Add a param to force use serial session in case of failure

Currently, we do have a logic in wait_for_login to
return serial session incase of failure if provided
by the user through function param, this patch extends
that functionality by adding a param which can be use set,
so that serial session is returned in case of failure,
this will be helpful as we most of the testcases using
wait_for_login with default params and we do not need
to modify the testcases, this can be useful during certain
env issues if we want to force use serial logins for the same test.

Signed-off-by: Satheesh Rajendran <[email protected]>

shared/cfg/base.cfg

@@ -120,6 +120,10 @@ q35, arm64-pci, arm64-mmio:
 # serials = "S1 S2 S3"
 serials = "serial0"
 
+# Enable this to "yes" if you want to force wait_for_login
+# to give serial session incase of failure
+force_use_serial_login = "no"
+
 # virtio_serialport and virtio_console ports
 # virtio_ports = "vs1 vs2 vc1"
 # Port types

virttest/virt_vm.py

@@ -1149,6 +1149,8 @@ def print_guest_network_info():
                     session.close()
 
         error = None
+        if not serial:
+            serial = self.params.get("force_use_serial_login", "no") == "yes"
         logging.debug("Attempting to log into '%s' (timeout %ds)",
                       self.name, timeout)
         start_time = time.time()