Provide support for Secure Memory Encryption (SME). This initial support defines the memory encryption mask as a variable for quick access and an accessor for retrieving the number of physical addressing bits lost if SME is enabled. Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> --- arch/x86/include/asm/mem_encrypt.h | 37 ++++++++++++++++++++++++++++++++++++ arch/x86/kernel/Makefile | 2 ++ arch/x86/kernel/mem_encrypt.S | 29 ++++++++++++++++++++++++++++ arch/x86/kernel/x8664_ksyms_64.c | 6 ++++++ 4 files changed, 74 insertions(+) create mode 100644 arch/x86/include/asm/mem_encrypt.h create mode 100644 arch/x86/kernel/mem_encrypt.S diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h new file mode 100644 index 0000000..747fc52 --- /dev/null +++ b/arch/x86/include/asm/mem_encrypt.h @@ -0,0 +1,37 @@ +/* + * 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; + +u8 sme_get_me_loss(void); + +#else /* !CONFIG_AMD_MEM_ENCRYPT */ + +#define sme_me_mask 0UL + +static inline u8 sme_get_me_loss(void) +{ + return 0; +} + +#endif /* CONFIG_AMD_MEM_ENCRYPT */ + +#endif /* __ASSEMBLY__ */ + +#endif /* __X86_MEM_ENCRYPT_H__ */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 9abf855..11536d9 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -126,6 +126,8 @@ obj-$(CONFIG_EFI) += sysfb_efi.o obj-$(CONFIG_PERF_EVENTS) += perf_regs.o obj-$(CONFIG_TRACING) += tracepoint.o +obj-y += mem_encrypt.o + ### # 64 bit specific files ifeq ($(CONFIG_X86_64),y) diff --git a/arch/x86/kernel/mem_encrypt.S b/arch/x86/kernel/mem_encrypt.S new file mode 100644 index 0000000..ef7f325 --- /dev/null +++ b/arch/x86/kernel/mem_encrypt.S @@ -0,0 +1,29 @@ +/* + * 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> + + .text + .code64 +ENTRY(sme_get_me_loss) + xor %rax, %rax + mov sme_me_loss(%rip), %al + ret +ENDPROC(sme_get_me_loss) + + .data + .align 16 +ENTRY(sme_me_mask) + .quad 0x0000000000000000 +sme_me_loss: + .byte 0x00 + .align 8 diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index cd05942..72cb689 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -11,6 +11,7 @@ #include <asm/uaccess.h> #include <asm/desc.h> #include <asm/ftrace.h> +#include <asm/mem_encrypt.h> #ifdef CONFIG_FUNCTION_TRACER /* mcount and __fentry__ are defined in assembly */ @@ -79,3 +80,8 @@ EXPORT_SYMBOL(native_load_gs_index); EXPORT_SYMBOL(___preempt_schedule); EXPORT_SYMBOL(___preempt_schedule_notrace); #endif + +#ifdef CONFIG_AMD_MEM_ENCRYPT +EXPORT_SYMBOL_GPL(sme_me_mask); +EXPORT_SYMBOL_GPL(sme_get_me_loss); +#endif -- 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>