>From f1235377724b4363cba27ef8b29fb89e2b36189a Mon Sep 17 00:00:00 2001 From: Jason Luan Date: Fri, 28 Dec 2012 15:43:06 +0800 Subject: [PATCH] xen-netback notify DomU to send ARP. When Xen Dom0's network circumstance changed, DomU should be notified in some special condition. For example the below circumstance: ping from Guest A to DomU: Guest A --> eth0 - bond0 - xenbr0 --VIF(DOMU) eth1 / when eth0 inactive, and eth1 active. Guest A --> eth0 bond0 - xenbr0 --VIF(DOMU) eth1 / Guest A will don't reach to DomU. After Guest A send ARP request and DomU respond, Guest A will reach DomU. But some more second will be elapsed. eth0 bond0 - xenbr0 --VIF(DOMU) Guest A --> eth1/ If Xen netback watch the network change, will notify DomU by change it own status. So netfront will watch netback's change, and DomU send ARP initiative. Signed-off-by: Jason Luan --- drivers/net/xen-netback/xenbus.c | 36 ++++++++++++++++++++++++++++++++++++ 1 files changed, 36 insertions(+), 0 deletions(-) diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 410018c..ead1a28 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -26,6 +26,7 @@ struct backend_info { struct xenvif *vif; enum xenbus_state frontend_state; struct xenbus_watch hotplug_status_watch; + struct notifier_block vif_notifier; u8 have_hotplug_status_watch:1; }; @@ -34,11 +35,42 @@ static void connect(struct backend_info *); static void backend_create_xenvif(struct backend_info *be); static void unregister_hotplug_status_watch(struct backend_info *be); +#define nb_to_backend(nb) container_of(nb, struct backend_info, vif_notifier) +/** + * When network condition of vif change, notify the frontend. + */ +static int netback_netdev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *event_dev = (struct net_device *)ptr; + struct backend_info *be = nb_to_backend(this); + + pr_debug("event_dev: %s, event: %lx\n", + event_dev ? event_dev->name : "None", event); + + if (!be->vif) + goto out; + + switch (event) { + case NETDEV_NOTIFY_PEERS: + /* Notify frontend to Send gratuitous ARP */ + xenbus_switch_state(be->dev, XenbusStateInitialised); + xenbus_switch_state(be->dev, XenbusStateConnected); + break; + default: + break; + } + +out: + return NOTIFY_DONE; +} + static int netback_remove(struct xenbus_device *dev) { struct backend_info *be = dev_get_drvdata(&dev->dev); unregister_hotplug_status_watch(be); + unregister_netdevice_notifier(&be->vif_notifier); if (be->vif) { kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE); xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status"); @@ -129,6 +161,10 @@ static int netback_probe(struct xenbus_device *dev, /* This kicks hotplug scripts, so do it immediately. */ backend_create_xenvif(be); + /* Register Frontend Event Notify */ + (be->vif_notifier).notifier_call = netback_netdev_event; + register_netdevice_notifier(&be->vif_notifier); + return 0; abort_transaction: -- 1.7.6.5