Mat Martineau says:

====================
mptcp: Userspace path manager prerequisites

This series builds upon the path manager mode selection changes merged
in 4994d4fa ("Merge branch 'mptcp-path-manager-mode-selection'") to
further modify the path manager code in preparation for adding the new
netlink commands to announce/remove advertised addresses and
create/destroy subflows of an MPTCP connection. The third and final
patch series for the userspace path manager will implement those
commands as discussed in
https://lore.kernel.org/netdev/23ff3b49-2563-1874-fa35-3af55d3088e7@linux.intel.com/#r

Patches 1, 5, and 7 remove some internal constraints on path managers
(in general) without changing in-kernel PM behavior.

Patch 2 adds a self test to validate MPTCP address advertisement ack
behavior.

Patches 3, 4, and 6 add new attributes to existing MPTCP netlink events
and track internal state for populating those attributes.
====================

Link: https://lore.kernel.org/r/20220502205237.129297-1-mathew.j.martineau@linux.intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This change allows userspace PM implementations to reissue ADD_ADDR
announcements (if necessary) based on their chosen policy.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This change records the 'server_side' attribute of MPTCP_EVENT_CREATED
and MPTCP_EVENT_ESTABLISHED events to inform their recipient about the
Client/Server role of the running MPTCP application.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/246Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This change updates internal logic to permit subflows to be
established from either the client or server ends of MPTCP
connections. This symmetry and added flexibility may be
harnessed by PM implementations running on either end in
creating new subflows.

The essence of this change lies in not relying on the
"server_side" flag (which continues to be available if needed).
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Per RFC 8684, if no port is specified in an ADD_ADDR message, MPTCP
SHOULD attempt to connect to the specified address on the same port
as the port that is already in use by the subflow on which the
ADD_ADDR signal was sent.

To facilitate that, this change reflects the specific remote port in
use by that subflow in MPTCP_EVENT_ANNOUNCED events.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This change reads the addr id assigned to the remote endpoint
of a subflow from the MP_JOIN SYN/ACK message and stores it
in the related subflow context. The remote id was not being
captured prior to this change, and will now provide a consistent
view of remote endpoints and their ids as seen through netlink
events.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Check userspace PM behavior to ensure ADD_ADDR echoes are only sent when
there is an active userspace daemon. If the daemon is restarting or
hasn't loaded yet, the missing echo will cause the peer to retransmit
the ADD_ADDR - and hopefully the daemon will be ready to receive it at
that later time.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Current limits on the # of addresses/subflows must apply only to
in-kernel PM managed sockets. Thus this change removes such
restrictions on connections overseen by non-kernel (e.g. userspace)
PMs. This change also ensures that the kernel does not record stats
inside struct mptcp_pm_data updated along kernel code paths when exercised
via non-kernel PMs.

Additionally, address announcements are acknolwedged and subflow
requests are honored only when it's deemed that	a userspace path
manager	is active at the time.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Saeed Mahameed says:

====================
mlx5-updates-2022-05-02

1) Trivial Misc updates to mlx5 driver

2) From Mark Bloch: Flow steering, general steering refactoring/cleaning

An issue with flow steering deletion flow (when creating a rule without
dests) turned out to be easy to fix but during the fix some issue
with the flow steering creation/deletion flows have been found.

The following patch series tries to fix long standing issues with flow
steering code and hopefully preventing silly future bugs.

  A) Fix an issue where a proper dest type wasn't assigned.
  B) Refactor and fix dests enums values, refactor deletion
     function and do proper bookkeeping of dests.
  C) Change mlx5_del_flow_rules() to delete rules when there are no
     no more rules attached associated with an FTE.
  D) Don't call hard coded deletion function but use the node's
     defined one.
  E) Add a WARN_ON() to catch future bugs when an FTE with dests
     is deleted.

