>> >> Examples include exposing HBM or PMEM to the VM. Just like on real HW, >> this memory is exposed via cpu-less, special nodes. In contrast to real >> HW, the memory is hotplugged later (I don't think HW supports hotplug >> like that yet, but it might just be a matter of time). > > I suppose some of that maybe covered by GENERIC_AFFINITY entries in SRAT > some by MEMORY entries. Or nodes created dynamically like with normal > hotplug memory. >
I'm certainly no SRAT expert, but seems like under VMWare something similar can happen: https://lkml.kernel.org/r/bae95f0c-faa7-40c6-a0d6-5049b1207...@vmware.com "VM was powered on with 4 vCPUs (4 NUMA nodes) and 4GB memory. ACPI SRAT reports 128 possible CPUs and 128 possible NUMA nodes." Note that that discussion is about hotplugging CPUs to memory-less, hotplugged nodes. But there seems to be some way to expose possible NUMA nodes. Maybe that's via GENERIC_AFFINITY. -- Thanks, David / dhildenb