Re: [PATCH v2 1/3] tests/acceptance: avocado_qemu: Introduce the 'accel' test parameter

[Thomas Huth]

On 10/01/2020 21.02, Wainer dos Santos Moschetta wrote:
> Hi Thomas,
> 
> On 12/18/19 4:48 PM, Thomas Huth wrote:
>> On 18/12/2019 18.00, Wainer dos Santos Moschetta wrote:
>>> The test case may need to boot the VM with an accelerator that
>>> isn't actually enabled on the QEMU binary and/or present in the host. In
>>> this case the test behavior is undefined, and the best course of
>>> action is to skip its execution.
>>>
>>> This change introduced the 'accel' parameter (and the handler of
>>> tag with same name) used to indicate the test case requires a
>>> given accelerator available. It was implemented a mechanism to
>>> skip the test case if the accelerator is not available. Moreover,
>>>   the QEMU --accel argument is set automatically to any VM
>>> launched if the parameter is present.
>>>
>>> Signed-off-by: Wainer dos Santos Moschetta <address@hidden>
>>> ---
>>>   docs/devel/testing.rst                    | 16 ++++++++++++++++
>>>   tests/acceptance/avocado_qemu/__init__.py | 23 +++++++++++++++++++++++
>>>   2 files changed, 39 insertions(+)
>>>
>>> diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
>>> index 27f286858a..6c2e0718e1 100644
>>> --- a/docs/devel/testing.rst
>>> +++ b/docs/devel/testing.rst
>>> @@ -757,6 +757,17 @@ name.  If one is not given explicitly, it will
>>> either be set to
>>>   ``None``, or, if the test is tagged with one (and only one)
>>>   ``:avocado: tags=machine:VALUE`` tag, it will be set to ``VALUE``.
>>>   +accel
>>> +~~~~~
>>> +The accelerator that will be set to all QEMUMachine instances created
>>> +by the test.
>>> +
>>> +The ``accel`` attribute will be set to the test parameter of the same
>>> +name.  If one is not given explicitly, it will either be set to
>>> +``None``, or, if the test is tagged with one (and only one)
>>> +``:avocado: tags=accel:VALUE`` tag, it will be set to ``VALUE``.
>>> Currently
>>> +``VALUE`` should be either ``kvm`` or ``tcg``.
>>> +
>>>   qemu_bin
>>>   ~~~~~~~~
>>>   @@ -798,6 +809,11 @@ machine
>>>   The machine type that will be set to all QEMUMachine instances created
>>>   by the test.
>>>   +accel
>>> +~~~~~
>>> +The accelerator that will be set to all QEMUMachine instances created
>>> +by the test. In case the accelerator is not available (both QEMU
>>> +binary and the host system are checked) then the test is canceled.
>>>     qemu_bin
>>>   ~~~~~~~~
>>> diff --git a/tests/acceptance/avocado_qemu/__init__.py
>>> b/tests/acceptance/avocado_qemu/__init__.py
>>> index 6618ea67c1..aff32668d9 100644
>>> --- a/tests/acceptance/avocado_qemu/__init__.py
>>> +++ b/tests/acceptance/avocado_qemu/__init__.py
>>> @@ -20,6 +20,7 @@ SRC_ROOT_DIR =
>>> os.path.join(os.path.dirname(__file__), '..', '..', '..')
>>>   sys.path.append(os.path.join(SRC_ROOT_DIR, 'python'))
>>>     from qemu.machine import QEMUMachine
>>> +from qemu.accel import kvm_available, tcg_available
>>>     def is_readable_executable_file(path):
>>>       return os.path.isfile(path) and os.access(path, os.R_OK | os.X_OK)
>>> @@ -111,6 +112,8 @@ class Test(avocado.Test):
>>>         def setUp(self):
>>>           self._vms = {}
>>> +        # VM argumments that are mapped from parameters
>>> +        self._param_to_vm_args = []
>>>             self.arch = self.params.get('arch',
>>>                                      
>>> default=self._get_unique_tag_val('arch'))
>>> @@ -124,10 +127,30 @@ class Test(avocado.Test):
>>>           if self.qemu_bin is None:
>>>               self.cancel("No QEMU binary defined or found in the
>>> source tree")
>>>   +        self.accel = self.params.get('accel',
>>> +                                    
>>> default=self._get_unique_tag_val('accel'))
>>> +        if self.accel:
>>> +            avail = False
>>> +            if self.accel == 'kvm':
>>> +                if kvm_available(self.arch, self.qemu_bin):
>>> +                    self._param_to_vm_args.append('-enable-kvm')
>> Could you please use "-accel kvm" instead? "-accel" is now our official
>> way to configure an accelerator ... so we should not use the old
>> wrappers in new code anymore if possible.
> Sure, I am going to adjust that on v3.
>>
>>   Thanks,
>>    Thomas
>>
>>
>> PS: Travis supports KVM now, too (with some tweaking of the permissions)
>> ... maybe we should now try to get some QEMU tests running with KVM
>> there, too...
> 
> I heard that but I failed miserably to enable nested virt on Travis.
> Actually I was expecting it enabled by default but not the case. I did
> not find documentation so I tried some tweaks like setting
> 'sudo:required' and using bionic but none of that worked out.
> 
> Do you know what needs to be done?

Yes, I recently enabled it for the kvm-unit-tests ... and yes, it's a
bit ugly: The user has to be in the "kvm" group which is not the case
for the user that runs the travis scripts. Tweaking the access rights of
/dev/kvm unfortunately does not work (at least not directly via chmod
o+rwx /dev/kvm ... but maybe there is a way via udev or something
similar?), so I ended up with:

      sudo chgrp kvm /usr/bin/qemu-system-*
      sudo chmod g+s /usr/bin/qemu-system-*

With that, the kvm-unit-tests are running now fine with KVM on Travis.

 Thomas