Igor Mammedov <imammedo@redhat.com> writes:
'-numa mem' option has a number of issues and mgmt often defaults to it. Unfortunately it's no possible to replace it with an alternative '-numa memdev' without breaking migration compatibility.
To be precise: -numa node,mem=... and -numa node,memdev=... Correct?
What's possible though is to deprecate it, keeping option working with old machine types. Once deprecation period expires, QEMU will disable '-numa mem' option, usage on new machine types and when the last machine type that supported it is removed we would be able to remove '-numa mem' with associated code.
In order to help mgmt to find out if being deprecated CLI option '-numa mem=SZ' is still supported by particular machine type, expose this information via "numa-mem-supported" machine property.
Users can use "qom-list-properties" QMP command to list machine type properties including initial proprety values (when probing for supported machine types with '-machine none') or at runtime at preconfig time before numa mapping is configured and decide if they should used legacy '-numa mem' or alternative '-numa memdev' option.
This sentence is impenetrable, I'm afraid :) If we only want to convey whether a machine type supports -numa node,mem=..., then adding a flag to query-machines suffices. Since I'm pretty sure you'd have figured that out yourself, I suspect I'm missing something. Can you give me some examples of intended usage?