tests: Sync between threads in vfio async event

Add waiting loops after reg event and before closing the async event to
make sure registration for events happens before triggering an event.

Signed-off-by: Bar Friedman <bfriedman@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>

Author: barfriedman2

tests/test_mlx5_vfio.py

@@ -24,6 +24,9 @@
 import pyverbs.mem_alloc as mem
 import pyverbs.dma_util as dma
 
+EVENT_TIMEOUT = 2  # In seconds
+EVENT_REGISTRATION_TIMEOUT = 3  # In seconds
+
 
 class Mlx5VfioResources(Mlx5DevxRcResources):
     def __init__(self, ib_port, pci_name, gid_index=None, ctx=None, activate_port_state=False):
@@ -204,6 +207,7 @@ def vfio_process_async_events(self):
         events_fd = self.server.msi_vector.fd
         with select.epoll() as epoll_events:
             epoll_events.register(events_fd, select.EPOLLIN)
+            self.reg_async_events = True
             while self.proc_events:
                 for fd, event in epoll_events.poll(timeout=0.1):
                     if fd == events_fd:
@@ -248,13 +252,18 @@ def test_mlx5vfio_async_event(self):
         self.event_ex = []
         self.proc_events = True
         self.caught_event = False
+        self.reg_async_events = False
         proc_events = Thread(target=self.vfio_process_events)
         proc_async_events = Thread(target=self.vfio_process_async_events)
         proc_events.start()
         proc_async_events.start()
         # Move the DevX QPs to RTS state
         self.pre_run()
         try:
+            start_reg_t = time.perf_counter()
+            while not self.reg_async_events:
+                if time.perf_counter() - start_reg_t >= EVENT_REGISTRATION_TIMEOUT:
+                    raise PyverbsRDMAError('Could not register async events')
             # Change port state
             self.server.change_port_state_with_registers(PortStatus.MLX5_PORT_UP)
             admin_status, oper_status = self.server.query_port_state_with_registers()
@@ -270,10 +279,12 @@ def test_mlx5vfio_async_event(self):
                 time.sleep(1)
         finally:
             # Stop listening to events
+            start_event_t = time.perf_counter()
+            while not self.caught_event:
+                if time.perf_counter() - start_event_t >= EVENT_TIMEOUT:
+                    raise PyverbsRDMAError('Failed to catch an async event')
             self.proc_events = False
             proc_events.join()
             proc_async_events.join()
             if self.event_ex:
                 raise PyverbsRDMAError(f'Received unexpected vfio events: {self.event_ex}')
-            if not self.caught_event:
-                raise PyverbsRDMAError('Failed to catch an async event')