[Xen-devel] [PATCH v1 6/8] vmw_balloon: mark inflated pages PG_offline

[David Hildenbrand <david@xxxxxxxxxx>]

Mark inflated and never onlined pages PG_offline, to tell the world that
the content is stale and should not be dumped.

Cc: Xavier Deguillard <xdeguillard@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Julien Freche <jfreche@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 drivers/misc/vmw_balloon.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index e6126a4b95d3..8cc8bd9a4e32 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -544,6 +544,36 @@ unsigned int vmballoon_page_order(enum 
vmballoon_page_size_type page_size)
        return page_size == VMW_BALLOON_2M_PAGE ? VMW_BALLOON_2M_ORDER : 0;
 }
 
+/**
+ * vmballoon_mark_page_offline() - mark a page as offline
+ * @page: pointer for the page
+ * @page_size: the size of the page.
+ */
+static void
+vmballoon_mark_page_offline(struct page *page,
+                           enum vmballoon_page_size_type page_size)
+{
+       int i;
+
+       for (i = 0; i < 1ULL << vmballoon_page_order(page_size); i++)
+               __SetPageOffline(page + i);
+}
+
+/**
+ * vmballoon_mark_page_online() - mark a page as online
+ * @page: pointer for the page
+ * @page_size: the size of the page.
+ */
+static void
+vmballoon_mark_page_online(struct page *page,
+                          enum vmballoon_page_size_type page_size)
+{
+       int i;
+
+       for (i = 0; i < 1ULL << vmballoon_page_order(page_size); i++)
+               __ClearPageOffline(page + i);
+}
+
 /**
  * vmballoon_page_in_frames() - returns the number of frames in a page.
  * @page_size: the size of the page.
@@ -612,6 +642,7 @@ static int vmballoon_alloc_page_list(struct vmballoon *b,
                                         ctl->page_size);
 
                if (page) {
+                       vmballoon_mark_page_offline(page, ctl->page_size);
                        /* Success. Add the page to the list and continue. */
                        list_add(&page->lru, &ctl->pages);
                        continue;
@@ -850,6 +881,7 @@ static void vmballoon_release_page_list(struct list_head 
*page_list,
 
        list_for_each_entry_safe(page, tmp, page_list, lru) {
                list_del(&page->lru);
+               vmballoon_mark_page_online(page, page_size);
                __free_pages(page, vmballoon_page_order(page_size));
        }
 
-- 
2.17.2


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel