Introduce an x86 version of the prot_guest_has() function. This will be used in the more generic x86 code to replace vendor specific calls like sev_active(), etc.
While the name suggests this is intended mainly for guests, it will also be used for host memory encryption checks in place of sme_active().
The amd_prot_guest_has() function does not use EXPORT_SYMBOL_GPL for the same reasons previously stated when changing sme_active(), sev_active and sme_me_mask to EXPORT_SYBMOL: commit 87df26175e67 ("x86/mm: Unbreak modules that rely on external PAGE_KERNEL availability") commit 9d5f38ba6c82 ("x86/mm: Unbreak modules that use the DMA API")
Cc: Thomas Gleixner tglx@linutronix.de Cc: Ingo Molnar mingo@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Peter Zijlstra peterz@infradead.org Co-developed-by: Andi Kleen ak@linux.intel.com Signed-off-by: Andi Kleen ak@linux.intel.com Co-developed-by: Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Tom Lendacky thomas.lendacky@amd.com --- arch/x86/Kconfig | 1 + arch/x86/include/asm/mem_encrypt.h | 2 ++ arch/x86/include/asm/protected_guest.h | 27 ++++++++++++++++++++++++++ arch/x86/mm/mem_encrypt.c | 25 ++++++++++++++++++++++++ include/linux/protected_guest.h | 5 +++++ 5 files changed, 60 insertions(+) create mode 100644 arch/x86/include/asm/protected_guest.h
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 49270655e827..e47213cbfc55 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1514,6 +1514,7 @@ config AMD_MEM_ENCRYPT select ARCH_HAS_FORCE_DMA_UNENCRYPTED select INSTRUCTION_DECODER select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS + select ARCH_HAS_PROTECTED_GUEST help Say yes to enable support for the encryption of system memory. This requires an AMD processor that supports Secure Memory diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 9c80c68d75b5..a46d47662772 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -53,6 +53,7 @@ void __init sev_es_init_vc_handling(void); bool sme_active(void); bool sev_active(void); bool sev_es_active(void); +bool amd_prot_guest_has(unsigned int attr);
#define __bss_decrypted __section(".bss..decrypted")
@@ -78,6 +79,7 @@ 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 bool amd_prot_guest_has(unsigned int attr) { return false; }
static inline int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; } diff --git a/arch/x86/include/asm/protected_guest.h b/arch/x86/include/asm/protected_guest.h new file mode 100644 index 000000000000..b4a267dddf93 --- /dev/null +++ b/arch/x86/include/asm/protected_guest.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Protected Guest (and Host) Capability checks + * + * Copyright (C) 2021 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky thomas.lendacky@amd.com + */ + +#ifndef _X86_PROTECTED_GUEST_H +#define _X86_PROTECTED_GUEST_H + +#include <linux/mem_encrypt.h> + +#ifndef __ASSEMBLY__ + +static inline bool prot_guest_has(unsigned int attr) +{ + if (sme_me_mask) + return amd_prot_guest_has(attr); + + return false; +} + +#endif /* __ASSEMBLY__ */ + +#endif /* _X86_PROTECTED_GUEST_H */ diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index ff08dc463634..7d3b2c6f5f88 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -20,6 +20,7 @@ #include <linux/bitops.h> #include <linux/dma-mapping.h> #include <linux/virtio_config.h> +#include <linux/protected_guest.h>
#include <asm/tlbflush.h> #include <asm/fixmap.h> @@ -389,6 +390,30 @@ bool noinstr sev_es_active(void) return sev_status & MSR_AMD64_SEV_ES_ENABLED; }
+bool amd_prot_guest_has(unsigned int attr) +{ + switch (attr) { + case PATTR_MEM_ENCRYPT: + return sme_me_mask != 0; + + case PATTR_SME: + case PATTR_HOST_MEM_ENCRYPT: + return sme_active(); + + case PATTR_SEV: + case PATTR_GUEST_MEM_ENCRYPT: + return sev_active(); + + case PATTR_SEV_ES: + case PATTR_GUEST_PROT_STATE: + return sev_es_active(); + + default: + return false; + } +} +EXPORT_SYMBOL(amd_prot_guest_has); + /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */ bool force_dma_unencrypted(struct device *dev) { diff --git a/include/linux/protected_guest.h b/include/linux/protected_guest.h index f8ed7b72967b..7a7120abbb62 100644 --- a/include/linux/protected_guest.h +++ b/include/linux/protected_guest.h @@ -17,6 +17,11 @@ #define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ #define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */
+/* 0x800 - 0x8ff reserved for AMD */ +#define PATTR_SME 0x800 +#define PATTR_SEV 0x801 +#define PATTR_SEV_ES 0x802 + #ifdef CONFIG_ARCH_HAS_PROTECTED_GUEST
#include <asm/protected_guest.h>