[PATCH] powerpc/pseries/vas: Don't print an error when VAS is unavailable

[Tyrel Datwyler]

On 11/26/21 2:31 AM, Nicholas Piggin wrote:
> Excerpts from Cédric Le Goater's message of November 26, 2021 5:13 pm:
>> On 11/26/21 06:21, Nicholas Piggin wrote:
>>> KVM does not support VAS so guests always print a useless error on boot
>>>
>>>      vas: HCALL(398) error -2, query_type 0, result buffer 0x57f2000
>>>
>>> Change this to only print the message if the error is not H_FUNCTION.
>>
>>
>> Just being curious, why is it even called since "ibm,compression" should
>> not be exposed in the DT ?
> 
> It looks like vas does not test for it. I guess in theory there can be 
> other functions than compression implemented as an accelerator. Maybe
> that's why?
> 
> Thanks,
> Nick
> 
Looks like pseries_vas_init() simply calls h_query_vas_capabilities() to test
for VAS coprocessor support. I would assume KVM doesn't expose hcall-vas or
hcall-nx in /rtas/ibm,hypertas-functions? Doesn't look like hcall-vas or
hcall-nx have been added to the hypertas_fw_feature matching, but maybe they
should and we can gate VAS initialization on those, or at the minimum
FW_FEATURE_VAS?

-Tyrel