@@ -43,6 +43,7 @@
#include <linux/moduleparam.h>
#include <linux/mm.h>
#include <linux/slab.h>
+#include <linux/completion.h>
#include <net/ip.h>
#include <xen/xen.h>
@@ -56,6 +57,12 @@
#include <xen/interface/memory.h>
#include <xen/interface/grant_table.h>
+enum netif_freeze_state {
+ NETIF_FREEZE_STATE_UNFROZEN,
+ NETIF_FREEZE_STATE_FREEZING,
+ NETIF_FREEZE_STATE_FROZEN,
+};
+
/* Module parameters */
#define MAX_QUEUES_DEFAULT 8
static unsigned int xennet_max_queues;
@@ -63,6 +70,12 @@ module_param_named(max_queues, xennet_max_queues, uint, 0644);
MODULE_PARM_DESC(max_queues,
"Maximum number of queues per virtual interface");
+static unsigned int netfront_freeze_timeout_secs = 10;
+module_param_named(freeze_timeout_secs,
+ netfront_freeze_timeout_secs, uint, 0644);
+MODULE_PARM_DESC(freeze_timeout_secs,
+ "timeout when freezing netfront device in seconds");
+
static const struct ethtool_ops xennet_ethtool_ops;
struct netfront_cb {
@@ -160,6 +173,10 @@ struct netfront_info {
struct netfront_stats __percpu *tx_stats;
atomic_t rx_gso_checksum_fixup;
+
+ int freeze_state;
+
+ struct completion wait_backend_disconnected;
};
struct netfront_rx_info {
@@ -721,6 +738,21 @@ static int xennet_close(struct net_device *dev)
return 0;
}
+static int xennet_disable_interrupts(struct net_device *dev)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ unsigned int num_queues = dev->real_num_tx_queues;
+ unsigned int queue_index;
+ struct netfront_queue *queue;
+
+ for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+ queue = &np->queues[queue_index];
+ disable_irq(queue->tx_irq);
+ disable_irq(queue->rx_irq);
+ }
+ return 0;
+}
+
static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
grant_ref_t ref)
{
@@ -1301,6 +1333,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
np->queues = NULL;
+ init_completion(&np->wait_backend_disconnected);
+
err = -ENOMEM;
np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
if (np->rx_stats == NULL)
@@ -1794,6 +1828,50 @@ static int xennet_create_queues(struct netfront_info *info,
return 0;
}
+static int netfront_freeze(struct xenbus_device *dev)
+{
+ struct netfront_info *info = dev_get_drvdata(&dev->dev);
+ unsigned long timeout = netfront_freeze_timeout_secs * HZ;
+ int err = 0;
+
+ xennet_disable_interrupts(info->netdev);
+
+ netif_device_detach(info->netdev);
+
+ info->freeze_state = NETIF_FREEZE_STATE_FREEZING;
+
+ /* Kick the backend to disconnect */
+ xenbus_switch_state(dev, XenbusStateClosing);
+
+ /* We don't want to move forward before the frontend is diconnected
+ * from the backend cleanly.
+ */
+ timeout = wait_for_completion_timeout(&info->wait_backend_disconnected,
+ timeout);
+ if (!timeout) {
+ err = -EBUSY;
+ xenbus_dev_error(dev, err, "Freezing timed out;"
+ "the device may become inconsistent state");
+ return err;
+ }
+
+ /* Tear down queues */
+ xennet_disconnect_backend(info);
+ xennet_destroy_queues(info);
+
+ info->freeze_state = NETIF_FREEZE_STATE_FROZEN;
+
+ return err;
+}
+
+static int netfront_restore(struct xenbus_device *dev)
+{
+ /* Kick the backend to re-connect */
+ xenbus_switch_state(dev, XenbusStateInitialising);
+
+ return 0;
+}
+
/* Common code used when first setting up, and when resuming. */
static int talk_to_netback(struct xenbus_device *dev,
struct netfront_info *info)
@@ -1999,6 +2077,8 @@ static int xennet_connect(struct net_device *dev)
spin_unlock_bh(&queue->rx_lock);
}
+ np->freeze_state = NETIF_FREEZE_STATE_UNFROZEN;
+
return 0;
}
@@ -2036,10 +2116,23 @@ static void netback_changed(struct xenbus_device *dev,
break;
case XenbusStateClosed:
- if (dev->state == XenbusStateClosed)
+ if (dev->state == XenbusStateClosed) {
+ /* dpm context is waiting for the backend */
+ if (np->freeze_state == NETIF_FREEZE_STATE_FREEZING)
+ complete(&np->wait_backend_disconnected);
break;
+ }
+
/* Fall through - Missed the backend's CLOSING state. */
case XenbusStateClosing:
+ /* We may see unexpected Closed or Closing from the backend.
+ * Just ignore it not to prevent the frontend from being
+ * re-connected in the case of PM suspend or hibernation.
+ */
+ if (np->freeze_state == NETIF_FREEZE_STATE_FROZEN &&
+ dev->state == XenbusStateInitialising) {
+ break;
+ }
xenbus_frontend_closed(dev);
break;
}
@@ -2186,6 +2279,9 @@ static struct xenbus_driver netfront_driver = {
.probe = netfront_probe,
.remove = xennet_remove,
.resume = netfront_resume,
+ .freeze = netfront_freeze,
+ .thaw = netfront_restore,
+ .restore = netfront_restore,
.otherend_changed = netback_changed,
};