Kexec HandOver "KHO" was merged for the in-development Linux 6.16 kernel as part of all the memory management "MM" changes. Kexec HandOver is providing the basis for some nifty low-level features moving forward.

Kexec HandOver allows for [1]some kernel state to be retained when Kexec'ing into a new kernel such as for maintenance/security updates on production servers where downtime should be avoided at all costs.

Google engineers have been driving the Kexec HandOver effort and in building off KHO they are also pursuing [2]the Live Update Orchestrator . The Live Update Orchestrator "LUO" is not merged for Linux 6.16 but will allow for some nifty live kernel upgrade scenarios with minimal downtime.

One of the desired use-cases is from Google Cloud with being able to maintain existing virtual machines (VMs) while replacing the host kernel. Again, not over the finish line for Linux 6.16 but at least the initial Kexec HandOver infrastructure is now merged.

More details for those interested via the [3]MM merge .



[1] https://www.phoronix.com/news/Kexec-HandOver-KHO-Linux-MM

[2] https://www.phoronix.com/news/Google-Live-Update-Orchestrator

[3] https://git.kernel.org/torvalds/c/00c010e130e58301db2ea0cec1eadc931e1cb8cf