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>

Use the registration/notification framework supported by the generic
failover infrastructure.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The failover module provides a generic interface for paravirtual drivers
to register a netdev and a set of ops with a failover instance. The ops
are used as event handlers that get called to handle netdev register/
unregister/link change/name change events on slave pci ethernet devices
with the same mac address as the failover netdev.

This enables paravirtual drivers to use a VF as an accelerated low latency
datapath. It also allows migration of VMs with direct attached VFs 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>

SCTP sockets originated in a VRF can improve their performance if CRC32c
computation is delegated to underlying devices: update device features,
setting NETIF_F_SCTP_CRC. Iterating the following command in the topology
proposed with [1],

 # ip vrf exec vrf-h2 netperf -H 192.0.2.1 -t SCTP_STREAM -- -m 10K

the measured throughput in Mbit/s improved from 2395 ± 1% to 2720 ± 1%.

[1] https://www.spinics.net/lists/netdev/msg486007.htmlSigned-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers, such as DWC EQOS on Tegra, need to perform operations that
can sleep under this lock (clk_set_rate() in tegra_eqos_fix_speed()) for
proper operation. Since there is no need for this lock to be a spinlock,
convert it to a mutex instead.

Fixes: e6ea2d16 ("net: stmmac: dwc-qos: Add Tegra186 support")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Tested-by: Bhadram Varka <vbhadram@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tx-timeout mostly happens due to some issue in the device. In such cases,
debug dump would be helpful for identifying the cause of the issue.
This patch adds support to spill debug data during the Tx timeout. Here
bnx2x_panic_dump() API is used instead of bnx2x_panic(), since we still
want to allow the Tx-timeout recovery a chance to succeed.

Changes from previous version:
-------------------------------
v2: Fixed a coding error.

Please consider applying this to "net-next".
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Lots of easy overlapping changes in the confict
resolutions here.
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: fix memory hotplug during boot
  kasan: free allocated shadow memory on MEM_CANCEL_ONLINE
  checkpatch: fix macro argument precedence test
  init/main.c: include <linux/mem_encrypt.h>
  kernel/sys.c: fix potential Spectre v1 issue
  mm/memory_hotplug: fix leftover use of struct page during hotplug
  proc: fix smaps and meminfo alignment
  mm: do not warn on offline nodes unless the specific node is explicitly requested
  mm, memory_hotplug: make has_unmovable_pages more robust
  mm/kasan: don't vfree() nonexistent vm_area
  MAINTAINERS: change hugetlbfs maintainer and update files
  ipc/shm: fix shmat() nil address after round-down when remapping
  Revert "ipc/shm: Fix shmat mmap nil-page protection"
  idr: fix invalid ptr dereference on item delete
  ocfs2: revert "ocfs2/o2hb: check len for bio_add_page() to avoid getting incorrect bio"
  mm: fix nr_rotate_swap leak in swapon() error case

Pull networking fixes from David Miller:
 "Let's begin the holiday weekend with some networking fixes:

   1) Whoops need to restrict cfg80211 wiphy names even more to 64
      bytes. From Eric Biggers.

   2) Fix flags being ignored when using kernel_connect() with SCTP,
      from Xin Long.

   3) Use after free in DCCP, from Alexey Kodanev.

   4) Need to check rhltable_init() return value in ipmr code, from Eric
      Dumazet.

   5) XDP handling fixes in virtio_net from Jason Wang.

   6) Missing RTA_TABLE in rtm_ipv4_policy[], from Roopa Prabhu.

   7) Need to use IRQ disabling spinlocks in mlx4_qp_lookup(), from Jack
      Morgenstein.

   8) Prevent out-of-bounds speculation using indexes in BPF, from
      Daniel Borkmann.

   9) Fix regression added by AF_PACKET link layer cure, from Willem de
      Bruijn.

  10) Correct ENIC dma mask, from Govindarajulu Varadarajan.

