[PATCHv2 06/59] mm/khugepaged: Handle encrypted pages

Kirill A. Shutemov
2019-07-31T15:10:28Z

For !NUMA khugepaged allocates page in advance, before we found a VMA
for collapse. We don't yet know which KeyID to use for the allocation.

The page is allocated with KeyID-0. Once we know that the VMA is
suitable for collapsing, we prepare the page for KeyID we need, based on
vma_keyid().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
mm/khugepaged.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index eaaa21b23215..ae9bd3b18aa1 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1059,6 +1059,16 @@ static void collapse_huge_page(struct mm_struct *mm,
*/
anon_vma_unlock_write(vma->anon_vma);

+ /*
+ * At this point new_page is allocated as non-encrypted.
+ * If VMA's KeyID is non-zero, we need to prepare it to be encrypted
+ * before coping data.
+ */
+ if (vma_keyid(vma)) {
+ prep_encrypted_page(new_page, HPAGE_PMD_ORDER,
+ vma_keyid(vma), false);
+ }
+
__collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl);
pte_unmap(pte);
__SetPageUptodate(new_page);
--
2.21.0