Allow nfp apps to add extra ethtool stats.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Report basic and extended RED statistics back to TC.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

AFAICT struct gnet_stats_queue.qlen is not used in Qdiscs.
It may, however, be useful for offloads to report HW queue
length there.  Add that value to the result of qdisc_qlen_sum().
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Offload simple RED configurations.  For now support only DCTCP
like scenarios where min and max are the same.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Queue levels for simple ECN marking are stored in _abi_nfd_out_q_lvls_X
symbol, where X is the PCIe PF id.  Find out the location of that symbol
and add helpers for modifying it.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ABM NIC FW has a cut-through mode where the PCIe queuing
is bypassed, thus working like our standard NIC FWs.  Use this
mode by default and only enable queuing in switchdev mode where
users can configure it.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers are using a bare number inside phys_port_name
as VF id and OpenStack's regexps will pick it up.  We can't
use a bare number for your vNICs, prefix the names with 'n'.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After recent change we started returning 0 from
ndo_get_phys_port_name for VFs.  The name parameter for
ndo_get_phys_port_name is not initialized by the stack so
this can lead to a crash.  We should have kept returning
-EOPNOTSUPP in the first place.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5e-updates-2018-05-25

This series includes updates for mlx5e netdev driver.

1) Allowr flow based VF vport mirroring under sriov switchdev scheme,
added support for offloading the TC mirred mirror sub-action, from
Chris Mi.

=================
From: Or Gerlitz <ogerlitz@mellanox.com>

The user will typically set the actions order such that the mirror
port (mirror VF) sees packets as the original port (VF under
mirroring) sent them or as it will receive them. In the general case,
it means that packets are potentially sent to the mirror port before
or after some actions were applied on them.

To properly do that, we follow on the exact action order as set for
the flow and make sure this will also be the case when we program the
HW offload.

If all the actions should apply before forwarding to the mirror and dest port,
mirroring is just multicasting to the two vports. Otherwise, we split
the TC flow to two HW rules, where the 1st applies only the actions
needed up to the mirror (if there are such) and the 2nd the rest of
the actions plus the forwarding to the dest vport.
=================

2) Move to order-0 only allocations (using fragmented work queues) for all
work queues used by the driver, RX and TX descriptor rings
(RQs, SQs and Completion Queues (CQs)), from Tariq Toukan.

3) Avoid resetting netdevice statistics on netdevice
state changes, from Eran Ben Elisha.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

bpfilter_process_sockopt is a callback that gets called from
ip_setsockopt() and ip_getsockopt(). However, when CONFIG_INET is
disabled, it never gets called at all, and assigning a function to the
callback pointer results in a link failure:

net/bpfilter/bpfilter_kern.o: In function `__stop_umh':
bpfilter_kern.c:(.text.unlikely+0x3): undefined reference to `bpfilter_process_sockopt'
net/bpfilter/bpfilter_kern.o: In function `load_umh':
bpfilter_kern.c:(.init.text+0x73): undefined reference to `bpfilter_process_sockopt'

Since there is no caller in this configuration, I assume we can
simply make the assignment conditional.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Salil Mehta says:

====================
Misc. bug fixes & some minor additions to HNS3 driver

This patch-set provides some bug fixes figured out during testing
and review. It also provides some additions due to running of the
existing code on the new revision of the HNS3 hardware.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When register a RoCE client with hnae3vf device, it needs to judge
the device whether support RoCE vf function. Otherwise, it will
lead to calltrace when RoCE is not support vf function and remove
roce device.

The calltrace as follows:
[   93.156614] Unable to handle kernel NULL pointer dereference at virtual address 00000015
 <SNIP>
[   93.278784] Call trace:
[   93.278788]  hnae3_match_n_instantiate+0x24/0xd8 [hnae3]
[   93.278790]  hnae3_register_client+0xcc/0x150 [hnae3]
[   93.278801]  hns_roce_hw_v2_init+0x18/0x1000 [hns_roce_hw_v2]
[   93.278805]  do_one_initcall+0x58/0x160
[   93.278807]  do_init_module+0x64/0x1d8
[   93.278809]  load_module+0x135c/0x15c8
[   93.278811]  SyS_finit_module+0x100/0x118
[   93.278816]  __sys_trace_return+0x0/0x4
[   93.278827] Code: aa0003f5 12001c56 aa1e03e0 d503201f (b9402660)

Fixes: e2cb1dec ("net: hns3: Add HNS3 VF HCL(Hardware Compatibility Layer) Support")
Reported-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Reported-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Firmware now supports control of all leds. Existing HNS3 driver code
only supported led locate command over SFP Fibre ports. But now it
is also supported over copper port.
This patch removes existing not needed code for the led locate
command and updates the led control command between driver and
firmware.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the previous implementation of led control for fibre port , parses the
port speed configuration, checks the link status and traffic status per
second, and updates the blink status of link led, traffic led and speed
led.

