[PATCH v4 08/10] KVM: SEV: Advertise SVM_SEV_FEAT_SNP_ACTIVE
Kim Phillips <[email protected]>
| Newsgroups | dev.linux.lists.linux-coco,org.kernel.vger.kvm,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
Allow userspace to set the feature in kvm_sev_init.vmsa_features. KVM still needs to set the flag for backwards compatibility, but disallowing SVM_SEV_FEAT_SNP_ACTIVE for an SNP guest is "bizarre." Suggested-by: Sean Christopherson <[email protected]> Cc: Borislav Petkov (AMD) <[email protected]> Link: https://lore.kernel.org/kvm/[email protected]/ Signed-off-by: Kim Phillips <[email protected]> Assisted-by: ClaudeCode:claude-opus-4-7 --- arch/x86/include/asm/svm.h | 3 ++- arch/x86/kvm/svm/sev.c | 8 ++++++-- tools/testing/selftests/kvm/x86/sev_init2_tests.c | 4 +++- 3 files changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index a206a0ed2c58..facabba26a91 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -311,7 +311,8 @@ static_assert((X2AVIC_4K_MAX_PHYSICAL_ID & AVIC_PHYSICAL_MAX_INDEX_MASK) == X2AV #define SVM_SEV_FEAT_DEBUG_SWAP BIT_ULL(5) #define SVM_SEV_FEAT_SECURE_TSC BIT_ULL(9) -#define SVM_SEV_FEAT_SNP_ONLY_MASK (SVM_SEV_FEAT_SECURE_TSC) +#define SVM_SEV_FEAT_SNP_ONLY_MASK (SVM_SEV_FEAT_SNP_ACTIVE | \ + SVM_SEV_FEAT_SECURE_TSC) #define VMCB_ALLOWED_SEV_FEATURES_VALID BIT_ULL(63) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 951f0e6be9e5..6baf458383f4 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -3219,8 +3219,12 @@ void __init sev_hardware_setup(void) cpu_feature_enabled(X86_FEATURE_NO_NESTED_DATA_BP)) sev_supported_vmsa_features |= SVM_SEV_FEAT_DEBUG_SWAP; - if (sev_snp_enabled && tsc_khz && cpu_feature_enabled(X86_FEATURE_SNP_SECURE_TSC)) - sev_supported_vmsa_features |= SVM_SEV_FEAT_SECURE_TSC; + if (sev_snp_enabled) { + sev_supported_vmsa_features |= SVM_SEV_FEAT_SNP_ACTIVE; + + if (tsc_khz && cpu_feature_enabled(X86_FEATURE_SNP_SECURE_TSC)) + sev_supported_vmsa_features |= SVM_SEV_FEAT_SECURE_TSC; + } } void sev_hardware_unsetup(void) diff --git a/tools/testing/selftests/kvm/x86/sev_init2_tests.c b/tools/testing/selftests/kvm/x86/sev_init2_tests.c index 5f4032239f7f..2e016cae4ebe 100644 --- a/tools/testing/selftests/kvm/x86/sev_init2_tests.c +++ b/tools/testing/selftests/kvm/x86/sev_init2_tests.c @@ -13,11 +13,13 @@ #include "svm_util.h" #include "kselftest.h" +#define SVM_SEV_FEAT_SNP_ACTIVE BIT_ULL(0) #define SVM_SEV_FEAT_DEBUG_SWAP BIT_ULL(5) #define SVM_SEV_FEAT_SECURE_TSC BIT_ULL(9) /* Features valid only for SNP guests, rejected for SEV-ES and below. */ -#define SNP_ONLY_FEATURES (SVM_SEV_FEAT_SECURE_TSC) +#define SNP_ONLY_FEATURES (SVM_SEV_FEAT_SNP_ACTIVE | \ + SVM_SEV_FEAT_SECURE_TSC) /* * Some features may have hidden dependencies, or may only work -- 2.43.0