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authorDavid Vrabel <david.vrabel@citrix.com>2014-10-22 14:08:53 +0100
committerDavid S. Miller <davem@davemloft.net>2014-10-25 14:15:20 -0400
commitbc96f648df1bbc2729abbb84513cf4f64273a1f1 (patch)
treead8044147004ba38641bc727bf3b0f866c2e05ac
parent5345c1d417c1b0caf46fd2766d16bb4357a347d8 (diff)
downloadop-kernel-dev-bc96f648df1bbc2729abbb84513cf4f64273a1f1.zip
op-kernel-dev-bc96f648df1bbc2729abbb84513cf4f64273a1f1.tar.gz
xen-netback: make feature-rx-notify mandatory
Frontends that do not provide feature-rx-notify may stall because netback depends on the notification from frontend to wake the guest Rx thread (even if can_queue is false). This could be fixed but feature-rx-notify was introduced in 2006 and I am not aware of any frontends that do not implement this. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/xen-netback/common.h5
-rw-r--r--drivers/net/xen-netback/interface.c12
-rw-r--r--drivers/net/xen-netback/xenbus.c13
3 files changed, 5 insertions, 25 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index d4eb8d2..93ca77c 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -228,9 +228,6 @@ struct xenvif {
u8 ip_csum:1;
u8 ipv6_csum:1;
- /* Internal feature information. */
- u8 can_queue:1; /* can queue packets for receiver? */
-
/* Is this interface disabled? True when backend discovers
* frontend is rogue.
*/
@@ -272,8 +269,6 @@ void xenvif_xenbus_fini(void);
int xenvif_schedulable(struct xenvif *vif);
-int xenvif_must_stop_queue(struct xenvif_queue *queue);
-
int xenvif_queue_stopped(struct xenvif_queue *queue);
void xenvif_wake_queue(struct xenvif_queue *queue);
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index f379689..c6759b1 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -60,16 +60,6 @@ void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
atomic_dec(&queue->inflight_packets);
}
-static inline void xenvif_stop_queue(struct xenvif_queue *queue)
-{
- struct net_device *dev = queue->vif->dev;
-
- if (!queue->vif->can_queue)
- return;
-
- netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
-}
-
int xenvif_schedulable(struct xenvif *vif)
{
return netif_running(vif->dev) &&
@@ -209,7 +199,7 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
if (!xenvif_rx_ring_slots_available(queue, min_slots_needed)) {
queue->rx_stalled.function = xenvif_rx_stalled;
queue->rx_stalled.data = (unsigned long)queue;
- xenvif_stop_queue(queue);
+ netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
mod_timer(&queue->rx_stalled,
jiffies + rx_drain_timeout_jiffies);
}
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 8079c31..9060857 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -873,15 +873,10 @@ static int read_xenbus_vif_flags(struct backend_info *be)
if (!rx_copy)
return -EOPNOTSUPP;
- if (vif->dev->tx_queue_len != 0) {
- if (xenbus_scanf(XBT_NIL, dev->otherend,
- "feature-rx-notify", "%d", &val) < 0)
- val = 0;
- if (val)
- vif->can_queue = 1;
- else
- /* Must be non-zero for pfifo_fast to work. */
- vif->dev->tx_queue_len = 1;
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
+ "feature-rx-notify", "%d", &val) < 0 || val == 0) {
+ xenbus_dev_fatal(dev, -EINVAL, "feature-rx-notify is mandatory");
+ return -EINVAL;
}
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
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