Now, the firmware takes responsibility to handle the led, the dirver just
needs to deal with locate command.

So the codes for link led, traffic led and speed led are useless now. This
patch removes these redundant codes.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we down the port, some packets are left in TX/RX buffer. When we
up the port again, these old packets are forwarded to protocol stack
or are sent to internet. It will make some problem. TX/RX buffer should
be cleared when stopping port. This patch adds some function to ensure
the buffer is clean when port is started. We should clear the rings
when clients are being un-initialized as well.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Our code will ensure that hns3_clear_tx_ring is not used to cleared
RX rings and hns3_clear_rx_ring is not used to cleared TX rings. So
the ring type check is unnecessary.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RX Buffer Descriptor contains a VALID bit which indicates if the BD
is valid and has some data. This field is set by HNS3 hardware to
intimate the driver of some valid data present in the BD. nd should
be reset by the driver when BD is being used again. In the existing
code this bit was not being (re-)initialized properly and hence was
causing problems.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

HNAE3 module supports kernel nic driver, user nic driver and roce driver,
and there are 3 client types. Driver uses one bit(HNAE3_CLIENT_INITED_B)
to indicate the client initialization state, it will cause confusion
for 3 client types. This patch fixes it by use 3 bits to indicate the
initialization state.

Fixes: 38caee9d ("net: hns3: Add support of the HNAE3 framework")
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before the firmware updates the crq's tail pointer, if the PF driver
reads the data in the crq, the data may be incomplete at this time,
which will lead to the driver read an unknown message.

This patch fixes it by checking if crq is not empty before reading the
message.

Fixes: c1a81619 ("net: hns3: Add mailbox interrupt handling to PF driver")
Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

HCLGE_PROMISC_TX_EN_B and HCLGE_PROMISC_RX_EN_B are not supported
on pdev revision(0x20), new revision(0x21) supports them.
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hardware Revision(0x21) Buffer Descriptor adds a field STRP_TAGP
for vlan stripped processed indication. STRP_TAGP field has 2 bits,
bit 0 is stripped indication of the vlan tag in outer vlan tag
field, bit 1 is stripped indication of the vlan tag in inner vlan
tag field. For each bit, 0 indicates the tag is not stripped and
1 indicates the tag is stripped.

This patch adds STRP_TAGP support for revision(0x21), and does not
change the revision(0x20) action.
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

HNS3 Hardware can support up to two VLAN tags in transmit leg, the PPP
module can handle the packets based on the tag1 and tag2 config. This
patch adds support for tag2 config for vlan handling
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the latest revision of the hardware, if a packet is spanning
across multiple BDs then only VLD bit and current data size info
is valid in each BD, and rest of the information is only valid
in the last BD of the packet. In such case we should make sure
we are fetching RX packet size from the first descriptor and
information like VLAN should be fetched from last BD.
Signed-off-by: Peng Li <lipeng321@huawei.com>
Reviewed-by: Yisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The struct Qdisc has a lot of holes, especially after commit
a53851e2 ("net: sched: explicit locking in gso_cpu fallback"),
which as a side effect, moved the fields just after 'busylock'
on a new cacheline.

Since both 'padded' and 'refcnt' are not updated frequently, and
there is a hole before 'gso_skb', we can move such fields there,
saving a cacheline without any performance side effect.

Before this commit:

pahole -C Qdisc net/sche/sch_generic.o
	# ...
        /* size: 384, cachelines: 6, members: 25 */
        /* sum members: 236, holes: 3, sum holes: 92 */
        /* padding: 56 */

After this commit:
pahole -C Qdisc net/sche/sch_generic.o
	# ...
	/* size: 320, cachelines: 5, members: 25 */
	/* sum members: 236, holes: 2, sum holes: 28 */
	/* padding: 56 */
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

SIMCOM are reusing a single device ID for many (all of their?)
different modems, based on different chipsets and firmwares. Newer
Qualcomm chipset generations require setting DTR to wake the QMI
function.  The SIM7600E modem is using such a chipset, making it
fail to work with this driver despite the device ID match.

