1 files changed, 23 insertions, 15 deletions

diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index cb854df031ce..e279be353e3f 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -57,8 +57,6 @@
 #define INVALID_GRANT_REF          ((grant_ref_t)-1)
 #define INVALID_GRANT_HANDLE       ((grant_handle_t)-1)
 
-#define GNTTAB_RESERVED_XENSTORE 1
-
 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
 #define NR_GRANT_FRAMES 4
 
@@ -97,33 +95,46 @@ int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
  * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
  * use.
  */
-int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
+int gnttab_end_foreign_access_ref(grant_ref_t ref);
 
 /*
  * Eventually end access through the given grant reference, and once that
  * access has been ended, free the given page too.  Access will be ended
  * immediately iff the grant entry is not in use, otherwise it will happen
- * some time later.  page may be 0, in which case no freeing will occur.
+ * some time later.  page may be NULL, in which case no freeing will occur.
+ * Note that the granted page might still be accessed (read or write) by the
+ * other side after gnttab_end_foreign_access() returns, so even if page was
+ * specified as NULL it is not allowed to just reuse the page for other
+ * purposes immediately. gnttab_end_foreign_access() will take an additional
+ * reference to the granted page in this case, which is dropped only after
+ * the grant is no longer in use.
+ * This requires that multi page allocations for areas subject to
+ * gnttab_end_foreign_access() are done via alloc_pages_exact() (and freeing
+ * via free_pages_exact()) in order to avoid high order pages.
  */
-void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
-			       unsigned long page);
-
-int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
+void gnttab_end_foreign_access(grant_ref_t ref, struct page *page);
 
-unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
-unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
-
-int gnttab_query_foreign_access(grant_ref_t ref);
+/*
+ * End access through the given grant reference, iff the grant entry is
+ * no longer in use.  In case of success ending foreign access, the
+ * grant reference is deallocated.
+ * Return 1 if the grant entry was freed, 0 if it is still in use.
+ */
+int gnttab_try_end_foreign_access(grant_ref_t ref);
 
 /*
  * operations on reserved batches of grant references
  */
 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
 
+int gnttab_alloc_grant_reference_seq(unsigned int count, grant_ref_t *first);
+
 void gnttab_free_grant_reference(grant_ref_t ref);
 
 void gnttab_free_grant_references(grant_ref_t head);
 
+void gnttab_free_grant_reference_seq(grant_ref_t head, unsigned int count);
+
 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
 
 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
@@ -147,9 +158,6 @@ static inline void gnttab_page_grant_foreign_access_ref_one(
 					readonly);
 }
 
-void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
-				       unsigned long pfn);
-
 static inline void
 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 		  uint32_t flags, grant_ref_t ref, domid_t domid)