  11) Missing config options for PMTU tests, from Stefano Brivio"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (48 commits)
  ibmvnic: Fix partial success login retries
  selftests/net: Add missing config options for PMTU tests
  mlx4_core: allocate ICM memory in page size chunks
  enic: set DMA mask to 47 bit
  ppp: remove the PPPIOCDETACH ioctl
  ipv4: remove warning in ip_recv_error
  net : sched: cls_api: deal with egdev path only if needed
  vhost: synchronize IOTLB message with dev cleanup
  packet: fix reserve calculation
  net/mlx5: IPSec, Fix a race between concurrent sandbox QP commands
  net/mlx5e: When RXFCS is set, add FCS data into checksum calculation
  bpf: properly enforce index mask to prevent out-of-bounds speculation
  net/mlx4: Fix irq-unsafe spinlock usage
  net: phy: broadcom: Fix bcm_write_exp()
  net: phy: broadcom: Fix auxiliary control register reads
  net: ipv4: add missing RTA_TABLE to rtm_ipv4_policy
  net/mlx4: fix spelling mistake: "Inrerface" -> "Interface" and rephrase message
  ibmvnic: Only do H_EOI for mobility events
  tuntap: correctly set SOCKWQ_ASYNC_NOSPACE
  virtio-net: fix leaking page for gso packet during mergeable XDP
  ...

Using module_init() is wrong.  E.g.  ACPI adds and onlines memory before
our memory notifier gets registered.

This makes sure that ACPI memory detected during boot up will not result
in a kernel crash.

Easily reproducible with QEMU, just specify a DIMM when starting up.

Link: http://lkml.kernel.org/r/20180522100756.18478-3-david@redhat.com
Fixes: 786a8959 ("kasan: disable memory hotplug")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We have to free memory again when we cancel onlining, otherwise a later
onlining attempt will fail.

Link: http://lkml.kernel.org/r/20180522100756.18478-2-david@redhat.com
Fixes: fa69b598 ("mm/kasan: add support for memory hotplug")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch's macro argument precedence test is broken so fix it.

Link: http://lkml.kernel.org/r/5dd900e9197febc1995604bb33c23c136d8b33ce.camel@perches.comSigned-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In commit c7753208 ("x86, swiotlb: Add memory encryption support") a
call to function `mem_encrypt_init' was added.  Include prototype
defined in header <linux/mem_encrypt.h> to prevent a warning reported
during compilation with W=1:

  init/main.c:494:20: warning: no previous prototype for `mem_encrypt_init' [-Wmissing-prototypes]

Link: http://lkml.kernel.org/r/20180522195533.31415-1-malat@debian.orgSigned-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Gargi Sharma <gs051095@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

`resource' can be controlled by user-space, hence leading to a potential
exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

  kernel/sys.c:1474 __do_compat_sys_old_getrlimit() warn: potential spectre issue 'get_current()->signal->rlim' (local cap)
  kernel/sys.c:1455 __do_sys_old_getrlimit() warn: potential spectre issue 'get_current()->signal->rlim' (local cap)

Fix this by sanitizing *resource* before using it to index
current->signal->rlim

Notice that given that speculation windows are large, the policy is to
kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Link: http://lkml.kernel.org/r/20180515030038.GA11822@embeddedor.comSigned-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The case of a new numa node got missed in avoiding using the node info
from page_struct during hotplug.  In this path we have a call to
register_mem_sect_under_node (which allows us to specify it is hotplug
so don't change the node), via link_mem_sections which unfortunately
does not.

Fix is to pass check_nid through link_mem_sections as well and disable
it in the new numa node path.

Note the bug only 'sometimes' manifests depending on what happens to be
in the struct page structures - there are lots of them and it only needs
to match one of them.

The result of the bug is that (with a new memory only node) we never
successfully call register_mem_sect_under_node so don't get the memory
associated with the node in sysfs and meminfo for the node doesn't
report it.

It came up whilst testing some arm64 hotplug patches, but appears to be
universal.  Whilst I'm triggering it by removing then reinserting memory
to a node with no other elements (thus making the node disappear then
appear again), it appears it would happen on hotplugging memory where
there was none before and it doesn't seem to be related the arm64
patches.

These patches call __add_pages (where most of the issue was fixed by
Pavel's patch).  If there is a node at the time of the __add_pages call
then all is well as it calls register_mem_sect_under_node from there
with check_nid set to false.  Without a node that function returns
having not done the sysfs related stuff as there is no node to use.
This is expected but it is the resulting path that fails...

Exact path to the problem is as follows:

 mm/memory_hotplug.c: add_memory_resource()

   The node is not online so we enter the 'if (new_node)' twice, on the
   second such block there is a call to link_mem_sections which calls
   into

  drivers/node.c: link_mem_sections() which calls

  drivers/node.c: register_mem_sect_under_node() which calls
     get_nid_for_pfn and keeps trying until the output of that matches
     the expected node (passed all the way down from
     add_memory_resource)

It is effectively the same fix as the one referred to in the fixes tag
just in the code path for a new node where the comments point out we
have to rerun the link creation because it will have failed in
register_new_memory (as there was no node at the time).  (actually that
comment is wrong now as we don't have register_new_memory any more it
got renamed to hotplug_memory_register in Pavel's patch).

