From 7744ccdbc16f0ac4adae21b3678af93775b3a386 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Mon, 17 Jul 2017 16:10:03 -0500 Subject: [PATCH] x86/mm: Add Secure Memory Encryption (SME) support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brijesh Singh Cc: Dave Young Cc: Dmitry Vyukov Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Larry Woodman Cc: Linus Torvalds Cc: Matt Fleming Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Radim Krčmář Cc: Rik van Riel Cc: Toshimitsu Kani Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/a6c34d16caaed3bc3e2d6f0987554275bd291554.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 25 +++++++++++++++++++++ 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 | 35 ++++++++++++++++++++++++++++++ 5 files changed, 112 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 781521b7cf9e..ba7b93d08d00 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1415,6 +1415,31 @@ config X86_DIRECT_GBPAGES supports them), so don't confuse the user by printing that we have them enabled. +config ARCH_HAS_MEM_ENCRYPT + def_bool y + +config AMD_MEM_ENCRYPT + bool "AMD Secure Memory Encryption (SME) support" + depends on X86_64 && CPU_SUP_AMD + ---help--- + Say yes to enable support for the encryption of system memory. + This requires an AMD processor that supports Secure Memory + Encryption (SME). + +config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT + bool "Activate AMD Secure Memory Encryption (SME) by default" + default y + depends on AMD_MEM_ENCRYPT + ---help--- + Say yes to have system memory encrypted by default if running on + an AMD processor that supports Secure Memory Encryption (SME). + + If set to Y, then the encryption of system memory can be + deactivated with the mem_encrypt=off command line option. + + If set to N, then the encryption of system memory can be + activated 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 000000000000..a1057961ac46 --- /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 + * + * 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 0fbdcb64f9f8..a94a7b663d5f 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 000000000000..b99d469c73e7 --- /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 + * + * 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 + +/* + * Since SME related variables are set early in the boot process they 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 000000000000..59769f7287e4 --- /dev/null +++ b/include/linux/mem_encrypt.h @@ -0,0 +1,35 @@ +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2016 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky + * + * 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_ARCH_HAS_MEM_ENCRYPT + +#include + +#else /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */ + +#define sme_me_mask 0UL + +#endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */ + +static inline bool sme_active(void) +{ + return !!sme_me_mask; +} + +#endif /* __ASSEMBLY__ */ + +#endif /* __MEM_ENCRYPT_H__ */ -- 2.20.1