2 files changed, 14 insertions, 4 deletions

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index bbc8b12fa443..5ad38ad07890 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -445,10 +445,20 @@ static inline int pte_same(pte_t a, pte_t b)
         return a.pte == b.pte;
 }
 
+static inline int pteval_present(pteval_t pteval)
+{
+        /*
+         * Yes Linus, _PAGE_PROTNONE == _PAGE_NUMA. Expressing it this
+         * way clearly states that the intent is that protnone and numa
+         * hinting ptes are considered present for the purposes of
+         * pagetable operations like zapping, protection changes, gup etc.
+         */
+        return pteval & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_NUMA);
+}
+
 static inline int pte_present(pte_t a)
 {
-        return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE |
-                               _PAGE_NUMA);
+        return pteval_present(pte_flags(a));
 }
 
 #define pte_accessible pte_accessible
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 2423ef04ffea..256282e7888b 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -365,7 +365,7 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 /* Assume pteval_t is equivalent to all the other *val_t types. */
 static pteval_t pte_mfn_to_pfn(pteval_t val)
 {
-        if (val & _PAGE_PRESENT) {
+        if (pteval_present(val)) {
                 unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
                 unsigned long pfn = mfn_to_pfn(mfn);
 
@@ -381,7 +381,7 @@ static pteval_t pte_mfn_to_pfn(pteval_t val)
 
 static pteval_t pte_pfn_to_mfn(pteval_t val)
 {
-        if (val & _PAGE_PRESENT) {
+        if (pteval_present(val)) {
                 unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
                 pteval_t flags = val & PTE_FLAGS_MASK;
                 unsigned long mfn;