Re: [kvm-unit-tests PATCH v2 3/9] s390x: irq: make IRQ handler weak

[Pierre Morel <pmorel@linux.ibm.com>]

On 2019-12-02 11:41, Thomas Huth wrote:
> On 29/11/2019 13.01, David Hildenbrand wrote:
>> On 28.11.19 13:46, Pierre Morel wrote:
>>> Having a weak function allows the tests programm to declare its own
>>> IRQ handler.
>>> This is helpfull for I/O tests to have the I/O IRQ handler having
>>> its special work to do.
>>>
>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>> ---
>>>   lib/s390x/interrupt.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
>>> index 3e07867..d70fde3 100644
>>> --- a/lib/s390x/interrupt.c
>>> +++ b/lib/s390x/interrupt.c
>>> @@ -140,7 +140,7 @@ void handle_mcck_int(void)
>>>   		     lc->mcck_old_psw.addr);
>>>   }
>>>   
>>> -void handle_io_int(void)
>>> +__attribute__((weak)) void handle_io_int(void)
>>>   {
>>>   	report_abort("Unexpected io interrupt: at %#lx",
>>>   		     lc->io_old_psw.addr);
>>>
>>
>> The clear alternative would be a way to register a callback function.
>> That way you can modify the callback during the tests. As long as not
>> registered, wrong I/Os can be caught easily here. @Thomas?
> 
> I don't mind too much, but I think I'd also slightly prefer a registered
> callback function here instead.
> 
>   Thomas
> 

As you like but I wonder why you prefer the complicated solution.
The kvm-unit-test is single task, if a test really need something 
complicated it can be done in the test not in the common code.

Anyway I do like you want.

-- 
Pierre Morel
IBM Lab Boeblingen