[PATCH v3 6/7] tests/acceptance: Add set_vm_arg() to the Test class

[Wainer dos Santos Moschetta <wainersm@redhat.com>]

The set_vm_arg method is added to avocado_qemu.Test class on this
change. Use that method to set (or replace) an argument to the list of
arguments given to the QEMU binary.

Suggested-by: Cleber Rosa <crosa@redhat.com>
Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
---
 tests/acceptance/avocado_qemu/__init__.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/acceptance/avocado_qemu/__init__.py b/tests/acceptance/avocado_qemu/__init__.py
index 7f8e703757..14c6ae70c8 100644
--- a/tests/acceptance/avocado_qemu/__init__.py
+++ b/tests/acceptance/avocado_qemu/__init__.py
@@ -240,6 +240,27 @@ def get_vm(self, *args, name=None):
                 self._vms[name].set_machine(self.machine)
         return self._vms[name]
 
+    def set_vm_arg(self, arg, value):
+        """
+        Set an argument to list of extra arguments to be given to the QEMU
+        binary. If the argument already exists then its value is replaced.
+
+        :param arg: the QEMU argument, such as "-cpu" in "-cpu host"
+        :type arg: str
+        :param value: the argument value, such as "host" in "-cpu host"
+        :type value: str
+        """
+        if not arg or not value:
+            return
+        if arg not in self.vm.args:
+            self.vm.args.extend([arg, value])
+        else:
+            idx = self.vm.args.index(arg) + 1
+            if idx < len(self.vm.args):
+                self.vm.args[idx] = value
+            else:
+                self.vm.args.append(value)
+
     def tearDown(self):
         for vm in self._vms.values():
             vm.shutdown()
-- 
2.29.2