[PATCH 3.11 32/66] virtio-net: dont respond to cpu hotplug notifier if were not ready

Greg Kroah-Hartman
2013-11-01T22:21:46Z

From: Jason Wang <jasowang@redhat.com>

[ Upstream commit 3ab098df35f8b98b6553edc2e40234af512ba877 ]

We're trying to re-configure the affinity unconditionally in cpu hotplug
callback. This may lead the issue during resuming from s3/s4 since

- virt queues haven't been allocated at that time.
- it's unnecessary since thaw method will re-configure the affinity.

Fix this issue by checking the config_enable and do nothing is we're not ready.

The bug were introduced by commit 8de4b2f3ae90c8fc0f17eeaab87d5a951b66ee17
(virtio-net: reset virtqueue affinity when doing cpu hotplug).

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/virtio_net.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1094,6 +1094,11 @@ static int virtnet_cpu_callback(struct n
{
struct virtnet_info *vi = container_of(nfb, struct virtnet_info, nb);

+ mutex_lock(&vi->config_lock);
+
+ if (!vi->config_enable)
+ goto done;
+
switch(action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
@@ -1106,6 +1111,9 @@ static int virtnet_cpu_callback(struct n
default:
break;
}
+
+done:
+ mutex_unlock(&vi->config_lock);
return NOTIFY_OK;
}