On Thu, 19 Sep 2024 14:11:16 +0800 Zhao Liu <zhao1.liu@xxxxxxxxx> wrote: > -smp maxsockets=1,maxdies=1,maxmodules=2,maxcores=2,maxthreads=2 > -machine pc,custom-topo=on \ > -device cpu-socket,id=sock0 \ > -device cpu-die,id=die0,bus=sock0 \ > -device cpu-module,id=mod0,bus=die0 \ > -device cpu-module,id=mod1,bus=die0 \ > -device x86-intel-core,id=core0,bus=mod0 \ > -device x86-intel-atom,id=core1,bus=mod1 \ > -device x86-intel-atom,id=core2,bus=mod1 \ > -device host-x86_64-cpu,id=cpu0,socket-id=0,die-id=0,module-id=0,core-id=0,thread-id=0 \ > -device host-x86_64-cpu,id=cpu1,socket-id=0,die-id=0,module-id=0,core-id=0,thread-id=1 \ > -device host-x86_64-cpu,id=cpu2,socket-id=0,die-id=0,module-id=1,core-id=0,thread-id=0 \ > -device host-x86_64-cpu,id=cpu3,socket-id=0,die-id=0,module-id=1,core-id=1,thread-id=0 I quite like this as a way of doing the configuration but that needs some review from others. Peter, Alex, do you think this scheme is flexible enough to ultimately allow us to support this for arm? > > This does not accommodate hybrid topologies. Therefore, we introduce > max* parameters: maxthreads/maxcores/maxmodules/maxdies/maxsockets > (for x86), to predefine the topology framework for the machine. These > parameters also constrain subsequent custom topologies, ensuring the > number of child devices under each parent device does not exceed the > specified max limits. To my thinking this seems like a good solution even though it's a bunch more smp parameters. What does this actually mean for hotplug of CPUs? What cases work with this setup? > Therefore, once user wants to customize topology by "-machine > custom-topo=on", the machine, that supports custom topology, will skip > the default topology creation as well as the default CPU creation. Seems sensible to me. Jonathan
