test: ensure swiotlb works

Add an integration test on ARM that configures an in-guest swiotlb
region to which all virtio devices should be bound.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

tests/integration_tests/functional/test_swiotlb.py

@@ -0,0 +1,28 @@
+# Copyright 2025 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+"""Test swiotlb related functionality."""
+
+import pytest
+
+from framework.properties import global_props
+
+pytestmark = pytest.mark.skipif(
+    global_props.cpu_architecture != "aarch64", reason="swiotlb only supported on ARM"
+)
+
+
+def test_swiotlb_boot(microvm_factory, guest_kernel_linux_6_1, rootfs):
+    """Tests that a VM can boot if all virtio devices are bound to a swiotlb region, and
+    that this swiotlb region is actually discovered by the guest."""
+    vm = microvm_factory.build(guest_kernel_linux_6_1, rootfs)
+    vm.spawn()
+    vm.basic_config(swiotlb_size=64)
+    vm.add_net_iface()
+    vm.start()
+
+    _, dmesg, _ = vm.ssh.check_output("dmesg")
+
+    assert (
+        "OF: reserved mem: initialized node bouncy_boi, compatible id restricted-dma-pool"
+        in dmesg
+    )