Index: sys/x86/x86/io_apic.c
===================================================================
--- sys/x86/x86/io_apic.c
+++ sys/x86/x86/io_apic.c
@@ -411,6 +411,10 @@
 	u_int old_vector, new_vector;
 	u_int old_id;
 
+	/* Stick to the first cpu for all I/O APIC pins on Hyper-V. */
+	if (vm_guest == VM_GUEST_HV)
+		apic_id = 0;
+
 	/*
 	 * keep 1st core as the destination for NMI
 	 */