xen: mark grant mapped pages as foreign
Use the "foreign" page flag to mark pages that have a grant map. Use
page->private to store information of the grant (the granting domain
and the grant reference).
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index b4f93c4..89dcca4 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -679,12 +679,27 @@
*/
int gnttab_alloc_pages(int nr_pages, struct page **pages)
{
+ int i;
int ret;
ret = alloc_xenballooned_pages(nr_pages, pages, false);
if (ret < 0)
return ret;
+ for (i = 0; i < nr_pages; i++) {
+#if BITS_PER_LONG < 64
+ struct xen_page_foreign *foreign;
+
+ foreign = kzalloc(sizeof(*foreign), GFP_KERNEL);
+ if (!foreign) {
+ gnttab_free_pages(nr_pages, pages);
+ return -ENOMEM;
+ }
+ set_page_private(pages[i], (unsigned long)foreign);
+#endif
+ SetPagePrivate(pages[i]);
+ }
+
return 0;
}
EXPORT_SYMBOL(gnttab_alloc_pages);
@@ -696,6 +711,16 @@
*/
void gnttab_free_pages(int nr_pages, struct page **pages)
{
+ int i;
+
+ for (i = 0; i < nr_pages; i++) {
+ if (PagePrivate(pages[i])) {
+#if BITS_PER_LONG < 64
+ kfree((void *)page_private(pages[i]));
+#endif
+ ClearPagePrivate(pages[i]);
+ }
+ }
free_xenballooned_pages(nr_pages, pages);
}
EXPORT_SYMBOL(gnttab_free_pages);
@@ -756,12 +781,22 @@
if (ret)
return ret;
- /* Retry eagain maps */
- for (i = 0; i < count; i++)
+ for (i = 0; i < count; i++) {
+ /* Retry eagain maps */
if (map_ops[i].status == GNTST_eagain)
gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
&map_ops[i].status, __func__);
+ if (map_ops[i].status == GNTST_okay) {
+ struct xen_page_foreign *foreign;
+
+ SetPageForeign(pages[i]);
+ foreign = xen_page_foreign(pages[i]);
+ foreign->domid = map_ops[i].dom;
+ foreign->gref = map_ops[i].ref;
+ }
+ }
+
return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
}
EXPORT_SYMBOL_GPL(gnttab_map_refs);
@@ -770,12 +805,16 @@
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count)
{
+ unsigned int i;
int ret;
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
if (ret)
return ret;
+ for (i = 0; i < count; i++)
+ ClearPageForeign(pages[i]);
+
return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
}
EXPORT_SYMBOL_GPL(gnttab_unmap_refs);