Link: http://lkml.kernel.org/r/20180504085311.1240-1-Jonathan.Cameron@huawei.com
Fixes: fc44f7f9 ("mm/memory_hotplug: don't read nid from struct page during hotplug")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The 4.17-rc /proc/meminfo and /proc/<pid>/smaps look ugly: single-digit
numbers (commonly 0) are misaligned.

Remove seq_put_decimal_ull_width()'s leftover optimization for single
digits: it's wrong now that num_to_str() takes care of the width.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1805241554210.1326@eggly.anvils
Fixes: d1be35cb ("proc: add seq_put_decimal_ull_width to speed up /proc/pid/smaps")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Oscar has noticed that we splat

   WARNING: CPU: 0 PID: 64 at ./include/linux/gfp.h:467 vmemmap_alloc_block+0x4e/0xc9
   [...]
   CPU: 0 PID: 64 Comm: kworker/u4:1 Tainted: G        W   E     4.17.0-rc5-next-20180517-1-default+ #66
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
   Workqueue: kacpi_hotplug acpi_hotplug_work_fn
   Call Trace:
    vmemmap_populate+0xf2/0x2ae
    sparse_mem_map_populate+0x28/0x35
    sparse_add_one_section+0x4c/0x187
    __add_pages+0xe7/0x1a0
    add_pages+0x16/0x70
    add_memory_resource+0xa3/0x1d0
    add_memory+0xe4/0x110
    acpi_memory_device_add+0x134/0x2e0
    acpi_bus_attach+0xd9/0x190
    acpi_bus_scan+0x37/0x70
    acpi_device_hotplug+0x389/0x4e0
    acpi_hotplug_work_fn+0x1a/0x30
    process_one_work+0x146/0x340
    worker_thread+0x47/0x3e0
    kthread+0xf5/0x130
    ret_from_fork+0x35/0x40

when adding memory to a node that is currently offline.

The VM_WARN_ON is just too loud without a good reason.  In this
particular case we are doing

	alloc_pages_node(node, GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN, order)

so we do not insist on allocating from the given node (it is more a
hint) so we can fall back to any other populated node and moreover we
explicitly ask to not warn for the allocation failure.

Soften the warning only to cases when somebody asks for the given node
explicitly by __GFP_THISNODE.

Link: http://lkml.kernel.org/r/20180523125555.30039-3-mhocko@kernel.orgSigned-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Oscar Salvador <osalvador@techadventures.net>
Tested-by: Oscar Salvador <osalvador@techadventures.net>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Oscar has reported:
: Due to an unfortunate setting with movablecore, memblocks containing bootmem
: memory (pages marked by get_page_bootmem()) ended up marked in zone_movable.
: So while trying to remove that memory, the system failed in do_migrate_range
: and __offline_pages never returned.
:
: This can be reproduced by running
: qemu-system-x86_64 -m 6G,slots=8,maxmem=8G -numa node,mem=4096M -numa node,mem=2048M
: and movablecore=4G kernel command line
:
: linux kernel: BIOS-provided physical RAM map:
: linux kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
: linux kernel: BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable
: linux kernel: BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000100000000-0x00000001bfffffff] usable
: linux kernel: NX (Execute Disable) protection: active
: linux kernel: SMBIOS 2.8 present.
: linux kernel: DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org
: linux kernel: Hypervisor detected: KVM
: linux kernel: e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
: linux kernel: e820: remove [mem 0x000a0000-0x000fffff] usable
: linux kernel: last_pfn = 0x1c0000 max_arch_pfn = 0x400000000
:
: linux kernel: SRAT: PXM 0 -> APIC 0x00 -> Node 0
: linux kernel: SRAT: PXM 1 -> APIC 0x01 -> Node 1
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x13fffffff]
: linux kernel: ACPI: SRAT: Node 1 PXM 1 [mem 0x140000000-0x1bfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x1c0000000-0x43fffffff] hotplug
: linux kernel: NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x0
: linux kernel: NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x13fffffff] -> [mem 0
: linux kernel: NODE_DATA(0) allocated [mem 0x13ffd6000-0x13fffffff]
: linux kernel: NODE_DATA(1) allocated [mem 0x1bffd3000-0x1bfffcfff]
:
: zoneinfo shows that the zone movable is placed into both numa nodes:
: Node 0, zone  Movable
:   pages free     160140
:         min      1823
:         low      2278
:         high     2733
:         spanned  262144
:         present  262144
:         managed  245670
: Node 1, zone  Movable
:   pages free     448427
:         min      3827
:         low      4783
:         high     5739
:         spanned  524288
:         present  524288
:         managed  515766

