Speaker
Description
Preserving subsystem state across a live update introduces a complex challenge: managing the dependencies of File Descriptors. Interconnected subsystems—such as VFIO and IOMMUFD with a lot of shared state, IOMMUFD's dependency on memory providers memfd/guest_memfd or KVMfd/guest_memfd dependency requires preservation ordering to guarantee state immutability and performance.
Currently, the burden of orchestrating this dependency falls on userspace (VMMs), which must navigate complex API contracts, which will become much more complex with circular dependencies between subsystems down the road.
This session talks about FD dependencies with examples and it proposes a unified, kernel-driven dependency resolution architecture that is handled by Live Update Orchestrator by introducing some extensions.
Looking forward to your feedback on this.