* tag 'mlx5-updates-2022-05-02' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5: fs, an FTE should have no dests when deleted
  net/mlx5: fs, call the deletion function of the node
  net/mlx5: fs, delete the FTE when there are no rules attached to it
  net/mlx5: fs, do proper bookkeeping for forward destinations
  net/mlx5: fs, add unused destination type
  net/mlx5: fs, jump to exit point and don't fall through
  net/mlx5: fs, refactor software deletion rule
  net/mlx5: fs, split software and IFC flow destination definitions
  net/mlx5e: TC, set proper dest type
  net/mlx5e: Remove unused mlx5e_dcbnl_build_rep_netdev function
  net/mlx5e: Drop error CQE handling from the XSK RX handler
  net/mlx5: Print initializing field in case of timeout
  net/mlx5: Delete redundant default assignment of runtime devlink params
  net/mlx5: Remove useless kfree
  net/mlx5: use kvfree() for kvzalloc() in mlx5_ct_fs_smfs_matcher_create
====================

Link: https://lore.kernel.org/r/Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Ido Schimmel says:

====================
mlxsw: Remove size limitations on egress descriptor buffer

Petr says:

Spectrum machines have two resources related to keeping packets in an
internal buffer: bytes (allocated in cell-sized units) for packet payload,
and descriptors, for keeping headers. Currently, mlxsw only configures the
bytes part of the resource management.

Spectrum switches permit a full parallel configuration for the descriptor
resources, including port-pool and port-TC-pool quotas. By default, these
are all configured to use pool 14, with an infinite quota. The ingress pool
14 is then infinite in size.

However, egress pool 14 has finite size by default. The size is chip
dependent, but always much lower than what the chip actually permits. As a
result, we can easily construct workloads that exhaust the configured
descriptor limit.

Going forward, mlxsw will have to fix this issue properly by maintaining
descriptor buffer sizes, TC bindings, and quotas that match the
architecture recommendation. Short term, fix the issue by configuring the
egress descriptor pool to be infinite in size as well. This will maintain
the same configuration philosophy, but will unlock all chip resources to be
usable.

In this patchset, patch #1 first adds the "desc" field into the pool
configuration register. Then in patch #2, the new field is used to
configure both ingress and egress pool 14 as infinite.

In patches #3 and #4, add a selftest that verifies that a large burst
can be absorbed by the shared buffer. This test specifically exercises a
scenario where descriptor buffer is the limiting factor and the test
fails without the above patches.
====================

Link: https://lore.kernel.org/r/20220502084926.365268-1-idosch@nvidia.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Add a test that sends 1Gbps of traffic through the switch, into which it
then injects a burst of traffic and tests that there are no drops.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Add two helpers, start_traffic_pktsize() and start_tcp_traffic_pktsize(),
that allow explicit overriding of packet size. Change start_traffic() and
start_tcp_traffic() to dispatch through these helpers with the default
packet size.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Spectrum machines have two resources related to keeping packets in an
internal buffer: bytes (allocated in cell-sized units) for packet payload,
and descriptors, for keeping metadata. Currently, mlxsw only configures the
bytes part of the resource management.

Spectrum switches permit a full parallel configuration for the descriptor
resources, including port-pool and port-TC-pool quotas. By default, these
are all configured to use pool 14, with an infinite quota. The ingress pool
14 is then infinite in size.

However, egress pool 14 has finite size by default. The size is chip
dependent, but always much lower than what the chip actually permits. As a
result, we can easily construct workloads that exhaust the configured
descriptor limit.

Fix the issue by configuring the egress descriptor pool to be infinite in
size as well. This will maintain the configuration philosophy of the
default configuration, but will unlock all chip resources to be usable.

In the code, include both the configuration of ingress and ingress, mostly
for clarity.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

SBPR, or Shared Buffer Pools Register, configures and retrieves the shared
buffer pools and configuration. The desc field determines whether the
configuration relates to the byte pool or the descriptor pool.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Tonghao Zhang says:

====================
use standard sysctl macro

From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

This patchset introduce sysctl macro or replace var
with macro.
====================

Link: https://lore.kernel.org/r/20220501035524.91205-1-xiangxia.m.yue@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Cc: Akhmat Karakotov <hmukos@yandex-team.ru>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This patch introdues the SYSCTL_THREE.

