Hyper-V: vPCI: limit 64 cpus for msi/msix interrupt handling on FreeBSD 13.x

[whu]

Summary

On older Hyper-V vPCI protocol version 1.1, only the first 64 cpus are able to handle msi/msix. This is true on FreeBSD 13.x and earlier releases. If MSI IRQ is assigned to cpu id greater than 63, it would lead to missing interrupts. Add check in set_interrupt_apic_ids() to only add first 64 cpus into the interrupt cpu set.

This doesn't apply to FreeBSD 14 and later, which already have vPCI 1.4 support.

[kib]

I suppose this is a direct commit to stable/13?

[stallamr_netapp.com]

Verified in NetApp lab.

[whu]

In D44297#1010461, @kib wrote:

I suppose this is a direct commit to stable/13?

Yes, it is.