[HotSwap] Live Update for Xen

[Ferdinand Brasser <ferdinand.brasser@trust.cased.de>]

Dear all,

My name is Ferdinand Brasser, research assistant at CASED/TU Darmstadt. 

Here at CASED, we have developed a live updating mechanism for Xen,
which we call it HotSwap. Currently we have a prototype for Xen 4.2 and
would like to know if there is any interest from the community to
integrate our approach into Xen. If so, some advice on how to proceed is
welcomed.

Our approach to update Xen is - very high level - to load a complete new
version of Xen at runtime and then transfer the state of the old version
to the new one. Afterwards the execution is continued by the new
version. We make use of Xen functions to disable all but one CPU and
interrupts during the update process to keep the state consistent while
transferring. We have evaluate our prototype with the result that the
update process takes about 45ms on our test system. 

We hope you guys find this work interesting and we would be happy to
work together with you to make our prototype a usable and reliable
function of Xen.

Regards,
Ferdinand