Re: [RFC PATCH 6/8] tests/qtest/libqtest: Allow checking for HVF accelerator

[Thomas Huth <thuth@redhat.com>]

On 19/01/2023 12.30, Philippe Mathieu-Daudé wrote:
> On 19/1/23 12:24, Thomas Huth wrote:
>> On 19/01/2023 11.05, Philippe Mathieu-Daudé wrote:
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>> ---
>>> RFC: CONFIG_HVF is poisoned.
>>>
>>> We could pass host config definitions to qtest using:
>>>
>>>    diff --git a/meson.build b/meson.build
>>>    @@ -2547,6 +2547,7 @@ foreach target : target_dirs
>>>
>>>       accel_kconfig = []
>>>       foreach sym: accelerators
>>>    +    config_host_data.set(sym + '_QTEST', '')
>>>         if sym == 'CONFIG_TCG' or target in accelerator_targets.get(sym, [])
>>>           config_target += { sym: 'y' }
>>>           config_all += { sym: 'y' }
>>>
>>> Then test for CONFIG_HVF_QTEST ...
>>
>> I don't think that would really work well. The qtests are build once for 
>> all targets, and HVF is only available in the target that matches the host 
>> architecture. It's poisoned on purpose.
>>
>> The TCG accelerator is special, since we have it in either none or in all 
>> targets, that's why we can use CONFIG_TCG there.
>>
>> The kvm part is also rather a hack... we should maybe rather additionally 
>> use the "query-kvm" QAPI command to check whether it is really available...?
>>
>> To fix this properly for HVF, I think you'd need a way to query the 
>> available accelerators via QMP, too... Hmmm, weren't there some patches 
>> for something like that in the past ... can't remember right now ...
> 
> https://lore.kernel.org/qemu-devel/20210505125806.1263441-3-philmd@redhat.com/ 
> :(

Ah, right, and we ended up with the competing patch from Igor since we could 
not quite settle on the QAPI extensions?

Hmm, what happens if you execute "query-qmp-schema" on a HVF-enabled host 
these days? Is there a "hvf"-related entry somewhere in the response?

  Thomas