Fix by unconditionally enabling the SET_DTR quirk for all SIMCOM
modems using this specific device ID.  This is similar to what
we already have done for another case of device IDs recycled over
multiple chipset generations: 14cf4a77 ("drivers: net: usb:
qmi_wwan: add QMI_QUIRK_SET_DTR for Telit PID 0x1201")

Initial testing on an older SIM7100 modem shows no immediate side
effects.
Reported-by: Sebastian Sjoholm <sebastian.sjoholm@gmail.com>
Cc: Reinhard Speyerer <rspmn@arcor.de>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Christophe Roullier says:

====================
net: ethernet: stmmac: add support for stm32mp1

Patches to have Ethernet support on stm32mp1
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch describes syscon DT bindings.
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Manage dwmac-4.20a version from synopsys
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add description for Ethernet MPU families fields
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Glue codes to support stm32mp157c device and stay
compatible with stm32 mcu familly
Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to add a documentation for ptp_qoriq dt-bindings.
The description for ptp_qoriq dt-bindings was actually moved
from Documentation/devicetree/bindings/net/fsl-tsec-phy.txt,
since gianfar_ptp driver was moved to ptp_qoriq driver.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Global variable gfar_phc_index was used to get and store
phc index through gianfar_ptp driver. However gianfar_ptp
had been renamed as ptp_qoriq for QorIQ common PTP driver.
This gfar_phc_index doesn't work any more, and the phc index
is stored in drvdata now. This patch is to support getting
phc index through ptp_qoriq drvdata.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is to move some definitions in ptp_qoriq.c
to the header file.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

gianfar_ptp was the PTP clock driver for 1588 timer
module of Freescale QorIQ eTSEC (Enhanced Three-Speed
Ethernet Controllers) platforms. Actually QorIQ DPAA
(Data Path Acceleration Architecture) platforms is
also using the same 1588 timer module in hardware.

This patch is to rework gianfar_ptp as QorIQ common
PTP driver to support both DPAA and eTSEC. Moved
gianfar_ptp.c to drivers/ptp/, renamed it as
ptp_qoriq.c, and renamed many variables. There were
not any function changes.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixup the checksum for CHECKSUM_COMPLETE when pulling skbs on RX path.
Otherwise we get splats when tc mirred is used to redirect packets to ifb.

Before fix:

nic: hw csum failure
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add RTL8211B suspend / resume callbacks.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sridhar Samudrala says:

====================
Enable virtio_net to act as a standby for a passthru device

The main motivation for this patch is to enable cloud service providers
to provide an accelerated datapath to virtio-net enabled VMs in a
transparent manner with no/minimal guest userspace changes. This also
enables hypervisor controlled live migration to be supported with VMs that
have direct attached SR-IOV VF devices.

Patch 1 introduces a failover module that 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.

Patch 2 refactors netvsc to use the registration/notification framework
introduced by failover module.

Patch 3 introduces a net_failover driver that provides an automated
failover mechanism to paravirtual drivers 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 infrastructure.

Patch 4 introduces a new feature bit VIRTIO_NET_F_STANDBY to virtio-net
that can be used by hypervisor to indicate that virtio_net interface
should act as a standby for another device with the same MAC address.

Patch 5 extends virtio_net to use alternate datapath when available and
registered. When STANDBY feature is enabled, virtio_net driver uese the
net_failover API to create an additional 'failover' netdev that acts as
a master device and controls 2 slave devices.  The original virtio_net
netdev is registered as 'standby' netdev and a passthru/vf device with
the same MAC gets registered as 'primary' 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.

As this patch series is initially focusing on usecases where hypervisor
fully controls the VM networking and the guest is not expected to directly
configure any hardware settings, it doesn't expose all the ndo/ethtool ops
that are supported by virtio_net at this time. To support additional usecases,
it should be possible to enable additional ops later by caching the state
in failover netdev and replaying when the 'primary' netdev gets registered.

At the time of live migration, the hypervisor needs to unplug the VF device
from the guest on the source host and reset the MAC filter of the VF to
initiate failover of datapath to virtio before starting the migration. After
the migration is completed, the destination hypervisor sets the MAC filter
on the VF and plugs it back to the guest to switch over to VF datapath.

