Commit cfc80d9a authored by Sridhar Samudrala's avatar Sridhar Samudrala Committed by David S. Miller
Browse files

net: Introduce net_failover driver



The net_failover driver provides an automated failover mechanism via APIs
to create and destroy a failover master netdev and manages a primary and
standby slave netdevs that get registered via the generic failover
infrastructure.

The failover netdev acts a master device and controls 2 slave devices. The
original paravirtual interface gets registered as 'standby' slave netdev and
a passthru/vf device with the same MAC gets registered as 'primary' slave
netdev. Both 'standby' and 'failover' netdevs are associated with the same
'pci' device. The user accesses the network interface via 'failover' netdev.
The 'failover' netdev chooses 'primary' netdev as default for transmits when
it is available with link up and running.

This can be used by paravirtual drivers to enable an alternate low latency
datapath. It also enables hypervisor controlled live migration of a VM with
direct attached VF by failing over to the paravirtual datapath when the VF
is unplugged.
Signed-off-by: default avatarSridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ff78076
.. SPDX-License-Identifier: GPL-2.0
============
NET_FAILOVER
============
Overview
========
The net_failover driver provides an automated failover mechanism via APIs
to create and destroy a failover master netdev and mananges a primary and
standby slave netdevs that get registered via the generic failover
infrastructrure.
The failover netdev acts a master device and controls 2 slave devices. The
original paravirtual interface is registered as 'standby' slave netdev and
a passthru/vf device with the same MAC gets registered as 'primary' slave
netdev. Both 'standby' and 'failover' netdevs are associated with the same
'pci' device. The user accesses the network interface via 'failover' netdev.
The 'failover' netdev chooses 'primary' netdev as default for transmits when
it is available with link up and running.
This can be used by paravirtual drivers to enable an alternate low latency
datapath. It also enables hypervisor controlled live migration of a VM with
direct attached VF by failing over to the paravirtual datapath when the VF
is unplugged.
......@@ -9654,6 +9654,14 @@ S: Maintained
F: Documentation/hwmon/nct6775
F: drivers/hwmon/nct6775.c
NET_FAILOVER MODULE
M: Sridhar Samudrala <sridhar.samudrala@intel.com>
L: netdev@vger.kernel.org
S: Supported
F: driver/net/net_failover.c
F: include/net/net_failover.h
F: Documentation/networking/net_failover.rst
NETEFFECT IWARP RNIC DRIVER (IW_NES)
M: Faisal Latif <faisal.latif@intel.com>
L: linux-rdma@vger.kernel.org
......
......@@ -510,4 +510,16 @@ config NETDEVSIM
To compile this driver as a module, choose M here: the module
will be called netdevsim.
config NET_FAILOVER
tristate "Failover driver"
select FAILOVER
help
This provides an automated failover mechanism via APIs to create
and destroy a failover master netdev and manages a primary and
standby slave netdevs that get registered via the generic failover
infrastructure. This can be used by paravirtual drivers to enable
an alternate low latency datapath. It alsoenables live migration of
a VM with direct attached VF by failing over to the paravirtual
datapath when the VF is unplugged.
endif # NETDEVICES
......@@ -78,3 +78,4 @@ obj-$(CONFIG_FUJITSU_ES) += fjes/
thunderbolt-net-y += thunderbolt.o
obj-$(CONFIG_THUNDERBOLT_NET) += thunderbolt-net.o
obj-$(CONFIG_NETDEVSIM) += netdevsim/
obj-$(CONFIG_NET_FAILOVER) += net_failover.o
This diff is collapsed.
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2018, Intel Corporation. */
#ifndef _NET_FAILOVER_H
#define _NET_FAILOVER_H
#include <net/failover.h>
/* failover state */
struct net_failover_info {
/* primary netdev with same MAC */
struct net_device __rcu *primary_dev;
/* standby netdev */
struct net_device __rcu *standby_dev;
/* primary netdev stats */
struct rtnl_link_stats64 primary_stats;
/* standby netdev stats */
struct rtnl_link_stats64 standby_stats;
/* aggregated stats */
struct rtnl_link_stats64 failover_stats;
/* spinlock while updating stats */
spinlock_t stats_lock;
};
struct failover *net_failover_create(struct net_device *standby_dev);
void net_failover_destroy(struct failover *failover);
#define FAILOVER_VLAN_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | \
NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
NETIF_F_HIGHDMA | NETIF_F_LRO)
#define FAILOVER_ENC_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | \
NETIF_F_RXCSUM | NETIF_F_ALL_TSO)
#endif /* _NET_FAILOVER_H */
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