[RFC PATCH v3 19/31] KVM: selftests: TDX: Add TDX MMIO writes test

Ackerley Tng
2023-01-21T00:18:58Z

From: Sagi Shahar <sagis@google.com>

The test verifies MMIO writes of various sizes from the guest to the host.

Signed-off-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
.../selftests/kvm/include/x86_64/tdx/tdx.h | 2 +
.../selftests/kvm/lib/x86_64/tdx/tdx.c | 14 +++
.../selftests/kvm/x86_64/tdx_vm_tests.c | 85 +++++++++++++++++++
3 files changed, 101 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 8dd6a65485260..f2a90ad8a55c6 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
@@ -24,5 +24,7 @@ uint64_t tdg_vp_vmcall_instruction_wrmsr(uint64_t index, uint64_t value);
uint64_t tdg_vp_vmcall_instruction_hlt(uint64_t interrupt_blocked_flag);
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);

#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 dcdacf08bcd60..8b12ac7049572 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
@@ -122,3 +122,17 @@ uint64_t tdg_vp_vmcall_ve_request_mmio_read(uint64_t address, uint64_t size,

return ret;
}
+
+uint64_t tdg_vp_vmcall_ve_request_mmio_write(uint64_t address, uint64_t size,
+ uint64_t data_in)
+{
+ struct tdx_hypercall_args args = {
+ .r11 = TDG_VP_VMCALL_VE_REQUEST_MMIO,
+ .r12 = size,
+ .r13 = TDG_VP_VMCALL_VE_REQUEST_MMIO_WRITE,
+ .r14 = address,
+ .r15 = data_in,
+ };
+
+ return __tdx_hypercall(&args, 0);
+}
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 88f0429db0176..dcc0940a74e92 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -892,6 +892,90 @@ void verify_mmio_reads(void)
printf("\t ... PASSED\n");
}

+void guest_mmio_writes(void)
+{
+ uint64_t ret;
+
+ ret = tdg_vp_vmcall_ve_request_mmio_write(TDX_MMIO_TEST_ADDR, 1, 0x12);
+ if (ret)
+ tdx_test_fatal(ret);
+
+ ret = tdg_vp_vmcall_ve_request_mmio_write(TDX_MMIO_TEST_ADDR, 2, 0x1234);
+ if (ret)
+ tdx_test_fatal(ret);
+
+ ret = tdg_vp_vmcall_ve_request_mmio_write(TDX_MMIO_TEST_ADDR, 4, 0x12345678);
+ if (ret)
+ tdx_test_fatal(ret);
+
+ ret = tdg_vp_vmcall_ve_request_mmio_write(TDX_MMIO_TEST_ADDR, 8, 0x1234567890ABCDEF);
+ if (ret)
+ tdx_test_fatal(ret);
+
+ // Write across page boundary.
+ ret = tdg_vp_vmcall_ve_request_mmio_write(PAGE_SIZE - 1, 8, 0);
+ if (ret)
+ tdx_test_fatal(ret);
+
+ tdx_test_success();
+}
+
+/*
+ * Varifies guest MMIO writes.
+ */
+void verify_mmio_writes(void)
+{
+ struct kvm_vm *vm;
+ struct kvm_vcpu *vcpu;
+
+ uint8_t byte_1;
+ uint16_t byte_2;
+ uint32_t byte_4;
+ uint64_t byte_8;
+
+ vm = td_create();
+ td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
+ vcpu = td_vcpu_add(vm, 0, guest_mmio_writes);
+ td_finalize(vm);
+
+ printf("Verifying TD MMIO writes:\n");
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 1, TDG_VP_VMCALL_VE_REQUEST_MMIO_WRITE);
+ byte_1 = *(uint8_t *)(vcpu->run->mmio.data);
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 2, TDG_VP_VMCALL_VE_REQUEST_MMIO_WRITE);
+ byte_2 = *(uint16_t *)(vcpu->run->mmio.data);
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 4, TDG_VP_VMCALL_VE_REQUEST_MMIO_WRITE);
+ byte_4 = *(uint32_t *)(vcpu->run->mmio.data);
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 8, TDG_VP_VMCALL_VE_REQUEST_MMIO_WRITE);
+ byte_8 = *(uint64_t *)(vcpu->run->mmio.data);
+
+ ASSERT_EQ(byte_1, 0x12);
+ ASSERT_EQ(byte_2, 0x1234);
+ ASSERT_EQ(byte_4, 0x12345678);
+ ASSERT_EQ(byte_8, 0x1234567890ABCDEF);
+
+ vcpu_run(vcpu);
+ ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_SYSTEM_EVENT);
+ ASSERT_EQ(vcpu->run->system_event.data[1], TDG_VP_VMCALL_INVALID_OPERAND);
+
+ vcpu_run(vcpu);
+ TDX_TEST_ASSERT_SUCCESS(vcpu);
+
+ kvm_vm_free(vm);
+ printf("\t ... PASSED\n");
+}
+
int main(int argc, char **argv)
{
setbuf(stdout, NULL);
@@ -912,6 +996,7 @@ int main(int argc, char **argv)
run_in_new_process(&verify_guest_msr_reads);
run_in_new_process(&verify_guest_hlt);
run_in_new_process(&verify_mmio_reads);
+ run_in_new_process(&verify_mmio_writes);

return 0;
}
--
2.39.0.246.g2a6d74b583-goog