From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [RFC PATCH net-next v6 2/4] net: Introduce generic bypass module Date: Wed, 18 Apr 2018 11:25:15 +0200 Message-ID: <20180418092515.GB1989@nanopsycho> References: <1523386790-12396-1-git-send-email-sridhar.samudrala@intel.com> <1523386790-12396-3-git-send-email-sridhar.samudrala@intel.com> <20180411155127.GQ2028@nanopsycho> <6a8c1ff5-153a-e40a-91b3-48532b8d3a38@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: mst@redhat.com, stephen@networkplumber.org, davem@davemloft.net, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org, jesse.brandeburg@intel.com, alexander.h.duyck@intel.com, kubakici@wp.pl, jasowang@redhat.com, loseweigh@gmail.com To: "Samudrala, Sridhar" Return-path: Received: from mail-wr0-f182.google.com ([209.85.128.182]:44774 "EHLO mail-wr0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751870AbeDRJZS (ORCPT ); Wed, 18 Apr 2018 05:25:18 -0400 Received: by mail-wr0-f182.google.com with SMTP id o15-v6so2825032wro.11 for ; Wed, 18 Apr 2018 02:25:17 -0700 (PDT) Content-Disposition: inline In-Reply-To: <6a8c1ff5-153a-e40a-91b3-48532b8d3a38@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: Wed, Apr 11, 2018 at 09:13:52PM CEST, sridhar.samudrala@intel.com wrote: >On 4/11/2018 8:51 AM, Jiri Pirko wrote: >> Tue, Apr 10, 2018 at 08:59:48PM CEST, sridhar.samudrala@intel.com wrote: >> > This provides a generic interface for paravirtual drivers to listen >> > for netdev register/unregister/link change events from pci ethernet >> > devices with the same MAC and takeover their datapath. The notifier and >> > event handling code is based on the existing netvsc implementation. >> > >> > It exposes 2 sets of interfaces to the paravirtual drivers. >> > 1. existing netvsc driver that uses 2 netdev model. In this model, no >> > master netdev is created. The paravirtual driver registers each bypass >> > instance along with a set of ops to manage the slave events. >> > bypass_master_register() >> > bypass_master_unregister() >> > 2. new virtio_net based solution that uses 3 netdev model. In this model, >> > the bypass module provides interfaces to create/destroy additional master >> > netdev and all the slave events are managed internally. >> > bypass_master_create() >> > bypass_master_destroy() >> > >> > Signed-off-by: Sridhar Samudrala >> > --- >> > include/linux/netdevice.h | 14 + >> > include/net/bypass.h | 96 ++++++ >> > net/Kconfig | 18 + >> > net/core/Makefile | 1 + >> > net/core/bypass.c | 844 ++++++++++++++++++++++++++++++++++++++++++++++ >> > 5 files changed, 973 insertions(+) >> > create mode 100644 include/net/bypass.h >> > create mode 100644 net/core/bypass.c >> > >> > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h >> > index cf44503ea81a..587293728f70 100644 >> > --- a/include/linux/netdevice.h >> > +++ b/include/linux/netdevice.h >> > @@ -1430,6 +1430,8 @@ enum netdev_priv_flags { >> > IFF_PHONY_HEADROOM = 1<<24, >> > IFF_MACSEC = 1<<25, >> > IFF_NO_RX_HANDLER = 1<<26, >> > + IFF_BYPASS = 1 << 27, >> > + IFF_BYPASS_SLAVE = 1 << 28, >> I wonder, why you don't follow the existing coding style... Also, please >> add these to into the comment above. > >To avoid checkpatch warnings. If it is OK to ignore these warnings, I can switch back >to the existing coding style to be consistent. Please do. > >> >> >> > }; >> > >> > #define IFF_802_1Q_VLAN IFF_802_1Q_VLAN >> > @@ -1458,6 +1460,8 @@ enum netdev_priv_flags { >> > #define IFF_RXFH_CONFIGURED IFF_RXFH_CONFIGURED >> > #define IFF_MACSEC IFF_MACSEC >> > #define IFF_NO_RX_HANDLER IFF_NO_RX_HANDLER >> > +#define IFF_BYPASS IFF_BYPASS >> > +#define IFF_BYPASS_SLAVE IFF_BYPASS_SLAVE >> > >> > /** >> > * struct net_device - The DEVICE structure. >> > @@ -4308,6 +4312,16 @@ static inline bool netif_is_rxfh_configured(const struct net_device *dev) >> > return dev->priv_flags & IFF_RXFH_CONFIGURED; >> > } >> > >> > +static inline bool netif_is_bypass_master(const struct net_device *dev) >> > +{ >> > + return dev->priv_flags & IFF_BYPASS; >> > +} >> > + >> > +static inline bool netif_is_bypass_slave(const struct net_device *dev) >> > +{ >> > + return dev->priv_flags & IFF_BYPASS_SLAVE; >> > +} >> > + >> > /* This device needs to keep skb dst for qdisc enqueue or ndo_start_xmit() */ >> > static inline void netif_keep_dst(struct net_device *dev) >> > { >> > diff --git a/include/net/bypass.h b/include/net/bypass.h >> > new file mode 100644 >> > index 000000000000..86b02cb894cf >> > --- /dev/null >> > +++ b/include/net/bypass.h >> > @@ -0,0 +1,96 @@ >> > +// SPDX-License-Identifier: GPL-2.0 >> > +/* Copyright (c) 2018, Intel Corporation. */ >> > + >> > +#ifndef _NET_BYPASS_H >> > +#define _NET_BYPASS_H >> > + >> > +#include >> > + >> > +struct bypass_ops { >> > + int (*slave_pre_register)(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev); >> > + int (*slave_join)(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev); >> > + int (*slave_pre_unregister)(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev); >> > + int (*slave_release)(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev); >> > + int (*slave_link_change)(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev); >> > + rx_handler_result_t (*handle_frame)(struct sk_buff **pskb); >> > +}; >> > + >> > +struct bypass_master { >> > + struct list_head list; >> > + struct net_device __rcu *bypass_netdev; >> > + struct bypass_ops __rcu *ops; >> > +}; >> > + >> > +/* bypass state */ >> > +struct bypass_info { >> > + /* passthru netdev with same MAC */ >> > + struct net_device __rcu *active_netdev; >> You still use "active"/"backup" names which is highly misleading as >> it has completely different meaning that in bond for example. >> I noted that in my previous review already. Please change it. > >I guess the issue is with only the 'active'  name. 'backup' should be fine as it also >matches with the BACKUP feature bit we are adding to virtio_net. I think that "backup" is also misleading. Both "active" and "backup" mean a *state* of slaves. This should be named differently. > >With regards to alternate names for 'active', you suggested 'stolen', but i >am not too happy with it. >netvsc uses vf_netdev, are you OK with this? Or another option is 'passthru' No. The netdev could be any netdevice. It does not have to be a "VF". I think "stolen" is quite appropriate since it describes the modus operandi. The bypass master steals some netdevice according to some match. But I don't insist on "stolen". Just sounds right. > > > >> >> >> > + >> > + /* virtio_net netdev */ >> > + struct net_device __rcu *backup_netdev; >> > + >> > + /* active netdev stats */ >> > + struct rtnl_link_stats64 active_stats; >> > + >> > + /* backup netdev stats */ >> > + struct rtnl_link_stats64 backup_stats; >> > + >> > + /* aggregated stats */ >> > + struct rtnl_link_stats64 bypass_stats; >> > + >> > + /* spinlock while updating stats */ >> > + spinlock_t stats_lock; >> > +}; >> > + >> > +#if IS_ENABLED(CONFIG_NET_BYPASS) >> > + >> > +int bypass_master_create(struct net_device *backup_netdev, >> > + struct bypass_master **pbypass_master); >> > +void bypass_master_destroy(struct bypass_master *bypass_master); >> > + >> > +int bypass_master_register(struct net_device *dev, struct bypass_ops *ops, >> > + struct bypass_master **pbypass_master); >> > +void bypass_master_unregister(struct bypass_master *bypass_master); >> > + >> > +int bypass_slave_unregister(struct net_device *slave_netdev); >> > + >> > +#else >> > + >> > +static inline >> > +int bypass_master_create(struct net_device *backup_netdev, >> > + struct bypass_master **pbypass_master); >> > +{ >> > + return 0; >> > +} >> > + >> > +static inline >> > +void bypass_master_destroy(struct bypass_master *bypass_master) >> > +{ >> > +} >> > + >> > +static inline >> > +int bypass_master_register(struct net_device *dev, struct bypass_ops *ops, >> > + struct pbypass_master **pbypass_master); >> > +{ >> > + return 0; >> > +} >> > + >> > +static inline >> > +void bypass_master_unregister(struct bypass_master *bypass_master) >> > +{ >> > +} >> > + >> > +static inline >> > +int bypass_slave_unregister(struct net_device *slave_netdev) >> > +{ >> > + return 0; >> > +} >> > + >> > +#endif >> > + >> > +#endif /* _NET_BYPASS_H */ >> > diff --git a/net/Kconfig b/net/Kconfig >> > index 0428f12c25c2..994445f4a96a 100644 >> > --- a/net/Kconfig >> > +++ b/net/Kconfig >> > @@ -423,6 +423,24 @@ config MAY_USE_DEVLINK >> > on MAY_USE_DEVLINK to ensure they do not cause link errors when >> > devlink is a loadable module and the driver using it is built-in. >> > >> > +config NET_BYPASS >> > + tristate "Bypass interface" >> > + ---help--- >> > + This provides a generic interface for paravirtual drivers to listen >> > + for netdev register/unregister/link change events from pci ethernet >> > + devices with the same MAC and takeover their datapath. This also >> > + enables live migration of a VM with direct attached VF by failing >> > + over to the paravirtual datapath when the VF is unplugged. >> > + >> > +config MAY_USE_BYPASS >> > + tristate >> > + default m if NET_BYPASS=m >> > + default y if NET_BYPASS=y || NET_BYPASS=n >> > + help >> > + Drivers using the bypass infrastructure should have a dependency >> > + on MAY_USE_BYPASS to ensure they do not cause link errors when >> > + bypass is a loadable module and the driver using it is built-in. >> > + >> > endif # if NET >> > >> > # Used by archs to tell that they support BPF JIT compiler plus which flavour. >> > diff --git a/net/core/Makefile b/net/core/Makefile >> > index 6dbbba8c57ae..a9727ed1c8fc 100644 >> > --- a/net/core/Makefile >> > +++ b/net/core/Makefile >> > @@ -30,3 +30,4 @@ obj-$(CONFIG_DST_CACHE) += dst_cache.o >> > obj-$(CONFIG_HWBM) += hwbm.o >> > obj-$(CONFIG_NET_DEVLINK) += devlink.o >> > obj-$(CONFIG_GRO_CELLS) += gro_cells.o >> > +obj-$(CONFIG_NET_BYPASS) += bypass.o >> > diff --git a/net/core/bypass.c b/net/core/bypass.c >> > new file mode 100644 >> > index 000000000000..b5b9cb554c3f >> > --- /dev/null >> > +++ b/net/core/bypass.c >> > @@ -0,0 +1,844 @@ >> > +// SPDX-License-Identifier: GPL-2.0 >> > +/* Copyright (c) 2018, Intel Corporation. */ >> > + >> > +/* A common module to handle registrations and notifications for paravirtual >> > + * drivers to enable accelerated datapath and support VF live migration. >> > + * >> > + * The notifier and event handling code is based on netvsc driver. >> > + */ >> > + >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > +#include >> > + >> > +static LIST_HEAD(bypass_master_list); >> > +static DEFINE_SPINLOCK(bypass_lock); >> > + >> > +static int bypass_slave_pre_register(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev, >> > + struct bypass_ops *bypass_ops) >> > +{ >> > + struct bypass_info *bi; >> > + bool backup; >> > + >> > + if (bypass_ops) { >> > + if (!bypass_ops->slave_pre_register) >> > + return -EINVAL; >> > + >> > + return bypass_ops->slave_pre_register(slave_netdev, >> > + bypass_netdev); >> > + } >> > + >> > + bi = netdev_priv(bypass_netdev); >> > + backup = (slave_netdev->dev.parent == bypass_netdev->dev.parent); >> > + if (backup ? rtnl_dereference(bi->backup_netdev) : >> > + rtnl_dereference(bi->active_netdev)) { >> > + netdev_err(bypass_netdev, "%s attempting to register as slave dev when %s already present\n", >> > + slave_netdev->name, backup ? "backup" : "active"); >> > + return -EEXIST; >> > + } >> > + >> > + /* Avoid non pci devices as active netdev */ >> > + if (!backup && (!slave_netdev->dev.parent || >> > + !dev_is_pci(slave_netdev->dev.parent))) >> > + return -EINVAL; >> > + >> > + return 0; >> > +} >> > + >> > +static int bypass_slave_join(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev, >> > + struct bypass_ops *bypass_ops) >> > +{ >> > + struct bypass_info *bi; >> > + bool backup; >> > + >> > + if (bypass_ops) { >> > + if (!bypass_ops->slave_join) >> > + return -EINVAL; >> > + >> > + return bypass_ops->slave_join(slave_netdev, bypass_netdev); >> > + } >> > + >> > + bi = netdev_priv(bypass_netdev); >> > + backup = (slave_netdev->dev.parent == bypass_netdev->dev.parent); >> > + >> > + dev_hold(slave_netdev); >> > + >> > + if (backup) { >> > + rcu_assign_pointer(bi->backup_netdev, slave_netdev); >> > + dev_get_stats(bi->backup_netdev, &bi->backup_stats); >> > + } else { >> > + rcu_assign_pointer(bi->active_netdev, slave_netdev); >> > + dev_get_stats(bi->active_netdev, &bi->active_stats); >> > + bypass_netdev->min_mtu = slave_netdev->min_mtu; >> > + bypass_netdev->max_mtu = slave_netdev->max_mtu; >> > + } >> > + >> > + netdev_info(bypass_netdev, "bypass slave:%s joined\n", >> > + slave_netdev->name); >> > + >> > + return 0; >> > +} >> > + >> > +/* Called when slave dev is injecting data into network stack. >> > + * Change the associated network device from lower dev to virtio. >> > + * note: already called with rcu_read_lock >> > + */ >> > +static rx_handler_result_t bypass_handle_frame(struct sk_buff **pskb) >> > +{ >> > + struct sk_buff *skb = *pskb; >> > + struct net_device *ndev = rcu_dereference(skb->dev->rx_handler_data); >> > + >> > + skb->dev = ndev; >> > + >> > + return RX_HANDLER_ANOTHER; >> > +} >> > + >> > +static struct net_device *bypass_master_get_bymac(u8 *mac, >> > + struct bypass_ops **ops) >> > +{ >> > + struct bypass_master *bypass_master; >> > + struct net_device *bypass_netdev; >> > + >> > + spin_lock(&bypass_lock); >> > + list_for_each_entry(bypass_master, &bypass_master_list, list) { >> As I wrote the last time, you don't need this list, spinlock. >> You can do just something like: >> for_each_net(net) { >> for_each_netdev(net, dev) { >> if (netif_is_bypass_master(dev)) { > >This function returns the upper netdev as well as the ops associated >with that netdev. >bypass_master_list is a list of 'struct bypass_master' that associates Well, can't you have it in netdev priv? >'bypass_netdev' with 'bypass_ops' and gets added via bypass_master_register(). >We need 'ops' only to support the 2 netdev model of netvsc. ops will be >NULL for 3-netdev model. I see :( > > >> >> >> >> >> > + bypass_netdev = rcu_dereference(bypass_master->bypass_netdev); >> > + if (ether_addr_equal(bypass_netdev->perm_addr, mac)) { >> > + *ops = rcu_dereference(bypass_master->ops); >> I don't see how rcu_dereference is ok here. >> 1) I don't see rcu_read_lock taken >> 2) Looks like bypass_master->ops has the same value across the whole >> existence. > >We hold rtnl_lock(), i think i need to change this to rtnl_dereference. >Yes. ops doesn't change. If it does not change, you can just access it directly. > >> >> >> > + spin_unlock(&bypass_lock); >> > + return bypass_netdev; >> > + } >> > + } >> > + spin_unlock(&bypass_lock); >> > + return NULL; >> > +} >> > + >> > +static int bypass_slave_register(struct net_device *slave_netdev) >> > +{ >> > + struct net_device *bypass_netdev; >> > + struct bypass_ops *bypass_ops; >> > + int ret, orig_mtu; >> > + >> > + ASSERT_RTNL(); >> > + >> > + bypass_netdev = bypass_master_get_bymac(slave_netdev->perm_addr, >> > + &bypass_ops); >> For master, could you