mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 08:58:07 +00:00
b3f0907c71
kvmclock defines few static variables which are shared with the hypervisor during the kvmclock initialization. When SEV is active, memory is encrypted with a guest-specific key, and if the guest OS wants to share the memory region with the hypervisor then it must clear the C-bit before sharing it. Currently, we use kernel_physical_mapping_init() to split large pages before clearing the C-bit on shared pages. But it fails when called from the kvmclock initialization (mainly because the memblock allocator is not ready that early during boot). Add a __bss_decrypted section attribute which can be used when defining such shared variable. The so-defined variables will be placed in the .bss..decrypted section. This section will be mapped with C=0 early during boot. The .bss..decrypted section has a big chunk of memory that may be unused when memory encryption is not active, free it when memory encryption is not active. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Radim Krčmář<rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Link: https://lkml.kernel.org/r/1536932759-12905-2-git-send-email-brijesh.singh@amd.com
100 lines
3 KiB
C
100 lines
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;
|
|
extern bool sev_enabled;
|
|
|
|
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(struct boot_params *bp);
|
|
void __init sme_enable(struct boot_params *bp);
|
|
|
|
int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
|
|
int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);
|
|
|
|
/* Architecture __weak replacement functions */
|
|
void __init mem_encrypt_init(void);
|
|
void __init mem_encrypt_free_decrypted_mem(void);
|
|
|
|
bool sme_active(void);
|
|
bool sev_active(void);
|
|
|
|
#define __bss_decrypted __attribute__((__section__(".bss..decrypted")))
|
|
|
|
#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(struct boot_params *bp) { }
|
|
static inline void __init sme_enable(struct boot_params *bp) { }
|
|
|
|
static inline bool sme_active(void) { return false; }
|
|
static inline bool sev_active(void) { return false; }
|
|
|
|
static inline int __init
|
|
early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
|
|
static inline int __init
|
|
early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
|
|
|
|
#define __bss_decrypted
|
|
|
|
#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)
|
|
|
|
extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif /* __X86_MEM_ENCRYPT_H__ */
|