create_vm_from_cloud_init takes cpu_type. Proxmox gives a VM created without
one the kvm64 model, which has no AVX, so MongoDB 5.0 and later do not start
there, and netOrk's graylog role failed on every VM it provisioned
(netork#494). Which model is right depends on the cluster: host cannot
live-migrate between different CPUs, x86-64-v3 does not start on a CPU older
than Haswell. So the caller chooses.
get_vm_cpu_types() is the new, optional listing behind that choice. Each
VMCpuTypeDict names the model, says what it is for, lists the /proc/cpuinfo
flags the guest gets (so a caller can ask "does this give AVX?" without
knowing model names), whether the node at hand can run it, and which one is
the default. A hypervisor whose VMs have no per-VM CPU model (VMware sets CPU
compatibility per cluster) does not implement it and must reject any
cpu_type other than None.
Both declarations sit under TYPE_CHECKING like the rest of the contract, so
hasattr stays a truthful capability probe; the tests read the signature from
the source.
christianmanivong