by Moshe Shemesh

[permalink] [raw]

Subject: Re: [PATCH net-next 16/16] devlink: Add Documentation/networking/devlink/devlink-reload.rst

On 10/3/2020 12:14 PM, Jiri Pirko wrote:
> Thu, Oct 01, 2020 at 03:59:19PM CEST, [email protected] wrote:
>> Add devlink reload rst documentation file.
>> Update index file to include it.
>>
>> Signed-off-by: Moshe Shemesh <[email protected]>
>> ---
>> RFCv5 -> v1:
>> - Rename reload_action_limit_level to reload_limit
>> RFCv4 -> RFCv5:
>> - Rephrase namespace chnage section
>> - Rephrase note on actions performed
>> RFCv3 -> RFCv4:
>> - Remove reload action fw_activate_no_reset
>> - Add reload actions limit levels and document the no_reset limit level
>> constrains
>> RFCv2 -> RFCv3:
>> - Devlink reload returns the actions done
>> - Replace fw_live_patch action by fw_activate_no_reset
>> - Explain fw_activate meaning
>> RFCv1 -> RFCv2:
>> - Instead of reload levels driver,fw_reset,fw_live_patch have reload
>> actions driver_reinit,fw_activate,fw_live_patch
>> ---
>> .../networking/devlink/devlink-reload.rst | 81 +++++++++++++++++++
>> Documentation/networking/devlink/index.rst | 1 +
>> 2 files changed, 82 insertions(+)
>> create mode 100644 Documentation/networking/devlink/devlink-reload.rst
>>
>> diff --git a/Documentation/networking/devlink/devlink-reload.rst b/Documentation/networking/devlink/devlink-reload.rst
>> new file mode 100644
>> index 000000000000..5abc5c2c75fd
>> --- /dev/null
>> +++ b/Documentation/networking/devlink/devlink-reload.rst
>> @@ -0,0 +1,81 @@
>> +.. SPDX-License-Identifier: GPL-2.0
>> +
>> +==============
>> +Devlink Reload
> No reason for capital "R".

It looks as the convention here for rst headers, as in
devlink-region.rst, devlink-trap.rst, devlink-resource.rst

>
>> +==============
>> +
>> +``devlink-reload`` provides mechanism to either reinit driver entities,
>> +applying ``devlink-params`` and ``devlink-resources`` new values or firmware
>> +activation depends on reload action selected.
> Could you perhaps split the sentense? It is hard to read.
Yes.
>
>> +
>> +Reload actions
>> +==============
>> +
>> +User may select a reload action.
>> +By default ``driver_reinit`` action is selected.
>> +
>> +.. list-table:: Possible reload actions
>> + :widths: 5 90
>> +
>> + * - Name
>> + - Description
>> + * - ``driver-reinit``
>> + - Devlink driver entities re-initialization, including applying
>> + new values to devlink entities which are used during driver
>> + load such as ``devlink-params`` in configuration mode
>> + ``driverinit`` or ``devlink-resources``
>> + * - ``fw_activate``
>> + - Firmware activate. Activates new firmware if such image is stored and
>> + pending activation. If no limitation specified this action may involve
>> + firmware reset. If no new image pending this action will reload current
>> + firmware image.
>> +
>> +Note that even though user asks for a specific action, the driver
>> +implementation might require to perform another action alongside with
>> +it. For example, some driver do not support driver reinitialization
>> +being performed without fw activation. Therefore, the devlink reload
>> +command returns the list of actions which were actrually performed.
>> +
>> +Reload limits
>> +=============
>> +
>> +By default reload actions are not limited and driver implementation may
>> +include reset or downtime as needed to perform the actions.
>> +
>> +However, some drivers support action limits, which limit the action
>> +implementation to specific constrains.
>> +
>> +.. list-table:: Possible reload limits
>> + :widths: 5 90
>> +
>> + * - Name
>> + - Description
>> + * - ``no_reset``
>> + - No reset allowed, no down time allowed, no link flap and no
>> + configuration is lost.
>> +
>> +Change namespace
>> +================
>> +
>> +The netns option allow user to be able to move devlink instances into
> "allows"
Ack.
>
>> +namespaces during devlink reload operation.
>> +By default all devlink instances are created in init_net and stay there.
>> +
>> +example usage
>> +-------------
>> +
>> +.. code:: shell
>> +
>> + $ devlink dev reload help
>> + $ devlink dev reload DEV [ netns { PID | NAME | ID } ] [ action { driver_reinit | fw_activate } ] [ limit no_reset ]
>> +
>> + # Run reload command for devlink driver entities re-initialization:
>> + $ devlink dev reload pci/0000:82:00.0 action driver_reinit
>> + reload_actions_performed:
>> + driver_reinit
>> +
>> + # Run reload command to activate firmware:
>> + # Note that mlx5 driver reloads the driver while activating firmware
>> + $ devlink dev reload pci/0000:82:00.0 action fw_activate
>> + reload_actions_performed:
>> + driver_reinit fw_activate
>> diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
>> index 7684ae5c4a4a..d82874760ae2 100644
>> --- a/Documentation/networking/devlink/index.rst
>> +++ b/Documentation/networking/devlink/index.rst
>> @@ -20,6 +20,7 @@ general.
>> devlink-params
>> devlink-region
>> devlink-resource
>> + devlink-reload
>> devlink-trap
>>
>> Driver-specific documentation
>> --
>> 2.18.2
>>

