Add a helper function to compute the tos/dsfield. In this way, we can
factor out some duplicate code. Also, the helper will be called from
more places in the next commit.
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 451ef36b ("ip_tunnels: Add new flow flags field to
ip_tunnel_key") added a new field to struct ip_tunnel_key to control
route lookups. Currently the flag is used by vxlan and geneve tunnels;
use it also in udp_tunnel_dst_lookup() so that it affects all tunnel
types relying on this function.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

We want to make the function more generic so that it can be used by
other UDP tunnel implementations such as geneve and vxlan. To do that,
add the following arguments:

 - source and destination UDP port;
 - ifindex of the output interface, needed by vxlan;
 - the tos, because in some cases it is not taken from struct
   ip_tunnel_info (for example, when it's inherited from the inner
   packet);
 - the dst cache, because not all tunnel types (e.g. vxlan) want to
   use the one from struct ip_tunnel_info.

With these parameters, the function no longer needs the full struct
ip_tunnel_info as argument and we can pass only the relevant part of
it (struct ip_tunnel_key).
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function is now UDP-specific, the protocol is always IPPROTO_UDP.
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

At the moment ip_route_output_tunnel() is used only by bareudp.
Ideally, other UDP tunnel implementations should use it, but to do so
the function needs to accept new parameters that are specific for UDP
tunnels, such as the ports.

Prepare for these changes by renaming the function to
udp_tunnel_dst_lookup() and move it to file
net/ipv4/udp_tunnel_core.c.
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

These variables are never referenced in the code, just remove them
Signed-off-by: zhujun2 <zhujun2@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Simplify logic for rspq_check_napi.
Drop redundant and wrong napi_is_scheduled call as it's not race free
and directly use the output of napi_schedule to understand if a napi is
pending or not.

rspq_check_napi main logic is to check if is_new_response is true and
check if a napi is not scheduled. The result of this function is then
used to detect if we are missing some interrupt and act on top of
this... With this knowing, we can rework and simplify the logic and make
it less problematic with testing an internal bit for napi.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xabier Marquiegui says:

====================
ptp: Support for multiple filtered timestamp event queue readers

On systems with multiple timestamp event channels, there can be scenarios
where multiple userspace readers want to access the timestamping data for
various purposes.

One such example is wanting to use a pps out for time synchronization, and
wanting to timestamp external events with the synchronized time base
simultaneously.

Timestmp event consumers on the other hand, are often interested in a
subset of the available timestamp channels. linuxptp ts2phc, for example,
is not happy if more than one timestamping channel is active on the device
it is reading from.

Linked lists are introduced to support multiple timestamp event queue
consumers, and timestamp event channel filters through IOCTLs, as well as
a debugfs interface to do some simple verifications.

Xabier Marquiegui (6):
  posix-clock: introduce posix_clock_context concept
  ptp: Replace timestamp event queue with linked list
  ptp: support multiple timestamp event readers
  ptp: support event queue reader channel masks
  ptp: add debugfs interface to see applied channel masks
  ptp: add testptp mask test

 drivers/ptp/ptp_chardev.c                   | 129 ++++++++++++++++----
 drivers/ptp/ptp_clock.c                     |  45 ++++++-
 drivers/ptp/ptp_private.h                   |  28 +++--
 drivers/ptp/ptp_sysfs.c                     |  13 +-
 include/linux/posix-clock.h                 |  35 ++++--
 include/uapi/linux/ptp_clock.h              |   2 +
 kernel/time/posix-clock.c                   |  36 ++++--
 tools/testing/selftests/ptp/ptpchmaskfmt.sh |  14 +++
 tools/testing/selftests/ptp/testptp.c       |  19 ++-
 9 files changed, 261 insertions(+), 60 deletions(-)
 create mode 100644 tools/testing/selftests/ptp/ptpchmaskfmt.sh

---
v6:
  - correct commit message
  - correct coding style
v5: https://lore.kernel.org/netdev/cover.1696804243.git.reibax@gmail.com/
  - fix spelling on commit message
  - fix memory leak on ptp_open
v4: https://lore.kernel.org/netdev/cover.1696511486.git.reibax@gmail.com/
  - split modifications in different patches for improved organization
  - rename posix_clock_user to posix_clock_context
  - remove unnecessary flush_users clock operation
  - remove unnecessary tests
  - simpler queue clean procedure
  - fix/clean comment lines
  - simplified release procedures
  - filter modifications exclusive to currently open instance for
    simplicity and security
  - expand mask to 2048 channels
  - make more secure and simple: mask is only applied to the testptp
    instance. Use debugfs to verify effects.
v3: https://lore.kernel.org/netdev/20230928133544.3642650-1-reibax@gmail.com/
  - add this patchset overview file
  - fix use of safe and non safe linked lists for loops
  - introduce new posix_clock private_data and ida object ids for better
    dicrimination of timestamp consumers
  - safer resource release procedures
  - filter application by object id, aided by process id
  - friendlier testptp implementation of event queue channel filters
v2: https://lore.kernel.org/netdev/20230912220217.2008895-1-reibax@gmail.com/
  - fix ptp_poll() return value
  - Style changes to comform to checkpatch strict suggestions
  - more coherent ptp_read error exit routines
  - fix testptp compilation error: unknown type name 'pid_t'
  - rename mask variable for easier code traceability
  - more detailed commit message with two examples
v1: https://lore.kernel.org/netdev/20230906104754.1324412-2-reibax@gmail.com/
====================
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add option to test timestamp event queue mask manipulation in testptp.

