On 05/11/2025 02:10, Hardik Garg wrote: > > Each guest has a private hypervisor mailbox and cannot access any other > guest’s communication path. Using an incorrect connection ID does not > allow eavesdropping or cause interference — it only results in failed > VMBus initialization because the host drops messages sent to an > unexpected port. Thus, exposing the correct connection ID to the guest > is safe and necessary for correct initialization. > >> If different values are important for the host, then all guests should >> use whatever 0 which will map to different values on host by other means >> of your protocol. >> > > Using a fixed value such as 0 for all guests would not work, because the > Hyper-V host differentiates between multiple control-plane contexts (for > example, VTL0 vs VTL2) using distinct connection IDs. The guest must use > the value assigned by the host, as there is no implicit mapping or > negotiation protocol to determine it otherwise.
Sorry, I am not going back to three months old discussion. Therefore I close this topic for me with: since the actual value does not matter for the host - it will discard all messages which are not intended to this guest - you can just use value 0 and your hypervisor will map to proper port. Best regards, Krzysztof
