Initial IOMMU driver hooks.

This is intentially stripped back to initialization and a hook to the
driver when the VM's memory map is changing. This will work as the
baseline from which changes can be made to fit the needs of the drivers.

Change-Id: I904279f511e2d6e4b1c062fb49a2892042b79005
diff --git a/src/mm_test.hh b/src/mm_test.hh
new file mode 100644
index 0000000..2e906aa
--- /dev/null
+++ b/src/mm_test.hh
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2019 The Hafnium Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <span>
+#include <vector>
+
+namespace mm_test
+{
+std::vector<std::span<pte_t, MM_PTE_PER_PAGE>> get_ptable(
+	const struct mm_ptable &ptable);
+
+} /* namespace mm_test */