KUnit:
[00:10:14] ================ sysctl_test (10 subtests) =================
[00:10:14] [PASSED] sysctl_test_api_dointvec_null_tbl_data
[00:10:14] [PASSED] sysctl_test_api_dointvec_table_maxlen_unset
[00:10:14] [PASSED] sysctl_test_api_dointvec_table_len_is_zero
[00:10:14] [PASSED] sysctl_test_api_dointvec_table_read_but_position_set
[00:10:14] [PASSED] sysctl_test_dointvec_read_happy_single_positive
[00:10:14] [PASSED] sysctl_test_dointvec_read_happy_single_negative
[00:10:14] [PASSED] sysctl_test_dointvec_write_happy_single_positive
[00:10:14] [PASSED] sysctl_test_dointvec_write_happy_single_negative
[00:10:14] [PASSED] sysctl_test_api_dointvec_write_single_less_int_min
[00:10:14] [PASSED] sysctl_test_api_dointvec_write_single_greater_int_max
[00:10:14] =================== [PASSED] sysctl_test ===================

./run_kselftest.sh -c sysctl
...
ok 1 selftests: sysctl: sysctl.sh

Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Cc: Akhmat Karakotov <hmukos@yandex-team.ru>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This patch replace two, four and long_one to SYSCTL_XXX.

Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Cc: Akhmat Karakotov <hmukos@yandex-team.ru>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

When deleting an FTE it should have no dests, which means
fte->dests_size should be 0. Add a WARN_ON() to catch bugs
where the proper tracking wasn't done.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Don't call del_hw_fte() directly, instead use the hardware deletion
function set. This is just a small cleanup and doesn't change anything
as for an FTE the deletion function is already set to del_hw_fte().
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

When an FTE has no children is means all the rules where removed
and the FTE can be deleted regardless of the dests_size value.
While dests_size should be 0 when there are no children
be extra careful not to leak memory or get firmware syndrome
if the proper bookkeeping of dests_size wasn't done.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Keep track after destinations that are forward destinations.
When a forward destinations is removed from an FTE check if
the actions bits need to be updated.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

When the caller doesn't pass a destination fs_core will create a unused
rule just so a context can be returned. This unused rule
is zeroed out and its type is 0 which can be mixed up with
MLX5_FLOW_DESTINATION_TYPE_VPORT.

Create a dedicated type to differentiate between the two
named MLX5_FLOW_DESTINATION_TYPE_NONE.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

For code clarity and to prevent future bugs make sure to jump
to the exit point once done handling that specific type.
This aligns the code with the rest logic in the function.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

When deleting a rule make sure that for every type dests_size is
decreased only once and no other logic is executed.

Without this dests_size might be decreased twice when dests_size == 1
so the if for that type won't be entered and if action has
MLX5_FLOW_CONTEXT_ACTION_FWD_DEST set dests_size will be decreased again.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Separate flow destinations between software and IFC.
Flow destination type passed by callers was used as the input in
firmware commands and over the years software only types were added
which resulted in mixing between the two.

Create an IFC enum that contains only the flow destinations defined
when talking to the firmware.

Now that there is a proper software only enum for flow destinations
the hardcoded values can be removed as the values are no longer used
in firmware commands.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Dest type isn't set, this works only because
MLX5_FLOW_DESTINATION_TYPE_VPORT is zero. Set the proper type.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Commit
7a9fb35e ("net/mlx5e: Do not reload ethernet ports when changing eswitch mode")
removed the usage of mlx5e_dcbnl_build_rep_netdev() from the driver,
delete the function.
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

This commit removes the redundant check and removes the unused cqe parameter
of skb_from_cqe handlers.
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Print the initializing field in case of FW couldn't initialize before
timeout. This will help to better understand the root cause in some
cases.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Runtime devlink params always read their values from the get() callbacks.
Also, it is an error to set driverinit_value for params which don't
support driverinit cmode. Delete such assignments.

In addition, move the set of default matching mode inside eswitch code.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

After alloc fail, we do not need to kfree.
Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

The memory of spec is allocated with kvzalloc(), the corresponding
release function should not be kfree(), use kvfree() instead.

