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-rw-r--r--drivers/net/xen-netback/netback.c11
-rw-r--r--drivers/xen/grant-table.c53
-rw-r--r--drivers/xen/xenbus/xenbus_client.c6
-rw-r--r--include/xen/grant_table.h12
4 files changed, 70 insertions, 12 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 682633bfe00f..05593d882023 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -635,9 +635,7 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk)
return;
BUG_ON(npo.copy_prod > ARRAY_SIZE(netbk->grant_copy_op));
- ret = HYPERVISOR_grant_table_op(GNTTABOP_copy, &netbk->grant_copy_op,
- npo.copy_prod);
- BUG_ON(ret != 0);
+ gnttab_batch_copy(netbk->grant_copy_op, npo.copy_prod);
while ((skb = __skb_dequeue(&rxq)) != NULL) {
sco = (struct skb_cb_overlay *)skb->cb;
@@ -1460,18 +1458,15 @@ static void xen_netbk_tx_submit(struct xen_netbk *netbk)
static void xen_netbk_tx_action(struct xen_netbk *netbk)
{
unsigned nr_gops;
- int ret;
nr_gops = xen_netbk_tx_build_gops(netbk);
if (nr_gops == 0)
return;
- ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
- netbk->tx_copy_ops, nr_gops);
- BUG_ON(ret);
- xen_netbk_tx_submit(netbk);
+ gnttab_batch_copy(netbk->tx_copy_ops, nr_gops);
+ xen_netbk_tx_submit(netbk);
}
static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx)
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index eea81cf8a2a5..3a567b15600b 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -38,6 +38,7 @@
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
#include <linux/io.h>
+#include <linux/delay.h>
#include <linux/hardirq.h>
#include <xen/xen.h>
@@ -823,6 +824,52 @@ unsigned int gnttab_max_grant_frames(void)
}
EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
+/* Handling of paged out grant targets (GNTST_eagain) */
+#define MAX_DELAY 256
+static inline void
+gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status,
+ const char *func)
+{
+ unsigned delay = 1;
+
+ do {
+ BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1));
+ if (*status == GNTST_eagain)
+ msleep(delay++);
+ } while ((*status == GNTST_eagain) && (delay < MAX_DELAY));
+
+ if (delay >= MAX_DELAY) {
+ printk(KERN_ERR "%s: %s eagain grant\n", func, current->comm);
+ *status = GNTST_bad_page;
+ }
+}
+
+void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count)
+{
+ struct gnttab_map_grant_ref *op;
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count))
+ BUG();
+ for (op = batch; op < batch + count; op++)
+ if (op->status == GNTST_eagain)
+ gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op,
+ &op->status, __func__);
+}
+EXPORT_SYMBOL_GPL(gnttab_batch_map);
+
+void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count)
+{
+ struct gnttab_copy *op;
+
+ if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count))
+ BUG();
+ for (op = batch; op < batch + count; op++)
+ if (op->status == GNTST_eagain)
+ gnttab_retry_eagain_gop(GNTTABOP_copy, op,
+ &op->status, __func__);
+}
+EXPORT_SYMBOL_GPL(gnttab_batch_copy);
+
int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
@@ -836,6 +883,12 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
if (ret)
return ret;
+ /* Retry eagain maps */
+ for (i = 0; i < count; i++)
+ if (map_ops[i].status == GNTST_eagain)
+ gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
+ &map_ops[i].status, __func__);
+
if (xen_feature(XENFEAT_auto_translated_physmap))
return ret;
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index b3e146edb51d..bcf3ba4a6ec1 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -490,8 +490,7 @@ static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
op.host_addr = arbitrary_virt_to_machine(pte).maddr;
- if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
- BUG();
+ gnttab_batch_map(&op, 1);
if (op.status != GNTST_okay) {
free_vm_area(area);
@@ -572,8 +571,7 @@ int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
gnttab_set_map_op(&op, (unsigned long)vaddr, GNTMAP_host_map, gnt_ref,
dev->otherend_id);
- if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
- BUG();
+ gnttab_batch_map(&op, 1);
if (op.status != GNTST_okay) {
xenbus_dev_fatal(dev, op.status,
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 11e27c3af3cb..ba0d77529a29 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -189,4 +189,16 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct page **pages, unsigned int count, bool clear_pte);
+/* Perform a batch of grant map/copy operations. Retry every batch slot
+ * for which the hypervisor returns GNTST_eagain. This is typically due
+ * to paged out target frames.
+ *
+ * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds.
+ *
+ * Return value in each iand every status field of the batch guaranteed
+ * to not be GNTST_eagain.
+ */
+void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
+void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
+
#endif /* __ASM_GNTTAB_H__ */