Memory Limit feature was introduce in RHV 4.1 and will be exposed in CloudForms in VM Provision dialog for RHV.
Several restrictions about it:
1. It is supported only when using the ovirt-engine-sdk (by setting ':use_ovirt_engine_sdk: true' in settings.yml.
2. RHV version should be >= 4.1
3. Maximum memory size is defined on engine-side, based on osinfo-*.properties files.
To allow the admin set the maximum memory of a VM during provision.
RHV vms are provisioned with their maximum memory configured.