--- old-xen-build/xen/include/asm-x86/shadow.h 2005-06-07 13:50:19.000000000 +0000 +++ new-xen-build/xen/include/asm-x86/shadow.h 2005-06-18 20:34:14.000000000 +0000 @@ -1700,7 +1700,8 @@ static inline void update_pagetables(str if ( likely(!shadow_mode_external(d)) ) { #ifdef __x86_64__ - if ( !(v->arch.flags & TF_kernel_mode) ) + if ( !(v->arch.flags & TF_kernel_mode) && + pagetable_get_pfn(v->arch.guest_table_user) ) v->arch.monitor_table = v->arch.guest_table_user; else #endif