Index: sys/dev/xen/bus/xen_intr.c
===================================================================
--- sys/dev/xen/bus/xen_intr.c
+++ sys/dev/xen/bus/xen_intr.c
@@ -136,7 +136,7 @@
 static int	xen_intr_source_pending(struct intsrc *isrc);
 static int	xen_intr_config_intr(struct intsrc *isrc,
 		     enum intr_trigger trig, enum intr_polarity pol);
-static int	xen_intr_assign_cpu(struct intsrc *isrc, u_int apic_id);
+static int	xen_intr_assign_cpu(struct intsrc *isrc, u_int to_cpu);
 
 /**
  * PIC interface for all event channel port types except physical IRQs.
@@ -686,7 +686,7 @@
 {
 #ifdef SMP
 	int cpu = isrc->xi_cpu;
-	int vcpu_id = pcpu_find(cpu)->pc_vcpu_id;
+	u_int vcpu_id = XEN_CPUID_TO_VCPUID(cpu);
 	int error;
 	struct evtchn_bind_ipi bind_ipi = { .vcpu = vcpu_id };
 
@@ -705,7 +705,7 @@
 xen_rebind_virq(struct xenisrc *isrc)
 {
 	int cpu = isrc->xi_cpu;
-	int vcpu_id = pcpu_find(cpu)->pc_vcpu_id;
+	u_int vcpu_id = XEN_CPUID_TO_VCPUID(cpu);
 	int error;
 	struct evtchn_bind_virq bind_virq = { .virq = isrc->xi_virq,
 	                                      .vcpu = vcpu_id };
@@ -743,8 +743,7 @@
 
 #ifdef SMP
 	isrc->xi_cpu = 0;
-	error = xen_intr_assign_cpu(&isrc->xi_intsrc,
-	                            cpu_apic_ids[cpu]);
+	error = xen_intr_assign_cpu(&isrc->xi_intsrc, cpu);
 	if (error)
 		panic("%s(): unable to rebind Xen channel %u to vCPU%u: %d",
 		    __func__, isrc->xi_port, cpu, error);
@@ -874,25 +873,22 @@
  * Configure CPU affinity for interrupt source event delivery.
  *
  * \param isrc     The interrupt source to configure.
- * \param apic_id  The apic id of the CPU for handling future events.
+ * \param to_cpu   The id of the CPU for handling future events.
  *
  * \returns  0 if successful, otherwise an errno.
  */
 static int
-xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
+xen_intr_assign_cpu(struct intsrc *base_isrc, u_int to_cpu)
 {
 #ifdef SMP
 	struct evtchn_bind_vcpu bind_vcpu;
 	struct xenisrc *isrc;
-	u_int to_cpu, vcpu_id;
+	u_int vcpu_id = XEN_CPUID_TO_VCPUID(to_cpu);
 	int error, masked;
 
 	if (!xen_has_percpu_evtchn())
 		return (EOPNOTSUPP);
 
-	to_cpu = apic_cpuid(apic_id);
-	vcpu_id = pcpu_find(to_cpu)->pc_vcpu_id;
-
 	mtx_lock(&xen_intr_isrc_lock);
 	isrc = (struct xenisrc *)base_isrc;
 	if (!is_valid_evtchn(isrc->xi_port)) {
@@ -1109,7 +1105,7 @@
     driver_filter_t filter, driver_intr_t handler, void *arg,
     enum intr_type flags, xen_intr_handle_t *port_handlep)
 {
-	int vcpu_id = pcpu_find(cpu)->pc_vcpu_id;
+	u_int vcpu_id = XEN_CPUID_TO_VCPUID(cpu);
 	struct xenisrc *isrc;
 	struct evtchn_bind_virq bind_virq = { .virq = virq, .vcpu = vcpu_id };
 	int error;
@@ -1150,7 +1146,7 @@
 		 * masks manually so events can't fire on the wrong cpu
 		 * during AP startup.
 		 */
-		xen_intr_assign_cpu(&isrc->xi_intsrc, cpu_apic_ids[cpu]);
+		xen_intr_assign_cpu(&isrc->xi_intsrc, cpu);
 	}
 #endif
 
@@ -1169,7 +1165,7 @@
     enum intr_type flags, xen_intr_handle_t *port_handlep)
 {
 #ifdef SMP
-	int vcpu_id = pcpu_find(cpu)->pc_vcpu_id;
+	u_int vcpu_id = XEN_CPUID_TO_VCPUID(cpu);
 	struct xenisrc *isrc;
 	struct evtchn_bind_ipi bind_ipi = { .vcpu = vcpu_id };
 	/* Same size as the one used by intr_handler->ih_name. */
@@ -1206,7 +1202,7 @@
 		 * masks manually so events can't fire on the wrong cpu
 		 * during AP startup.
 		 */
-		xen_intr_assign_cpu(&isrc->xi_intsrc, cpu_apic_ids[cpu]);
+		xen_intr_assign_cpu(&isrc->xi_intsrc, cpu);
 	}
 
 	/*
Index: sys/dev/xen/debug/debug.c
===================================================================
--- sys/dev/xen/debug/debug.c
+++ sys/dev/xen/debug/debug.c
@@ -78,7 +78,7 @@
 
 	mtx_lock_spin(&lock);
 	sbuf_clear(buf);
-	xc_printf("Printing stack trace vCPU%d\n", PCPU_GET(vcpu_id));
+	xc_printf("Printing stack trace vCPU%u\n", XEN_VCPUID());
 	stack_sbuf_print_ddb(buf, &st);
 	sbuf_finish(buf);
 	mtx_unlock_spin(&lock);
Index: sys/x86/include/xen/xen-os.h
===================================================================
--- sys/x86/include/xen/xen-os.h
+++ sys/x86/include/xen/xen-os.h
@@ -40,6 +40,8 @@
 /* Everything below this point is not included by assembler (.S) files. */
 #ifndef __ASSEMBLY__
 
+#include <sys/pcpu.h>
+
 /* If non-zero, the hypervisor has been configured to use a direct vector */
 extern int xen_vector_callback_enabled;
 
@@ -51,6 +53,13 @@
 
 extern uint32_t xen_cpuid_base;
 
+static inline u_int
+XEN_CPUID_TO_VCPUID(u_int cpuid)
+{
+
+	return (pcpu_find(cpuid)->pc_vcpu_id);
+}
+
 static inline bool
 xen_has_percpu_evtchn(void)
 {
Index: sys/xen/xen-os.h
===================================================================
--- sys/xen/xen-os.h
+++ sys/xen/xen-os.h
@@ -44,6 +44,8 @@
 #include <xen/hvm.h>
 #include <contrib/xen/event_channel.h>
 
+#define XEN_VCPUID() XEN_CPUID_TO_VCPUID(PCPU_GET(cpuid))
+
 static inline vm_paddr_t
 xen_get_xenstore_mfn(void)
 {