On Mon, Nov 01, 2021 at 04:11:42PM -0500, Eric W. Biederman wrote:
I seem to remember the consensus when this was reviewed that it was unnecessary and there is already support for doing something like this at a more fine grained level so we don't need a new kexec hook.
Well, the executive summary is that you have a guest whose memory *and* registers are encrypted so the hypervisor cannot have a poke inside and reset the vCPU like it would normally do. So you need to do that dance differently, i.e, the patchset.
If you try to kexec such a guest now, it'll init only the BSP, as Joerg said. So I guess a single-threaded kdump.
And yes, one of the prominent use cases is kdumping from such a guest, as distros love doing kdump for debugging.
I hope that explains it better.