1 files changed, 46 insertions, 0 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 4740cda36563..e95955968ba3 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -560,6 +560,29 @@ void xen_pgd_pin(pgd_t *pgd)
         xen_mc_issue(0);
 }
 
+/*
+ * On save, we need to pin all pagetables to make sure they get their
+ * mfns turned into pfns.  Search the list for any unpinned pgds and pin
+ * them (unpinned pgds are not currently in use, probably because the
+ * process is under construction or destruction).
+ */
+void xen_mm_pin_all(void)
+{
+        unsigned long flags;
+        struct page *page;
+
+        spin_lock_irqsave(&pgd_lock, flags);
+
+        list_for_each_entry(page, &pgd_list, lru) {
+                if (!PagePinned(page)) {
+                        xen_pgd_pin((pgd_t *)page_address(page));
+                        SetPageSavePinned(page);
+                }
+        }
+
+        spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
 /* The init_mm pagetable is really pinned as soon as its created, but
    that's before we have page structures to store the bits.  So do all
    the book-keeping now. */
@@ -617,6 +640,29 @@ static void xen_pgd_unpin(pgd_t *pgd)
         xen_mc_issue(0);
 }
 
+/*
+ * On resume, undo any pinning done at save, so that the rest of the
+ * kernel doesn't see any unexpected pinned pagetables.
+ */
+void xen_mm_unpin_all(void)
+{
+        unsigned long flags;
+        struct page *page;
+
+        spin_lock_irqsave(&pgd_lock, flags);
+
+        list_for_each_entry(page, &pgd_list, lru) {
+                if (PageSavePinned(page)) {
+                        BUG_ON(!PagePinned(page));
+                        printk("unpinning pinned %p\n", page_address(page));
+                        xen_pgd_unpin((pgd_t *)page_address(page));
+                        ClearPageSavePinned(page);
+                }
+        }
+
+        spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
 void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
 {
         spin_lock(&next->page_table_lock);