AIA Virtualization in KVM RISC-V - Advanced Interrupt Architecture Overview

Explore the RISC-V Advanced Interrupt Architecture (AIA) and its virtualization features in KVM RISC-V in this informative conference talk. Gain insights into the AIA specification, which introduces new interrupt controllers supporting wired interrupts, message signaled interrupts (MSIs), MSI virtualization, and software interrupt (IPI) virtualization for large-scale CPU systems. Discover how AIA addresses limitations in existing RISC-V platforms and learn about its implementation in KVM RISC-V, including virtual IPIs, device MSIs, WFI wake-up mechanisms, and IMSIC file updates in VCPU run-loops. Understand the current software status of AIA and its potential impact on RISC-V virtualization capabilities.

Intro
RISC-V AIA Specification
AIA: Extended local interrupts
AIA: IPIs as software injected MSIs
AIA: Wired interrupts using APLIC direct mode
AIA: Wired interrupts using APLIC MSI mode
AIA Virtualization support
AIA Support in KVM RISC-V
KVM: Virtual IPIs using IMSIC VS-files
KVM: Device MSIs using IMSIC VS-files
KVM: WFI wake-up using IMSIC VS-files
KVM: Updating IMSIC file in VCPU run-loop
AIA Software Status