Explore host and guest tracing in virtualization environments through this 20-minute conference talk presented by Stefano De Venuto from SUSE and Tzvetomir Stoyanov from VMware. Delve into the intricacies of kernel tracing across host and guest systems, focusing on trace data transfer and time stamp synchronization using PTP. Learn about the tools and libraries employed in this process, and understand the methods for verifying and validating results. Examine the accuracy of time synchronization through event-based approaches, including hrtimer, MSR events, idle task, and HLT events. Discover an automated tool for evaluation and compare PTP and KVM synchronization methods. Gain valuable insights into the challenges and solutions for maintaining accurate timing in virtualized environments, essential for effective debugging and performance analysis.
Host and Guest Tracing in Virtualization - To Sync or Not to Sync
Overview
Syllabus
Intro
Ftrace
Host-Guest kernel tracing
Trace data transfer
Time stamps synchronisation - PTP
Tools & Libraries
Verifying the results
Validation: kvm_entry & kvm_exit events
Validation: what we expect?
Time-sync accuracy evaluation: an event-based approa
First set: hrtimer & MSR events
Second set: idle task & HLT events
Let's automate it: final tool
PTP vs KVM: analysis
PTP vs KVM: evaluation
Conclusion
Links & Acknowledgments
Taught by
Linux Foundation
