diff -r 4c96da4993b8 drivers/char/tpm/tpm_xen.c
--- a/drivers/char/tpm/tpm_xen.c	Mon Nov 12 10:17:44 2007 +0000
+++ b/drivers/char/tpm/tpm_xen.c	Wed Nov 14 11:47:09 2007 +0000
@@ -266,8 +266,7 @@ static void destroy_tpmring(struct tpm_p
 	tpmif_set_connected_state(tp, 0);
 
 	if (tp->ring_ref != GRANT_INVALID_REF) {
-		gnttab_end_foreign_access(tp->ring_ref, 0,
-					  (unsigned long)tp->tx);
+		gnttab_end_foreign_access(tp->ring_ref, (unsigned long)tp->tx);
 		tp->ring_ref = GRANT_INVALID_REF;
 		tp->tx = NULL;
 	}
diff -r 4c96da4993b8 drivers/xen/blkfront/blkfront.c
--- a/drivers/xen/blkfront/blkfront.c	Mon Nov 12 10:17:44 2007 +0000
+++ b/drivers/xen/blkfront/blkfront.c	Wed Nov 14 16:22:32 2007 +0000
@@ -622,7 +622,7 @@ static int blkif_queue_request(struct re
 				ref,
 				info->xbdev->otherend_id,
 				buffer_mfn,
-				rq_data_dir(req) );
+				rq_data_dir(req) ? GTF_readonly : 0 );
 
 			info->shadow[id].frame[ring_req->nr_segments] =
 				mfn_to_pfn(buffer_mfn);
@@ -790,7 +790,7 @@ static void blkif_free(struct blkfront_i
 
 	/* Free resources associated with old device channel. */
 	if (info->ring_ref != GRANT_INVALID_REF) {
-		gnttab_end_foreign_access(info->ring_ref, 0,
+		gnttab_end_foreign_access(info->ring_ref, 
 					  (unsigned long)info->ring.sring);
 		info->ring_ref = GRANT_INVALID_REF;
 		info->ring.sring = NULL;
@@ -804,7 +804,7 @@ static void blkif_completion(struct blk_
 {
 	int i;
 	for (i = 0; i < s->req.nr_segments; i++)
-		gnttab_end_foreign_access(s->req.seg[i].gref, 0, 0UL);
+		gnttab_end_foreign_access(s->req.seg[i].gref, 0UL);
 }
 
 static void blkif_recover(struct blkfront_info *info)
@@ -846,9 +846,9 @@ static void blkif_recover(struct blkfron
 				req->seg[j].gref,
 				info->xbdev->otherend_id,
 				pfn_to_mfn(info->shadow[req->id].frame[j]),
-				rq_data_dir(
-					(struct request *)
-					info->shadow[req->id].request));
+				rq_data_dir((struct request *)
+					    info->shadow[req->id].request) ?
+				GTF_readonly : 0);
 		info->shadow[req->id].req = *req;
 
 		info->ring.req_prod_pvt++;
diff -r 4c96da4993b8 drivers/xen/core/gnttab.c
--- a/drivers/xen/core/gnttab.c	Mon Nov 12 10:17:44 2007 +0000
+++ b/drivers/xen/core/gnttab.c	Wed Nov 14 16:25:45 2007 +0000
@@ -140,7 +140,7 @@ static void put_free_entry(grant_ref_t r
  */
 
 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
-				int readonly)
+				int flags)
 {
 	int ref;
 
@@ -150,19 +150,21 @@ int gnttab_grant_foreign_access(domid_t 
 	shared[ref].frame = frame;
 	shared[ref].domid = domid;
 	wmb();
-	shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
+	BUG_ON(flags & (GTF_accept_transfer | GTF_reading | GTF_writing));
+	shared[ref].flags = GTF_permit_access | flags;
 
 	return ref;
 }
 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access);
 
