fix(test/balloon): remove racy checks

Those negative checks depend on how slow the balloon device activates.
If it activates fast, the checks fail.

One of the checks is already done in unit tests.

The other check we don't have an equivalent for, but the use case should
be rare enough to not matter (configuring a balloon, starting the VM and
checking that replacing it fails). We continute testing that the balloon
can be replaced after it is activated.

Signed-off-by: Pablo Barbáchano <[email protected]>

Author: pb8o

src/vmm/src/devices/virtio/balloon/device.rs

@@ -1132,10 +1132,15 @@ pub(crate) mod tests {
     }
 
     #[test]
-    fn test_num_pages() {
+    fn test_cannot_update_inactive_device() {
         let mut balloon = Balloon::new(0, true, 0, false).unwrap();
         // Assert that we can't update an inactive device.
         balloon.update_size(1).unwrap_err();
+    }
+
+    #[test]
+    fn test_num_pages() {
+        let mut balloon = Balloon::new(0, true, 0, false).unwrap();
         // Switch the state to active.
         balloon.device_state = DeviceState::Activated(single_region_mem(0x1));
 

tests/integration_tests/functional/test_api.py

@@ -1056,16 +1056,6 @@ def test_api_balloon(uvm_nano):
     # Start the microvm.
     test_microvm.start()
 
-    # Updating should fail as driver didn't have time to initialize.
-    with pytest.raises(RuntimeError):
-        test_microvm.api.balloon.patch(amount_mib=4)
-
-    # Overwriting the existing device should give an error now.
-    with pytest.raises(RuntimeError):
-        test_microvm.api.balloon.put(
-            amount_mib=3, deflate_on_oom=False, stats_polling_interval_s=3
-        )
-
     # Give the balloon driver time to initialize.
     # 500 ms is the maximum acceptable boot time.
     time.sleep(0.5)