Option -F allows the user to specify a single channel that will be
applied on the mask filter via IOCTL.

The test program will maintain the file open until user input is
received.

This allows checking the effect of the IOCTL in debugfs.

eg:

Console 1:
```
Channel 12 exclusively enabled. Check on debugfs.
Press any key to continue
```

Console 2:
```
0x00000000 0x00000001 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000
```
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use debugfs to be able to view channel mask applied to every timestamp
event queue.

Every time the device is opened, a new entry is created in
`$DEBUGFS_MOUNTPOINT/ptpN/$INSTANCE_ADDRESS/mask`.

The mask value can be viewed grouped in 32bit decimal values using cat,
or converted to hexadecimal with the included `ptpchmaskfmt.sh` script.
32 bit values are listed from least significant to most significant.
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On systems with multiple timestamp event channels, some readers might
want to receive only a subset of those channels.

Add the necessary modifications to support timestamp event channel
filtering, including two IOCTL operations:

- Clear all channels
- Enable one channel

The mask modification operations will be applied exclusively on the
event queue assigned to the file descriptor used on the IOCTL operation,
so the typical procedure to have a reader receiving only a subset of the
enabled channels would be:

- Open device file
- ioctl: clear all channels
- ioctl: enable one channel
- start reading

Calling the enable one channel ioctl more than once will result in
multiple enabled channels.
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use linked lists to create one event queue per open file. This enables
simultaneous readers for timestamp event queues.
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce linked lists to access the timestamp event queue.
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the necessary structure to support custom private-data per
posix-clock user.

The previous implementation of posix-clock assumed all file open
instances need access to the same clock structure on private_data.

The need for individual data structures per file open instance has been
identified when developing support for multiple timestamp event queue
users for ptp_clock.
Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Arkadiusz Kubalewski says:

====================
dpll: add phase-offset and phase-adjust

Improve monitoring and control over dpll devices.
Allow user to receive measurement of phase difference between signals
on pin and dpll (phase-offset).
Allow user to receive and control adjustable value of pin's signal
phase (phase-adjust).

v4->v5:
- rebase series on top of net-next/main, fix conflict - remove redundant
  attribute type definition in subset definition

v3->v4:
- do not increase do version of uAPI header as it is not needed (v3 did
  not have this change)
- fix spelling around commit messages, argument descriptions and docs
- add missing extack errors on failure set callbacks for pin phase
  adjust and frequency
- remove ice check if value is already set, now redundant as checked in
  the dpll subsystem

v2->v3:
- do not increase do version of uAPI header as it is not needed

v1->v2:
- improve handling for error case of requesting the phase adjust set
- align handling for error case of frequency set request with the
approach introduced for phase adjust
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Align the approach of pin frequency set behavior with the approach
introduced with pin phase adjust set.
Fail the request if any of devices did not registered the callback ops.
If callback op on any pin's registered device fails, return error and
rollback the value to previous one.
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement new callback ops related to measurement and adjustment of
signal phase for pin-dpll in ice driver.
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add callback ops for pin-dpll phase measurement.
Add callback for pin signal phase adjustment.
Add min and max phase adjustment values to pin proprties.
Invoke callbacks in dpll_netlink.c when filling the pin details to
provide user with phase related attribute values.
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add attributes for providing the user with:
- measurement of signals phase offset between pin and dpll
- ability to adjust the phase of pin signal
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add documentation on:
- measurement of phase of signal between pin and dpll
- adjustment of pin signal phase
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ivan Vecera says:

====================
i40e: Add basic devlink support

The series adds initial support for devlink to i40e driver.

Patch-set overview:
Patch 1: Adds initial devlink support (devlink and port registration)
Patch 2: Refactors and split i40e_nvm_version_str()
Patch 3: Adds support for 'devlink dev info'
Patch 4: Refactors existing helper function to read PBA ID
Patch 5: Adds 'board.id' to 'devlink dev info' using PBA ID
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Expose stored PBA ID string as unique board identifier via
devlink's .info_get command.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Function i40e_read_pba_string() is currently unused but will be used
by subsequent patch to provide board ID via devlink device info.

