https://arstechnica.com/gadgets/2018/01/whats-behind-the-intel-design-flaw-forcing-numerous-patches/

Both Windows and Linux are receiving significant security updates that can, in the worst case, cause performance to drop by half, to defend against a problem that as yet hasn't been fully disclosed.

Patches to the Linux kernel have been trickling in over the past few weeks. Microsoft has been testing the Windows updates in the Insider program since November, and it is expected to put the alterations into mainstream Windows builds on Patch Tuesday next week. Microsoft's Azure has scheduled maintenance next week, and Amazon's AWS is scheduled for maintenance on Friday—presumably related.