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 (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e.g.</i>, 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 <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gem5</monospace> lack support for these techniques and suffer from limited bandwidth due to outdated networking models.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 <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pNet-gem5</monospace>, a full-system simulation framework designed to model server systems under high-performance network workloads, targeting data center architecture research. <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pNet-gem5</monospace> extends <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gem5</monospace> 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, <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pNet-gem5</monospace> enables flexible experimentation with custom policies. As a result, <monospace xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pNet-gem5</monospace> 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.