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.
Please make sure the patchset compiles on non-s390x platforms and check that the documentation generates correctly. You will need to install : python3-sphinx python3-sphinx_rtd_theme 'configure' should then enable doc generation. Thanks, C.