Re: [kvm-unit-tests PATCH v4 3/4] s390x: topology: Check the Perform Topology Function

Pierre Morel
2022-02-15T09:19:41Z

On 2/15/22 09:50, Pierre Morel wrote:
>
>
> On 2/9/22 12:37, Nico Boehr wrote:
>> On Tue, 2022-02-08 at 14:27 +0100, Pierre Morel wrote:
>>> We check the PTF instruction.
>>
>> You could test some very basic things as well:
>>
>> - you get a privileged pgm int in problem state,
>> - reserved bits in first operand cause specification pgm int,
>> - reserved FC values result in a specification pgm int,
>> - second operand is ignored.
>
> Which second operand?

Sorry got it
>
>>
>>>
>>> - We do not expect to support vertical polarization.
>>>
>>> - We do not expect the Modified Topology Change Report to be
>> [...]
>>
>> Forgive me if I'm missing something, but why _Modified_ Topology Change
>> Report?
>>
>>> diff --git a/s390x/topology.c b/s390x/topology.c
>>> new file mode 100644
>>> index 00000000..a1f9ce51
>>> --- /dev/null
>>> +++ b/s390x/topology.c
>>
>> [...]
>>
>>> +static int ptf(unsigned long fc, unsigned long *rc)
>>> +{
>>> +       int cc;
>>> +
>>> +       asm volatile(
>>> +               "       .insn   rre,0xb9a20000,%1,0\n"
>>> +               "       ipm     %0\n"
>>> +               "       srl     %0,28\n"
>>> +               : "=d" (cc), "+d" (fc)
>>> +               : "d" (fc)
>>
>> Why list fc here again?
>>
>>
>

--
Pierre Morel
IBM Lab Boeblingen