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

Ackerley Tng
2023-01-21T00:19:00Z

From: Sagi Shahar <sagis@google.com>

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@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
.../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