tests/functional/test_aarch64_rme_virt: fix sporadic failure

This test was randomly failing on our CI, and on dev machines,
especially with QEMU debug builds.

>From the information collected, it's related to an implementation choice
in edk2 QEMU virt support. The workaround is to disable KASLR, to avoid
accessing protected memory.
Note: this is *not* needed for the similar test_aarch64_rme_sbsaref.

More information is available on the associated GitLab issue.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2823
Signed-off-by: Pierrick Bouvier <[email protected]>
Reviewed-by: Alex Bennée <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
Message-ID: <[email protected]>

Author: pbo-linaro

tests/functional/test_aarch64_rme_virt.py

@@ -87,7 +87,9 @@ def test_aarch64_rme_virt(self):
         self.vm.add_args('-fsdev', f'local,security_model=none,path={rme_stack},id=shr0')
         self.vm.add_args('-device', 'virtio-net-pci,netdev=net0')
         self.vm.add_args('-netdev', 'user,id=net0')
-        self.vm.add_args('-append', 'root=/dev/vda')
+        # We need to add nokaslr to avoid triggering this sporadic bug:
+        # https://gitlab.com/qemu-project/qemu/-/issues/2823
+        self.vm.add_args('-append', 'root=/dev/vda nokaslr')
 
         self.vm.launch()
         # Wait for host VM boot to complete.