A fundamental design flaw in Intel’s processor chips has forced a significant redesign of the Linux and Windows kernels to defang the chip-level security bug.

Source: ‘Kernel memory leaking’ Intel processor design flaw forces Linux, Windows redesign • The Register

There were rumors of a severe hypervisor bug – possibly in Xen – doing the rounds at the end of 2017. It may be that this hardware flaw is that rumored bug: that hypervisors can be attacked via this kernel memory access cockup, and thus need to be patched, forcing a mass restart of guest virtual machines.