Explore NVMe emulation performance optimization techniques in this 21-minute conference talk. Learn about QEMU's NVMe emulation challenges and solutions, including shadow doorbell buffer support, ioeventfd mechanism, iothread utilization, and doorbell memory polling. Discover how these optimizations led to an 11x performance improvement, increasing from 30 KIOPS to 330 KIOPS. Gain insights into the implementation process, challenges faced, and lessons learned. Understand the impact of NVMe spec violations and their fixes. Ideal for developers interested in applying these techniques to their subsystems and improving emulation performance.