Bug in XEN support with IPIs?

[McCarthy, Brian]

it appears, that for FreeBSD XEN guests with SMP support, The IPIs get messed up by intr_shuffle_irqs. The symptom is a smp_ipi_mtx
timeout during TLB shootdown. I've seen this mentioned in e-mails, with the solution (without explanation) being to enable EARLY_AP_STARTUP.
The reason this works in BSD11 is that int_shuffle_irqs is conditionalixed out on EARLY_AP_STARTUP. The real solution seems to be that
xi_cpu and/or ie_cpu should be set. I'm trying to figure out where that would be (for our somewhat modified FreeBSD kernel).

-Brian McCarthy, NetApp