Subject: Re: [PATCH net-next 09/10] net/mlx5e: Create IPsec table with tunnel support only when encap is disabled

From: Leon Romanovsky <[email-masked]>
Date: Mon, 10 Apr 2023 19:49:20 +0300

On Mon, Apr 10, 2023 at 04:29:09PM +0200, Simon Horman wrote:
> On Mon, Apr 10, 2023 at 09:19:11AM +0300, Leon Romanovsky wrote:
> > From: Leon Romanovsky <[email-masked]>
> > 
> > Current hardware doesn't support double encapsulation which is
> > happening when IPsec packet offload tunnel mode is configured
> > together with eswitch encap option.
> > 
> > Any user attempt to add new SA/policy after he/she sets encap mode, will
> > generate the following FW syndrome:
> > 
> >  mlx5_core 0000:08:00.0: mlx5_cmd_out_err:803:(pid 1904): CREATE_FLOW_TABLE(0x930) op_mod(0x0) failed,
> >  status bad parameter(0x3), syndrome (0xa43321), err(-22)
> > 
> > Make sure that we block encap changes before creating flow steering tables.
> > This is applicable only for packet offload in tunnel mode, while packet
> > offload in transport mode and crypto offload, don't have such limitation
> > as they don't perform encapsulation.
> > 
> > Reviewed-by: Raed Salem <[email-masked]>
> > Signed-off-by: Leon Romanovsky <[email-masked]>
> 
> Hi Raed and Leon,
> 
> some minor feedback from me below.
> 
> > ---
> >  .../mellanox/mlx5/core/en_accel/ipsec.c       |  7 ++++
> >  .../mellanox/mlx5/core/en_accel/ipsec.h       |  1 +
> >  .../mellanox/mlx5/core/en_accel/ipsec_fs.c    | 33 +++++++++++++++++--
> >  3 files changed, 38 insertions(+), 3 deletions(-)
> > 
> > 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 b64281fd4142..e95004ac7a20 100644
> > --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
> > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
> > @@ -668,6 +668,13 @@ static int mlx5e_xfrm_add_state(struct xfrm_state *x,
> >  	if (err)
> >  		goto err_hw_ctx;
> >  
> > +	if (x->props.mode == XFRM_MODE_TUNNEL &&
> > +	    x->xso.type == XFRM_DEV_OFFLOAD_PACKET &&
> > +	    !mlx5e_ipsec_fs_tunnel_enabled(sa_entry)) {
> > +		NL_SET_ERR_MSG_MOD(extack, "Packet offload tunnel mode is disabled due to encap settings");
> > +		goto err_add_rule;
> 
> The err_add_rule will return err.
> But err is zero here.
> Perhaps it should be set to an negative error code?

Thanks, I overlooked it.

> 
> Flagged by Smatch as:
> 
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c:753 mlx5e_xfrm_free_state() error: we previously assumed 'sa_entry->work' could be null (see line 744)

I don't get such warnings from my CI, will try to understand why.

What are the command line arguments you use to run smatch?
What is the version of smatch?

Thanks

> 
> > +	}
> > +
> >  	/* We use *_bh() variant because xfrm_timer_handler(), which runs
> >  	 * in softirq context, can reach our state delete logic and we need
> >  	 * xa_erase_bh() there.
> 
> ...