diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index 9ec984cf8674..71aa290c583f 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -1014,6 +1014,8 @@ static inline struct kvm_cpuid_entry2 *__vcpu_get_cpuid_entry(struct kvm_vcpu *v
 							      uint32_t function,
 							      uint32_t index)
 {
+	TEST_ASSERT(vcpu->cpuid, "Must do vcpu_init_cpuid() first (or equivalent)");
+
 	return (struct kvm_cpuid_entry2 *)get_cpuid_entry(vcpu->cpuid,
 							  function, index);
 }