Note how only Node 0 has a hutplugable memory region which would rule it
out from the early memblock allocations (most likely memmap).  Node1
will surely contain memmaps on the same node and those would prevent
offlining to succeed.  So this is arguably a configuration issue.
Although one could argue that we should be more clever and rule early
allocations from the zone movable.  This would be correct but probably
not worth the effort considering what a hack movablecore is.

Anyway, We could do better for those cases though.  We rely on
start_isolate_page_range resp.  has_unmovable_pages to do their job.
The first one isolates the whole range to be offlined so that we do not
allocate from it anymore and the later makes sure we are not stumbling
over non-migrateable pages.

has_unmovable_pages is overly optimistic, however.  It doesn't check all
the pages if we are withing zone_movable because we rely that those
pages will be always migrateable.  As it turns out we are still not
perfect there.  While bootmem pages in zonemovable sound like a clear
bug which should be fixed let's remove the optimization for now and warn
if we encounter unmovable pages in zone_movable in the meantime.  That
should help for now at least.

Btw.  this wasn't a real problem until commit 72b39cfc ("mm,
memory_hotplug: do not fail offlining too early") because we used to
have a small number of retries and then failed.  This turned out to be
too fragile though.

Link: http://lkml.kernel.org/r/20180523125555.30039-2-mhocko@kernel.orgSigned-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Oscar Salvador <osalvador@techadventures.net>
Tested-by: Oscar Salvador <osalvador@techadventures.net>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

KASAN uses different routines to map shadow for hot added memory and
memory obtained in boot process.  Attempt to offline memory onlined by
normal boot process leads to this:

    Trying to vfree() nonexistent vm area (000000005d3b34b9)
    WARNING: CPU: 2 PID: 13215 at mm/vmalloc.c:1525 __vunmap+0x147/0x190

    Call Trace:
     kasan_mem_notifier+0xad/0xb9
     notifier_call_chain+0x166/0x260
     __blocking_notifier_call_chain+0xdb/0x140
     __offline_pages+0x96a/0xb10
     memory_subsys_offline+0x76/0xc0
     device_offline+0xb8/0x120
     store_mem_state+0xfa/0x120
     kernfs_fop_write+0x1d5/0x320
     __vfs_write+0xd4/0x530
     vfs_write+0x105/0x340
     SyS_write+0xb0/0x140

Obviously we can't call vfree() to free memory that wasn't allocated via
vmalloc().  Use find_vm_area() to see if we can call vfree().

Unfortunately it's a bit tricky to properly unmap and free shadow
allocated during boot, so we'll have to keep it.  If memory will come
online again that shadow will be reused.

Matthew asked: how can you call vfree() on something that isn't a
vmalloc address?

  vfree() is able to free any address returned by
  __vmalloc_node_range().  And __vmalloc_node_range() gives you any
  address you ask.  It doesn't have to be an address in [VMALLOC_START,
  VMALLOC_END] range.

  That's also how the module_alloc()/module_memfree() works on
  architectures that have designated area for modules.

[aryabinin@virtuozzo.com: improve comments]
  Link: http://lkml.kernel.org/r/dabee6ab-3a7a-51cd-3b86-5468718e0390@virtuozzo.com
[akpm@linux-foundation.org: fix typos, reflow comment]
Link: http://lkml.kernel.org/r/20180201163349.8700-1-aryabinin@virtuozzo.com
Fixes: fa69b598 ("mm/kasan: add support for memory hotplug")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Paul Menzel <pmenzel+linux-kasan-dev@molgen.mpg.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The current hugetlbfs maintainer has not been active for more than a few
years.  I have been been active in this area for more than two years and
plan to remain active in the foreseeable future.

Also, update the hugetlbfs entry to include linux-mm mail list and
additional hugetlbfs related files.  hugetlb.c and hugetlb.h are not
100% hugetlbfs, but a majority of their content is hugetlbfs related.

