linux/arch/x86/include/asm/mem_encrypt.h
Borislav Petkov 21d9bb4a05 x86/mm: Make the SME mask a u64
The SME encryption mask is for masking 64-bit pagetable entries. It
being an unsigned long works fine on X86_64 but on 32-bit builds in
truncates bits leading to Xen guests crashing very early.

And regardless, the whole SME mask handling shouldnt've leaked into
32-bit because SME is X86_64-only feature. So, first make the mask u64.
And then, add trivial 32-bit versions of the __sme_* macros so that
nothing happens there.

Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tom Lendacky <Thomas.Lendacky@amd.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas <Thomas.Lendacky@amd.com>
Fixes: 21729f81ce ("x86/mm: Provide general kernel support for memory encryption")
Link: http://lkml.kernel.org/r/20170907093837.76zojtkgebwtqc74@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07 11:53:11 +02:00

81 lines
2.3 KiB
C

/*
* 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__
#include <linux/init.h>
#include <asm/bootparam.h>
#ifdef CONFIG_AMD_MEM_ENCRYPT
extern u64 sme_me_mask;
void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
unsigned long decrypted_kernel_vaddr,
unsigned long kernel_len,
unsigned long encryption_wa,
unsigned long encryption_pgd);
void __init sme_early_encrypt(resource_size_t paddr,
unsigned long size);
void __init sme_early_decrypt(resource_size_t paddr,
unsigned long size);
void __init sme_map_bootdata(char *real_mode_data);
void __init sme_unmap_bootdata(char *real_mode_data);
void __init sme_early_init(void);
void __init sme_encrypt_kernel(void);
void __init sme_enable(struct boot_params *bp);
/* Architecture __weak replacement functions */
void __init mem_encrypt_init(void);
void swiotlb_set_mem_attributes(void *vaddr, unsigned long size);
#else /* !CONFIG_AMD_MEM_ENCRYPT */
#define sme_me_mask 0ULL
static inline void __init sme_early_encrypt(resource_size_t paddr,
unsigned long size) { }
static inline void __init sme_early_decrypt(resource_size_t paddr,
unsigned long size) { }
static inline void __init sme_map_bootdata(char *real_mode_data) { }
static inline void __init sme_unmap_bootdata(char *real_mode_data) { }
static inline void __init sme_early_init(void) { }
static inline void __init sme_encrypt_kernel(void) { }
static inline void __init sme_enable(struct boot_params *bp) { }
#endif /* CONFIG_AMD_MEM_ENCRYPT */
/*
* The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
* writing to or comparing values from the cr3 register. Having the
* encryption mask set in cr3 enables the PGD entry to be encrypted and
* avoid special case handling of PGD allocations.
*/
#define __sme_pa(x) (__pa(x) | sme_me_mask)
#define __sme_pa_nodebug(x) (__pa_nodebug(x) | sme_me_mask)
#endif /* __ASSEMBLY__ */
#endif /* __X86_MEM_ENCRYPT_H__ */