Re: [PATCH v5 3/9] KVM: selftests: SEV-SNP test for KVM_SEV_INIT2

Nikunj A Dadhania
2025-01-28T12:13:54Z

"Pratik R. Sampat" <prsampat@amd.com> writes:

> Add the X86_FEATURE_SNP CPU feature to the architectural definition for
> the SEV-SNP VM type to exercise the KVM_SEV_INIT2 call. Ensure that the
> SNP test is skipped in scenarios where CPUID supports it but KVM does
> not, preventing reporting of failure in such cases.
>
> Signed-off-by: Pratik R. Sampat <prsampat@amd.com>

With a minor nit below:

Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>

> ---
> tools/testing/selftests/kvm/include/x86/processor.h | 1 +
> tools/testing/selftests/kvm/x86/sev_init2_tests.c | 13 +++++++++++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
> index d60da8966772..1e05e610bb06 100644
> --- a/tools/testing/selftests/kvm/include/x86/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86/processor.h
> @@ -199,6 +199,7 @@ struct kvm_x86_cpu_feature {
> #define X86_FEATURE_VGIF KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 16)
> #define X86_FEATURE_SEV KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 1)
> #define X86_FEATURE_SEV_ES KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 3)
> +#define X86_FEATURE_SNP KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 4)

Can we keep the naming same as in cpufeatures.h: X86_FEATURE_SEV_SNP ?

Regards
Nikunj

>
> /*
> * KVM defined paravirt features.
> diff --git a/tools/testing/selftests/kvm/x86/sev_init2_tests.c b/tools/testing/selftests/kvm/x86/sev_init2_tests.c
> index 3fb967f40c6a..3f8fb2cc3431 100644
> --- a/tools/testing/selftests/kvm/x86/sev_init2_tests.c
> +++ b/tools/testing/selftests/kvm/x86/sev_init2_tests.c
> @@ -28,6 +28,7 @@
> int kvm_fd;
> u64 supported_vmsa_features;
> bool have_sev_es;
> +bool have_snp;
>
> static int __sev_ioctl(int vm_fd, int cmd_id, void *data)
> {
> @@ -83,6 +84,9 @@ void test_vm_types(void)
> if (have_sev_es)
> test_init2(KVM_X86_SEV_ES_VM, &(struct kvm_sev_init){});
>
> + if (have_snp)
> + test_init2(KVM_X86_SNP_VM, &(struct kvm_sev_init){});
> +
> test_init2_invalid(0, &(struct kvm_sev_init){},
> "VM type is KVM_X86_DEFAULT_VM");
> if (kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM))
> @@ -138,15 +142,24 @@ int main(int argc, char *argv[])
> "sev-es: KVM_CAP_VM_TYPES (%x) does not match cpuid (checking %x)",
> kvm_check_cap(KVM_CAP_VM_TYPES), 1 << KVM_X86_SEV_ES_VM);
>
> + have_snp = kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SNP_VM);
> + TEST_ASSERT(!have_snp || kvm_cpu_has(X86_FEATURE_SNP),
> + "sev-snp: KVM_CAP_VM_TYPES (%x) indicates SNP support (bit %d), but CPUID does not",
> + kvm_check_cap(KVM_CAP_VM_TYPES), KVM_X86_SNP_VM);
> +
> test_vm_types();
>
> test_flags(KVM_X86_SEV_VM);
> if (have_sev_es)
> test_flags(KVM_X86_SEV_ES_VM);
> + if (have_snp)
> + test_flags(KVM_X86_SNP_VM);
>
> test_features(KVM_X86_SEV_VM, 0);
> if (have_sev_es)
> test_features(KVM_X86_SEV_ES_VM, supported_vmsa_features);
> + if (have_snp)
> + test_features(KVM_X86_SNP_VM, supported_vmsa_features);
>
> return 0;
> }
> --
> 2.43.0