2020-10-05 18:44:06

by Jacob Keller

[permalink] [raw]

Subject: Re: [PATCH net-next 02/16] devlink: Add reload action option to devlink reload command

On 10/1/2020 6:59 AM, Moshe Shemesh wrote:
> Add devlink reload action to allow the user to request a specific reload
> action. The action parameter is optional, if not specified then devlink
> driver re-init action is used (backward compatible).
> Note that when required to do firmware activation some drivers may need
> to reload the driver. On the other hand some drivers may need to reset
> the firmware to reinitialize the driver entities. Therefore, the devlink
> reload command returns the actions which were actually performed.
> Reload actions supported are:
> driver_reinit: driver entities re-initialization, applying devlink-param
> and devlink-resource values.
> fw_activate: firmware activate.
>
> command examples:
> $devlink dev reload pci/0000:82:00.0 action driver_reinit
> reload_actions_performed:
> driver_reinit
>
> $devlink dev reload pci/0000:82:00.0 action fw_activate
> reload_actions_performed:
> driver_reinit fw_activate
>
> Signed-off-by: Moshe Shemesh <[email protected]>

Looks straight forward.

Reviewed-by: Jacob Keller <[email protected]>

> ---
> RFCv5 -> v1:
> - Rename supported_reload_actions to reload_actions.
> - Rename devlink_nl_reload_actions_performed_fill() to
> devlink_nl_reload_actions_performed_snd() and add genlmsg_reply() to it
> - Actions_performed sent to user space as a mask
> - Driver can initialize actions_performed before done as devlink ignores
> in case of failure
> - Use nla_poilcy range validation and remove the range check in
> devlink_nl_cmd_reload
> RFCv4 -> RFCv5:
> - Always pass actions_performed to unload_up() instead of checking in
> each driver
> - Verify returned actions_performed includes the requested action
> - Changed devlink_reload_actions_verify(devlink) to get ops
> - Changed devlink_reload_actions_verify() to return bool and rename to
> devlink_reload_actions_valid()
> - Only generate the reply if request uses new attributes
> RFCv3 -> RFCv4:
> - Removed fw_activate_no_reset as an action (next patch adds limit
> levels instead).
> - Renamed actions_done to actions_performed
> RFCv2 -> RFCv3:
> - Replace fw_live_patch action by fw_activate_no_reset
> - Devlink reload returns the actions done over netlink reply
> RFCv1 -> RFCv2:
> - Instead of reload levels driver,fw_reset,fw_live_patch have reload
> actions driver_reinit,fw_activate,fw_live_patch
> - Remove driver default level, the action driver_reinit is the default
> action for all drivers
> ---
> drivers/net/ethernet/mellanox/mlx4/main.c | 7 +-
> .../net/ethernet/mellanox/mlx5/core/devlink.c | 7 +-
> drivers/net/ethernet/mellanox/mlxsw/core.c | 11 +-
> drivers/net/netdevsim/dev.c | 8 +-
> include/net/devlink.h | 7 +-
> include/uapi/linux/devlink.h | 18 ++++
> net/core/devlink.c | 101 ++++++++++++++++--
> 7 files changed, 139 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
> index 70cf24ba71e4..a44d8b733db3 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/main.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/main.c
> @@ -3946,6 +3946,7 @@ static int mlx4_restart_one_up(struct pci_dev *pdev, bool reload,
> struct devlink *devlink);
>
> static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
> + enum devlink_reload_action action,
> struct netlink_ext_ack *extack)
> {

I might have opted to convert reload_down to take a structure of
parameters, given that we're about to add 2 parameters. Not really that
significant either way.