[RFC PATCH] tests/avocado: probe for multi-process support before running test

["Alex Bennée" <alex.bennee@linaro.org>]

A recent attempt to let avocado run more tests on the CentOS stream
build failed because there was no gating on the multiprocess feature.
Like missing accelerators avocado should gracefully skip when the
feature is not enabled.

In this case we use the existence of the proxy device as a proxy for
multi-process support.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Cc: Jagannathan Raman <jag.raman@oracle.com>
Cc: John G Johnson <john.g.johnson@oracle.com>
---
 tests/avocado/avocado_qemu/__init__.py | 10 ++++++++++
 tests/avocado/multiprocess.py          |  1 +
 2 files changed, 11 insertions(+)

diff --git a/tests/avocado/avocado_qemu/__init__.py b/tests/avocado/avocado_qemu/__init__.py
index a313e88c07..cb71f50db9 100644
--- a/tests/avocado/avocado_qemu/__init__.py
+++ b/tests/avocado/avocado_qemu/__init__.py
@@ -309,6 +309,16 @@ def require_netdev(self, netdevname):
         if netdevhelp.find('\n' + netdevname + '\n') < 0:
             self.cancel('no support for user networking')
 
+    def require_multiprocess(self):
+        """
+        Test for the presence of the x-pci-proxy-dev which is required
+        to support multiprocess.
+        """
+        devhelp = run_cmd([self.qemu_bin,
+                           '-M', 'none', '-device', 'help'])[0];
+        if devhelp.find('x-pci-proxy-dev') < 0:
+            self.cancel('no support for multiprocess device emulation')
+
     def _new_vm(self, name, *args):
         self._sd = tempfile.TemporaryDirectory(prefix="qemu_")
         vm = QEMUMachine(self.qemu_bin, base_temp_dir=self.workdir,
diff --git a/tests/avocado/multiprocess.py b/tests/avocado/multiprocess.py
index 80a3b8f442..9112a4cacc 100644
--- a/tests/avocado/multiprocess.py
+++ b/tests/avocado/multiprocess.py
@@ -22,6 +22,7 @@ def do_test(self, kernel_url, initrd_url, kernel_command_line,
                 machine_type):
         """Main test method"""
         self.require_accelerator('kvm')
+        self.require_multiprocess()
 
         # Create socketpair to connect proxy and remote processes
         proxy_sock, remote_sock = socket.socketpair(socket.AF_UNIX,
-- 
2.39.2