8aeb879baf12 - significant system call latency regression, bisected

["H. Peter Anvin" (Intel)]

So I was trying to figure out a significant -- about 13% -- increase
in system call latency between v7.0 and the current master, and it
bisects down to:

	8aeb879baf12 x86/kvm/vmx: Fix x86_64 CFI build

This is on Panther Lake (Core Ultra X7 358H) with FRED enabled. This
is a bare metal boot, no KVM.

I'm personally extremely puzzled how this could possibly be related,
and I will be investigating the possibility that this is a false
bisect, but it is not a Heisenbug in any way; it has been extremely
reproducible, and the difference is statistically valid by close to 10
sigma. Futhermore, the bisection at least gave the appearance of
stability.

Given how late in the cycle this is I wanted to send an alert sooner
rather than later; I will update as I get more data.

       -hpa