On Mon, 2021-12-20 at 12:54 -0600, Tom Lendacky wrote:
> Took the tree back to commit df9726cb7178 and then applied this change. 
> I'm unable to trigger any kind of failure with this change.

Hm... I fired up an EC2 m6a.48xlarge instance (192 CPUs) to play with.

I can reproduce your triple-fault on SMP bringup, but only with kexec.
And I basically can't get *anything* to kexec without that triple-
fault. Not a clean 5.16-rc2, not the Fedora stock 5.14.10 kernel.

If I *boot* instead of kexec, I have not yet seen the problem at all.
This is using Legacy BIOS not UEFI.