tests/acceptance: Makes linux_initrd and empty_cpu_model use QEMUMachine

On linux_initrd and empty_cpu_model tests the same effect of
calling QEMU through run() to inspect the terminated process is
achieved with a sequence of set_qmp_monitor() / launch() / wait()
commands on an QEMUMachine object. This patch changes those
tests to use QEMUMachine instead, so they follow the same pattern
to launch QEMU found on other acceptance tests.

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20191211185536.16962-3-wainersm@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>

tests/acceptance/empty_cpu_model.py

@@ -7,13 +7,13 @@
 #
 # This work is licensed under the terms of the GNU GPL, version 2 or
 # later.  See the COPYING file in the top-level directory.
-import subprocess
 from avocado_qemu import Test
 
 class EmptyCPUModel(Test):
     def test(self):
-        cmd = [self.qemu_bin, '-S', '-display', 'none', '-machine', 'none', '-cpu', '']
-        r = subprocess.run(cmd, stderr=subprocess.PIPE, stdout=subprocess.PIPE)
-        self.assertEquals(r.returncode, 1, "QEMU exit code should be 1")
-        self.assertEquals(r.stdout, b'', "QEMU stdout should be empty")
-        self.assertNotEquals(r.stderr, b'', "QEMU stderr shouldn't be empty")
+        self.vm.add_args('-S', '-display', 'none', '-machine', 'none', '-cpu', '')
+        self.vm.set_qmp_monitor(enabled=False)
+        self.vm.launch()
+        self.vm.wait()
+        self.assertEquals(self.vm.exitcode(), 1, "QEMU exit code should be 1")
+        self.assertRegex(self.vm.get_log(), r'-cpu option cannot be empty')

tests/acceptance/linux_initrd.py

@@ -10,7 +10,6 @@
 
 import logging
 import tempfile
-from avocado.utils.process import run
 
 from avocado_qemu import Test
 
@@ -41,13 +40,15 @@ class LinuxInitrd(Test):
             initrd.seek(max_size)
             initrd.write(b'\0')
             initrd.flush()
-            cmd = "%s -kernel %s -initrd %s -m 4096" % (
-                  self.qemu_bin, kernel_path, initrd.name)
-            res = run(cmd, ignore_status=True)
-            self.assertEqual(res.exit_status, 1)
+            self.vm.add_args('-kernel', kernel_path, '-initrd', initrd.name,
+                             '-m', '4096')
+            self.vm.set_qmp_monitor(enabled=False)
+            self.vm.launch()
+            self.vm.wait()
+            self.assertEqual(self.vm.exitcode(), 1)
             expected_msg = r'.*initrd is too large.*max: \d+, need %s.*' % (
                 max_size + 1)
-            self.assertRegex(res.stderr_text, expected_msg)
+            self.assertRegex(self.vm.get_log(), expected_msg)
 
     def test_with_2gib_file_should_work_with_linux_v4_16(self):
         """