* [PATCH 1/2] xen-netfront: fix oops when disconnected from backend
2014-06-18 9:47 [PATCHv1 0/2 net] xen-netfront: fix resume regressions in 3.16-rc1 David Vrabel
@ 2014-06-18 9:47 ` David Vrabel
2014-06-18 14:23 ` [Xen-devel] " Wei Liu
2014-06-18 9:47 ` [PATCH 2/2] xen-netfront: recreate queues correctly when reconnecting David Vrabel
2014-06-21 23:15 ` [PATCHv1 0/2 net] xen-netfront: fix resume regressions in 3.16-rc1 David Miller
2 siblings, 1 reply; 6+ messages in thread
From: David Vrabel @ 2014-06-18 9:47 UTC (permalink / raw)
To: netdev; +Cc: xen-devel, Boris Ostrovsky, David Vrabel
xennet_disconnect_backend() was not correctly iterating over all the
queues.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
drivers/net/xen-netfront.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 5a7872a..daaf1e5 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1287,7 +1287,7 @@ static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
if (likely(netif_carrier_ok(dev) &&
RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
- napi_schedule(&queue->napi);
+ napi_schedule(&queue->napi);
return IRQ_HANDLED;
}
@@ -1437,10 +1437,11 @@ static void xennet_end_access(int ref, void *page)
static void xennet_disconnect_backend(struct netfront_info *info)
{
unsigned int i = 0;
- struct netfront_queue *queue = NULL;
unsigned int num_queues = info->netdev->real_num_tx_queues;
for (i = 0; i < num_queues; ++i) {
+ struct netfront_queue *queue = &info->queues[i];
+
/* Stop old i/f to prevent errors whilst we rebuild the state. */
spin_lock_bh(&queue->rx_lock);
spin_lock_irq(&queue->tx_lock);
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/2] xen-netfront: recreate queues correctly when reconnecting
2014-06-18 9:47 [PATCHv1 0/2 net] xen-netfront: fix resume regressions in 3.16-rc1 David Vrabel
2014-06-18 9:47 ` [PATCH 1/2] xen-netfront: fix oops when disconnected from backend David Vrabel
@ 2014-06-18 9:47 ` David Vrabel
2014-06-18 14:25 ` [Xen-devel] " Wei Liu
2014-06-21 23:15 ` [PATCHv1 0/2 net] xen-netfront: fix resume regressions in 3.16-rc1 David Miller
2 siblings, 1 reply; 6+ messages in thread
From: David Vrabel @ 2014-06-18 9:47 UTC (permalink / raw)
To: netdev; +Cc: xen-devel, Boris Ostrovsky, David Vrabel
When reconnecting to the backend (after a resume/migration, for example),
a different number of queues may be required (since the guest may have
moved to a different host with different capabilities). During the
reconnection the old queues are torn down and new ones created.
Introduce xennet_create_queues() and xennet_destroy_queues() that fixes
three bugs during the reconnection.
- The old info->queues was leaked.
- The old queue's napi instances were not deleted.
- The new queue's napi instances were left disabled (which meant no
packets could be received).
The xennet_destroy_queues() calls is deferred until the reconnection
instead of the disconnection (in xennet_disconnect_backend()) because
napi_disable() might sleep.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
drivers/net/xen-netfront.c | 104 ++++++++++++++++++++++++++++++--------------
1 file changed, 72 insertions(+), 32 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index daaf1e5..2ccb4a0 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1699,8 +1699,6 @@ static int xennet_init_queue(struct netfront_queue *queue)
goto exit_free_tx;
}
- netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll, 64);
-
return 0;
exit_free_tx:
@@ -1791,6 +1789,70 @@ error:
return err;
}
+static void xennet_destroy_queues(struct netfront_info *info)
+{
+ unsigned int i;
+
+ rtnl_lock();
+
+ for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
+ struct netfront_queue *queue = &info->queues[i];
+
+ if (netif_running(info->netdev))
+ napi_disable(&queue->napi);
+ netif_napi_del(&queue->napi);
+ }
+
+ rtnl_unlock();
+
+ kfree(info->queues);
+ info->queues = NULL;
+}
+
+static int xennet_create_queues(struct netfront_info *info,
+ unsigned int num_queues)
+{
+ unsigned int i;
+ int ret;
+
+ info->queues = kcalloc(num_queues, sizeof(struct netfront_queue),
+ GFP_KERNEL);
+ if (!info->queues)
+ return -ENOMEM;
+
+ rtnl_lock();
+
+ for (i = 0; i < num_queues; i++) {
+ struct netfront_queue *queue = &info->queues[i];
+
+ queue->id = i;
+ queue->info = info;
+
+ ret = xennet_init_queue(queue);
+ if (ret < 0) {
+ dev_warn(&info->netdev->dev, "only created %d queues\n",
+ num_queues);
+ num_queues = i;
+ break;
+ }
+
+ netif_napi_add(queue->info->netdev, &queue->napi,
+ xennet_poll, 64);
+ if (netif_running(info->netdev))
+ napi_enable(&queue->napi);
+ }
+
+ netif_set_real_num_tx_queues(info->netdev, num_queues);
+
+ rtnl_unlock();
+
+ if (num_queues == 0) {
+ dev_err(&info->netdev->dev, "no queues\n");
+ return -EINVAL;
+ }
+ 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)
@@ -1827,42 +1889,20 @@ static int talk_to_netback(struct xenbus_device *dev,
goto out;
}
- /* Allocate array of queues */
- info->queues = kcalloc(num_queues, sizeof(struct netfront_queue), GFP_KERNEL);
- if (!info->queues) {
- err = -ENOMEM;
- goto out;
- }
- rtnl_lock();
- netif_set_real_num_tx_queues(info->netdev, num_queues);
- rtnl_unlock();
+ if (info->queues)
+ xennet_destroy_queues(info);
+
+ err = xennet_create_queues(info, num_queues);
+ if (err < 0)
+ goto destroy_ring;
/* Create shared ring, alloc event channel -- for each queue */
for (i = 0; i < num_queues; ++i) {
queue = &info->queues[i];
- queue->id = i;
- queue->info = info;
- err = xennet_init_queue(queue);
- if (err) {
- /* xennet_init_queue() cleans up after itself on failure,
- * but we still have to clean up any previously initialised
- * queues. If i > 0, set num_queues to i, then goto
- * destroy_ring, which calls xennet_disconnect_backend()
- * to tidy up.
- */
- if (i > 0) {
- rtnl_lock();
- netif_set_real_num_tx_queues(info->netdev, i);
- rtnl_unlock();
- goto destroy_ring;
- } else {
- goto out;
- }
- }
err = setup_netfront(dev, queue, feature_split_evtchn);
if (err) {
- /* As for xennet_init_queue(), setup_netfront() will tidy
- * up the current queue on error, but we need to clean up
+ /* setup_netfront() will tidy up the current
+ * queue on error, but we need to clean up
* those already allocated.
*/
if (i > 0) {
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread