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diff --git a/kitten/arch/x86_64/kernel/xcall.c b/kitten/arch/x86_64/kernel/xcall.c
new file mode 100644
index 0000000..9afe497
--- /dev/null
+++ b/kitten/arch/x86_64/kernel/xcall.c
@@ -0,0 +1,137 @@
+#include <lwk/kernel.h>
+#include <lwk/spinlock.h>
+#include <lwk/xcall.h>
+#include <arch/apic.h>
+#include <arch/idt_vectors.h>
+#include <arch/processor.h>
+
+/**
+ * Used to pass data to and synchronize the CPUs targeted by a cross-call.
+ */
+struct xcall_data_struct {
+	void		(*func)(void *info);
+	void *		info;
+	atomic_t	started;
+	atomic_t	finished;
+	bool		wait;
+};
+
+/**
+ * Global cross-call data pointer, protected by xcall_data_lock.
+ */
+static struct xcall_data_struct *xcall_data;
+static DEFINE_SPINLOCK(xcall_data_lock);
+
+/**
+ * x86_64 specific code for carrying out inter-CPU function calls. 
+ * This function should not be called directly. Call xcall_function() instead.
+ *
+ * Arguments:
+ *       [IN] cpu_mask: The target CPUs of the cross-call.
+ *       [IN] func:     The function to execute on each target CPU.
+ *       [IN] info:     Argument to pass to func().
+ *       [IN] wait:     true = wait for cross-call to fully complete.
+ *
+ * Returns:
+ *       Success: 0
+ *       Failure: Error code
+ */
+int
+arch_xcall_function(
+	cpumask_t	cpu_mask,
+	void		(*func)(void *info),
+	void *		info,
+	bool		wait
+)
+{
+	struct xcall_data_struct data;
+	unsigned int num_cpus;
+	unsigned int cpu;
+
+	BUG_ON(irqs_disabled());
+
+	/* Count how many CPUs are being targeted */
+	num_cpus = cpus_weight(cpu_mask);
+	if (!num_cpus)
+		return 0;
+
+	/* Fill in the xcall data structure on our stack */
+	data.func = func;
+	data.info = info;
+	atomic_set(&data.started, 0);
+	if (wait)
+		atomic_set(&data.finished, 0);
+	data.wait = wait;
+
+	/* Spin with IRQs enabled */
+	while (!spin_trylock_irq(&xcall_data_lock))
+		;
+	/* IRQs are now disabled */
+
+	/* Set the global xcall data pointer */
+	xcall_data = &data;
+	wmb();
+
+	/* Send inter-processor interrupts to the target CPUs */
+	for_each_cpu_mask(cpu, cpu_mask)
+		lapic_send_ipi(cpu, XCALL_FUNCTION_VECTOR);
+
+	/* Wait for initiation responses */
+	while (atomic_read(&data.started) != num_cpus)
+		cpu_relax();
+
+	/* If requested, wait for completion responses */
+	if (wait) {
+		while (atomic_read(&data.finished) != num_cpus)
+			cpu_relax();
+	}
+	spin_unlock_irq(&xcall_data_lock);
+
+	return 0;
+}
+
+/**
+ * The interrupt handler for inter-CPU function calls.
+ */
+void
+arch_xcall_function_interrupt(struct pt_regs *regs, unsigned int vector)
+{
+	void (*func)(void *info) = xcall_data->func;
+	void *info               = xcall_data->info;
+	int wait                 = xcall_data->wait;
+
+	/* Notify initiating CPU that we've started */
+	mb();
+	atomic_inc(&xcall_data->started);
+
+	/* Execute the cross-call function */
+	(*func)(info);
+
+	/* Notify initiating CPU that the cross-call function has completed */
+	if (wait) {
+		mb();
+		atomic_inc(&xcall_data->finished);
+	}
+}
+
+/**
+ * Sends a reschedule inter-processor interrupt to the target CPU.
+ * This causes the target CPU to call schedule().
+ */
+void
+arch_xcall_reschedule(id_t cpu)
+{
+	lapic_send_ipi(cpu, XCALL_RESCHEDULE_VECTOR);
+}
+
+/**
+ * The interrupt handler for inter-CPU reschedule calls.
+ */
+void
+arch_xcall_reschedule_interrupt(struct pt_regs *regs, unsigned int vector)
+{
+	/*
+	 * Nothing to do, schedule() will be automatically
+	 * called before returning to user-space
+	 */
+}