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

[Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>]

On Fri, Jul 26, 2019 at 08:39:43PM +0800, wenxu wrote:
> 
> 在 2019/7/26 20:19, Or Gerlitz 写道:
> > On Fri, Jul 26, 2019 at 12:24 AM Saeed Mahameed <saeedm@mellanox.com> wrote:
> >> On Thu, 2019-07-25 at 19:24 +0800, wenxu@ucloud.cn wrote:
> >>> From: wenxu <wenxu@ucloud.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@ucloud.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

Note that on
[PATCH net-next] netfilter: nf_table_offload: Fix zero prio of flow_cls_common_offload
I asked Pablo on how nftables should behave on this situation.

It's the same issue as in the patch above but being fixed at a
different level.