From 22fae97d863679994b951799dd4bbe7afd95897b Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Tue, 2 Feb 2016 11:55:05 +0000 Subject: xen-netback: implement dynamic multicast control My recent patch to the Xen Project documents a protocol for 'dynamic multicast control' in netif.h. This extends the previous multicast control protocol to not require a shared ring reconnection to turn the feature off. Instead the backend watches the "request-multicast-control" key in xenstore and turns the feature off if the key value is written to zero. This patch adds support for dynamic multicast control in xen-netback. Signed-off-by: Paul Durrant Cc: Ian Campbell Cc: Wei Liu Acked-by: Wei Liu Signed-off-by: David S. Miller --- drivers/net/xen-netback/xenbus.c | 89 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 81 insertions(+), 8 deletions(-) (limited to 'drivers/net/xen-netback/xenbus.c') diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 56ebd8267386..39a303de20dd 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -327,7 +327,7 @@ static int netback_probe(struct xenbus_device *dev, goto abort_transaction; } - /* We support multicast-control. */ + /* We support dynamic multicast-control. */ err = xenbus_printf(xbt, dev->nodename, "feature-multicast-control", "%d", 1); if (err) { @@ -335,6 +335,14 @@ static int netback_probe(struct xenbus_device *dev, goto abort_transaction; } + err = xenbus_printf(xbt, dev->nodename, + "feature-dynamic-multicast-control", + "%d", 1); + if (err) { + message = "writing feature-dynamic-multicast-control"; + goto abort_transaction; + } + err = xenbus_transaction_end(xbt, 0); } while (err == -EAGAIN); @@ -683,7 +691,8 @@ static void xen_net_rate_changed(struct xenbus_watch *watch, } } -static int xen_register_watchers(struct xenbus_device *dev, struct xenvif *vif) +static int xen_register_credit_watch(struct xenbus_device *dev, + struct xenvif *vif) { int err = 0; char *node; @@ -708,7 +717,7 @@ static int xen_register_watchers(struct xenbus_device *dev, struct xenvif *vif) return err; } -static void xen_unregister_watchers(struct xenvif *vif) +static void xen_unregister_credit_watch(struct xenvif *vif) { if (vif->credit_watch.node) { unregister_xenbus_watch(&vif->credit_watch); @@ -717,6 +726,75 @@ static void xen_unregister_watchers(struct xenvif *vif) } } +static void xen_mcast_ctrl_changed(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + struct xenvif *vif = container_of(watch, struct xenvif, + mcast_ctrl_watch); + struct xenbus_device *dev = xenvif_to_xenbus_device(vif); + int val; + + if (xenbus_scanf(XBT_NIL, dev->otherend, + "request-multicast-control", "%d", &val) < 0) + val = 0; + vif->multicast_control = !!val; +} + +static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, + struct xenvif *vif) +{ + int err = 0; + char *node; + unsigned maxlen = strlen(dev->otherend) + + sizeof("/request-multicast-control"); + + if (vif->mcast_ctrl_watch.node) { + pr_err_ratelimited("Watch is already registered\n"); + return -EADDRINUSE; + } + + node = kmalloc(maxlen, GFP_KERNEL); + if (!node) { + pr_err("Failed to allocate memory for watch\n"); + return -ENOMEM; + } + snprintf(node, maxlen, "%s/request-multicast-control", + dev->otherend); + vif->mcast_ctrl_watch.node = node; + vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed; + err = register_xenbus_watch(&vif->mcast_ctrl_watch); + if (err) { + pr_err("Failed to set watcher %s\n", + vif->mcast_ctrl_watch.node); + kfree(node); + vif->mcast_ctrl_watch.node = NULL; + vif->mcast_ctrl_watch.callback = NULL; + } + return err; +} + +static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif) +{ + if (vif->mcast_ctrl_watch.node) { + unregister_xenbus_watch(&vif->mcast_ctrl_watch); + kfree(vif->mcast_ctrl_watch.node); + vif->mcast_ctrl_watch.node = NULL; + } +} + +static void xen_register_watchers(struct xenbus_device *dev, + struct xenvif *vif) +{ + xen_register_credit_watch(dev, vif); + xen_register_mcast_ctrl_watch(dev, vif); +} + +static void xen_unregister_watchers(struct xenvif *vif) +{ + xen_unregister_mcast_ctrl_watch(vif); + xen_unregister_credit_watch(vif); +} + static void unregister_hotplug_status_watch(struct backend_info *be) { if (be->have_hotplug_status_watch) { @@ -1030,11 +1108,6 @@ static int read_xenbus_vif_flags(struct backend_info *be) val = 0; vif->ipv6_csum = !!val; - if (xenbus_scanf(XBT_NIL, dev->otherend, "request-multicast-control", - "%d", &val) < 0) - val = 0; - vif->multicast_control = !!val; - return 0; } -- cgit v1.2.3-59-g8ed1b