CA-392459: Avoid opening /dev/mem when calling biosdevname

biosdevname opens /dev/mem to read the $PIR PCI interrupt routing table.
This fails with Secure Boot enabled and causes a warning in the kernel.
log. Since the $PIR PCI interrupt routing table is used for routing PCI
interrupts to ISA IRQs, it is not useful on any modern system so pass
"-x" to biosdevname to avoid this behaviour.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

tests/test_biosdevname.py

@@ -45,8 +45,8 @@ def test(self):
         # check after the fact that we mocked the proper calls
         self.assertEqual(popen_mock.call_count, 2)
         calls = popen_mock.call_args_list
-        self.assertEqual(calls[0].args[0], ['/sbin/biosdevname', '--policy', 'physical', '-d'])
-        self.assertEqual(calls[1].args[0], ['/sbin/biosdevname', '--policy', 'all_ethN', '-d'])
+        self.assertEqual(calls[0].args[0], ['/sbin/biosdevname', '--policy', 'physical', '-d', '-x'])
+        self.assertEqual(calls[1].args[0], ['/sbin/biosdevname', '--policy', 'all_ethN', '-d', '-x'])
         popen_kwargs = {"stdout": PIPE, "stderr": PIPE, "universal_newlines": True}
         self.assertEqual(calls[0].kwargs, popen_kwargs)
         self.assertEqual(calls[1].kwargs, popen_kwargs)

xcp/net/biosdevname.py

@@ -40,7 +40,7 @@ def __run_all_devices(policy = "physical"):
     """
 
     proc = Popen(["/sbin/biosdevname", "--policy", policy,
-                  "-d"], stdout=PIPE, stderr=PIPE, universal_newlines=True)
+                  "-d", "-x"], stdout=PIPE, stderr=PIPE, universal_newlines=True)
 
     stdout, stderr = proc.communicate()