Merge pull request #2074 from michiboo/chardev_port

add test for acpi description of serial and parallel ports correctness

qemu/tests/cfg/chardev_acpi.cfg

+- chardev_acpi:
+    only x86_64, i386
+    only RHEL
+    type = chardev_acpi
+    serials += ' vs1 '
+    chardev_backend_vs1 = tty
+    chardev_path_vs1 = /dev/ttyS0
+    guest_cmd = 'udevadm info --query path --name /dev/ttyS0'

qemu/tests/chardev_acpi.py

+from virttest import error_context
+from virttest import env_process
+
+
+@error_context.context_aware
+def run(test, params, env):
+    """
+    acpi description of serial and parallel ports incorrect
+    with -chardev/-device:
+    1) Boot guest A with isa-serial with tty chardev backend
+    2) Enter into guest A
+        udevadm info --query path --name /dev/ttyS0
+        !! --attribute-walk | grep looking
+    3) Boot guest B with -serial /dev/ttyS0
+    4) repeat step 2 for guest B
+    5) Check if the result are same for A and B.
+    :param test: QEMU test object
+    :param params: Dictionary with the test parameters
+    :param env: Dictionary with test environment.
+    """
+    outputs = []
+    guest_cmd = params['guest_cmd']
+    for x in range(2):
+        if x >= 1:
+            params['serials'] = " ".join(params['serials'].split()[:-1])
+            params['extra_params'] = params.get('extra_params', '') + ' -serial /dev/ttyS0'
+            env_process.preprocess(test, params, env)
+        vm = env.get_vm(params["main_vm"])
+        session = vm.wait_for_login()
+        vm_output1 = session.cmd_status_output(guest_cmd)
+        # !! cannot be used because of echo $?
+        vm_output2 = session.cmd_status_output("{} --attribute-walk | grep looking".format(guest_cmd))
+        outputs.append([vm_output1, vm_output2])
+        vm.destroy()
+    assert outputs.count(outputs[0]) == len(outputs), 'output 1: {} and output 2: {} are not the same'.format(outputs[0], outputs[1])