This patch is based on the discussion initiated by Jesse on this thread.
https://marc.info/?l=linux-virtualization&m=151189725224231&w=2

v12:
- Tested live migration with virtio-net/AVF(i40evf) configured in failover
  mode while running iperf in background. Tried static ip and dhcp
  configurations using 'network' scripts and Network Manager.
- Build tested netvsc module.
Updates:
- Extended generic failover module to do common functions like setting
  FAILOVER_SLAVE flag, registering rx-handler and linking to upper dev in
  the generic register/unregister handlers.
  This required adding 3 additional failover ops pre_register, pre_unregister
  and handle_frame.  netvsc and net_failover drivers are updated to support
  these ops.

v11:
- Split net_failover module into 2 components.
  1. 'failover' module that provides generic failover infrastructure
  to register a failover instance and listen for slave events.
  2. 'net_failover' driver that provides APIs to create/destroy upper
  netdev and supports 3-netdev model used by virtio-net.
- Added documentation

v10:
- fix net_failover_open() to update failover CARRIER correctly based on
  standby and primary states.
- fix net_failover_handle_frame() to handle frames received on standby
  when primary is present.
- replace netdev_upper_dev_link with netdev_master_upper_dev_link and
  handle lower dev state changes.
- fix net_failver_create() and net_failover_register() interfaces to
  use ERR_PTR and avoid arg **
- disable setting mac address when virtio-net in STANDBY mode
- document exported symbols
- added entry to MAINTAINERS file

v9:
Select NET_FAILOVER automatically when VIRTIO_NET/HYPERV_NET
are enabled. (stephen)

v8:
- Made the failover managment routines more robust by updating the feature
  bits/other fields in the failover netdev when slave netdevs are
  registered/unregistered. (mst)
- added support for handling vlans.
- Limited the changes in netvsc to only use the notifier/event/lookups
  from the failover module. The slave register/unregister/link-change
  handlers are only updated to use the getbymac routine to get the
  upper netdev. There is no change in their functionality. (stephen)
- renamed structs/function/file names to use net_failover prefix. (mst)

v7
- Rename 'bypass/active/backup' terminology with 'failover/primary/standy'
  (jiri, mst)
- re-arranged dev_open() and dev_set_mtu() calls in the register routines
  so that they don't get called for 2-netdev model. (stephen)
- fixed select_queue() routine to do queue selection based on VF if it is
  registered as primary. (stephen)
-  minor bugfixes

v6 RFC:
  Simplified virtio_net changes by moving all the ndo_ops of the
  bypass_netdev and create/destroy of bypass_netdev to 'bypass' module.
  avoided 2 phase registration(driver + instances).
  introduced IFF_BYPASS/IFF_BYPASS_SLAVE dev->priv_flags
  replaced mutex with a spinlock

v5 RFC:
  Based on Jiri's comments, moved the common functionality to a 'bypass'
  module so that the same notifier and event handlers to handle child
  register/unregister/link change events can be shared between virtio_net
  and netvsc.
  Improved error handling based on Siwei's comments.
v4:
- Based on the review comments on the v3 version of the RFC patch and
  Jakub's suggestion for the naming issue with 3 netdev solution,
  proposed 3 netdev in-driver bonding solution for virtio-net.
v3 RFC:
- Introduced 3 netdev model and pointed out a couple of issues with
  that model and proposed 2 netdev model to avoid these issues.
- Removed broadcast/multicast optimization and only use virtio as
  backup path when VF is unplugged.
v2 RFC:
- Changed VIRTIO_NET_F_MASTER to VIRTIO_NET_F_BACKUP (mst)
- made a small change to the virtio-net xmit path to only use VF datapath
  for unicasts. Broadcasts/multicasts use virtio datapath. This avoids
  east-west broadcasts to go over the PCI link.
- added suppport for the feature bit in qemu
====================
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch enables virtio_net to switch over to a VF datapath when STANDBY
feature is enabled and a VF netdev is present with the same MAC address.
It allows live migration of a VM with a direct attached VF without the need
to setup a bond/team between a VF and virtio net device in the guest.

It uses the API that is exported by the net_failover driver to create and
and destroy a master failover netdev. When STANDBY feature is enabled, an
additional netdev(failover netdev) is created that acts as a master device
and tracks the state of the 2 lower netdevs. The original virtio_net netdev
is marked as 'standby' netdev and a passthru device with the same MAC is
registered as 'primary' netdev.

The hypervisor needs to unplug the VF device from the guest on the source
host and reset the MAC filter of the VF to initiate failover of datapath
to virtio before starting the migration. After the migration is completed,
the destination hypervisor sets the MAC filter on the VF and plugs it back
to the guest to switch over to VF datapath.

This patch is based on the discussion initiated by Jesse on this thread.
https://marc.info/?l=linux-virtualization&m=151189725224231&w=2Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This feature bit can be used by hypervisor to indicate virtio_net device to
act as a standby for another device with the same MAC address.

VIRTIO_NET_F_STANDBY is defined as bit 62 as it is a device feature bit.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>