xen: arm: implement share_xen_page_with_privileged_guests

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

xen/arch/arm/dummy.S

@@ -8,6 +8,3 @@ x:	mov pc, lr
 	
 /* PIRQ support */
 DUMMY(nr_irqs_gsi);
-
-/* Other */
-DUMMY(share_xen_page_with_privileged_guests);

xen/arch/arm/mm.c

@@ -506,6 +506,12 @@ void share_xen_page_with_guest(struct page_info *page,
     spin_unlock(&d->page_alloc_lock);
 }
 
+void share_xen_page_with_privileged_guests(
+    struct page_info *page, int readonly)
+{
+    share_xen_page_with_guest(page, dom_xen, readonly);
+}
+
 static int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,