The function reads PBA block from NVM so it cannot be called during
adapter reset and as we would like to provide PBA ID via devlink
info it is better to read the PBA ID during i40e_probe() and cache
it in i40e_hw structure to avoid a waiting for potential adapter
reset in devlink info callback.

So...
- Remove pba_num and pba_num_size arguments from the function,
  allocate resource managed buffer to store PBA ID string and
  save resulting pointer to i40e_hw->pba_id field
- Make the function void as the PBA ID can be missing and in this
  case (or in case of NVM reading failure) the i40e_hw->pba_id
  will be NULL
- Rename the function to i40e_get_pba_string() to align with other
  functions like i40e_get_oem_version() i40e_get_port_mac_addr()...
- Call this function on init during i40e_probe()
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Provide devlink .info_get callback to allow the driver to report
detailed version information. The following info is reported:

 "serial_number" -> The PCI DSN of the adapter
 "fw.mgmt" -> The version of the firmware
 "fw.mgmt.api" -> The API version of interface exposed over the AdminQ
 "fw.psid" -> The version of the NVM image
 "fw.bundle_id" -> Unique identifier for the combined flash image
 "fw.undi" -> The combo image version

With this, 'devlink dev info' provides at least the same amount
information as is reported by ETHTOOL_GDRVINFO:

$ ethtool -i enp2s0f0 | egrep '(driver|firmware)'
driver: i40e
firmware-version: 9.30 0x8000e5f3 1.3429.0

$ devlink dev info pci/0000:02:00.0
pci/0000:02:00.0:
  driver i40e
  serial_number c0-de-b7-ff-ff-ef-ec-3c
  versions:
      running:
        fw.mgmt 9.130.73618
        fw.mgmt.api 1.15
        fw.psid 9.30
        fw.bundle_id 0x8000e5f3
        fw.undi 1.3429.0
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function formats NVM version string according adapter's
EETrackID value. If this value OEM specific (0xffffffff) then
the reported version is with format:
"<gen>.<snap>.<release>"
and in other case
"<nvm_maj>.<nvm_min> <eetrackid> <cvid_maj>.<cvid_bld>.<cvid_min>"

These versions are reported in the subsequent patch in this series
that implements devlink .info_get but separately.

So split the function into separate ones, refactor it to use them
and remove ugly static string buffer.
Additionally convert NVM/OEM version mask macros to use GENMASK and
use FIELD_GET/FIELD_PREP for them in i40e_nvm_version_str() and
i40e_get_oem_version(). This makes code more readable and allows
us to remove related shift macros.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add an initial support for devlink interface to i40e driver.

Similarly to ice driver the implementation doe not enable devlink
to manage device-wide configuration and devlink instance is created
for each physical function of PCIe device.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we are trying to timestamp a TX packet, there may be
occasions when the TX timestamp register is still not
updated with the latest timestamp even if the timestamp
packet descriptor is marked as complete.
This usually happens in cases where the system is under
stress or flow control is affecting the transmit side.

We will solve this problem by saving the snapshot of the
timestamp register when we are posting the TX descriptor.
At this time, the register contains previously timestamped
packet's value and valid timestamp of the current packet must
be different than this.
Upon completion of the current descriptor, we will check if
the timestamp register is updated or not before timestamping
the skb. If not updated, we will schedule the ptp worker to
fetch the updated time later and timestamp the skb.
Also now we restrict number of outstanding PTP TX packet
requests to 1.
Reported-by: Simon White <Simon.White@viavisolutions.com>
Link: https://lore.kernel.org/netdev/CACKFLikGdN9XPtWk-fdrzxdcD=+bv-GHBvfVfSpJzHY7hrW39g@mail.gmail.com/Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a section to netdev maintainer doc encouraging reviewers
to chime in on the mailing list.

The questions about "when is it okay to share feedback"
keep coming up (most recently at netconf) and the answer
is "pretty much always".

Extend the section of 7.AdvancedTopics.rst which deals
with reviews a little bit to add stuff we had been recommending
locally.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Edward Cree says:

====================
sfc: support conntrack NAT offload

The EF100 MAE supports performing NAT (and NPT) on packets which match in
 the conntrack table.  This series adds that capability to the driver.
====================
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an IP address and/or L4 port for NAPT is available from a CT match,
 the MAE will perform the edits; if no CT lookup has been performed for
 this packet, the CT lookup did not return a match, or the matched CT
 entry did not include NAPT, the action will have no effect.
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The MAE can edit either address, L4 port, or both, for either source
 or destination.  These can't be mixed; i.e. it can edit source addr
 and source port, but not (say) source addr and dest port.
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Arseniy Krasnov says:

====================
vsock/virtio/vhost: MSG_ZEROCOPY preparations

this patchset is first of three parts of another big patchset for
MSG_ZEROCOPY flag support:
https://lore.kernel.org/netdev/20230701063947.3422088-1-AVKrasnov@sberdevices.ru/

During review of this series, Stefano Garzarella <sgarzare@redhat.com>
suggested to split it for three parts to simplify review and merging:

1) virtio and vhost updates (for fragged skbs) <--- this patchset
2) AF_VSOCK updates (allows to enable MSG_ZEROCOPY mode and read
   tx completions) and update for Documentation/.
3) Updates for tests and utils.

