Linux kernel source tree
Go to file
Amit Cohen 30f5312d2c mlxsw: Avoid warnings when not offloaded FDB entry with IPv6 is removed
FDB entries that perform VXLAN encapsulation with an IPv6 underlay hold
a reference on a resource - the KVDL entry where the IPv6 underlay
destination IP is stored. For that, the driver maintains two hash tables:
1. Maps IPv6 to KVDL index
2. Maps {MAC, FID index} to IPv6 address

When a FDB entry is removed, the second table is used to find the relevant
IPv6 address and the first table is used to remove the reference count and
free the index if is not used anymore.

In order for a packet to be forwarded to a single remote VTEP, FDB
entries need to be configured at both the bridge and VXLAN devices' FDB
tables. Both entries are squashed into one {MAC, VLAN/VNI} -> IP entry
in the hardware. Therefore, in case one entry is removed, the entry will
be removed from the hardware and the remaining entry will be unmarked
with 'offload' flag since it is not offloaded anymore.

For example, the two FDB entries should be added to allow packets to be
forwarded via vx10:
$ bridge fdb add dev vx10 aa:bb:cc:dd:ee:ff self static dst 2001:db8:5::1
$ bridge fdb add dev vx10 aa:bb:cc:dd:ee:ff master static vlan 10

When one entry will be removed, the second one will not be offloaded
anymore. When the first entry (in VXLAN FDB) will be removed / will not be
offloaded anymore, the two mappings in IPv6 hash tables will be removed.

In case that the second entry is removed before the first one, unexpected
warnings[1][2] will be shown in user space as a result of removing the
first entry. The issue is that not offloaded entry is removed, the driver
tries to search the relevant entries in the hash tables, does not find them
and therefore warns.

Do not handle removing of not offloaded VXLAN FDB entries, as they were
already removed when the offload flag was removed.

[1]:
WARNING: CPU: 1 PID: 239 at drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c:914 mlxsw_sp_nve_ipv6_addr_map_del+0x6b/0x80 [mlxsw_spectrum]
...
Hardware name: Mellanox Technologies Ltd. Mellanox switch/Mellanox switch, BIOS 4.6.5 05/21/2015
Workqueue: mlxsw_core_ordered mlxsw_sp_switchdev_vxlan_fdb_event_work [mlxsw_spectrum]
RIP: 0010:mlxsw_sp_nve_ipv6_addr_map_del+0x6b/0x80 [mlxsw_spectrum]
...
Call Trace:
  <TASK>
  mlxsw_sp_port_fdb_tunnel_uc_op+0x6cf/0x7b0 [mlxsw_spectrum]
  mlxsw_sp_switchdev_vxlan_fdb_event_work+0x17c/0x420 [mlxsw_spectrum]
  ? finish_task_switch.isra.0+0x8c/0x290
  process_one_work+0x1cd/0x390
  worker_thread+0x48/0x3c0
  ? process_one_work+0x390/0x390
  kthread+0xe0/0x110
  ? kthread_complete_and_exit+0x20/0x20
  ret_from_fork+0x1f/0x30
  </TASK>

[2]:
WARNING: CPU: 0 PID: 239 at drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3035 mlxsw_sp_ipv6_addr_put+0x142/0x220 [mlxsw_spectrum]
...
Hardware name: Mellanox Technologies Ltd. Mellanox switch/Mellanox switch, BIOS 4.6.5 05/21/2015
Workqueue: mlxsw_core_ordered mlxsw_sp_switchdev_vxlan_fdb_event_work [mlxsw_spectrum]
RIP: 0010:mlxsw_sp_ipv6_addr_put+0x142/0x220 [mlxsw_spectrum]
...
Call Trace:
  <TASK>
  ? mlxsw_sp_port_fdb_tun_uc_op6_sfd_write+0x5c1/0x610 [mlxsw_spectrum]
  mlxsw_sp_port_fdb_tunnel_uc_op+0x6ec/0x7b0 [mlxsw_spectrum]
  mlxsw_sp_switchdev_vxlan_fdb_event_work+0x17c/0x420 [mlxsw_spectrum]
  ? finish_task_switch.isra.0+0x8c/0x290
  process_one_work+0x1cd/0x390
  worker_thread+0x48/0x3c0
  ? process_one_work+0x390/0x390
  kthread+0xe0/0x110
  ? kthread_complete_and_exit+0x20/0x20
  ret_from_fork+0x1f/0x30
  </TASK>

Fixes: 0860c76416 ("mlxsw: spectrum_nve: Keep track of IPv6 addresses used by FDB entries")
Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/c186de8cbd28e3eb661e06f31f7f2f2dff30020f.1668184350.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-14 18:38:27 -08:00
arch Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2022-11-11 18:27:40 -08:00
block block-6.1-2022-11-05 2022-11-05 09:02:28 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
Documentation Including fixes from netfilter, wifi, can and bpf. 2022-11-10 17:31:15 -08:00
drivers mlxsw: Avoid warnings when not offloaded FDB entry with IPv6 is removed 2022-11-14 18:38:27 -08:00
fs for-6.1-rc4-tag 2022-11-10 08:58:29 -08:00
include Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2022-11-11 18:27:40 -08:00
init init: Kconfig: fix spelling mistake "satify" -> "satisfy" 2022-10-20 21:27:22 -07:00
io_uring io_uring: unlock if __io_run_local_work locked inside 2022-10-27 09:52:12 -06:00
ipc ipc/msg.c: fix percpu_counter use after free 2022-10-28 13:37:22 -07:00
kernel Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2022-11-11 18:27:40 -08:00
lib Networking fixes for 6.1-rc4, including fixes from bluetooth and 2022-11-03 10:51:59 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2022-11-11 18:27:40 -08:00
net net: dsa: make dsa_master_ioctl() see through port_hwtstamp_get() shims 2022-11-14 11:30:49 +00:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
scripts kconfig: fix segmentation fault in menuconfig search 2022-11-02 17:32:05 +09:00
security lsm/stable-6.1 PR 20221031 2022-10-31 12:09:42 -07:00
sound ALSA: aoa: Fix I2S device accounting 2022-10-27 08:53:08 +02:00
tools Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2022-11-11 18:27:40 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt Merge tag 'kvmarm-fixes-6.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD 2022-11-06 03:30:49 -05:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap mailmap: update email for Qais Yousef 2022-10-20 21:27:21 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Vivien to CREDITS 2022-11-10 13:53:53 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Including fixes from netfilter, wifi, can and bpf. 2022-11-10 17:31:15 -08:00
Makefile Linux 6.1-rc4 2022-11-06 15:07:11 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.