[PATCH v8 03/40] x86/mm: Extend cc_attr to include AMD SEV-SNP
From: Brijesh Singh <hidden>
Date: 2021-12-10 15:46:57
Also in:
kvm, linux-coco, linux-efi, lkml, platform-driver-x86
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
The CC_ATTR_SEV_SNP can be used by the guest to query whether the SNP - Secure Nested Paging feature is active. Signed-off-by: Brijesh Singh <redacted> --- arch/x86/include/asm/msr-index.h | 2 ++ arch/x86/kernel/cc_platform.c | 2 ++ arch/x86/mm/mem_encrypt.c | 4 ++++ include/linux/cc_platform.h | 8 ++++++++ 4 files changed, 16 insertions(+)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 01e2650b9585..98a64b230447 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h@@ -481,8 +481,10 @@ #define MSR_AMD64_SEV 0xc0010131 #define MSR_AMD64_SEV_ENABLED_BIT 0 #define MSR_AMD64_SEV_ES_ENABLED_BIT 1 +#define MSR_AMD64_SEV_SNP_ENABLED_BIT 2 #define MSR_AMD64_SEV_ENABLED BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT) #define MSR_AMD64_SEV_ES_ENABLED BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT) +#define MSR_AMD64_SEV_SNP_ENABLED BIT_ULL(MSR_AMD64_SEV_SNP_ENABLED_BIT) #define MSR_AMD64_VIRT_SPEC_CTRL 0xc001011f
diff --git a/arch/x86/kernel/cc_platform.c b/arch/x86/kernel/cc_platform.c
index 03bb2f343ddb..e05310f5ec2f 100644
--- a/arch/x86/kernel/cc_platform.c
+++ b/arch/x86/kernel/cc_platform.c@@ -50,6 +50,8 @@ static bool amd_cc_platform_has(enum cc_attr attr) case CC_ATTR_GUEST_STATE_ENCRYPT: return sev_status & MSR_AMD64_SEV_ES_ENABLED; + case CC_ATTR_SEV_SNP: + return sev_status & MSR_AMD64_SEV_SNP_ENABLED; default: return false; }
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 35487305d8af..3ba801ff6afc 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c@@ -487,6 +487,10 @@ static void print_mem_encrypt_feature_info(void) if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) pr_cont(" SEV-ES"); + /* Secure Nested Paging */ + if (cc_platform_has(CC_ATTR_SEV_SNP)) + pr_cont(" SEV-SNP"); + pr_cont("\n"); }
diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h
index a075b70b9a70..ef5e2209c9b8 100644
--- a/include/linux/cc_platform.h
+++ b/include/linux/cc_platform.h@@ -61,6 +61,14 @@ enum cc_attr { * Examples include SEV-ES. */ CC_ATTR_GUEST_STATE_ENCRYPT, + + /** + * @CC_ATTR_SEV_SNP: Guest SNP is active. + * + * The platform/OS is running as a guest/virtual machine and actively + * using AMD SEV-SNP features. + */ + CC_ATTR_SEV_SNP = 0x100, }; #ifdef CONFIG_ARCH_HAS_CC_PLATFORM
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2.25.1