1. A method, comprising: executing, by a particular machine, a single machine-code instruction including a reference into a command-message-building data structure stored in memory; wherein said executing the single machine-code instruction includes generating a command message and initiating communication of the command message to a hardware accelerator, with said generating the command message including copying command information from the command-message-building data structure based on the reference into the command message; receiving, by the hardware accelerator, the command message; and executing, by the hardware accelerator, the command message.