KVM: introduce KVM_PFN_ERR_HWPOISON

Then, get_hwpoison_pfn and is_hwpoison_pfn can be removed
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/mmu.c

@@ -2649,7 +2649,7 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *
 static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, pfn_t pfn)
 {
 	kvm_release_pfn_clean(pfn);
-	if (is_hwpoison_pfn(pfn)) {
+	if (pfn == KVM_PFN_ERR_HWPOISON) {
 		kvm_send_hwpoison_signal(gfn_to_hva(vcpu->kvm, gfn), current);
 		return 0;
 	}

include/linux/kvm_host.h

@@ -49,6 +49,7 @@
 	(KVM_MMIO_SIZE / KVM_USER_MMIO_SIZE + KVM_EXTRA_MMIO_FRAGMENTS)
 
 #define KVM_PFN_ERR_FAULT	(-EFAULT)
+#define KVM_PFN_ERR_HWPOISON	(-EHWPOISON)
 
 /*
  * vcpu->requests bit members
@@ -395,7 +396,6 @@ extern struct page *bad_page;
 
 int is_error_page(struct page *page);
 int is_error_pfn(pfn_t pfn);
-int is_hwpoison_pfn(pfn_t pfn);
 int is_noslot_pfn(pfn_t pfn);
 int is_invalid_pfn(pfn_t pfn);
 int kvm_is_error_hva(unsigned long addr);

virt/kvm/kvm_main.c

@@ -939,17 +939,6 @@ static pfn_t get_bad_pfn(void)
 	return -ENOENT;
 }
 
-static pfn_t get_hwpoison_pfn(void)
-{
-	return -EHWPOISON;
-}
-
-int is_hwpoison_pfn(pfn_t pfn)
-{
-	return pfn == -EHWPOISON;
-}
-EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
-
 int is_noslot_pfn(pfn_t pfn)
 {
 	return pfn == -ENOENT;
@@ -1115,7 +1104,7 @@ static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
 		if (npages == -EHWPOISON ||
 			(!async && check_user_page_hwpoison(addr))) {
 			up_read(&current->mm->mmap_sem);
-			return get_hwpoison_pfn();
+			return KVM_PFN_ERR_HWPOISON;
 		}
 
 		vma = find_vma_intersection(current->mm, addr, addr+1);