FHIR vs VMR? is FHIR enough in CDS implementation?

In my understanding, FHIR is an interoperability standard, however FHIR resources actually “define” the data model (structure, data type) for the patient, right?
In this sense, what are the relationship (or the difference) between FHIR and VMR?
Can we understand FHIR already contains the built-in patient record model, meaning that we may use FHIR considerring it defines both interoperability standard and the medical record model (aka VMR) already?

Yes, there are FHIR resources for both the administrative and clinical aspects of patient information. The resources are at various levels of maturity, and depending on the use cases that have driven that maturity, there may be various extensions required to support particular decision support use cases. But in general, yes, FHIR provides a sufficient (and IMHO well-suited) platform for the expression and evaluation of decision support.