Looking at the wiki they are basically saying no over subscription as in
if you have a host with 12 total physical cores, then you can deploy any combination of virtual machines where the total number of vCPU on those virtual machines adds up to 12.
For memory, reservation would work but sounds like CPU would be the limiting factor in this instance.
yeah I have to apply both cpu and memory dedicated resources, do you know how to map vCPU to pCPU?
well apart from not provisioning more vCPU then pCPU on the host, CPU reservation would have to do, while this ensures the resources it still competes for execution time if the host is over provisioned as a whole.
CPU affinity is an option but not recommended and cant be used in a DRS cluster anyway.