linux.git/net/core/devlink.c, branch v6.2-rc2

devlink: protect devlink dump by the instance lock

2022-12-17T05:16:28+00:00

Take the instance lock around devlink_nl_fill() when dumping,
doit takes it already.

We are only dumping basic info so in the worst case we were risking
data races around the reload statistics. Until the big devlink mutex
was removed all relevant code was protected by it, so the missing
instance lock was not exposed.

Fixes: d3efc2a6a6d8 ("net: devlink: remove devlink_mutex")
Reviewed-by: Jiri Pirko 
Reviewed-by: Jacob Keller 
Link: https://lore.kernel.org/r/20221216044122.1863550-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

devlink: hold region lock when flushing snapshots

2022-12-16T10:21:36+00:00

Netdevsim triggers a splat on reload, when it destroys regions
with snapshots pending:

  WARNING: CPU: 1 PID: 787 at net/core/devlink.c:6291 devlink_region_snapshot_del+0x12e/0x140
  CPU: 1 PID: 787 Comm: devlink Not tainted 6.1.0-07460-g7ae9888d6e1c #580
  RIP: 0010:devlink_region_snapshot_del+0x12e/0x140
  Call Trace:
   
   devl_region_destroy+0x70/0x140
   nsim_dev_reload_down+0x2f/0x60 [netdevsim]
   devlink_reload+0x1f7/0x360
   devlink_nl_cmd_reload+0x6ce/0x860
   genl_family_rcv_msg_doit.isra.0+0x145/0x1c0

This is the locking assert in devlink_region_snapshot_del(),
we're supposed to be holding the region->snapshot_lock here.

Fixes: 2dec18ad826f ("net: devlink: remove region snapshots list dependency on devlink->lock")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: devlink: Add missing error check to devlink_resource_put()

2022-12-10T04:04:32+00:00

When the resource size changes, the return value of the
'nla_put_u64_64bit' function is not checked. That has been fixed to avoid
rechecking at the next step.

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.

Note that this is harmless, we'd error out at the next put().

Signed-off-by: Ilia.Gavrilov 
Link: https://lore.kernel.org/r/20221208082821.3927937-1-Ilia.Gavrilov@infotecs.ru
Signed-off-by: Jakub Kicinski

devlink: Expose port function commands to control migratable

2022-12-08T04:09:18+00:00

Expose port function commands to enable / disable migratable
capability, this is used to set the port function as migratable.

Live migration is the process of transferring a live virtual machine
from one physical host to another without disrupting its normal
operation.

In order for a VM to be able to perform LM, all the VM components must
be able to perform migration. e.g.: to be migratable.
In order for VF to be migratable, VF must be bound to VFIO driver with
migration support.

When migratable capability is enabled for a function of the port, the
device is making the necessary preparations for the function to be
migratable, which might include disabling features which cannot be
migrated.

Example of LM with migratable function configuration:
Set migratable of the VF's port function.

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 migratable disable

$ devlink port function set pci/0000:06:00.0/2 migratable enable

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 migratable enable

Bind VF to VFIO driver with migration support:
$ echo  > /sys/bus/pci/devices/0000:08:00.0/driver/unbind
$ echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:08:00.0/driver_override
$ echo  > /sys/bus/pci/devices/0000:08:00.0/driver/bind

Attach VF to the VM.
Start the VM.
Perform LM.

Signed-off-by: Shay Drory 
Reviewed-by: Jiri Pirko 
Acked-by: Shannon Nelson 
Signed-off-by: Jakub Kicinski

devlink: Expose port function commands to control RoCE

2022-12-08T04:09:18+00:00

Expose port function commands to enable / disable RoCE, this is used to
control the port RoCE device capabilities.

When RoCE is disabled for a function of the port, function cannot create
any RoCE specific resources (e.g GID table).
It also saves system memory utilization. For example disabling RoCE enable a
VF/SF saves 1 Mbytes of system memory per function.

Example of a PCI VF port which supports function configuration:
Set RoCE of the VF's port function.

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 roce enable

$ devlink port function set pci/0000:06:00.0/2 roce disable

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 roce disable

Signed-off-by: Shay Drory 
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski

devlink: Validate port function request

2022-12-08T04:09:18+00:00

In order to avoid partial request processing, validate the request
before processing it.

Signed-off-by: Shay Drory 
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski

net: devlink: convert port_list into xarray

2022-12-02T10:37:03+00:00

Some devlink instances may contain thousands of ports. Storing them in
linked list and looking them up is not scalable. Convert the linked list
into xarray.

Signed-off-by: Jiri Pirko 
Acked-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net: devlink: make the devlink_ops::info_get() callback optional

2022-12-01T05:49:39+00:00

Some drivers only reported the driver name in their
devlink_ops::info_get() callback. Now that the core provides this
information, the callback became empty. For such drivers, just
removing the callback would prevent the core from executing
devlink_nl_info_fill() meaning that "devlink dev info" would not
return anything.

Make the callback function optional by executing
devlink_nl_info_fill() even if devlink_ops::info_get() is NULL.

N.B.: the drivers with devlink support which previously did not
implement devlink_ops::info_get() will now also be able to report
the driver name.

Signed-off-by: Vincent Mailhol 
Reviewed-by: Jacob Keller  
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski

net: devlink: let the core report the driver name instead of the drivers

2022-12-01T05:49:38+00:00

The driver name is available in device_driver::name. Right now,
drivers still have to report this piece of information themselves in
their devlink_ops::info_get callback function.

In order to factorize code, make devlink_nl_info_fill() add the driver
name attribute.

Now that the core sets the driver name attribute, drivers are not
supposed to call devlink_info_driver_name_put() anymore. Remove
devlink_info_driver_name_put() and clean-up all the drivers using this
function in their callback.

Signed-off-by: Vincent Mailhol 
Tested-by: Ido Schimmel  # mlxsw
Reviewed-by: Jacob Keller  
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski

devlink: support directly reading from region memory

2022-12-01T04:54:30+00:00

To read from a region, user space must currently request a new snapshot of
the region and then read from that snapshot. This can sometimes be overkill
if user space only reads a tiny portion. They first create the snapshot,
then request a read, then destroy the snapshot.

For regions which have a single underlying "contents", it makes sense to
allow supporting direct reading of the region data.

Extend the DEVLINK_CMD_REGION_READ to allow direct reading from a region if
requested via the new DEVLINK_ATTR_REGION_DIRECT. If this attribute is set,
then perform a direct read instead of using a snapshot. Direct read is
mutually exclusive with DEVLINK_ATTR_REGION_SNAPSHOT_ID, and care is taken
to ensure that we reject commands which provide incorrect attributes.

Regions must enable support for direct read by implementing the .read()
callback function. If a region does not support such direct reads, a
suitable extended error message is reported.

Signed-off-by: Jacob Keller 
Reviewed-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski