Re: [kvm-unit-tests PATCH v2 3/9] s390x: gs: move to new header file

Janosch Frank
2022-03-25T15:09:06Z

On 3/25/22 15:30, Claudio Imbrenda wrote:
> On Fri, 25 Mar 2022 08:29:11 +0100
> Janosch Frank <frankja@linux.ibm.com> wrote:
>
>> On 3/24/22 18:40, Heiko Carstens wrote:
>>> On Wed, Mar 23, 2022 at 06:03:19PM +0100, Nico Boehr wrote:
>>> ...
>>>> +static inline unsigned long load_guarded(unsigned long *p)
>>>> +{
>>>> + unsigned long v;
>>>> +
>>>> + asm(".insn rxy,0xe3000000004c, %0,%1"
>>>> + : "=d" (v)
>>>> + : "m" (*p)
>>>> + : "r14", "memory");
>>>> + return v;
>>>> +}
>>>
>>> It was like that before, but why is r14 within the clobber list?
>>> That doesn't make sense.
>>
>> r14 is changed in the gs handler of the gs test which is executed if the
>> "guarded" part of the load takes place.
>
> I will add a comment explaining that when picking the patch

Do we need load_guarded() in this new header?
The load/store_gscb() functions have potential to be shared across tests
but the lg doesn't need to be executed, no?

We could opt to leave it in gs.c instead