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.