Re: [PATCH v3 2/4] KVM: selftests: Verify SNP VMs are rejected from migration and mirroring

[Atish Patra <atish.patra@linux.dev>]

On 6/2/26 3:11 PM, Atish Patra wrote:
> From: Atish Patra <atishp@meta.com>
>
> Migration and mirroring of SEV-SNP VMs are not supported yet.
>
> Add two selftests that verify KVM rejects intra-host migration and
> mirroring when the source VM is an SNP VM, so the restriction stays enforced
> until proper SNP state transfer is implemented.
>
> Signed-off-by: Atish Patra <atishp@meta.com>
> ---
>   .../testing/selftests/kvm/x86/sev_migrate_tests.c  | 47 ++++++++++++++++++++++
>   1 file changed, 47 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
> index 6b0928e69051..acef6ab26d3d 100644
> --- a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
> +++ b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
> @@ -313,6 +313,49 @@ static void test_sev_mirror_parameters(void)
>   	kvm_vm_free(vm_no_vcpu);
>   }
>   
> +static void test_sev_snp_migrate_reject(void)
> +{
> +	struct kvm_vm *src_vm, *dst_vm;
> +	int ret;
> +
> +	src_vm = vm_create_barebones_type(KVM_X86_SNP_VM);
> +	snp_vm_init(src_vm);
> +	__vm_vcpu_add(src_vm, 0);
> +	vm_sev_launch(src_vm, snp_default_policy(), NULL);
> +
> +	dst_vm = vm_create_barebones_type(KVM_X86_SNP_VM);
> +	__vm_vcpu_add(dst_vm, 0);
> +
> +	ret = __sev_migrate_from(dst_vm, src_vm);
> +	TEST_ASSERT(ret == -1 && errno == EINVAL,
> +		    "SNP VM migration should be rejected. ret: %d, errno: %d",
> +		    ret, errno);
> +
> +	kvm_vm_free(src_vm);
> +	kvm_vm_free(dst_vm);
> +}
> +
> +static void test_sev_snp_mirror_reject(void)
> +{
> +	struct kvm_vm *src_vm, *dst_vm;
> +	int ret;
> +
> +	src_vm = vm_create_barebones_type(KVM_X86_SNP_VM);
> +	snp_vm_init(src_vm);
> +	__vm_vcpu_add(src_vm, 0);
> +	vm_sev_launch(src_vm, snp_default_policy(), NULL);
> +
> +	dst_vm = aux_vm_create(false);
> +
> +	ret = __sev_mirror_create(dst_vm, src_vm);
> +	TEST_ASSERT(ret == -1 && errno == EINVAL,
> +		    "SNP VM mirroring should be rejected. ret: %d, errno: %d",
> +		    ret, errno);
> +
> +	kvm_vm_free(src_vm);
> +	kvm_vm_free(dst_vm);
> +}
> +
>   static void test_sev_move_copy(void)
>   {
>   	struct kvm_vm *dst_vm, *dst2_vm, *dst3_vm, *sev_vm, *mirror_vm,
> @@ -384,12 +427,16 @@ int main(int argc, char *argv[])
>   		test_sev_migrate_parameters();
>   		if (kvm_has_cap(KVM_CAP_VM_COPY_ENC_CONTEXT_FROM))
>   			test_sev_move_copy();
> +		if (kvm_cpu_has(X86_FEATURE_SEV_SNP))
> +			test_sev_snp_migrate_reject();
>   	}
>   	if (kvm_has_cap(KVM_CAP_VM_COPY_ENC_CONTEXT_FROM)) {
>   		test_sev_mirror(/* es= */ false);
>   		if (have_sev_es)
>   			test_sev_mirror(/* es= */ true);
>   		test_sev_mirror_parameters();
> +		if (kvm_cpu_has(X86_FEATURE_SEV_SNP))
> +			test_sev_snp_mirror_reject();
>   	}
>   	return 0;
>   }
>
gentle ping for any feedback on this patch ?