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Commit d8aa7eea authored by Tom Lendacky's avatar Tom Lendacky Committed by Thomas Gleixner
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x86/mm: Add Secure Encrypted Virtualization (SEV) support 



Provide support for Secure Encrypted Virtualization (SEV). This initial
support defines a flag that is used by the kernel to determine if it is
running with SEV active.

Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Tested-by: default avatarBorislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20171020143059.3291-3-brijesh.singh@amd.com
parent 33e63acc

arch/x86/include/asm/mem_encrypt.h

+6 −0
Original line number Original line Diff line number Diff line
@@ -47,6 +47,9 @@ void __init mem_encrypt_init(void); 




void swiotlb_set_mem_attributes(void *vaddr, unsigned long size);

void swiotlb_set_mem_attributes(void *vaddr, unsigned long size);





bool sme_active(void);

bool sev_active(void);



#else	/* !CONFIG_AMD_MEM_ENCRYPT */

#else	/* !CONFIG_AMD_MEM_ENCRYPT */





#define sme_me_mask	0ULL

#define sme_me_mask	0ULL
@@ -64,6 +67,9 @@ static inline void __init sme_early_init(void) { } 
static inline void __init sme_encrypt_kernel(void) { }

static inline void __init sme_encrypt_kernel(void) { }

static inline void __init sme_enable(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; }



#endif	/* CONFIG_AMD_MEM_ENCRYPT */

#endif	/* CONFIG_AMD_MEM_ENCRYPT */





/*

/*

arch/x86/mm/mem_encrypt.c

+26 −0
Original line number Original line Diff line number Diff line
@@ -42,6 +42,8 @@ static char sme_cmdline_off[] __initdata = "off"; 
u64 sme_me_mask __section(.data) = 0;

u64 sme_me_mask __section(.data) = 0;

EXPORT_SYMBOL_GPL(sme_me_mask);

EXPORT_SYMBOL_GPL(sme_me_mask);





static bool sev_enabled __section(.data);



/* Buffer used for early in-place encryption by BSP, no locking needed */

/* Buffer used for early in-place encryption by BSP, no locking needed */

static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);

static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
@@ -192,6 +194,30 @@ void __init sme_early_init(void) 
		protection_map[i] = pgprot_encrypted(protection_map[i]);

		protection_map[i] = pgprot_encrypted(protection_map[i]);

}

}





/*

 * SME and SEV are very similar but they are not the same, so there are

 * times that the kernel will need to distinguish between SME and SEV. The

 * sme_active() and sev_active() functions are used for this.  When a

 * distinction isn't needed, the mem_encrypt_active() function can be used.

 *

 * The trampoline code is a good example for this requirement.  Before

 * paging is activated, SME will access all memory as decrypted, but SEV

 * will access all memory as encrypted.  So, when APs are being brought

 * up under SME the trampoline area cannot be encrypted, whereas under SEV

 * the trampoline area must be encrypted.

 */

bool sme_active(void)

{

	return sme_me_mask && !sev_enabled;

}

EXPORT_SYMBOL_GPL(sme_active);



bool sev_active(void)

{

	return sme_me_mask && sev_enabled;

}

EXPORT_SYMBOL_GPL(sev_active);



/* Architecture __weak replacement functions */

/* Architecture __weak replacement functions */

void __init mem_encrypt_init(void)

void __init mem_encrypt_init(void)

{

{

include/linux/mem_encrypt.h

+5 −2
Original line number Original line Diff line number Diff line
@@ -23,11 +23,14 @@ 




#define sme_me_mask	0ULL

#define sme_me_mask	0ULL





static inline bool sme_active(void) { return false; }

static inline bool sev_active(void) { return false; }



#endif	/* CONFIG_ARCH_HAS_MEM_ENCRYPT */

#endif	/* CONFIG_ARCH_HAS_MEM_ENCRYPT */





static inline bool sme_active(void)

static inline bool mem_encrypt_active(void)

{

{

	return !!sme_me_mask;

	return sme_me_mask;

}

}





static inline u64 sme_get_me_mask(void)

static inline u64 sme_get_me_mask(void)