Link: http://lkml.kernel.org/r/20180518225236.19079-1-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

shmat()'s SHM_REMAP option forbids passing a nil address for; this is in
fact the very first thing we check for.  Andrea reported that for
SHM_RND|SHM_REMAP cases we can end up bypassing the initial addr check,
but we need to check again if the address was rounded down to nil.  As
of this patch, such cases will return -EINVAL.

Link: http://lkml.kernel.org/r/20180503204934.kk63josdu6u53fbd@linux-n805Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "ipc/shm: shmat() fixes around nil-page".

These patches fix two issues reported[1] a while back by Joe and Andrea
around how shmat(2) behaves with nil-page.

The first reverts a commit that it was incorrectly thought that mapping
nil-page (address=0) was a no no with MAP_FIXED.  This is not the case,
with the exception of SHM_REMAP; which is address in the second patch.

I chose two patches because it is easier to backport and it explicitly
reverts bogus behaviour.  Both patches ought to be in -stable and ltp
testcases need updated (the added testcase around the cve can be
modified to just test for SHM_RND|SHM_REMAP).

[1] lkml.kernel.org/r/20180430172152.nfa564pvgpk3ut7p@linux-n805

This patch (of 2):

Commit 95e91b83 ("ipc/shm: Fix shmat mmap nil-page protection")
worked on the idea that we should not be mapping as root addr=0 and
MAP_FIXED.  However, it was reported that this scenario is in fact
valid, thus making the patch both bogus and breaks userspace as well.

For example X11's libint10.so relies on shmat(1, SHM_RND) for lowmem
initialization[1].

[1] https://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/os-support/linux/int10/linux.c#n347
Link: http://lkml.kernel.org/r/20180503203243.15045-2-dave@stgolabs.net
Fixes: 95e91b83 ("ipc/shm: Fix shmat mmap nil-page protection")
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If the radix tree underlying the IDR happens to be full and we attempt
to remove an id which is larger than any id in the IDR, we will call
__radix_tree_delete() with an uninitialised 'slot' pointer, at which
point anything could happen.  This was easiest to hit with a single
entry at id 0 and attempting to remove a non-0 id, but it could have
happened with 64 entries and attempting to remove an id >= 64.

Roman said:

  The syzcaller test boils down to opening /dev/kvm, creating an
  eventfd, and calling a couple of KVM ioctls. None of this requires
  superuser. And the result is dereferencing an uninitialized pointer
  which is likely a crash. The specific path caught by syzbot is via
  KVM_HYPERV_EVENTD ioctl which is new in 4.17. But I guess there are
  other user-triggerable paths, so cc:stable is probably justified.

Matthew added:

  We have around 250 calls to idr_remove() in the kernel today. Many of
  them pass an ID which is embedded in the object they're removing, so
  they're safe. Picking a few likely candidates:

  drivers/firewire/core-cdev.c looks unsafe; the ID comes from an ioctl.
  drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c is similar
  drivers/atm/nicstar.c could be taken down by a handcrafted packet

Link: http://lkml.kernel.org/r/20180518175025.GD6361@bombadil.infradead.org
Fixes: 0a835c4f ("Reimplement IDR and IDA using the radix tree")
Reported-by: <syzbot+35666cba7f0a337e2e79@syzkaller.appspotmail.com>
Debugged-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit ba16ddfb ("ocfs2/o2hb: check len for
bio_add_page() to avoid getting incorrect bio").

In my testing, this patch introduces a problem that mkfs can't have
slots more than 16 with 4k block size.

And the original logic is safe actually with the situation it mentions
so revert this commit.

Attach test log:
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 0, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 1, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 2, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 3, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 4, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 5, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 6, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 7, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 8, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 9, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 10, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 11, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 12, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 13, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 14, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 15, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 16, vec_len = 4096, vec_start = 0
  (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:471 ERROR: Adding page[16] to bio failed, page ffffea0002d7ed40, len 0, vec_len 4096, vec_start 0,bi_sector 8192
  (mkfs.ocfs2,27479,2):o2hb_read_slots:500 ERROR: status = -5
  (mkfs.ocfs2,27479,2):o2hb_populate_slot_data:1911 ERROR: status = -5
  (mkfs.ocfs2,27479,2):o2hb_region_dev_write:2012 ERROR: status = -5

Link: http://lkml.kernel.org/r/SIXPR06MB0461721F398A5A92FC68C39ED5920@SIXPR06MB0461.apcprd06.prod.outlook.comSigned-off-by: Changwei Ge <ge.changwei@h3c.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If swapon() fails after incrementing nr_rotate_swap, we don't decrement
it and thus effectively leak it.  Make sure we decrement it if we
incremented it.