 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
-				     unsigned long frame, int readonly)
+				     unsigned long frame, int flags)
 {
 	shared[ref].frame = frame;
 	shared[ref].domid = domid;
 	wmb();
-	shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
+	BUG_ON(flags & (GTF_accept_transfer | GTF_reading | GTF_writing));
+	shared[ref].flags = GTF_permit_access | flags;
 }
 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref);
 
@@ -177,7 +179,7 @@ int gnttab_query_foreign_access(grant_re
 }
 EXPORT_SYMBOL_GPL(gnttab_query_foreign_access);
 
-int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
+int gnttab_end_foreign_access_ref(grant_ref_t ref)
 {
 	u16 flags, nflags;
 
@@ -194,10 +196,9 @@ int gnttab_end_foreign_access_ref(grant_
 }
 EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref);
 
-void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
-			       unsigned long page)
-{
-	if (gnttab_end_foreign_access_ref(ref, readonly)) {
+void gnttab_end_foreign_access(grant_ref_t ref, unsigned long page)
+{
+	if (gnttab_end_foreign_access_ref(ref)) {
 		put_free_entry(ref);
 		if (page != 0)
 			free_page(page);
diff -r 4c96da4993b8 drivers/xen/netfront/netfront.c
--- a/drivers/xen/netfront/netfront.c	Mon Nov 12 10:17:44 2007 +0000
+++ b/drivers/xen/netfront/netfront.c	Wed Nov 14 16:22:57 2007 +0000
@@ -663,8 +663,7 @@ static void network_tx_buf_gc(struct net
 				       "domain.\n");
 				BUG();
 			}
-			gnttab_end_foreign_access_ref(
-				np->grant_tx_ref[id], GNTMAP_readonly);
+			gnttab_end_foreign_access_ref(np->grant_tx_ref[id]);
 			gnttab_release_grant_reference(
 				&np->gref_tx_head, np->grant_tx_ref[id]);
 			np->grant_tx_ref[id] = GRANT_INVALID_REF;
@@ -888,7 +887,7 @@ static void xennet_make_frags(struct sk_
 
 		mfn = virt_to_mfn(data);
 		gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
-						mfn, GNTMAP_readonly);
+						mfn, GTF_readonly);
 
 		tx->gref = np->grant_tx_ref[id] = ref;
 		tx->offset = offset;
@@ -910,7 +909,7 @@ static void xennet_make_frags(struct sk_
 
 		mfn = pfn_to_mfn(page_to_pfn(frag->page));
 		gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
-						mfn, GNTMAP_readonly);
+						mfn, GTF_readonly);
 
 		tx->gref = np->grant_tx_ref[id] = ref;
 		tx->offset = frag->page_offset;
@@ -972,7 +971,7 @@ static int network_start_xmit(struct sk_
 	BUG_ON((signed short)ref < 0);
 	mfn = virt_to_mfn(data);
 	gnttab_grant_foreign_access_ref(
-		ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
+		ref, np->xbdev->otherend_id, mfn, GTF_readonly);
 	tx->gref = np->grant_tx_ref[id] = ref;
 	tx->offset = offset;
 	tx->size = len;
@@ -1198,7 +1197,7 @@ static int xennet_get_responses(struct n
 			}
 			pages_flipped++;
 		} else {
-			ret = gnttab_end_foreign_access_ref(ref, 0);
+			ret = gnttab_end_foreign_access_ref(ref);
 			BUG_ON(!ret);
 		}
 
@@ -1531,8 +1530,7 @@ static void netif_release_tx_bufs(struct
 			continue;
 
 		skb = np->tx_skbs[i];
-		gnttab_end_foreign_access_ref(
-			np->grant_tx_ref[i], GNTMAP_readonly);
+		gnttab_end_foreign_access_ref(np->grant_tx_ref[i]);
 		gnttab_release_grant_reference(
 			&np->gref_tx_head, np->grant_tx_ref[i]);
 		np->grant_tx_ref[i] = GRANT_INVALID_REF;
@@ -1642,7 +1640,7 @@ static void netif_release_rx_bufs_copy(s
 
 		skb = np->rx_skbs[i];
 