Generated by: scripts/coccinelle/api/kfree_mismatch.cocci
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Stefano Garzarella says:

====================
vsock/virtio: add support for device suspend/resume

Vilas reported that virtio-vsock no longer worked properly after
suspend/resume (echo mem >/sys/power/state).
It was impossible to connect to the host and vice versa.

Indeed, the support has never been implemented.

This series implement .freeze and .restore callbacks of struct virtio_driver
to support device suspend/resume.

The first patch factors our the code to initialize and delete VQs.
The second patch uses that code to support device suspend/resume.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
====================

Link: https://lore.kernel.org/r/20220428132241.152679-1-sgarzare@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Implement .freeze and .restore callbacks of struct virtio_driver
to support device suspend/resume.

During suspension all connected sockets are reset and VQs deleted.
During resume the VQs are re-initialized.

Reported by: Vilas R K <vilas.r.k@intel.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add virtio_vsock_vqs_init() and virtio_vsock_vqs_del() with the code
that was in virtio_vsock_probe() and virtio_vsock_remove to initialize
and delete VQs.

These new functions will be used in the next commit to support device
suspend/resume
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The Felix VSC9959 switch in NXP LS1028A supports the tc-gate action
which enforced time-based access control per stream. A stream as seen by
this switch is identified by {MAC DA, VID}.

We use the standard forwarding selftest topology with 2 host interfaces
and 2 switch interfaces. The host ports must require timestamping non-IP
packets and supporting tc-etf offload, for isochron to work. The
isochron program monitors network sync status (ptp4l, phc2sys) and
deterministically transmits packets to the switch such that the tc-gate
action either (a) always accepts them based on its schedule, or
(b) always drops them.

I tried to keep as much of the logic that isn't specific to the NXP
LS1028A in a new tsn_lib.sh, for future reuse. This covers
synchronization using ptp4l and phc2sys, and isochron.

The cycle-time chosen for this selftest isn't particularly impressive
(and the focus is the functionality of the switch), but I didn't really
know what to do better, considering that it will mostly be run during
debugging sessions, various kernel bloatware would be enabled, like
lockdep, KASAN, etc, and we certainly can't run any races with those on.

I tried to look through the kselftest framework for other real time
applications and didn't really find any, so I'm not sure how better to
prepare the environment in case we want to go for a lower cycle time.
At the moment, the only thing the selftest is ensuring is that dynamic
frequency scaling is disabled on the CPU that isochron runs on. It would
probably be useful to have a blacklist of kernel config options (checked
through zcat /proc/config.gz) and some cyclictest scripts to run
beforehand, but I saw none of those.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20220501112953.3298973-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

ARPHRD_TUNNEL interface can't process rs packets
and will generate TX errors

ex:
ip tunnel add ethn mode ipip local 192.168.1.1 remote 192.168.1.2
ifconfig ethn x.x.x.x

ethn: flags=209<UP,POINTOPOINT,RUNNING,NOARP>  mtu 1480
	inet x.x.x.x  netmask 255.255.255.255  destination x.x.x.x
	inet6 fe80::5efe:ac1e:3cdb  prefixlen 64  scopeid 0x20<link>
	tunnel   txqueuelen 1000  (IPIP Tunnel)
	RX packets 0  bytes 0 (0.0 B)
	RX errors 0  dropped 0  overruns 0  frame 0
	TX packets 0  bytes 0 (0.0 B)
	TX errors 3  dropped 0 overruns 0  carrier 0  collisions 0
Signed-off-by: jianghaoran <jianghaoran@kylinos.cn>
Link: https://lore.kernel.org/r/20220429053802.246681-1-jianghaoran@kylinos.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

It's expensive to make a copy of 40B struct iov_iter to the point it
was taking 0.2-0.5% of all cycles in my tests. iov_iter_revert() should
be fine as it's a simple case without nested reverts/truncates.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a7e1690c00c5dfe700c30eb9a8a81ec59f6545dd.1650884401.git.asml.silence@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Current memory failure code in the debugfs returns -ENOSPC. This is
normally used for indicating that there is no space left on the
device and is not applicable for memory allocation failures.
Replace this with -ENOMEM.
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Link: https://lore.kernel.org/r/20220430194656.44357-1-dossche.niels@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>