Due to software license restrictions, we would need a particular VM to be configured with CPU affinity, so it's only using a dedicated set of physical cores. Now there are a lot of documents and articles about the effects of CPU pinning, but I have not yet found a firm statement on the effects on HA.
VM-VM and VM-Host affinity can be set as a preferred option or a mandatory option, changing the HA behavior accordingly. But will HA, by default, restart a VM on another host if the host to which the CPU allocations were made is offline? In other words, is CPU affinity considered a a preferential setting or a required setting?
CPU Affinity and HA works and is supported as far as I am aware, I have never seen anything else stated. However vMotion is not supported so keep that in mind when it is also a DRS cluster as you would have to disable DRS or set it to Manual for this VM.
PS: I tested the restart in my lab...