tests/acceptance: verify s390x device detection

The kernel/initrd combination does not provide the virtio-net
driver; therefore, simply check whether the presented device type
is indeed virtio-net for the two virtio-net-{ccw,pci} devices.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
[re-formatted overlong lines]
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-Id: <20201130180216.15366-3-cohuck@redhat.com>

tests/acceptance/machine_s390_ccw_virtio.py

@@ -82,3 +82,14 @@ def test_s390x_devices(self):
         exec_command_and_wait_for_pattern(self,
                         'cat /sys/bus/ccw/devices/0.3.1234/virtio?/features',
                         virtio_rng_features)
+        # verify that we indeed have virtio-net devices (without having the
+        # virtio-net driver handy)
+        exec_command_and_wait_for_pattern(self,
+                                    'cat /sys/bus/ccw/devices/0.1.1111/cutype',
+                                    '3832/01')
+        exec_command_and_wait_for_pattern(self,
+                    'cat /sys/bus/pci/devices/0005\:00\:00.0/subsystem_vendor',
+                    '0x1af4')
+        exec_command_and_wait_for_pattern(self,
+                    'cat /sys/bus/pci/devices/0005\:00\:00.0/subsystem_device',
+                    '0x0001')