x86/mm/pageattr: Add a PTE pagetable populating function

Handle last level by unconditionally writing the PTEs into the PTE page
while paying attention to the NX bit.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 968398b023c0..2a1308a8c072 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -686,7 +686,27 @@ static int alloc_pmd_page(pud_t *pud)
         return 0;
 }
 
-#define populate_pte(cpa, start, end, pages, pmd, pgprot)       do {} while (0)
+static void populate_pte(struct cpa_data *cpa,
+                         unsigned long start, unsigned long end,
+                         unsigned num_pages, pmd_t *pmd, pgprot_t pgprot)
+{
+        pte_t *pte;
+
+        pte = pte_offset_kernel(pmd, start);
+
+        while (num_pages-- && start < end) {
+
+                /* deal with the NX bit */
+                if (!(pgprot_val(pgprot) & _PAGE_NX))
+                        cpa->pfn &= ~_PAGE_NX;
+
+                set_pte(pte, pfn_pte(cpa->pfn >> PAGE_SHIFT, pgprot));
+
+                start    += PAGE_SIZE;
+                cpa->pfn += PAGE_SIZE;
+                pte++;
+        }
+}
 
 static int populate_pmd(struct cpa_data *cpa,
                         unsigned long start, unsigned long end,