Open Source Summit India 2026

Linux kernel development has long since moved past the point of lacking contributors, with around 2,000 developers participating in each release and up to 330 first-time committers [1]. What the development process is missing, however, are reviewers and maintainers.

If you ever thought that becoming a Linux kernel maintainer was something reserved for members of a secret kernel lodge, join this talk in which we will explain why - and how - you should become a Linux kernel maintainer, with a focus on improving the Embedded Linux ecosystem.

Intention of this talk is not only present Krzysztof's ideas how to become Linux kernel maintainer, but also bring discussion with the audience, hoping more senior kernel maintainers will join and participate with their ideas and comments. Thus it could be considered a sort of half-Birds of Feather session.

[1] LWN.net: Some 6.18 development statistics, https://lwn.net/Articles/1046966/

Performance profiling in virtualized environments has traditionally required trade-offs between accuracy and overhead. Mediated PMU, a recent change to Linux's built-in KVM hypervisor, fundamentally changes this by providing guests direct access to hardware Performance Monitoring Units (PMUs).

This talk will:
- Explore the differences between the old and new approaches.
- Demonstrate a reduction in PMU virtualization overhead and improvement in profiling accuracy.
- Discuss the key trade-off: while guests gain direct hardware access, the host loses the ability to profile guest workloads through perf.

This talk is ideal for virtualization engineers, kernel developers, and anyone performing performance analysis in cloud or virtualized environments who needs accurate, low-overhead profiling data.

Virtualizing Performance Monitoring Units (PMUs) requires careful coordination between hardware and software to provide guests with accurate, low-overhead performance monitoring while maintaining security and isolation.

This talk examines what it takes to virtualize PMU features, focusing on a hardware-assisted approach built on the upstream Mediated PMU framework in the Linux kernel.
This talk will
1. Explore motivations such as protecting confidential guests, reducing context-switch overhead, and maintaining host-guest boundaries.
2. Cover hardware support for selective interception, direct interrupt delivery to guests, and automated guest state management, as well as software handling of host state for registers not saved by hardware.
3. Demonstrate performance monitoring counters and instruction-based sampling virtualization, showing how hardware automation improves software-based state management and strengthens security for confidential computing workloads.

This talk is aimed at virtualization engineers, kernel developers, and performance analysts working in cloud or confidential computing environments.