From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v3 09/11] virtio: net: Add freeze, restore handlers to support S4 Date: Thu, 17 Nov 2011 14:19:09 +0200 Message-ID: <20111117121907.GA19682@redhat.com> References: <85eca44fe83d2deabfdf402bfed72531ebad6026.1321530505.git.amit.shah@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <85eca44fe83d2deabfdf402bfed72531ebad6026.1321530505.git.amit.shah@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Amit Shah Cc: linux-kernel@vger.kernel.org, levinsasha928@gmail.com, Virtualization List List-Id: virtualization@lists.linuxfoundation.org On Thu, Nov 17, 2011 at 05:27:40PM +0530, Amit Shah wrote: > Remove all the vqs and detach from the netdev on hibernation. > > Re-create vqs after restoring from a hibernated image and re-attach the > netdev. This keeps networking working across hibernation. > > Signed-off-by: Amit Shah > --- > drivers/net/virtio_net.c | 37 ++++++++++++++++++++++++++++++++++--- > 1 files changed, 34 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index fbff37a..167b555 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1127,6 +1127,9 @@ static void remove_vq_common(struct virtnet_info *vi) > { > cancel_delayed_work_sync(&vi->refill); > > + /* Stop all the virtqueues. */ > + vi->vdev->config->reset(vi->vdev); > + > /* Free unused buffers in both send and recv, if any. */ > free_unused_bufs(vi); > > @@ -1140,9 +1143,6 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) > { > struct virtnet_info *vi = vdev->priv; > > - /* Stop all the virtqueues. */ > - vdev->config->reset(vdev); > - > unregister_netdev(vi->dev); > > remove_vq_common(vi); > @@ -1151,6 +1151,33 @@ 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; > + > + netif_device_detach(vi->dev); > + remove_vq_common(vi); This stops TX in progress, if any, but not RX which might use the RX VQ. Then remove_vq_common might delete this VQ while it's still in use. So I think we need to call something like napi_disable. However, the subtle twist is that we need to call that *after interrupts have been disabled*. Otherwise we might schedule another napi callback. > + > + 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; > + > + try_fill_recv(vi, GFP_KERNEL); > + > + netif_device_attach(vi->dev); > + return 0; > +} > +#endif > + > static struct virtio_device_id id_table[] = { > { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, > { 0 }, > @@ -1175,6 +1202,10 @@ 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) > -- > 1.7.7.1