use word "master" in the variables so it is clear? >> Also, "dev" is fine instead of "netdev". >> Something like "bpmaster_dev" > >bypass_master is of  type struct bypass_master,  bypass_netdev is of type struct net_device. I was trying to point out, that "bypass_netdev" represents a "master" netdev, yet it does not say master. That is why I suggested "bpmaster_dev" >I can change all _netdev suffixes to _dev to make the names shorter. ok. > > >> >> >> > + if (!bypass_netdev) >> > + goto done; >> > + >> > + ret = bypass_slave_pre_register(slave_netdev, bypass_netdev, >> > + bypass_ops); >> > + if (ret != 0) >> Just "if (ret)" will do. You have this on more places. > >OK. > > >> >> >> > + goto done; >> > + >> > + ret = netdev_rx_handler_register(slave_netdev, >> > + bypass_ops ? bypass_ops->handle_frame : >> > + bypass_handle_frame, bypass_netdev); >> > + if (ret != 0) { >> > + netdev_err(slave_netdev, "can not register bypass rx handler (err = %d)\n", >> > + ret); >> > + goto done; >> > + } >> > + >> > + ret = netdev_upper_dev_link(slave_netdev, bypass_netdev, NULL); >> > + if (ret != 0) { >> > + netdev_err(slave_netdev, "can not set master device %s (err = %d)\n", >> > + bypass_netdev->name, ret); >> > + goto upper_link_failed; >> > + } >> > + >> > + slave_netdev->priv_flags |= IFF_BYPASS_SLAVE; >> > + >> > + if (netif_running(bypass_netdev)) { >> > + ret = dev_open(slave_netdev); >> > + if (ret && (ret != -EBUSY)) { >> > + netdev_err(bypass_netdev, "Opening slave %s failed ret:%d\n", >> > + slave_netdev->name, ret); >> > + goto err_interface_up; >> > + } >> > + } >> > + >> > + /* Align MTU of slave with master */ >> > + orig_mtu = slave_netdev->mtu; >> > + ret = dev_set_mtu(slave_netdev, bypass_netdev->mtu); >> > + if (ret != 0) { >> > + netdev_err(bypass_netdev, "unable to change mtu of %s to %u register failed\n", >> > + slave_netdev->name, bypass_netdev->mtu); >> > + goto err_set_mtu; >> > + } >> > + >> > + ret = bypass_slave_join(slave_netdev, bypass_netdev, bypass_ops); >> > + if (ret != 0) >> > + goto err_join; >> > + >> > + call_netdevice_notifiers(NETDEV_JOIN, slave_netdev); >> > + >> > + netdev_info(bypass_netdev, "bypass slave:%s registered\n", >> > + slave_netdev->name); >> > + >> > + goto done; >> > + >> > +err_join: >> > + dev_set_mtu(slave_netdev, orig_mtu); >> > +err_set_mtu: >> > + dev_close(slave_netdev); >> > +err_interface_up: >> > + netdev_upper_dev_unlink(slave_netdev, bypass_netdev); >> > + slave_netdev->priv_flags &= ~IFF_BYPASS_SLAVE; >> > +upper_link_failed: >> > + netdev_rx_handler_unregister(slave_netdev); >> > +done: >> > + return NOTIFY_DONE; >> > +} >> > + >> > +static int bypass_slave_pre_unregister(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev, >> > + struct bypass_ops *bypass_ops) >> > +{ >> > + struct net_device *backup_netdev, *active_netdev; >> > + struct bypass_info *bi; >> > + >> > + if (bypass_ops) { >> > + if (!bypass_ops->slave_pre_unregister) >> > + return -EINVAL; >> > + >> > + return bypass_ops->slave_pre_unregister(slave_netdev, >> > + bypass_netdev); >> > + } >> > + >> > + bi = netdev_priv(bypass_netdev); >> > + active_netdev = rtnl_dereference(bi->active_netdev); >> > + backup_netdev = rtnl_dereference(bi->backup_netdev); >> > + >> > + if (slave_netdev != active_netdev && slave_netdev != backup_netdev) >> > + return -EINVAL; >> > + >> > + return 0; >> > +} >> > + >> > +static int bypass_slave_release(struct net_device *slave_netdev, >> > + struct net_device *bypass_netdev, >> > + struct bypass_ops *bypass_ops) >> > +{ >> > + struct net_device *backup_netdev, *active_netdev; >> > + struct bypass_info *bi; >> > + >> > + if (bypass_ops) { >> > + if (!bypass_ops->slave_release) >> > + return -EINVAL; >> I think it would be good to make the API to the driver more strict and >> have a separate set of ops for "active" and "backup" netdevices. >> That should stop people thinking about extending this to more slaves in >> the future. > >We have checks in slave_pre_register() that allows only 1 'backup' and 1 >'active' slave. I'm very well aware of that. I just thought that explicit ops for the two slaves would make this more clear. > > >> >> >> >> > + >> > + return bypass_ops->slave_release(slave_netdev, bypass_netdev); >> > + } >> > + >> > + bi = netdev_priv(bypass_netdev); >> > + active_netdev = rtnl_dereference(bi->active_netdev); >> > + backup_netdev = rtnl_dereference(bi->backup_netdev); >> > + >> > + if (slave_netdev == backup_netdev) { >> > + RCU_INIT_POINTER(bi->backup_netdev, NULL); >> > + } else { >> > + RCU_INIT_POINTER(bi->active_netdev, NULL); >> > + if (backup_netdev) { >> > + bypass_netdev->min_mtu = backup_netdev->min_mtu; >> > + bypass_netdev->max_mtu = backup_netdev->max_mtu; >> > + } >> > + } >> > + >> > + dev_put(slave_netdev); >> > + >> > + netdev_info(bypass_netdev, "bypass slave:%s released\n", >> > + slave_netdev->name); >> > + >> > + return 0; >> > +} >> > + >> > +int bypass_slave_unregister(struct net_device *slave_netdev) >> > +{ >> > + struct net_device *bypass_netdev; >> > + struct bypass_ops *bypass_ops; >> > + int ret; >> > + >> > + if (!netif_is_bypass_slave(slave_netdev)) >> > + goto done; >> > + >> > + ASSERT_RTNL(); >> > + >> > + bypass_netdev = bypass_master_get_bymac(slave_netdev->perm_addr, >> > + &bypass_ops); >> > + if (!bypass_netdev) >> > + goto done; >> > + >> > + ret = bypass_slave_pre_unregister(slave_netdev, bypass_netdev, >> > + bypass_ops); >> > + if (ret != 0) >> > + goto done; >> > + >> > + netdev_rx_handler_unregister(slave_netdev); >> > + netdev_upper_dev_unlink(slave_netdev, bypass_netdev); >> > + slave_netdev->priv_flags &= ~IFF_BYPASS_SLAVE; >> > + >> > + bypass_slave_release(slave_netdev, bypass_netdev, bypass_ops); >> > + >> > + netdev_info(bypass_netdev, "bypass slave:%s unregistered\n", >> > + slave_netdev->name); >> > + >> > +done: >> > + return NOTIFY_DONE; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_slave_unregister); >> > + >> > +static bool bypass_xmit_ready(struct net_device *dev) >> > +{ >> > + return netif_running(dev) && netif_carrier_ok(dev); >> > +} >> > + >> > +static int bypass_slave_link_change(struct net_device *slave_netdev) >> > +{ >> > + struct net_device *bypass_netdev, *active_netdev, *backup_netdev; >> > + struct bypass_ops *bypass_ops; >> > + struct bypass_info *bi; >> > + >> > + if (!netif_is_bypass_slave(slave_netdev)) >> > + goto done; >> > + >> > + ASSERT_RTNL(); >> > + >> > + bypass_netdev = bypass_master_get_bymac(slave_netdev->perm_addr, >> > + &bypass_ops); >> > + if (!bypass_netdev) >> > + goto done; >> > + >> > + if (bypass_ops) { >> > + if (!bypass_ops->slave_link_change) >> > + goto done; >> > + >> > + return bypass_ops->slave_link_change(slave_netdev, >> > + bypass_netdev); >> > + } >> > + >> > + if (!netif_running(bypass_netdev)) >> > + return 0; >> > + >> > + bi = netdev_priv(bypass_netdev); >> > + >> > + active_netdev = rtnl_dereference(bi->active_netdev); >> > + backup_netdev = rtnl_dereference(bi->backup_netdev); >> > + >> > + if (slave_netdev != active_netdev && slave_netdev != backup_netdev) >> > + goto done; >> You don't need this check. "if (!netif_is_bypass_slave(slave_netdev))" >> above is enough. > >I think we need this check to not allow events from a slave that is not >attached to this master but has the same MAC. Why do we need such events? Seems wrong to me. Consider: bp1 bp2 a1 b1 a2 b2 a1 and a2 have the same mac and bp1 and bp2 have the same mac. Now bypass_master_get_bymac() will return always bp1 or bp2 - depending on the order of creation. Let's say it will return bp1. Then when we have event for a2, the bypass_ops->slave_link_change is called with (a2, bp1). That is wrong. You cannot use bypass_master_get_bymac() here. > >> >> >> > + >> > + if ((active_netdev && bypass_xmit_ready(active_netdev)) || >> > + (backup_netdev && bypass_xmit_ready(backup_netdev))) { >> > + netif_carrier_on(bypass_netdev); >> > + netif_tx_wake_all_queues(bypass_netdev); >> > + } else { >> > + netif_carrier_off(bypass_netdev); >> > + netif_tx_stop_all_queues(bypass_netdev); >> > + } >> > + >> > +done: >> > + return NOTIFY_DONE; >> > +} >> > + >> > +static bool bypass_validate_event_dev(struct net_device *dev) >> > +{ >> > + /* Skip parent events */ >> > + if (netif_is_bypass_master(dev)) >> > + return false; >> > + >> > + /* Avoid non-Ethernet type devices */ >> > + if (dev->type != ARPHRD_ETHER) >> > + return false; >> > + >> > + /* Avoid Vlan dev with same MAC registering as VF */ >> > + if (is_vlan_dev(dev)) >> > + return false; >> > + >> > + /* Avoid Bonding master dev with same MAC registering as slave dev */ >> > + if ((dev->priv_flags & IFF_BONDING) && (dev->flags & IFF_MASTER)) >> Yeah, this is certainly incorrect. One thing is, you should be using the >> helpers netif_is_bond_master(). >> But what about the rest? macsec, macvlan, team, bridge, ovs and others? >> >> You need to do it not by blacklisting, but with whitelisting. You need >> to whitelist VF devices. My port flavours patchset might help with this. > >May be i can use netdev_has_lower_dev() helper to make sure that the slave I don't see such function in the code. >device is not an upper dev. >Can you point to your port flavours patchset? Is it upstream? I sent rfc couple of weeks ago: [patch net-next RFC 00/12] devlink: introduce port flavours and common phys_port_name generation > >> >> >> > + return false; >> > + >> > + return true; >> > +} >> > + >> > +static int >> > +bypass_event(struct notifier_block *this, unsigned long event, void *ptr) >> > +{ >> > + struct net_device *event_dev = netdev_notifier_info_to_dev(ptr); >> > + >> > + if (!bypass_validate_event_dev(event_dev)) >> > + return NOTIFY_DONE; >> > + >> > + switch (event) { >> > + case NETDEV_REGISTER: >> > + return bypass_slave_register(event_dev); >> > + case NETDEV_UNREGISTER: >> > + return bypass_slave_unregister(event_dev); >> > + case NETDEV_UP: >> > + case NETDEV_DOWN: >> > + case NETDEV_CHANGE: >> > + return bypass_slave_link_change(event_dev); >> > + default: >> > + return