From patchwork Tue Feb 2 11:55:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 577109 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 28178140556 for ; Tue, 2 Feb 2016 23:02:50 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754915AbcBBMCp (ORCPT ); Tue, 2 Feb 2016 07:02:45 -0500 Received: from smtp.citrix.com ([66.165.176.89]:36749 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754542AbcBBMCo (ORCPT ); Tue, 2 Feb 2016 07:02:44 -0500 X-IronPort-AV: E=Sophos;i="5.22,384,1449532800"; d="scan'208";a="329118806" From: Paul Durrant To: , CC: Paul Durrant , Ian Campbell , Wei Liu Subject: [PATCH net-next v3] xen-netback: implement dynamic multicast control Date: Tue, 2 Feb 2016 11:55:05 +0000 Message-ID: <1454414105-13327-1-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 X-DLP: MIA1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- v3: - Log (rate limited) error when watch is already registered v2: - Log error on failure to allocate memory for multicast watch --- drivers/net/xen-netback/common.h | 1 + drivers/net/xen-netback/xenbus.c | 89 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 82 insertions(+), 8 deletions(-) diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 0333ab0..1128252 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -251,6 +251,7 @@ struct xenvif { unsigned int stalled_queues; struct xenbus_watch credit_watch; + struct xenbus_watch mcast_ctrl_watch; spinlock_t lock; diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 56ebd82..39a303d 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; }