Re: [PATCH v12 0/7] s390x: CPU Topology

[Pierre Morel]

On 12/1/22 09:45, Cédric Le Goater wrote:
> Hello Pierre
>
> On 11/29/22 18:41, Pierre Morel wrote:
> > Hi,
> >
> > The implementation of the CPU Topology in QEMU has been modified
> > since the last patch series.
> >
> > - The two preliminary patches have been accepted and are no longer
> >    part of this series.
> >
> > - The topology machine property has been abandoned
> >
> > - the topology_capable QEMU capability has been abandoned
> >
> > - both where replaced with a new CPU feature, topology-disable
> >    to fence per default the ctop topology information feature.
> >
> > To use the QEMU patches, you will need Linux V6-rc1 or newer,
> > or use the following Linux mainline patches:
> >
> > f5ecfee94493 2022-07-20 KVM: s390: resetting the Topology-Change-Report
> > 24fe0195bc19 2022-07-20 KVM: s390: guest support for topology function
> > 0130337ec45b 2022-07-20 KVM: s390: Cleanup ipte lock access and SIIF 
> > fac..
> >
> > Currently this code is for KVM only, I have no idea if it is interesting
> > to provide a TCG patch. If ever it will be done in another series.
> >
> > To have a better understanding of the S390x CPU Topology and its
> > implementation in QEMU you can have a look at the documentation in the
> > last patch of this series.
> >
> > The admin will want to match the host and the guest topology, taking
> > into account that the guest does not recognize multithreading.
> > Consequently, two vCPU assigned to threads of the same real CPU should
> > preferably be assigned to the same socket of the guest machine.

Hello Cedric,

> Please make sure the patchset compiles on non-s390x platforms and check

Yes,

> that the documentation generates correctly. You will need to install :
>
>    python3-sphinx python3-sphinx_rtd_theme
>
> 'configure' should then enable doc generation.

Yes, thanks,

Pierre

> Thanks,
>
> C.

--
Pierre Morel
IBM Lab Boeblingen