Re: [net-next,V5,11/15] net/mlx5: Expose a function to clear a vport's parent

[Jakub Kicinski <kuba@kernel.org>]

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---
net/mlx5e: Skip ESN replay window setup for IPsec crypto offload

This patch fixes a WARN_ON being triggered for crypto offload by adding
a check to skip the replay window setup when the offload type is not
XFRM_DEV_OFFLOAD_PACKET.

> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
> index a8fb4bec369c..63aa23f5c49e 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
> @@ -430,7 +430,8 @@ void mlx5e_ipsec_build_accel_xfrm_attrs(struct mlx5e_ipsec_sa_entry *sa_entry,
>  		attrs->replay_esn.esn = sa_entry->esn_state.esn;
>  		attrs->replay_esn.esn_msb = sa_entry->esn_state.esn_msb;
>  		attrs->replay_esn.overlap = sa_entry->esn_state.overlap;
> -		if (attrs->dir == XFRM_DEV_OFFLOAD_OUT)
> +		if (attrs->dir == XFRM_DEV_OFFLOAD_OUT ||
> +		    attrs->type != XFRM_DEV_OFFLOAD_PACKET)
>  			goto skip_replay_window;

At this point in mlx5e_ipsec_build_accel_xfrm_attrs(), attrs->type has not
been initialized yet. The function starts with memset(attrs, 0, ...) which
sets attrs->type to 0 (XFRM_DEV_OFFLOAD_UNSPECIFIED).

The assignment attrs->type = x->xso.type happens later after the
skip_replay_window label. This means the condition attrs->type !=
XFRM_DEV_OFFLOAD_PACKET evaluates as 0 != 2 which is always true.

As a result, the replay window setup will be skipped for all inbound
configurations, not just crypto offload. Should this check use x->xso.type
instead of attrs->type, or should attrs->type be assigned earlier in the
function before this check?