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authorTom Lendacky <thomas.lendacky@amd.com>2017-07-17 16:10:03 -0500
committerIngo Molnar <mingo@kernel.org>2017-07-18 11:37:59 +0200
commit7744ccdbc16f0ac4adae21b3678af93775b3a386 (patch)
tree7b30f32f09141cae07a9f07ab4eba1e3e734ed91
parent9af9b94068fb1ea3206a700fc222075966fbef14 (diff)
x86/mm: Add Secure Memory Encryption (SME) support
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@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> 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 <mingo@kernel.org>
-rw-r--r--arch/x86/Kconfig25
-rw-r--r--arch/x86/include/asm/mem_encrypt.h30
-rw-r--r--arch/x86/mm/Makefile1
-rw-r--r--arch/x86/mm/mem_encrypt.c21
-rw-r--r--include/linux/mem_encrypt.h35
5 files changed, 112 insertions, 0 deletions
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 <thomas.lendacky@amd.com>
+ *
+ * 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 <thomas.lendacky@amd.com>
+ *
+ * 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 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 <thomas.lendacky@amd.com>
+ *
+ * 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 <asm/mem_encrypt.h>
+
+#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__ */