KVM Forum 2019

When emulating a system using QEMU's Tiny Code Generator we must inspect and translate every single instruction that gets executed. As we completely control the system we should be able to extract some interesting information about how the code executes. While other code instrumentation systems exist (DynamoRIO, Pin, Valgrind) QEMU is unique in supporting system emulation as well as not requiring the host system to have the same instruction set as the guest. In this talk we shall discuss how we can answer some interesting questions about programs running under QEMU. We shall examine some of the drawbacks of QEMU's current introspection support. Finally we shall discuss if a plugin system will allow for more detailed experiments without comprising our ability to continually improve the quality of our emulation code.