QEMU's Tiny Code Generator: Unpacking Dynamic Emulation

As systems architects, we often find ourselves pushing the boundaries of what’s possible with virtualization and emulation. While hardware-accelerated virtualization like KVM gets a lot of attention, there’s an unsung hero that enables QEMU’s incredible flexibility: the Tiny Code Generator, or TCG. For anyone who’s ever needed to run code on an architecture different from their host, or debug a complex system without native hardware, TCG is the foundational technology that makes it all happen. It’s not just an academic curiosity; understanding TCG is crucial for optimizing performance in non-accelerated environments, troubleshooting tricky emulation issues, and even contributing to QEMU itself. Let’s break this down and explore the core mechanics of TCG, a journey that remains just as relevant today as it was when this “part 1” concept first surfaced in 2021.