Re: [Qemu-devel] [PATCH v1 5/6] target/s390x: add basic MSA features

[Thomas Huth]

On 09.08.2017 15:01, Cornelia Huck wrote:
> On Fri, 21 Jul 2017 14:56:08 +0200
> David Hildenbrand <address@hidden> wrote:
> 
> Finally got around to that one...
> 
>> The STFLE bits for the MSA (extension) facilities simply indicate that
>> the respective instructions can be executed. The QUERY subfunction can then
>> be used to identify which features exactly are available.
>>
>> Availability of subfunctions can also vary on real hardware. For now, we
>> simply implement a CPU model without any available subfunctions except
>> QUERY (which is always around).
>>
>> As all MSA functions behave quite similarly, we can use one translation
>> handler for now. Prepare the code for implementation of actual subfunctions.
> 
> Sounds reasonable.
> 
>>
>> At least MSA is helpful for now, as older Linux kernels require this
>> facility when compiled for a z9 model. Allow to enable the facilities
>> for the qemu cpu model.
> 
> Do you remember which kernels?

Basically everything before kernel version 4.13 - the patch to lift this
requirement has just been merged very recently:

 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8aa8680aa383bf6e2ac2a7d3369097268c75f7da

 Thomas