KVM: introduce KVM_HVA_ERR_BAD

Then, remove bad_hva and inline kvm_is_error_hva

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4fd33e0..b9bba60 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -82,6 +82,13 @@
 	return !is_noslot_pfn(pfn) && is_error_pfn(pfn);
 }
 
+#define KVM_HVA_ERR_BAD	(PAGE_OFFSET)
+
+static inline bool kvm_is_error_hva(unsigned long addr)
+{
+	return addr == PAGE_OFFSET;
+}
+
 #define KVM_ERR_PTR_BAD_PAGE	(ERR_PTR(-ENOENT))
 
 static inline bool is_error_page(struct page *page)
@@ -430,7 +437,6 @@
 	return slot;
 }
 
-int kvm_is_error_hva(unsigned long addr);
 int kvm_set_memory_region(struct kvm *kvm,
 			  struct kvm_userspace_memory_region *mem,
 			  int user_alloc);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c89d1b5..e3e1658 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -931,17 +931,6 @@
 }
 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
 
-static inline unsigned long bad_hva(void)
-{
-	return PAGE_OFFSET;
-}
-
-int kvm_is_error_hva(unsigned long addr)
-{
-	return addr == bad_hva();
-}
-EXPORT_SYMBOL_GPL(kvm_is_error_hva);
-
 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 {
 	return __gfn_to_memslot(kvm_memslots(kvm), gfn);
@@ -988,7 +977,7 @@
 				     gfn_t *nr_pages)
 {
 	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
-		return bad_hva();
+		return KVM_HVA_ERR_BAD;
 
 	if (nr_pages)
 		*nr_pages = slot->npages - (gfn - slot->base_gfn);