Re: [PATCH v6 09/11] virtio: net: Add freeze, restore handlers to support S4
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2011-12-29 16:13:27
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On Thu, Dec 22, 2011 at 04:58:33PM +0530, Amit Shah wrote:
quoted hunk ↗ jump to hunk
Remove all the vqs, disable napi and detach from the netdev on hibernation. Re-create vqs after restoring from a hibernated image, re-enable napi and re-attach the netdev. This keeps networking working across hibernation. Signed-off-by: Amit Shah <redacted> --- drivers/net/virtio_net.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 46 insertions(+), 0 deletions(-)diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7a2a5bf..b31670f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c@@ -1159,6 +1159,48 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) free_netdev(vi->dev); } +#ifdef CONFIG_PM +static int virtnet_freeze(struct virtio_device *vdev) +{ + struct virtnet_info *vi = vdev->priv; + + virtqueue_disable_cb(vi->rvq); + virtqueue_disable_cb(vi->svq); + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) + virtqueue_disable_cb(vi->cvq); + + netif_device_detach(vi->dev); + cancel_delayed_work_sync(&vi->refill); + + if (netif_running(vi->dev)) + napi_disable(&vi->napi); + + remove_vq_common(vi); + + return 0; +} + +static int virtnet_restore(struct virtio_device *vdev) +{ + struct virtnet_info *vi = vdev->priv; + int err; + + err = init_vqs(vi); + if (err) + return err; + + if (netif_running(vi->dev))
Can virtnet close run at this point? If yes it's a bug.
+ virtnet_napi_enable(vi); + + netif_device_attach(vi->dev); +
Not that open/close start/stop refill, I wonder whether this is a problem. For example, can virtnet_close run at this point, and cancel refill?
+ if (!try_fill_recv(vi, GFP_KERNEL)) + schedule_delayed_work(&vi->refill, 0);
This needs to be switched to non reentrant wq too?
quoted hunk ↗ jump to hunk
+ + return 0; +} +#endif + static struct virtio_device_id id_table[] = { { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, { 0 },@@ -1183,6 +1225,10 @@ static struct virtio_driver virtio_net_driver = { .probe = virtnet_probe, .remove = __devexit_p(virtnet_remove), .config_changed = virtnet_config_changed, +#ifdef CONFIG_PM + .freeze = virtnet_freeze, + .restore = virtnet_restore, +#endif }; static int __init init(void)-- 1.7.7.4