From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [RFC v3 PATCH 5/4 PATCH] virtio-net: send gratuitous packet when needed Date: Thu, 27 Oct 2011 16:57:41 +0800 Message-ID: <20111027085740.15655.37609.stgit@dhcp-8-146.nay.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: aliguori@us.ibm.com, mst@redhat.com, jan.kiszka@siemens.com, rusty@rustcorp.com.au, linux-kernel@vger.kernel.org, blauwirbel@gmail.com, netdev@vger.kernel.org, stefanha@gmail.com Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: netdev.vger.kernel.org As hypervior does not have the knowledge of guest network configuration, it's better to ask guest to send gratuitous packet when needed. This make let virtio-net driver can send gratuitous packet. Guest check VIRTIO_NET_S_ANNOUNCE during config change interrupt. When this bit is set, a workqueue would be scheduled to send gratuitous packet through NETDEV_NOTIFY_PEERS. This feature is negotiated through bit VIRTIO_NET_F_GUEST_ANNOUNCE. Changes from v2: - Fix the race between unregister_dev() and workqueue Signed-off-by: Jason Wang --- drivers/net/virtio_net.c | 32 ++++++++++++++++++++++++++++++-- include/linux/virtio_net.h | 2 ++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index b8225f3..19ee718 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -71,6 +71,9 @@ struct virtnet_info { /* Work struct for refilling if we run low on memory. */ struct delayed_work refill; + /* Work struct for sending gratituous packet. */ + struct work_struct announce; + /* Chain pages by the private ptr. */ struct page *pages; @@ -507,6 +510,13 @@ static void refill_work(struct work_struct *work) schedule_delayed_work(&vi->refill, HZ/2); } +static void announce_work(struct work_struct *work) +{ + struct virtnet_info *vi = container_of(work, struct virtnet_info, + announce); + netif_notify_peers(vi->dev); +} + static int virtnet_poll(struct napi_struct *napi, int budget) { struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); @@ -923,11 +933,23 @@ static void virtnet_update_status(struct virtnet_info *vi) &v, sizeof(v)); /* Ignore unknown (future) status bits */ - v &= VIRTIO_NET_S_LINK_UP; + v &= VIRTIO_NET_S_LINK_UP | VIRTIO_NET_S_ANNOUNCE; if (vi->status == v) return; + if (v & VIRTIO_NET_S_ANNOUNCE) { + v &= ~VIRTIO_NET_S_ANNOUNCE; + vi->vdev->config->set(vi->vdev, + offsetof(struct virtio_net_config, + status), + &v, sizeof(v)); + + if ((v & VIRTIO_NET_S_LINK_UP) && + virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ANNOUNCE)) + schedule_work(&vi->announce); + } + vi->status = v; if (vi->status & VIRTIO_NET_S_LINK_UP) { @@ -1016,6 +1038,8 @@ static int virtnet_probe(struct virtio_device *vdev) goto free; INIT_DELAYED_WORK(&vi->refill, refill_work); + if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE)) + INIT_WORK(&vi->announce, announce_work); sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); @@ -1075,6 +1099,8 @@ static int virtnet_probe(struct virtio_device *vdev) return 0; unregister: + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ANNOUNCE)) + cancel_work_sync(&vi->announce); unregister_netdev(dev); cancel_delayed_work_sync(&vi->refill); free_vqs: @@ -1115,7 +1141,8 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) /* Stop all the virtqueues. */ vdev->config->reset(vdev); - + if(virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ANNOUNCE)) + cancel_work_sync(&vi->announce); unregister_netdev(vi->dev); cancel_delayed_work_sync(&vi->refill); @@ -1144,6 +1171,7 @@ static unsigned int features[] = { VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, + VIRTIO_NET_F_GUEST_ANNOUNCE, }; static struct virtio_driver virtio_net_driver = { diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 970d5a2..44a38d6 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -49,8 +49,10 @@ #define VIRTIO_NET_F_CTRL_RX 18 /* Control channel RX mode support */ #define VIRTIO_NET_F_CTRL_VLAN 19 /* Control channel VLAN filtering */ #define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support */ +#define VIRTIO_NET_F_GUEST_ANNOUNCE 21 /* Guest can send gratituous packet */ #define VIRTIO_NET_S_LINK_UP 1 /* Link is up */ +#define VIRTIO_NET_S_ANNOUNCE 2 /* Announcement is needed */ struct virtio_net_config { /* The config defining mac address (if VIRTIO_NET_F_MAC) */