diff -r 986538da9be0 linux-2.6-xen-sparse/arch/ia64/xen/hypercall.S
--- a/linux-2.6-xen-sparse/arch/ia64/xen/hypercall.S	Wed Mar 29 19:41:33 2006
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypercall.S	Fri Mar 31 06:38:54 2006
@@ -363,3 +363,13 @@
 	br.ret.sptk.many rp
 END(xen_set_eflag)
 #endif
+
+GLOBAL_ENTRY(xen_send_ipi)
+        mov r8=r32
+        mov r9=r33
+        mov r2=0x380
+        break 0x1000
+        ;;
+        br.ret.sptk.many rp
+        ;;
+END(xen_send_ipi)
diff -r 986538da9be0 linux-2.6-xen-sparse/include/asm-ia64/xen/privop.h
--- a/linux-2.6-xen-sparse/include/asm-ia64/xen/privop.h	Wed Mar 29 19:41:33 2006
+++ b/linux-2.6-xen-sparse/include/asm-ia64/xen/privop.h	Fri Mar 31 06:38:54 2006
@@ -38,6 +38,7 @@
 #define	XEN_HYPER_GET_PMD		break 0x15
 #define	XEN_HYPER_GET_EFLAG		break 0x16
 #define	XEN_HYPER_SET_EFLAG		break 0x17
+#define XEN_HYPER_SEND_IPI              break 0x18
 #endif
 
 #ifndef __ASSEMBLY__