linux/arch/x86/include/asm/mem_encrypt.h
Ashish Kalra f4495615d7 x86/kvm: Add guest support for detecting and enabling SEV Live Migration feature.
The guest support for detecting and enabling SEV Live migration
feature uses the following logic :

 - kvm_init_plaform() checks if its booted under the EFI

   - If not EFI,

     i) if kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL), issue a wrmsrl()
         to enable the SEV live migration support

   - If EFI,

     i) If kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL), read
        the UEFI variable which indicates OVMF support for live migration

     ii) the variable indicates live migration is supported, issue a wrmsrl() to
          enable the SEV live migration support

The EFI live migration check is done using a late_initcall() callback.

Also, ensure that _bss_decrypted section is marked as decrypted in the
hypervisor's guest page encryption status tracking.

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Reviewed-by: Steve Rutherford <srutherford@google.com>
Message-Id: <b4453e4c87103ebef12217d2505ea99a1c3e0f0f.1629726117.git.ashish.kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11 07:37:36 -05:00

120 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* AMD Memory Encryption Support
*
* Copyright (C) 2016 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <thomas.lendacky@amd.com>
*/
#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 u64 sev_status;
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 sev_setup_arch(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);
void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages,
bool enc);
void __init mem_encrypt_free_decrypted_mem(void);
/* Architecture __weak replacement functions */
void __init mem_encrypt_init(void);
void __init sev_es_init_vc_handling(void);
bool sme_active(void);
bool sev_active(void);
bool sev_es_active(void);
#define __bss_decrypted __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 sev_setup_arch(void) { }
static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
static inline void __init sme_enable(struct boot_params *bp) { }
static inline void sev_es_init_vc_handling(void) { }
static inline bool sme_active(void) { return false; }
static inline bool sev_active(void) { return false; }
static inline bool sev_es_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; }
static inline void __init
early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc) {}
static inline void mem_encrypt_free_decrypted_mem(void) { }
#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[];
static inline bool mem_encrypt_active(void)
{
return sme_me_mask;
}
static inline u64 sme_get_me_mask(void)
{
return sme_me_mask;
}
#endif /* __ASSEMBLY__ */
#endif /* __X86_MEM_ENCRYPT_H__ */