diff -r c6f0968fdfe2 xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c	Mon Jan 25 14:34:36 2010 +0100
+++ b/xen/arch/x86/hvm/svm/svm.c	Wed Jan 27 14:17:31 2010 +0100
@@ -192,6 +192,7 @@ static int svm_vmcb_save(struct vcpu *v,
     c->sysenter_cs = v->arch.hvm_svm.guest_sysenter_cs;
     c->sysenter_esp = v->arch.hvm_svm.guest_sysenter_esp;
     c->sysenter_eip = v->arch.hvm_svm.guest_sysenter_eip;
+    c->shadow_gs = vmcb->kerngsbase;
 
     c->pending_event = 0;
     c->error_code = 0;
@@ -251,6 +252,7 @@ static int svm_vmcb_restore(struct vcpu 
     v->arch.hvm_svm.guest_sysenter_cs = c->sysenter_cs;
     v->arch.hvm_svm.guest_sysenter_esp = c->sysenter_esp;
     v->arch.hvm_svm.guest_sysenter_eip = c->sysenter_eip;
+    vmcb->kerngsbase = c->shadow_gs;
 
     if ( paging_mode_hap(v->domain) )
     {