-		if (!gnttab_end_foreign_access_ref(ref, 0))
+		if (!gnttab_end_foreign_access_ref(ref))
 		{
 			busy++;
 			continue;
@@ -2151,7 +2149,7 @@ static void end_access(int ref, void *pa
 static void end_access(int ref, void *page)
 {
 	if (ref != GRANT_INVALID_REF)
-		gnttab_end_foreign_access(ref, 0, (unsigned long)page);
+		gnttab_end_foreign_access(ref, (unsigned long)page);
 }
 
 
diff -r 4c96da4993b8 drivers/xen/pcifront/xenbus.c
--- a/drivers/xen/pcifront/xenbus.c	Mon Nov 12 10:17:44 2007 +0000
+++ b/drivers/xen/pcifront/xenbus.c	Wed Nov 14 11:47:07 2007 +0000
@@ -57,7 +57,7 @@ static void free_pdev(struct pcifront_de
 		xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
 
 	if (pdev->gnt_ref != INVALID_GRANT_REF)
-		gnttab_end_foreign_access(pdev->gnt_ref, 0,
+		gnttab_end_foreign_access(pdev->gnt_ref,
 					  (unsigned long)pdev->sh_info);
 
 	pdev->xdev->dev.driver_data = NULL;
diff -r 4c96da4993b8 include/xen/gnttab.h
--- a/include/xen/gnttab.h	Mon Nov 12 10:17:44 2007 +0000
+++ b/include/xen/gnttab.h	Wed Nov 14 09:51:06 2007 +0000
@@ -51,14 +51,14 @@ struct gnttab_free_callback {
 };
 
 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
-				int readonly);
+				int flags);
 
 /*
  * End access through the given grant reference, iff the grant entry is no
  * 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
@@ -66,8 +66,7 @@ int gnttab_end_foreign_access_ref(grant_
  * 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.
  */
-void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
-			       unsigned long page);
+void gnttab_end_foreign_access(grant_ref_t ref, unsigned long page);
 
 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
 
@@ -97,7 +96,7 @@ void gnttab_cancel_free_callback(struct 
 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
 
 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
-				     unsigned long frame, int readonly);
+				     unsigned long frame, int flags);
 
 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
 				       unsigned long pfn);
diff -r 4c96da4993b8 include/xen/interface/grant_table.h
--- a/include/xen/interface/grant_table.h	Mon Nov 12 10:17:44 2007 +0000
+++ b/include/xen/interface/grant_table.h	Wed Nov 14 09:46:25 2007 +0000
@@ -119,6 +119,7 @@ typedef struct grant_entry grant_entry_t
  *  GTF_readonly: Restrict @domid to read-only mappings and accesses. [GST]
  *  GTF_reading: Grant entry is currently mapped for reading by @domid. [XEN]
  *  GTF_writing: Grant entry is currently mapped for writing by @domid. [XEN]
+ *  GTF_PAT, GTF_PWT, GTF_PCD: Cache attribute flags for the grant [GST]
  */
 #define _GTF_readonly       (2)
 #define GTF_readonly        (1U<<_GTF_readonly)
@@ -126,6 +127,12 @@ typedef struct grant_entry grant_entry_t
 #define GTF_reading         (1U<<_GTF_reading)
 #define _GTF_writing        (4)
 #define GTF_writing         (1U<<_GTF_writing)
+#define _GTF_PAT            (5)
+#define GTF_PAT             (1U<<_GTF_PAT)
+#define _GTF_PWT            (6)
+#define GTF_PWT             (1U<<_GTF_PWT)
+#define _GTF_PCD            (7)
+#define GTF_PCD             (1U<<_GTF_PCD)
 
 /*
  * Subflags for GTF_accept_transfer: