Re: [PATCH v11 2/3] KVM: s390: guest support for topology function

Janis Schoetterl-Glausch
2022-07-04T09:14:47Z

On 7/4/22 11:08, Janis Schoetterl-Glausch wrote:
> On 7/1/22 18:25, Pierre Morel wrote:
>> We report a topology change to the guest for any CPU hotplug.
>>
>> The reporting to the guest is done using the Multiprocessor
>> Topology-Change-Report (MTCR) bit of the utility entry in the guest's
>> SCA which will be cleared during the interpretation of PTF.
>>
>> On every vCPU creation we set the MCTR bit to let the guest know the
>> next time he uses the PTF with command 2 instruction that the> topology changed and that he should use the STSI(15.1.x) instruction
> s/he/it (twice)
>> to get the topology details.
>>
>> STSI(15.1.x) gives information on the CPU configuration topology.
>> Let's accept the interception of STSI with the function code 15 and
>> let the userland part of the hypervisor handle it when userland
>> support the CPU Topology facility.

Oops, quoted my own comment, should have been:

And the user STSI capability.
Also: supportS.