xen/p2m: Use SetPagePrivate and its friends for M2P overrides.

We use the page->private field and hence should use the proper
macros and set proper bits. Also WARN_ON in case somebody
tries to overwrite our data.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index cc2f8dcf8dd..6e56b65edaf 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -692,8 +692,9 @@ int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
                                         "m2p_add_override: pfn %lx not mapped", pfn))
                         return -EINVAL;
         }
-
-        page->private = mfn;
+        WARN_ON(PagePrivate(page));
+        SetPagePrivate(page);
+        set_page_private(page, mfn);
         page->index = pfn_to_mfn(pfn);
 
         if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
@@ -736,7 +737,8 @@ int m2p_remove_override(struct page *page, bool clear_pte)
         list_del(&page->lru);
         spin_unlock_irqrestore(&m2p_override_lock, flags);
         set_phys_to_machine(pfn, page->index);
-
+        WARN_ON(!PagePrivate(page));
+        ClearPagePrivate(page);
         if (clear_pte && !PageHighMem(page))
                 set_pte_at(&init_mm, address, ptep,
                                 pfn_pte(pfn, PAGE_KERNEL));
@@ -758,7 +760,7 @@ struct page *m2p_find_override(unsigned long mfn)
         spin_lock_irqsave(&m2p_override_lock, flags);
 
         list_for_each_entry(p, bucket, lru) {
-                if (p->private == mfn) {
+                if (page_private(p) == mfn) {
                         ret = p;
                         break;
                 }