NOTIFY_DONE; >> > + } >> > +} >> > + >> > +static struct notifier_block bypass_notifier = { >> > + .notifier_call = bypass_event, >> > +}; >> > + >> > +int bypass_open(struct net_device *dev) >> > +{ >> > + struct bypass_info *bi = netdev_priv(dev); >> > + struct net_device *active_netdev, *backup_netdev; >> > + int err; >> > + >> > + netif_carrier_off(dev); >> > + netif_tx_wake_all_queues(dev); >> > + >> > + active_netdev = rtnl_dereference(bi->active_netdev); >> > + if (active_netdev) { >> > + err = dev_open(active_netdev); >> > + if (err) >> > + goto err_active_open; >> > + } >> > + >> > + backup_netdev = rtnl_dereference(bi->backup_netdev); >> > + if (backup_netdev) { >> > + err = dev_open(backup_netdev); >> > + if (err) >> > + goto err_backup_open; >> > + } >> > + >> > + return 0; >> > + >> > +err_backup_open: >> > + dev_close(active_netdev); >> > +err_active_open: >> > + netif_tx_disable(dev); >> > + return err; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_open); >> > + >> > +int bypass_close(struct net_device *dev) >> > +{ >> > + struct bypass_info *vi = netdev_priv(dev); >> This should be probably "bi" > >Yes. > > >> >> >> > + struct net_device *slave_netdev; >> > + >> > + netif_tx_disable(dev); >> > + >> > + slave_netdev = rtnl_dereference(vi->active_netdev); >> > + if (slave_netdev) >> > + dev_close(slave_netdev); >> > + >> > + slave_netdev = rtnl_dereference(vi->backup_netdev); >> > + if (slave_netdev) >> > + dev_close(slave_netdev); >> > + >> > + return 0; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_close); >> > + >> > +static netdev_tx_t bypass_drop_xmit(struct sk_buff *skb, struct net_device *dev) >> > +{ >> > + atomic_long_inc(&dev->tx_dropped); >> > + dev_kfree_skb_any(skb); >> > + return NETDEV_TX_OK; >> > +} >> > + >> > +netdev_tx_t bypass_start_xmit(struct sk_buff *skb, struct net_device *dev) >> > +{ >> > + struct bypass_info *bi = netdev_priv(dev); >> If you rename the other variable to "bpmaster_dev", it would be nice to >> rename this to bpinfo or something more descriptive. "bi" is too short >> to know what that is right away. > >Will rename bypass_netdev to bypass_dev. bypass indicates that it is >an upper master dev. > > >> >> >> > + struct net_device *xmit_dev; >> Don't mix "dev" and "netdev" in one .c file. Just use "dev" for all. > >OK. > > >> >> >> >> > + >> > + /* Try xmit via active netdev followed by backup netdev */ >> > + xmit_dev = rcu_dereference_bh(bi->active_netdev); >> > + if (!xmit_dev || !bypass_xmit_ready(xmit_dev)) { >> > + xmit_dev = rcu_dereference_bh(bi->backup_netdev); >> > + if (!xmit_dev || !bypass_xmit_ready(xmit_dev)) >> > + return bypass_drop_xmit(skb, dev); >> > + } >> > + >> > + skb->dev = xmit_dev; >> > + skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping; >> > + >> > + return dev_queue_xmit(skb); >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_start_xmit); >> > + >> > +u16 bypass_select_queue(struct net_device *dev, struct sk_buff *skb, >> > + void *accel_priv, select_queue_fallback_t fallback) >> > +{ >> > + /* This helper function exists to help dev_pick_tx get the correct >> > + * destination queue. Using a helper function skips a call to >> > + * skb_tx_hash and will put the skbs in the queue we expect on their >> > + * way down to the bonding driver. >> > + */ >> > + u16 txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0; >> > + >> > + /* Save the original txq to restore before passing to the driver */ >> > + qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; >> > + >> > + if (unlikely(txq >= dev->real_num_tx_queues)) { >> > + do { >> > + txq -= dev->real_num_tx_queues; >> > + } while (txq >= dev->real_num_tx_queues); >> > + } >> > + >> > + return txq; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_select_queue); >> > + >> > +/* fold stats, assuming all rtnl_link_stats64 fields are u64, but >> > + * that some drivers can provide 32bit values only. >> > + */ >> > +static void bypass_fold_stats(struct rtnl_link_stats64 *_res, >> > + const struct rtnl_link_stats64 *_new, >> > + const struct rtnl_link_stats64 *_old) >> > +{ >> > + const u64 *new = (const u64 *)_new; >> > + const u64 *old = (const u64 *)_old; >> > + u64 *res = (u64 *)_res; >> > + int i; >> > + >> > + for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { >> > + u64 nv = new[i]; >> > + u64 ov = old[i]; >> > + s64 delta = nv - ov; >> > + >> > + /* detects if this particular field is 32bit only */ >> > + if (((nv | ov) >> 32) == 0) >> > + delta = (s64)(s32)((u32)nv - (u32)ov); >> > + >> > + /* filter anomalies, some drivers reset their stats >> > + * at down/up events. >> > + */ >> > + if (delta > 0) >> > + res[i] += delta; >> > + } >> > +} >> > + >> > +void bypass_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats) >> > +{ >> > + struct bypass_info *bi = netdev_priv(dev); >> You can WARN_ON and return in case the dev is not bypass master, just >> to catch buggy drivers. Same with other helpers. > >I can make this static and not export this helper as well as all >bypass_netdev