Re: [PATCH mlx5-next 11/15] RDMA/mlx5: Add vport metadata matching for IB representors

[Mark Bloch <markb@mellanox.com>]

On 6/19/2019 00:43, Leon Romanovsky wrote:
> On Wed, Jun 19, 2019 at 07:26:54AM +0000, Mark Bloch wrote:
>>
>>
>> On 6/18/2019 23:51, Leon Romanovsky wrote:
>>> On Wed, Jun 19, 2019 at 06:40:16AM +0000, Jianbo Liu wrote:
>>>> The 06/19/2019 13:04, Leon Romanovsky wrote:
>>>>> On Wed, Jun 19, 2019 at 04:44:26AM +0000, Jianbo Liu wrote:
>>>>>> The 06/18/2019 18:19, Leon Romanovsky wrote:
>>>>>>> On Mon, Jun 17, 2019 at 07:23:30PM +0000, Saeed Mahameed wrote:
>>>>>>>> From: Jianbo Liu <jianbol@mellanox.com>
>>>>>>>>
>>>>>>>> If vport metadata matching is enabled in eswitch, the rule created
>>>>>>>> must be changed to match on the metadata, instead of source port.
>>>>>>>>
>>>>>>>> Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
>>>>>>>> Reviewed-by: Roi Dayan <roid@mellanox.com>
>>>>>>>> Reviewed-by: Mark Bloch <markb@mellanox.com>
>>>>>>>> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
>>>>>>>> ---
>>>>>>>>  drivers/infiniband/hw/mlx5/ib_rep.c | 11 +++++++
>>>>>>>>  drivers/infiniband/hw/mlx5/ib_rep.h | 16 ++++++++++
>>>>>>>>  drivers/infiniband/hw/mlx5/main.c   | 45 +++++++++++++++++++++++------
>>>>>>>>  3 files changed, 63 insertions(+), 9 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/infiniband/hw/mlx5/ib_rep.c b/drivers/infiniband/hw/mlx5/ib_rep.c
>>>>>>>> index 22e651cb5534..d4ed611de35d 100644
>>>>>>>> --- a/drivers/infiniband/hw/mlx5/ib_rep.c
>>>>>>>> +++ b/drivers/infiniband/hw/mlx5/ib_rep.c
>>>>>>>> @@ -131,6 +131,17 @@ struct mlx5_eswitch_rep *mlx5_ib_vport_rep(struct mlx5_eswitch *esw, int vport)
>>>>>>>>  	return mlx5_eswitch_vport_rep(esw, vport);
>>>>>>>>  }
>>>>>>>>
>>>>>>>> +u32 mlx5_ib_eswitch_vport_match_metadata_enabled(struct mlx5_eswitch *esw)
>>>>>>>> +{
>>>>>>>> +	return mlx5_eswitch_vport_match_metadata_enabled(esw);
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +u32 mlx5_ib_eswitch_get_vport_metadata_for_match(struct mlx5_eswitch *esw,
>>>>>>>> +						 u16 vport)
>>>>>>>> +{
>>>>>>>> +	return mlx5_eswitch_get_vport_metadata_for_match(esw, vport);
>>>>>>>> +}
>>>>>>>
>>>>>>> 1. There is no need to introduce one line functions, call to that code directly.
>>>>>>
>>>>>> No. They are in IB, and we don't want them be mixed up by the original
>>>>>> functions in eswitch. Please ask Mark more about it.
>>>>>
>>>>> Please enlighten me.
>>>>
>>>> It was suggested by Mark in prevouis review.
>>>> I think it's because there are in different modules, and better to with
>>>> different names, so introduce there extra one line functions.
>>>> Please correct me if I'm wrong, Mark...
>>>
>>> mlx5_ib is full of direct function calls to mlx5_core and it is done on
>>> purpose for at least two reasons. First is to control in one place
>>> all compilation options and expose proper API interface with and without
>>> specific kernel config is on. Second is to emphasize that this is core
>>> function and save us time in refactoring and reviewing.
>>
>> This was done in order to avoid #ifdef CONFIG_MLX5_ESWITCH,
>> I want to hide (as much as possible) the interactions with the eswitch level in ib_rep.c/ib_rep.h
>> so ib_rep.h will provide the stubs needed in case CONFIG_MLX5_ESWITCH isn't defined.
>> (Today include/linux/mlx5/eswitch.h) doesn't provide any stubs, mlx5_eswitch_get_encap_mode()
>> should have probably done the same.
> 
> This is exactly the problem, eswitch.h should provide stubs for all
> exported functions, so other clients of eswitch won't need to deal with
> various unrelated config options.

The way it works today, code in drivers/infiniband/hw/mlx5/main.c doesn't call eswitch layer directly
but the functions in ib_rep.{c,h} as most often there is additional logic we must do before calling
the eswitch layer.

If you look at drivers/infiniband/hw/mlx5/Makefile you will see ib_rep is complied only when
CONFIG_MLX5_ESWITCH id defined.

so instead of having to deal with two places that contain stubs, we need to deal with only one (ib_rep.h).
For me it makes it easier to follow, but I can adept if you don't like it.

Mark

> 
>>
>> As my long term goal is to break drivers/infiniband/hw/mlx5/main.c (that file is already 7000 LOC)
>> I want to group together stuff in separate files.
> 
> Yes, it is right thing to do.
> 
>>
>> If you prefer direct calls that's okay as well.
> 
> Yes, please.
> 
>>
>> Mark
>>
>>>
>>>>
>>>>>
>>>>>>
>>>>>>> 2. It should be bool and not u32.
>>>>>>>
>>>>>>> Thanks
>>>>>>
>>>>>> --
>>>>
>>>> --