KVM: introduce KVM_PFN_ERR_BAD

Then, remove get_bad_pfn
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

include/linux/kvm_host.h

@@ -50,6 +50,7 @@
 
 #define KVM_PFN_ERR_FAULT	(-EFAULT)
 #define KVM_PFN_ERR_HWPOISON	(-EHWPOISON)
+#define KVM_PFN_ERR_BAD		(-ENOENT)
 
 /*
  * vcpu->requests bit members

virt/kvm/kvm_main.c

@@ -934,11 +934,6 @@ int is_error_pfn(pfn_t pfn)
 }
 EXPORT_SYMBOL_GPL(is_error_pfn);
 
-static pfn_t get_bad_pfn(void)
-{
-	return -ENOENT;
-}
-
 int is_noslot_pfn(pfn_t pfn)
 {
 	return pfn == -ENOENT;
@@ -1143,7 +1138,7 @@ static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
 
 	addr = gfn_to_hva(kvm, gfn);
 	if (kvm_is_error_hva(addr))
-		return get_bad_pfn();
+		return KVM_PFN_ERR_BAD;
 
 	return hva_to_pfn(addr, atomic, async, write_fault, writable);
 }