Introduction

This document describes how to enable direct interrupt injection for VMs on Kunpeng servers using openEuler, optimizing VM performance.

Traditional virtualization relies on the Virtual Machine Monitor (VMM) to handle interrupts. Physical device interrupts are intercepted by the VMM and then emulated in software before reaching the VM. This process adds noticeable latency and reduces efficiency.

Direct interrupt injection eliminates this bottleneck by allowing VMs to process physical interrupts without VMM mediation. Combining hardware acceleration with software optimization, this method minimizes interrupt handling delays and substantially boosts VM performance.

Generic Interrupt Controller (GIC) v4.1, Arm's enhanced interrupt controller, improves virtualization performance by enabling direct injection of virtual interrupts (including vLPIs and vSGIs).

When hardware-assisted virtualization acceleration is enabled on Kunpeng 920 processors, the direct interrupt injection of GICv4.1 (including vSGI passthrough) cuts interrupt response times and enhances throughput for demanding network and I/O workloads.