[nova][ptg] Summary: Persistent Memory
- Base: https://review.openstack.org/601596
- Libvirt: https://review.openstack.org/622893
- Support persistent memory in units of "namespaces" with custom
resource class names.
- Namespaces to be pre-carved out by admin/deployer (not by Nova).
- Custom RC names mapped to byte sizes via "conf"  so virt driver can
know how to map them back to the real resources.
- "Ignore NUMA for now" (sean-k-mooney will have to tell you what that
- Spec needs to list support-or-not for all instance lifecycle operations.
- Keep one spec for base enablement and one for libvirt, but make sure
the right bits are in the right spec.
 There has been a recurring theme of needing "some kind of config" -
not necessarily nova.conf or any oslo.config - that can describe:
- Resource provider name/uuid/parentage, be it an existing provider (the
compute root RP in this case) or a new nested provider;
- Inventory (e.g. pmem namespace resource in this case);
- Physical resource(s) to which the inventory corresponds;
- Traits, aggregates, other?
As of this writing, no specifics have been decided, even to the point of
positing that it could be the same file for some/all of the specs for
which the issue arose.