0 +1,21 @@ +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2016 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lendacky@xxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/linkage.h> + +/* + * Since sme_me_mask is set early in the boot process it must reside in + * the .data section so as not to be zeroed out when the .bss section is + * later cleared. + */ +unsigned long sme_me_mask __section(.data) = 0; +EXPORT_SYMBOL_GPL(sme_me_mask); diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h new file mode 100644 index 0000000..9fed068 --- /dev/null +++ b/include/linux/mem_encrypt.h @@ -0,0 +1,30 @@ +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2016 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lendacky@xxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __MEM_ENCRYPT_H__ +#define __MEM_ENCRYPT_H__ + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_AMD_MEM_ENCRYPT + +#include <asm/mem_encrypt.h> + +#else /* !CONFIG_AMD_MEM_ENCRYPT */ + +#define sme_me_mask 0UL + +#endif /* CONFIG_AMD_MEM_ENCRYPT */ + +#endif /* __ASSEMBLY__ */ + +#endif /* __MEM_ENCRYPT_H__ */ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>