diff -r 3f660d0e12f7 xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c	Fri Aug 19 15:26:03 2011 +0200
+++ b/xen/arch/x86/mm/p2m.c	Mon Aug 22 13:52:51 2011 +0200
@@ -247,6 +247,7 @@ int p2m_alloc_table(struct p2m_domain *p
     P2M_PRINTK("populating p2m table\n");
 
     /* Initialise physmap tables for slot zero. Other code assumes this. */
+    p2m->defer_nested_flush = 1;
     if ( !set_p2m_entry(p2m, 0, _mfn(INVALID_MFN), 0,
                         p2m_invalid, p2m->default_access) )
     {
@@ -277,6 +278,7 @@ int p2m_alloc_table(struct p2m_domain *p
         }
         spin_unlock(&p2m->domain->page_alloc_lock);
     }
+    p2m->defer_nested_flush = 0;
 
     P2M_PRINTK("p2m table initialised (%u pages)\n", page_count);
     p2m_unlock(p2m);