diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h b/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h
index 95a5d5be7f0b..af0ddbfe8d71 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h
@@ -9,6 +9,9 @@
 #define TDX_TEST_SUCCESS_PORT 0x30
 #define TDX_TEST_SUCCESS_SIZE 4
 
+#define TDX_TEST_REPORT_PORT 0x31
+#define TDX_TEST_REPORT_SIZE 4
+
 /**
  * Assert that some IO operation involving tdg_vp_vmcall_instruction_io() was
  * called in the guest.
@@ -102,4 +105,10 @@ void tdx_test_fatal(uint64_t error_code);
  */
 void tdx_test_fatal_with_data(uint64_t error_code, uint64_t data_gpa);
 
+/**
+ * Report a 32 bit value from the guest to user space using TDG.VP.VMCALL
+ * <Instruction.IO> call. Data is reported on port TDX_TEST_REPORT_PORT.
+ */
+uint64_t tdx_test_report_to_user_space(uint32_t data);
+
 #endif // SELFTEST_TDX_TEST_UTIL_H
diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c
index 0419c3c54341..36d2647210da 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c
@@ -42,3 +42,14 @@ void tdx_test_fatal(uint64_t error_code)
 {
 	tdx_test_fatal_with_data(error_code, 0);
 }
+
+uint64_t tdx_test_report_to_user_space(uint32_t data)
+{
+	/* Upcast data to match tdg_vp_vmcall_instruction_io signature */
+	uint64_t data_64 = data;
+
+	return tdg_vp_vmcall_instruction_io(TDX_TEST_REPORT_PORT,
+					TDX_TEST_REPORT_SIZE,
+					TDG_VP_VMCALL_INSTRUCTION_IO_WRITE,
+					&data_64);
+}
diff --git a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
index cde4b171446f..d68ace3db097 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -2,6 +2,7 @@
 
 #include <signal.h>
 #include "kvm_util_base.h"
+#include "processor.h"
 #include "tdx/tdcall.h"
 #include "tdx/tdx.h"
 #include "tdx/tdx_util.h"
@@ -155,6 +156,110 @@ void verify_td_ioexit(void)
 	printf("\t ... PASSED\n");
 }
 
+/*
+ * Verifies CPUID functionality by reading CPUID values in guest. The guest
+ * will then send the values to userspace using an IO write to be checked
+ * against the expected values.
+ */
+void guest_code_cpuid(void)
+{
+	uint64_t err;
+	uint32_t ebx, ecx;
+
+	/* Read CPUID leaf 0x1 */
+	asm volatile (
+		"cpuid"
+		: "=b" (ebx), "=c" (ecx)
+		: "a" (0x1)
+		: "edx");
+
+	err = tdx_test_report_to_user_space(ebx);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_to_user_space(ecx);
+	if (err)
+		tdx_test_fatal(err);
+
+	tdx_test_success();
+}
+
+void verify_td_cpuid(void)
+{
+	struct kvm_vm *vm;
+	struct kvm_vcpu *vcpu;
+
+	uint32_t ebx, ecx;
+	const struct kvm_cpuid_entry2 *cpuid_entry;
+	uint32_t guest_clflush_line_size;
+	uint32_t guest_max_addressable_ids, host_max_addressable_ids;
+	uint32_t guest_sse3_enabled;
+	uint32_t guest_fma_enabled;
+	uint32_t guest_initial_apic_id;
+
+	vm = td_create();
+	td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
+	vcpu = td_vcpu_add(vm, 0, guest_code_cpuid);
+	td_finalize(vm);
+
+	printf("Verifying TD CPUID:\n");
+
+	/* Wait for guest to report ebx value */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	TDX_TEST_ASSERT_IO(vcpu, TDX_TEST_REPORT_PORT, 4,
+			TDG_VP_VMCALL_INSTRUCTION_IO_WRITE);
+	ebx = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset);
+
+	/* Wait for guest to report either ecx value or error */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	TDX_TEST_ASSERT_IO(vcpu, TDX_TEST_REPORT_PORT, 4,
+			TDG_VP_VMCALL_INSTRUCTION_IO_WRITE);
+	ecx = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset);
+
+	/* Wait for guest to complete execution */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	TDX_TEST_ASSERT_SUCCESS(vcpu);
+
+	/* Verify the CPUID values we got from the guest. */
+	printf("\t ... Verifying CPUID values from guest\n");
+
+	/* Get KVM CPUIDs for reference */
+	cpuid_entry = get_cpuid_entry(kvm_get_supported_cpuid(), 1, 0);
+	TEST_ASSERT(cpuid_entry, "CPUID entry missing\n");
+
+	host_max_addressable_ids = (cpuid_entry->ebx >> 16) & 0xFF;
+
+	guest_sse3_enabled = ecx & 0x1;  // Native
+	guest_clflush_line_size = (ebx >> 8) & 0xFF;  // Fixed
+	guest_max_addressable_ids = (ebx >> 16) & 0xFF;  // As Configured
+	guest_fma_enabled = (ecx >> 12) & 0x1;  // As Configured (if Native)
+	guest_initial_apic_id = (ebx >> 24) & 0xFF;  // Calculated
+
+	ASSERT_EQ(guest_sse3_enabled, 1);
+	ASSERT_EQ(guest_clflush_line_size, 8);
+	ASSERT_EQ(guest_max_addressable_ids, host_max_addressable_ids);
+
+	/* TODO: This only tests the native value. To properly test
+	 * "As Configured (if Native)" we need to override this value
+	 * in the TD params
+	 */
+	ASSERT_EQ(guest_fma_enabled, 1);
+
+	/* TODO: guest_initial_apic_id is calculated based on the number of
+	 * VCPUs in the TD. From the spec: "Virtual CPU index, starting from 0
+	 * and allocated sequentially on each successful TDH.VP.INIT"
+	 * To test non-trivial values we either need a TD with multiple VCPUs
+	 * or to pick a different calculated value.
+	 */
+	ASSERT_EQ(guest_initial_apic_id, 0);
+
+	kvm_vm_free(vm);
+	printf("\t ... PASSED\n");
+}
+
 int main(int argc, char **argv)
 {
 	setbuf(stdout, NULL);
@@ -167,6 +272,7 @@ int main(int argc, char **argv)
 	run_in_new_process(&verify_td_lifecycle);
 	run_in_new_process(&verify_report_fatal_error);
 	run_in_new_process(&verify_td_ioexit);
+	run_in_new_process(&verify_td_cpuid);
 
 	return 0;
 }
