pNet-gem5: Full-System Simulation With High-Performance Networking Enabled by Parallel Network Packet Processing

Modern server processors in data centers equipped with high-performance networking technologies (e.g., 100 Gigabit Ethernet) commonly support parallel packet processing via multi-queue NICs, enabling multiple cores to efficiently handle massive traffic loads. However, existing architectural simulators such as gem5 lack support for these techniques and suffer from limited bandwidth due to outdated networking models. Although a recent study introduced a simulation framework supporting userspace high-performance networking via the Data Plane Development Kit (DPDK), many applications still rely on kernel-based networking. To address these limitations, we present pNet-gem5, a full-system simulation framework designed to model server systems under high-performance network workloads, targeting data center architecture research. pNet-gem5 extends gem5 by supporting parallel packet processing on multi-core systems through the integration of multiple hardware queues and a more advanced interrupt mechanism—Message Signaled Interrupts (MSI)—which allows each NIC queue to be mapped to a dedicated core with its own IRQ. It also provides a high-performance network interface and device driver that support scalable and configurable packet distribution between hardware and software. Moreover, by decoupling packet distribution and scheduling from NIC core logic, pNet-gem5 enables flexible experimentation with custom policies. As a result, pNet-gem5 enables more realistic simulation of modern server environments by modeling multi-queue NICs and supporting bandwidths up to 46 Gbps—a significant improvement over the previous limit of only a few Gbps and more closely aligned with today’s tens-of-Gbps networks.