[RFC PATCH v2 04/17] KVM: selftest: TDX: Add report_fatal_error test

Sagi Shahar
2022-08-30T22:20:43Z

The test checks report_fatal_error functionality.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
tools/testing/selftests/kvm/lib/x86_64/tdx.h | 17 ++++++
.../selftests/kvm/x86_64/tdx_vm_tests.c | 55 +++++++++++++++++++
2 files changed, 72 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx.h b/tools/testing/selftests/kvm/lib/x86_64/tdx.h
index d5de52657112..351ece3e80e2 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx.h
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx.h
@@ -51,6 +51,7 @@
#define _PAGE_RW (1UL<<1) /* writeable */
#define _PAGE_PS (1UL<<7) /* page size bit*/

+#define TDX_REPORT_FATAL_ERROR 0x10003
#define TDX_INSTRUCTION_IO 30

#define TDX_SUCCESS_PORT 0x30
@@ -212,6 +213,22 @@ static inline void tdvmcall_success(void)
tdvmcall_io(TDX_SUCCESS_PORT, /*size=*/4, TDX_IO_WRITE, &code);
}

+/*
+ * Report an error to user space.
+ * data_gpa may point to an optional shared guest memory holding the error string.
+ * Return value from tdvmcall is ignored since execution is not expected to
+ * continue beyond this point.
+ */
+static inline void tdvmcall_fatal(uint64_t error_code)
+{
+ struct kvm_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+ regs.r11 = TDX_REPORT_FATAL_ERROR;
+ regs.r12 = error_code;
+ regs.rcx = 0x1C00;
+ tdcall(&regs);
+}

#define TDX_FUNCTION_SIZE(name) ((uint64_t)&__stop_sec_ ## name -\
(uint64_t)&__start_sec_ ## name) \
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 590e45aa7570..1db5400ca5ef 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -91,6 +91,60 @@ void verify_td_lifecycle(void)
printf("\t ... PASSED\n");
}

+/*
+ * Verifies TDX_REPORT_FATAL_ERROR functionality.
+ */
+TDX_GUEST_FUNCTION(guest_code_report_fatal_error)
+{
+ uint64_t err;
+ /* Note: err should follow the GHCI spec definition:
+ * bits 31:0 should be set to 0.
+ * bits 62:32 are used for TD-specific extended error code.
+ * bit 63 is used to mark additional information in shared memory.
+ */
+ err = 0x0BAAAAAD00000000;
+
+ if (err)
+ tdvmcall_fatal(err);
+
+ tdvmcall_success();
+}
+
+void verify_report_fatal_error(void)
+{
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+
+ printf("Verifying report_fatal_error:\n");
+ /* Create a TD VM with no memory.*/
+ vm = vm_create_tdx();
+
+ /* Allocate TD guest memory and initialize the TD.*/
+ initialize_td(vm);
+
+ /* Initialize the TD vcpu and copy the test code to the guest memory.*/
+ vcpu = vm_vcpu_add_tdx(vm, 0);
+
+ /* Setup and initialize VM memory */
+ prepare_source_image(vm, guest_code_report_fatal_error,
+ TDX_FUNCTION_SIZE(guest_code_report_fatal_error),
+ 0);
+ finalize_td_memory(vm);
+
+ vcpu_run(vcpu);
+ ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_SYSTEM_EVENT);
+ ASSERT_EQ(vcpu->run->system_event.ndata, 3);
+ ASSERT_EQ(vcpu->run->system_event.data[0], TDX_REPORT_FATAL_ERROR);
+ ASSERT_EQ(vcpu->run->system_event.data[1], 0x0BAAAAAD00000000);
+ ASSERT_EQ(vcpu->run->system_event.data[2], 0);
+
+ vcpu_run(vcpu);
+ CHECK_GUEST_COMPLETION(vcpu);
+
+ kvm_vm_free(vm);
+ printf("\t ... PASSED\n");
+}
+
int main(int argc, char **argv)
{
if (!is_tdx_enabled()) {
@@ -99,6 +153,7 @@ int main(int argc, char **argv)
}

run_in_new_process(&verify_td_lifecycle);
+ run_in_new_process(&verify_report_fatal_error);

return 0;
}
--
2.37.2.789.g6183377224-goog