ops. Ok. > >> >> >> > + const struct rtnl_link_stats64 *new; >> > + struct rtnl_link_stats64 temp; >> > + struct net_device *slave_netdev; >> > + >> > + spin_lock(&bi->stats_lock); >> > + memcpy(stats, &bi->bypass_stats, sizeof(*stats)); >> > + >> > + rcu_read_lock(); >> > + >> > + slave_netdev = rcu_dereference(bi->active_netdev); >> > + if (slave_netdev) { >> > + new = dev_get_stats(slave_netdev, &temp); >> > + bypass_fold_stats(stats, new, &bi->active_stats); >> > + memcpy(&bi->active_stats, new, sizeof(*new)); >> > + } >> > + >> > + slave_netdev = rcu_dereference(bi->backup_netdev); >> > + if (slave_netdev) { >> > + new = dev_get_stats(slave_netdev, &temp); >> > + bypass_fold_stats(stats, new, &bi->backup_stats); >> > + memcpy(&bi->backup_stats, new, sizeof(*new)); >> > + } >> > + >> > + rcu_read_unlock(); >> > + >> > + memcpy(&bi->bypass_stats, stats, sizeof(*stats)); >> > + spin_unlock(&bi->stats_lock); >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_get_stats); >> > + >> > +int bypass_change_mtu(struct net_device *dev, int new_mtu) >> > +{ >> > + struct bypass_info *bi = netdev_priv(dev); >> > + struct net_device *active_netdev, *backup_netdev; >> > + int ret = 0; >> Pointless initialization. >> >> >> > + >> > + active_netdev = rcu_dereference(bi->active_netdev); >> > + if (active_netdev) { >> > + ret = dev_set_mtu(active_netdev, new_mtu); >> > + if (ret) >> > + return ret; >> > + } >> > + >> > + backup_netdev = rcu_dereference(bi->backup_netdev); >> > + if (backup_netdev) { >> > + ret = dev_set_mtu(backup_netdev, new_mtu); >> > + if (ret) { >> > + dev_set_mtu(active_netdev, dev->mtu); >> > + return ret; >> > + } >> > + } >> > + >> > + dev->mtu = new_mtu; >> > + return 0; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_change_mtu); >> > + >> > +void bypass_set_rx_mode(struct net_device *dev) >> > +{ >> > + struct bypass_info *bi = netdev_priv(dev); >> > + struct net_device *slave_netdev; >> > + >> > + rcu_read_lock(); >> > + >> > + slave_netdev = rcu_dereference(bi->active_netdev); >> > + if (slave_netdev) { >> > + dev_uc_sync_multiple(slave_netdev, dev); >> > + dev_mc_sync_multiple(slave_netdev, dev); >> > + } >> > + >> > + slave_netdev = rcu_dereference(bi->backup_netdev); >> > + if (slave_netdev) { >> > + dev_uc_sync_multiple(slave_netdev, dev); >> > + dev_mc_sync_multiple(slave_netdev, dev); >> > + } >> > + >> > + rcu_read_unlock(); >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_set_rx_mode); >> > + >> > +static const struct net_device_ops bypass_netdev_ops = { >> > + .ndo_open = bypass_open, >> > + .ndo_stop = bypass_close, >> > + .ndo_start_xmit = bypass_start_xmit, >> > + .ndo_select_queue = bypass_select_queue, >> > + .ndo_get_stats64 = bypass_get_stats, >> > + .ndo_change_mtu = bypass_change_mtu, >> > + .ndo_set_rx_mode = bypass_set_rx_mode, >> > + .ndo_validate_addr = eth_validate_addr, >> > + .ndo_features_check = passthru_features_check, >> > +}; >> > + >> > +#define BYPASS_DRV_NAME "bypass" >> > +#define BYPASS_DRV_VERSION "0.1" >> > + >> > +static void bypass_ethtool_get_drvinfo(struct net_device *dev, >> > + struct ethtool_drvinfo *drvinfo) >> > +{ >> > + strlcpy(drvinfo->driver, BYPASS_DRV_NAME, sizeof(drvinfo->driver)); >> > + strlcpy(drvinfo->version, BYPASS_DRV_VERSION, sizeof(drvinfo->version)); >> > +} >> > + >> > +int bypass_ethtool_get_link_ksettings(struct net_device *dev, >> > + struct ethtool_link_ksettings *cmd) >> > +{ >> > + struct bypass_info *bi = netdev_priv(dev); >> > + struct net_device *slave_netdev; >> > + >> > + slave_netdev = rtnl_dereference(bi->active_netdev); >> > + if (!slave_netdev || !bypass_xmit_ready(slave_netdev)) { >> > + slave_netdev = rtnl_dereference(bi->backup_netdev); >> > + if (!slave_netdev || !bypass_xmit_ready(slave_netdev)) { >> > + cmd->base.duplex = DUPLEX_UNKNOWN; >> > + cmd->base.port = PORT_OTHER; >> > + cmd->base.speed = SPEED_UNKNOWN; >> > + >> > + return 0; >> > + } >> > + } >> > + >> > + return __ethtool_get_link_ksettings(slave_netdev, cmd); >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_ethtool_get_link_ksettings); >> > + >> > +static const struct ethtool_ops bypass_ethtool_ops = { >> > + .get_drvinfo = bypass_ethtool_get_drvinfo, >> > + .get_link = ethtool_op_get_link, >> > + .get_link_ksettings = bypass_ethtool_get_link_ksettings, >> > +}; >> > + >> > +static void bypass_register_existing_slave(struct net_device *bypass_netdev) >> > +{ >> > + struct net *net = dev_net(bypass_netdev); >> > + struct net_device *dev; >> > + >> > + rtnl_lock(); >> > + for_each_netdev(net, dev) { >> > + if (dev == bypass_netdev) >> > + continue; >> > + if (!bypass_validate_event_dev(dev)) >> > + continue; >> > + if (ether_addr_equal(bypass_netdev->perm_addr, dev->perm_addr)) >> > + bypass_slave_register(dev); >> > + } >> > + rtnl_unlock(); >> > +} >> > + >> > +int bypass_master_register(struct net_device *dev, struct bypass_ops *ops, >> > + struct bypass_master **pbypass_master) >> > +{ >> > + struct bypass_master *bypass_master; >> > + >> > + bypass_master = kzalloc(sizeof(*bypass_master), GFP_KERNEL); >> > + if (!bypass_master) >> > + return -ENOMEM; >> > + >> > + rcu_assign_pointer(bypass_master->ops, ops); >> > + dev_hold(dev); >> > + dev->priv_flags |= IFF_BYPASS; >> > + rcu_assign_pointer(bypass_master->bypass_netdev, dev); >> > + >> > + spin_lock(&bypass_lock); >> > + list_add_tail(&bypass_master->list, &bypass_master_list); >> > + spin_unlock(&bypass_lock); >> > + >> > + bypass_register_existing_slave(dev); >> > + >> > + *pbypass_master = bypass_master; >> > + return 0; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_master_register); >> > + >> > +void bypass_master_unregister(struct bypass_master *bypass_master) >> > +{ >> > + struct net_device *bypass_netdev; >> > + >> > + bypass_netdev = rcu_dereference(bypass_master->bypass_netdev); >> > + >> > + bypass_netdev->priv_flags &= ~IFF_BYPASS; >> > + dev_put(bypass_netdev); >> > + >> > + spin_lock(&bypass_lock); >> > + list_del(&bypass_master->list); >> > + spin_unlock(&bypass_lock); >> > + >> > + kfree(bypass_master); >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_master_unregister); >> > + >> > +int bypass_master_create(struct net_device *backup_netdev, >> > + struct bypass_master **pbypass_master) >> > +{ >> > + struct device *dev = backup_netdev->dev.parent; >> > + struct net_device *bypass_netdev; >> > + int err; >> > + >> > + /* Alloc at least 2 queues, for now we are going with 16 assuming >> > + * that most devices being bonded won't have too many queues. >> > + */ >> > + bypass_netdev = alloc_etherdev_mq(sizeof(struct bypass_info), 16); >> > + if (!bypass_netdev) { >> > + dev_err(dev, "Unable to allocate bypass_netdev!\n"); >> > + return -ENOMEM; >> > + } >> > + >> > + dev_net_set(bypass_netdev, dev_net(backup_netdev)); >> > + SET_NETDEV_DEV(bypass_netdev, dev); >> > + >> > + bypass_netdev->netdev_ops = &bypass_netdev_ops; >> > + bypass_netdev->ethtool_ops = &bypass_ethtool_ops; >> > + >> > + /* Initialize the device options */ >> > + bypass_netdev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; >> > + bypass_netdev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | >> > + IFF_TX_SKB_SHARING); >> > + >> > + /* don't acquire bypass netdev's netif_tx_lock when transmitting */ >> > + bypass_netdev->features |= NETIF_F_LLTX; >> > + >> > + /* Don't allow bypass devices to change network namespaces. */ >> > + bypass_netdev->features |= NETIF_F_NETNS_LOCAL; >> > + >> > + bypass_netdev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG | >> > + NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | >> > + NETIF_F_HIGHDMA | NETIF_F_LRO; >> > + >> > + bypass_netdev->hw_features |= NETIF_F_GSO_ENCAP_ALL; >> > + bypass_netdev->features |= bypass_netdev->hw_features; >> > + >> > + memcpy(bypass_netdev->dev_addr, backup_netdev->dev_addr, >> > + bypass_netdev->addr_len); >> > + >> > + bypass_netdev->min_mtu = backup_netdev->min_mtu; >> > + bypass_netdev->max_mtu = backup_netdev->max_mtu; >> > + >> > + err = register_netdev(bypass_netdev); >> > + if (err < 0) { >> > + dev_err(dev, "Unable to register bypass_netdev!\n"); >> > + goto err_register_netdev; >> > + } >> > + >> > + netif_carrier_off(bypass_netdev); >> > + >> > + err = bypass_master_register(bypass_netdev, NULL, pbypass_master); >> > + if (err < 0) >> just "if (err)" would do. > >OK > >> >> >> > + goto err_bypass; >> > + >> > + return 0; >> > + >> > +err_bypass: >> > + unregister_netdev(bypass_netdev); >> > +err_register_netdev: >> > + free_netdev(bypass_netdev); >> > + >> > + return err; >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_master_create); >> > + >> > +void bypass_master_destroy(struct bypass_master *bypass_master) >> > +{ >> > + struct net_device *bypass_netdev; >> > + struct net_device *slave_netdev; >> > + struct bypass_info *bi; >> > + >> > + if (!bypass_master) >> > + return; >> > + >> > + bypass_netdev = rcu_dereference(bypass_master->bypass_netdev); >> > + bi = netdev_priv(bypass_netdev); >> > + >> > + netif_device_detach(bypass_netdev); >> > + >> > + rtnl_lock(); >> > + >> > + slave_netdev = rtnl_dereference(bi->active_netdev); >> > + if (slave_netdev) >> > + bypass_slave_unregister(slave_netdev); >> > + >> > + slave_netdev = rtnl_dereference(bi->backup_netdev); >> > + if (slave_netdev) >> > + bypass_slave_unregister(slave_netdev); >> > + >> > + bypass_master_unregister(bypass_master); >> > + >> > + unregister_netdevice(bypass_netdev); >> > + >> > + rtnl_unlock(); >> > + >> > + free_netdev(bypass_netdev); >> > +} >> > +EXPORT_SYMBOL_GPL(bypass_master_destroy); >> > + >> > +static __init int >> > +bypass_init(void) >> > +{ >> > + register_netdevice_notifier(&bypass_notifier); >> > + >> > + return 0; >> > +} >> > +module_init(bypass_init); >> > + >> > +static __exit >> > +void bypass_exit(void) >> > +{ >> > + unregister_netdevice_notifier(&bypass_notifier); >> > +} >> > +module_exit(bypass_exit); >> > + >> > +MODULE_DESCRIPTION("Bypass infrastructure/interface for Paravirtual drivers"); >> > +MODULE_LICENSE("GPL v2"); >> > -- >> > 2.14.3 >> > >