Getting in the weeds a little bit, you could query the IaaS MSSQL database directly for this kind of information. If you were to query the HostStorageReservationPolicy table you can capture the names, descriptions, and most importantly any IDs associated to your storage reservation policies. With that information you can join to the HostToStorageID table with the ID (HostStorageReservationPolicyID) and relate to the StoragePath field.
Hopefully this gets you started on what you're looking for. As always the typical disclaimer of take caution when querying this DB directly, especially if the query is large or takes a long time to compute rule applies.
Thanks for the suggestion...
My need was to just be able to assign a datastore I choose to the VM disks so at the end I was able to do it without Storage reservation policy but just using VirtualMachine.Storage.Name / VirtualMachine.DiskN.Storage but being able to query the DB can be a good idea in some cases.
I've now some difficulties to set ip addresses