[RFC PATCH v3 20/31] KVM: selftests: TDX: Add TDX CPUID TDVMCALL test

[Ackerley Tng]

From: Sagi Shahar <sagis@xxxxxxxxxx>

This test issues a CPUID TDVMCALL from inside the guest to get the CPUID
values as seen by KVM.

Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
---
 .../selftests/kvm/include/x86_64/tdx/tdx.h    |  4 +
 .../selftests/kvm/lib/x86_64/tdx/tdx.c        | 26 +++++
 .../selftests/kvm/x86_64/tdx_vm_tests.c       | 94 +++++++++++++++++++
 3 files changed, 124 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
index f2a90ad8a55c6..e746372206a25 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
@@ -7,6 +7,7 @@
 #define TDG_VP_VMCALL_GET_TD_VM_CALL_INFO 0x10000
 #define TDG_VP_VMCALL_REPORT_FATAL_ERROR 0x10003
 
+#define TDG_VP_VMCALL_INSTRUCTION_CPUID 10
 #define TDG_VP_VMCALL_INSTRUCTION_HLT 12
 #define TDG_VP_VMCALL_INSTRUCTION_IO 30
 #define TDG_VP_VMCALL_INSTRUCTION_RDMSR 31
@@ -26,5 +27,8 @@ uint64_t tdg_vp_vmcall_ve_request_mmio_read(uint64_t address, uint64_t size,
 					uint64_t *data_out);
 uint64_t tdg_vp_vmcall_ve_request_mmio_write(uint64_t address, uint64_t size,
 					uint64_t data_in);
+uint64_t tdg_vp_vmcall_instruction_cpuid(uint32_t eax, uint32_t ecx,
+					uint32_t *ret_eax, uint32_t *ret_ebx,
+					uint32_t *ret_ecx, uint32_t *ret_edx);
 
 #endif // SELFTEST_TDX_TDX_H
diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
index 8b12ac7049572..d9d60dd58dfdd 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
@@ -136,3 +136,29 @@ uint64_t tdg_vp_vmcall_ve_request_mmio_write(uint64_t address, uint64_t size,
 
 	return __tdx_hypercall(&args, 0);
 }
+
+uint64_t tdg_vp_vmcall_instruction_cpuid(uint32_t eax, uint32_t ecx,
+					uint32_t *ret_eax, uint32_t *ret_ebx,
+					uint32_t *ret_ecx, uint32_t *ret_edx)
+{
+	uint64_t ret;
+	struct tdx_hypercall_args args = {
+		.r11 = TDG_VP_VMCALL_INSTRUCTION_CPUID,
+		.r12 = eax,
+		.r13 = ecx,
+	};
+
+
+	ret = __tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT);
+
+	if (ret_eax)
+		*ret_eax = args.r12;
+	if (ret_ebx)
+		*ret_ebx = args.r13;
+	if (ret_ecx)
+		*ret_ecx = args.r14;
+	if (ret_edx)
+		*ret_edx = args.r15;
+
+	return ret;
+}
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 dcc0940a74e92..b9d96b5f6521f 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -976,6 +976,99 @@ void verify_mmio_writes(void)
 	printf("\t ... PASSED\n");
 }
 
+/*
+ * Verifies CPUID TDVMCALL functionality.
+ * The guest will then send the values to userspace using an IO write to be
+ * checked against the expected values.
+ */
+void guest_code_cpuid_tdcall(void)
+{
+	uint64_t err;
+	uint32_t eax, ebx, ecx, edx;
+
+	// Read CPUID leaf 0x1 from host.
+	err = tdg_vp_vmcall_instruction_cpuid(/*eax=*/1, /*ecx=*/0,
+					&eax, &ebx, &ecx, &edx);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_to_user_space(eax);
+	if (err)
+		tdx_test_fatal(err);
+
+	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);
+
+	err = tdx_test_report_to_user_space(edx);
+	if (err)
+		tdx_test_fatal(err);
+
+	tdx_test_success();
+}
+
+void verify_td_cpuid_tdcall(void)
+{
+	struct kvm_vm *vm;
+	struct kvm_vcpu *vcpu;
+
+	uint32_t eax, ebx, ecx, edx;
+	const struct kvm_cpuid_entry2 *cpuid_entry;
+
+	vm = td_create();
+	td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
+	vcpu = td_vcpu_add(vm, 0, guest_code_cpuid_tdcall);
+	td_finalize(vm);
+
+	printf("Verifying TD CPUID TDVMCALL:\n");
+
+	/* Wait for guest to report CPUID values */
+	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);
+	eax = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset);
+
+	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);
+
+	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);
+
+	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);
+	edx = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset);
+
+	vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	TDX_TEST_ASSERT_SUCCESS(vcpu);
+
+	/* Get KVM CPUIDs for reference */
+	cpuid_entry = kvm_get_supported_cpuid_entry(1);
+	TEST_ASSERT(cpuid_entry, "CPUID entry missing\n");
+
+	ASSERT_EQ(cpuid_entry->eax, eax);
+	// Mask lapic ID when comparing ebx.
+	ASSERT_EQ(cpuid_entry->ebx & ~0xFF000000, ebx & ~0xFF000000);
+	ASSERT_EQ(cpuid_entry->ecx, ecx);
+	ASSERT_EQ(cpuid_entry->edx, edx);
+
+	kvm_vm_free(vm);
+	printf("\t ... PASSED\n");
+}
+
 int main(int argc, char **argv)
 {
 	setbuf(stdout, NULL);
@@ -997,6 +1090,7 @@ int main(int argc, char **argv)
 	run_in_new_process(&verify_guest_hlt);
 	run_in_new_process(&verify_mmio_reads);
 	run_in_new_process(&verify_mmio_writes);
+	run_in_new_process(&verify_td_cpuid_tdcall);
 
 	return 0;
 }
-- 
2.39.0.246.g2a6d74b583-goog