fix(test): validate restored test works in test_valid_handler

In test_valid_handler, we had a comment to validate that the guest still
works if we mess with the balloon after UFFD-based restoration. However,
we didn't actually do so. Fix this by running some simple SSH command
after both inflation and deflation.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

tests/integration_tests/functional/test_uffd.py

@@ -118,10 +118,14 @@ def test_valid_handler(uvm_plain, snapshot, uffd_handler_paths):
     # Inflate balloon.
     vm.api.balloon.patch(amount_mib=200)
 
+    # Verify if the restored guest works.
+    vm.ssh.check_output("true")
+
     # Deflate balloon.
     vm.api.balloon.patch(amount_mib=0)
 
     # Verify if the restored guest works.
+    vm.ssh.check_output("true")
 
 
 def test_malicious_handler(uvm_plain, snapshot, uffd_handler_paths):