netdev - Re: [PATCH] net/mlx5e: Fix zero table prio set by user.

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Date:   Fri, 26 Jul 2019 20:39:43 +0800
From:   wenxu <wenxu@...oud.cn>
To:     Or Gerlitz <gerlitz.or@...il.com>,
        Saeed Mahameed <saeedm@...lanox.com>
Cc:     Roi Dayan <roid@...lanox.com>, Mark Bloch <markb@...lanox.com>,
        Paul Blakey <paulb@...lanox.com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH] net/mlx5e: Fix zero table prio set by user.


在 2019/7/26 20:19, Or Gerlitz 写道:
> On Fri, Jul 26, 2019 at 12:24 AM Saeed Mahameed <saeedm@...lanox.com> wrote:
>> On Thu, 2019-07-25 at 19:24 +0800, wenxu@...oud.cn wrote:
>>> From: wenxu <wenxu@...oud.cn>
>>>
>>> The flow_cls_common_offload prio is zero
>>>
>>> It leads the invalid table prio in hw.
>>>
>>> Error: Could not process rule: Invalid argument
>>>
>>> kernel log:
>>> mlx5_core 0000:81:00.0: E-Switch: Failed to create FDB Table err -22
>>> (table prio: 65535, level: 0, size: 4194304)
>>>
>>> table_prio = (chain * FDB_MAX_PRIO) + prio - 1;
>>> should check (chain * FDB_MAX_PRIO) + prio is not 0
>>>
>>> Signed-off-by: wenxu <wenxu@...oud.cn>
>>> ---
>>>  drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c | 4 +++-
>>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git
>>> a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
>>> b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
>>> index 089ae4d..64ca90f 100644
>>> --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
>>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
>>> @@ -970,7 +970,9 @@ static int esw_add_fdb_miss_rule(struct
>> this piece of code isn't in this function, weird how it got to the
>> diff, patch applies correctly though !
>>
>>> mlx5_eswitch *esw)
>>>               flags |= (MLX5_FLOW_TABLE_TUNNEL_EN_REFORMAT |
>>>                         MLX5_FLOW_TABLE_TUNNEL_EN_DECAP);
>>>
>>> -     table_prio = (chain * FDB_MAX_PRIO) + prio - 1;
>>> +     table_prio = (chain * FDB_MAX_PRIO) + prio;
>>> +     if (table_prio)
>>> +             table_prio = table_prio - 1;
>>>
>> This is black magic, even before this fix.
>> this -1 seems to be needed in order to call
>> create_next_size_table(table_prio) with the previous "table prio" ?
>> (table_prio - 1)  ?
>>
>> The whole thing looks wrong to me since when prio is 0 and chain is 0,
>> there is not such thing table_prio - 1.
>>
>> mlnx eswitch guys in the cc, please advise.
> basically, prio 0 is not something we ever get in the driver, since if
> user space
> specifies 0, the kernel generates some random non-zero prio, and we support
> only prios 1-16 -- Wenxu -- what do you run to get this error?
>
>
I run offload with nfatbles(but not tc), there is no prio for each rule.

prio of flow_cls_common_offload init as 0.

static void nft_flow_offload_common_init(struct flow_cls_common_offload *common,

                     __be16 proto,
                    struct netlink_ext_ack *extack)
{
    common->protocol = proto;
    common->extack = extack;
}


flow_cls_common_offload