KVM: ppc: Report bad GFNs

This code shouldn't be hit anyways, but when it is, it's useful to have a
little more information about the failure.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index 1c48d61..75dff7c 100644
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -145,7 +145,7 @@
 	down_read(&current->mm->mmap_sem);
 	new_page = gfn_to_page(vcpu->kvm, gfn);
 	if (is_error_page(new_page)) {
-		printk(KERN_ERR "Couldn't get guest page!\n");
+		printk(KERN_ERR "Couldn't get guest page for gfn %lx!\n", gfn);
 		kvm_release_page_clean(new_page);
 		up_read(&current->mm->mmap_sem);
 		return;