1. A computer-implemented method for upgrading a descriptor engine for a network interface card (NIC), the method comprising: quiescing, by a processing device, a transmit stream to the NIC; stopping, by the processing device, a descriptor engine from providing new receive descriptors to the NIC; creating, by the processing device, a copy in a memory of any receive descriptors already available to the NIC prior to the stopping the descriptor engine; setting, by the processing device, a controller to redirect inbound traffic to the memory; and restoring, by the processing device, a transmit configuration and a transmit state of the descriptor engine subsequent to updating the descriptor engine.