From 8da7633f168b5428e2cfb7342408b2c44088f5df Mon Sep 17 00:00:00 2001
From: Jennifer Herbert <jennifer.herbert@citrix.com>
Date: Wed, 24 Dec 2014 14:17:06 +0000
Subject: 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>
---
 include/xen/grant_table.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'include/xen/grant_table.h')

diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 949803e20872..d3bef563e8da 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -45,6 +45,8 @@
 #include <asm/xen/hypervisor.h>
 
 #include <xen/features.h>
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
 
 #define GNTTAB_RESERVED_XENSTORE 1
 
@@ -185,4 +187,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
 
+
+struct xen_page_foreign {
+	domid_t domid;
+	grant_ref_t gref;
+};
+
+static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
+{
+	if (!PageForeign(page))
+		return NULL;
+#if BITS_PER_LONG < 64
+	return (struct xen_page_foreign *)page->private;
+#else
+	BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
+	return (struct xen_page_foreign *)&page->private;
+#endif
+}
+
 #endif /* __ASM_GNTTAB_H__ */
-- 
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