Making io_uring Pervasive in QEMU

Explore how Linux's io_uring asynchronous I/O interface is being integrated throughout QEMU in this 26-minute conference talk from KVM Forum. Learn about the evolution of io_uring since its 2019 introduction as a file I/O interface to its current role as a general-purpose asynchronous system call interface that minimizes system call overhead. Discover the recent development of QEMU's new aio_add_sqe() API that enables custom io_uring operations to be submitted while integrating seamlessly with QEMU's event loop. Understand how io_uring-based file descriptor monitoring has been implemented to replace traditional ppoll(2) or epoll(7) methods, allowing io_uring to drive the entire event loop. Gain insights into the technical challenges, performance implications, and practical use cases for io_uring within QEMU, making this presentation valuable for developers planning to implement io_uring in QEMU as well as anyone seeking to understand how applications can effectively leverage io_uring capabilities.