[PATCH v7 15/30] KVM: selftests: TDX: Add TDX IO reads test

[Sagi Shahar <sagis@google.com>]

The test verifies IO reads of various sizes from the host to the guest.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/x86/tdx_vm_test.c | 76 ++++++++++++++++++-
 1 file changed, 75 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/x86/tdx_vm_test.c b/tools/testing/selftests/kvm/x86/tdx_vm_test.c
index f646da032004..ae5749e5c605 100644
--- a/tools/testing/selftests/kvm/x86/tdx_vm_test.c
+++ b/tools/testing/selftests/kvm/x86/tdx_vm_test.c
@@ -383,6 +383,78 @@ void verify_guest_writes(void)
 	printf("\t ... PASSED\n");
 }
 
+#define TDX_IO_READS_TEST_PORT 0x52
+
+/*
+ * Verifies IO functionality by reading values of different sizes
+ * from the host.
+ */
+void guest_io_reads(void)
+{
+	uint64_t data;
+	uint64_t ret;
+
+	ret = tdg_vp_vmcall_instruction_io(TDX_IO_READS_TEST_PORT, 1,
+					   PORT_READ, &data);
+	tdx_assert_error(ret);
+	if (data != 0xAB)
+		tdx_test_fatal(1);
+
+	ret = tdg_vp_vmcall_instruction_io(TDX_IO_READS_TEST_PORT, 2,
+					   PORT_READ, &data);
+	tdx_assert_error(ret);
+	if (data != 0xABCD)
+		tdx_test_fatal(2);
+
+	ret = tdg_vp_vmcall_instruction_io(TDX_IO_READS_TEST_PORT, 4,
+					   PORT_READ, &data);
+	tdx_assert_error(ret);
+	if (data != 0xFFABCDEF)
+		tdx_test_fatal(4);
+
+	/* Read an invalid number of bytes. */
+	ret = tdg_vp_vmcall_instruction_io(TDX_IO_READS_TEST_PORT, 5,
+					   PORT_READ, &data);
+	tdx_assert_error(ret);
+
+	tdx_test_success();
+}
+
+void verify_guest_reads(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = td_create();
+	td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
+	vcpu = td_vcpu_add(vm, 0, guest_io_reads);
+	td_finalize(vm);
+
+	printf("Verifying guest reads:\n");
+
+	tdx_run(vcpu);
+	tdx_test_assert_io(vcpu, TDX_IO_READS_TEST_PORT, 1, PORT_READ);
+	*(uint8_t *)((void *)vcpu->run + vcpu->run->io.data_offset) = 0xAB;
+
+	tdx_run(vcpu);
+	tdx_test_assert_io(vcpu, TDX_IO_READS_TEST_PORT, 2, PORT_READ);
+	*(uint16_t *)((void *)vcpu->run + vcpu->run->io.data_offset) = 0xABCD;
+
+	tdx_run(vcpu);
+	tdx_test_assert_io(vcpu, TDX_IO_READS_TEST_PORT, 4, PORT_READ);
+	*(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset) = 0xFFABCDEF;
+
+	td_vcpu_run(vcpu);
+	TEST_ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_SYSTEM_EVENT);
+	TEST_ASSERT_EQ(vcpu->run->system_event.data[12], TDG_VP_VMCALL_INVALID_OPERAND);
+
+	tdx_run(vcpu);
+	tdx_test_assert_success(vcpu);
+
+	kvm_vm_free(vm);
+	printf("\t ... PASSED\n");
+}
+
 int main(int argc, char **argv)
 {
 	ksft_print_header();
@@ -390,7 +462,7 @@ int main(int argc, char **argv)
 	if (!is_tdx_enabled())
 		ksft_exit_skip("TDX is not supported by the KVM. Exiting.\n");
 
-	ksft_set_plan(6);
+	ksft_set_plan(7);
 	ksft_test_result(!run_in_new_process(&verify_td_lifecycle),
 			 "verify_td_lifecycle\n");
 	ksft_test_result(!run_in_new_process(&verify_report_fatal_error),
@@ -403,6 +475,8 @@ int main(int argc, char **argv)
 			 "verify_get_td_vmcall_info\n");
 	ksft_test_result(!run_in_new_process(&verify_guest_writes),
 			 "verify_guest_writes\n");
+	ksft_test_result(!run_in_new_process(&verify_guest_reads),
+			 "verify_guest_reads\n");
 
 	ksft_finished();
 	return 0;
-- 
2.50.0.rc2.692.g299adb8693-goog