Link: http://lkml.kernel.org/r/b6fe6b879f17fa68eee6cbd876f459f6e5e33495.1526491581.git.osandov@fb.com
Fixes: 81a0298b ("mm, swap: don't use VMA based swap readahead if HDD is used as swap")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove redundant debug prints from phy_read/write since we can trace those
calls through trace events. Enhance dynamic debug prints to print arguments
which helps figuring how what is going on at the driver level with higher level
configuration interfaces.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Yi-Hung Wei says:

====================
openvswitch: Support conntrack zone limit

Currently, nf_conntrack_max is used to limit the maximum number of
conntrack entries in the conntrack table for every network namespace.
For the VMs and containers that reside in the same namespace,
they share the same conntrack table, and the total # of conntrack entries
for all the VMs and containers are limited by nf_conntrack_max.  In this
case, if one of the VM/container abuses the usage the conntrack entries,
it blocks the others from committing valid conntrack entries into the
conntrack table.  Even if we can possibly put the VM in different network
namespace, the current nf_conntrack_max configuration is kind of rigid
that we cannot limit different VM/container to have different # conntrack
entries.

To address the aforementioned issue, this patch proposes to have a
fine-grained mechanism that could further limit the # of conntrack entries
per-zone.  For example, we can designate different zone to different VM,
and set conntrack limit to each zone.  By providing this isolation, a
mis-behaved VM only consumes the conntrack entries in its own zone, and
it will not influence other well-behaved VMs.  Moreover, the users can
set various conntrack limit to different zone based on their preference.

The proposed implementation utilizes Netfilter's nf_conncount backend
to count the number of connections in a particular zone.  If the number of
connection is above a configured limitation, OVS will return ENOMEM to the
userspace.  If userspace does not configure the zone limit, the limit
defaults to zero that is no limitation, which is backward compatible to
the behavior without this patch.

The first patch defines the conntrack limit netlink definition, and the
second patch provides the implementation.

v4->v5:
  - Addresses comments from Parvin that include log error msg in
    ovs_ct_limit_init(), handle deletion for default limit, and
    add a common helper for get zone limit.
  - Rebases to master.

v3->v4:
  - Addresses comments from Parvin that include simplify netlink API,
    and remove unncessary RCU lockings.
  - Rebases to master.

v2->v3:
  - Addresses comments from Parvin that include using static keys to check
    if ovs_ct_limit features is used, only check ct_limit when a ct entry
    is unconfirmed, and reports rate limited warning messages when the ct
    limit is reached.
  - Rebases to master.

v1->v2:
  - Fixes commit log typos suggested by Greg.
  - Fixes memory free issue that Julia found.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, nf_conntrack_max is used to limit the maximum number of
conntrack entries in the conntrack table for every network namespace.
For the VMs and containers that reside in the same namespace,
they share the same conntrack table, and the total # of conntrack entries
for all the VMs and containers are limited by nf_conntrack_max.  In this
case, if one of the VM/container abuses the usage the conntrack entries,
it blocks the others from committing valid conntrack entries into the
conntrack table.  Even if we can possibly put the VM in different network
namespace, the current nf_conntrack_max configuration is kind of rigid
that we cannot limit different VM/container to have different # conntrack
entries.

To address the aforementioned issue, this patch proposes to have a
fine-grained mechanism that could further limit the # of conntrack entries
per-zone.  For example, we can designate different zone to different VM,
and set conntrack limit to each zone.  By providing this isolation, a
mis-behaved VM only consumes the conntrack entries in its own zone, and
it will not influence other well-behaved VMs.  Moreover, the users can
set various conntrack limit to different zone based on their preference.

The proposed implementation utilizes Netfilter's nf_conncount backend
to count the number of connections in a particular zone.  If the number of
connection is above a configured limitation, ovs will return ENOMEM to the
userspace.  If userspace does not configure the zone limit, the limit
defaults to zero that is no limitation, which is backward compatible to
the behavior without this patch.

The following high leve APIs are provided to the userspace:
  - OVS_CT_LIMIT_CMD_SET:
    * set default connection limit for all zones
    * set the connection limit for a particular zone
  - OVS_CT_LIMIT_CMD_DEL:
    * remove the connection limit for a particular zone
  - OVS_CT_LIMIT_CMD_GET:
    * get the default connection limit for all zones
    * get the connection limit for a particular zone
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Define netlink messages and attributes to support user kernel
communication that uses the conntrack limit feature.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>