Xen Summit 2026

What does the term “Low Level Requirement” (LLR) mean to Xen? This talk provides an update to the ongoing work of Xen’s Functional Safety Working Group in the form of a worked case study for a challenging example: list.h We will show

1) When we should use a technique called “requirements mapping” (to reuse requirements rather than invent them ourselves)
2) How to test the preprocessor macros and occasional static inline functions in our list.h example to satisfy the DO-178C’s LLR-to-verification “trace data” obligations
3) How to produce a subject matter expert (SME) to review list.h LLRs (i.e., for “necessary and complete LLR”), via a training course about its RCU algorithm and the requirements behind that algorithm.

We hope to engage the broader Xen community’s SMEs by focusing not on “FuSa” specifically, but more broadly on “How does Xen really work?”