This series enables handling of fragged skbs in virtio and vhost parts.
Newly logic won't be triggered, because SO_ZEROCOPY options is still
impossible to enable at this moment (next bunch of patches from big
set above will enable it).

I've included changelog to some patches anyway, because there were some
comments during review of last big patchset from the link above.

Head for this patchset is:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=f2fa1c812c91e99d0317d1fc7d845e1e05f39716

Link to v1:
https://lore.kernel.org/netdev/20230717210051.856388-1-AVKrasnov@sberdevices.ru/
Link to v2:
https://lore.kernel.org/netdev/20230718180237.3248179-1-AVKrasnov@sberdevices.ru/
Link to v3:
https://lore.kernel.org/netdev/20230720214245.457298-1-AVKrasnov@sberdevices.ru/
Link to v4:
https://lore.kernel.org/netdev/20230727222627.1895355-1-AVKrasnov@sberdevices.ru/
Link to v5:
https://lore.kernel.org/netdev/20230730085905.3420811-1-AVKrasnov@sberdevices.ru/
Link to v6:
https://lore.kernel.org/netdev/20230814212720.3679058-1-AVKrasnov@sberdevices.ru/
Link to v7:
https://lore.kernel.org/netdev/20230827085436.941183-1-avkrasnov@salutedevices.com/
Link to v8:
https://lore.kernel.org/netdev/20230911202234.1932024-1-avkrasnov@salutedevices.com/

Changelog:
 v3 -> v4:
 * Patchset rebased and tested on new HEAD of net-next (see hash above).
 v4 -> v5:
 * See per-patch changelog after ---.
 v5 -> v6:
 * Patchset rebased and tested on new HEAD of net-next (see hash above).
 * See per-patch changelog after ---.
 v6 -> v7:
 * Patchset rebased and tested on new HEAD of net-next (see hash above).
 * See per-patch changelog after ---.
 v7 -> v8:
 * Patchset rebased and tested on new HEAD of net-next (see hash above).
 * See per-patch changelog after ---.
 v8 -> v9:
 * Patchset rebased and tested on new HEAD of net-next (see hash above).
 * See per-patch changelog after ---.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds set of tests which use io_uring for rx/tx. This test suite is
implemented as separated util like 'vsock_test' and has the same set of
input arguments as 'vsock_test'. These tests only cover cases of data
transmission (no connect/bind/accept etc).
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To use this option pass '--zerocopy' parameter:

./vsock_perf --zerocopy --sender <cid> ...

With this option MSG_ZEROCOPY flag will be passed to the 'send()' call.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds three tests for MSG_ZEROCOPY feature:
1) SOCK_STREAM tx with different buffers.
2) SOCK_SEQPACKET tx with different buffers.
3) SOCK_STREAM test to read empty error queue of the socket.

Patch also works as preparation for the next patches for tools in this
patchset: vsock_perf and vsock_uring_test:
1) Adds several new functions to util.c - they will be also used by
   vsock_uring_test.
2) Adds two new functions for MSG_ZEROCOPY handling to a new source
   file - such source will be shared between vsock_test, vsock_perf and
   vsock_uring_test, thus avoiding code copy-pasting.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds description of MSG_ZEROCOPY flag support for AF_VSOCK type of
socket.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For AF_VSOCK, zerocopy tx mode depends on transport, so this option must
be set in AF_VSOCK implementation where transport is accessible (if
transport is not set during setting SO_ZEROCOPY: for example socket is
not connected, then SO_ZEROCOPY will be enabled, but once transport will
be assigned, support of this type of transmission will be checked).

To handle SO_ZEROCOPY, AF_VSOCK implementation uses SOCK_CUSTOM_SOCKOPT
bit, thus handling SOL_SOCKET option operations, but all of them except
SO_ZEROCOPY will be forwarded to the generic handler by calling
'sock_setsockopt()'.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add 'msgzerocopy_allow()' callback for loopback transport.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add 'msgzerocopy_allow()' callback for virtio transport.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add 'msgzerocopy_allow()' callback for vhost transport.
Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>