Re: [PATCH] s390x: pv: Fence additional unavailable SCLP facilities for PV guests

[David Hildenbrand <david@redhat.com>]

On 08.12.20 17:11, Christian Borntraeger wrote:
> 
> 
> On 08.12.20 15:55, David Hildenbrand wrote:
>> On 08.12.20 14:29, Christian Borntraeger wrote:
>>>
>>>
>>> On 04.12.20 09:36, Janosch Frank wrote:
>>>> There's no VSIE support for a protected guest, so let's better not
>>>> advertise it and its support facilities.
>>>>
>>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>>
>>> Looks sane. Assuming that all features that depend on SIE are named S390_FEAT_SIE_*
>>> this should take care of everything. (i compared to gen-facilities.c)
>>
>> We could add dependency checks to
>> target/s390x/cpu_models.c:check_consistency()
> 
> That could be an additional patch, right?

Yeah sure.

> 
>>
>> What about
>>
>> DEF_FEAT(ESOP, "esop", SCLP_CONF_CHAR, 46,
>> "Enhanced-suppression-on-protection facility")
> 
> ESOP does make sense independent from SIE see chapter 3-15 in the POP
> in "Suppression on Protection"
> 

Rings a bell :)

> 
>> DEF_FEAT(HPMA2, "hpma2", SCLP_CONF_CHAR, 90, "Host page management
>> assist 2 Facility")
> 
> Right. We should also fence of hpma2.

I was also wondering about CMM, but as the guest senses it by executing
the instruction, protected guests will never see it I assume.

-- 
Thanks,

David / dhildenb