diff -rc -x '*.cmd' linux-2.6.16-xen/arch/ia64/kernel/irq_ia64.c linux-2.6.16-xen.orig/arch/ia64/kernel/irq_ia64.c
*** linux-2.6.16-xen/arch/ia64/kernel/irq_ia64.c	2006-03-20 06:53:29.000000000 +0100
--- linux-2.6.16-xen.orig/arch/ia64/kernel/irq_ia64.c	2006-03-30 11:43:51.000000000 +0200
***************
*** 260,265 ****
--- 260,273 ----
  	unsigned long ipi_data;
  	unsigned long phys_cpu_id;
  
+ #ifdef CONFIG_XEN
+         if (running_on_xen) {
+                 extern void xen_send_ipi (int cpu, int vec);
+                 xen_send_ipi (cpu, vector);
+                 return;
+         }
+ #endif /* CONFIG_XEN */
+ 
  #ifdef CONFIG_SMP
  	phys_cpu_id = cpu_physical_id(cpu);
  #else
diff -rc -x '*.cmd' linux-2.6.16-xen/arch/ia64/kernel/time.c linux-2.6.16-xen.orig/arch/ia64/kernel/time.c
*** linux-2.6.16-xen/arch/ia64/kernel/time.c	2006-03-20 06:53:29.000000000 +0100
--- linux-2.6.16-xen.orig/arch/ia64/kernel/time.c	2006-03-30 13:20:36.000000000 +0200
***************
*** 207,213 ****
  	local_cpu_data->nsec_per_cyc = ((NSEC_PER_SEC<<IA64_NSEC_PER_CYC_SHIFT)
  					+ itc_freq/2)/itc_freq;
  
! 	if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
  		itc_interpolator.frequency = local_cpu_data->itc_freq;
  		itc_interpolator.drift = itc_drift;
  #ifdef CONFIG_SMP
--- 207,213 ----
  	local_cpu_data->nsec_per_cyc = ((NSEC_PER_SEC<<IA64_NSEC_PER_CYC_SHIFT)
  					+ itc_freq/2)/itc_freq;
  
! 	if (1 || !(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
  		itc_interpolator.frequency = local_cpu_data->itc_freq;
  		itc_interpolator.drift = itc_drift;
  #ifdef CONFIG_SMP