Am 17.05.22 um 18:36 schrieb Janosch Frank:
Sometimes dumping inside of a VM fails, is unavailable or doesn't yield the required data. For these occasions we dump the VM from the outside, writing memory and cpu data to a file. Up to now PV guests only supported dumping from the inside of the guest through dumpers like KDUMP. A PV guest can be dumped from the hypervisor but the data will be stale and / or encrypted. To get the actual state of the PV VM we need the help of the Ultravisor who safeguards the VM state. New UV calls have been added to initialize the dump, dump storage state data, dump cpu data and complete the dump process. I chose not to document the dump data provided by the Ultravisor since KVM doesn't interprete it in any way. We're currently searching for a location and enough cycles to make it available to all. v6: * Added patch that explains KVM's rc/rrc writes * Added rev-bys * Improved documentation * Reworked capability indication * Moved the dump completion into a new function
I queued this now for kvms390/next. Its likely too late for this merge window, though. (I also applied the fixup proposed by Claudio in patch 6).
