Linux Fixing A "Hilarious/Revolting Performance Regression" Around Intel KVM Virtualization

It's not too often that "fixes" to the Kernel-based Virtual Machine (KVM) are noteworthy but today is an interesting exception with among the KVM fixes sent in today ahead of the Linux 6.13-rc3 tagging is for beginning to deal with a "hilarious/revolting" performance regression affecting recent generations of Intel processors. This performance regression won't be fully worked around until Linux 6.14 but at least there is an interim step in place once the code is merged later today...