[PATCH net 0/2] mlxsw: Two fixes

[PATCH net 0/2] mlxsw: Two fixes

[Ido Schimmel]

From: Ido Schimmel <idosch@mellanox.com>

This patchset contains two fixes for mlxsw.

Patch #1 from Petr fixes an issue in which DSCP rewrite can occur even
if the egress port was switched to Trust L2 mode where priority mapping
is based on PCP.

Patch #2 fixes a problem where packets can be learned on a non-existing
FID if a tc filter with a redirect action is configured on a bridged
port. The problem and fix are explained in detail in the commit message.

Please consider both patches for 5.2.y

Ido Schimmel (1):
  mlxsw: spectrum: Do not process learned records with a dummy FID

Petr Machata (1):
  mlxsw: spectrum_dcb: Configure DSCP map as the last rule is removed

 drivers/net/ethernet/mellanox/mlxsw/spectrum.h   |  1 +
 .../net/ethernet/mellanox/mlxsw/spectrum_dcb.c   | 16 ++++++++--------
 .../net/ethernet/mellanox/mlxsw/spectrum_fid.c   | 10 ++++++++++
 .../ethernet/mellanox/mlxsw/spectrum_switchdev.c |  6 ++++++
 4 files changed, 25 insertions(+), 8 deletions(-)

-- 
2.21.0

[PATCH net 1/2] mlxsw: spectrum_dcb: Configure DSCP map as the last rule is removed

[Ido Schimmel]

From: Petr Machata <petrm@mellanox.com>

Spectrum systems use DSCP rewrite map to update DSCP field in egressing
packets to correspond to priority that the packet has. Whether rewriting
will take place is determined at the point when the packet ingresses the
switch: if the port is in Trust L3 mode, packet priority is determined from
the DSCP map at the port, and DSCP rewrite will happen. If the port is in
Trust L2 mode, 802.1p is used for packet prioritization, and no DSCP
rewrite will happen.

The driver determines the port trust mode based on whether any DSCP
prioritization rules are in effect at given port. If there are any, trust
level is L3, otherwise it's L2. When the last DSCP rule is removed, the
port is switched to trust L2. Under that scenario, if DSCP of a packet
should be rewritten, it should be rewritten to 0.

However, when switching to Trust L2, the driver neglects to also update the
DSCP rewrite map. The last DSCP rule thus remains in effect, and packets
egressing through this port, if they have the right priority, will have
their DSCP set according to this rule.

Fix by first configuring the rewrite map, and only then switching to trust
L2 and bailing out.

Fixes: b2b1dab6884e ("mlxsw: spectrum: Support ieee_setapp, ieee_delapp")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reported-by: Alex Veber <alexve@mellanox.com>
Tested-by: Alex Veber <alexve@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
---
 .../net/ethernet/mellanox/mlxsw/spectrum_dcb.c   | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
index b25048c6c761..21296fa7f7fb 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
@@ -408,14 +408,6 @@ static int mlxsw_sp_port_dcb_app_update(struct mlxsw_sp_port *mlxsw_sp_port)
 	have_dscp = mlxsw_sp_port_dcb_app_prio_dscp_map(mlxsw_sp_port,
 							&prio_map);
 
-	if (!have_dscp) {
-		err = mlxsw_sp_port_dcb_toggle_trust(mlxsw_sp_port,
-					MLXSW_REG_QPTS_TRUST_STATE_PCP);
-		if (err)
-			netdev_err(mlxsw_sp_port->dev, "Couldn't switch to trust L2\n");
-		return err;
-	}
-
 	mlxsw_sp_port_dcb_app_dscp_prio_map(mlxsw_sp_port, default_prio,
 					    &dscp_map);
 	err = mlxsw_sp_port_dcb_app_update_qpdpm(mlxsw_sp_port,
@@ -432,6 +424,14 @@ static int mlxsw_sp_port_dcb_app_update(struct mlxsw_sp_port *mlxsw_sp_port)
 		return err;
 	}
 
+	if (!have_dscp) {
+		err = mlxsw_sp_port_dcb_toggle_trust(mlxsw_sp_port,
+					MLXSW_REG_QPTS_TRUST_STATE_PCP);
+		if (err)
+			netdev_err(mlxsw_sp_port->dev, "Couldn't switch to trust L2\n");
+		return err;
+	}
+
 	err = mlxsw_sp_port_dcb_toggle_trust(mlxsw_sp_port,
 					     MLXSW_REG_QPTS_TRUST_STATE_DSCP);
 	if (err) {
-- 
2.21.0

[PATCH net 2/2] mlxsw: spectrum: Do not process learned records with a dummy FID

[Ido Schimmel]

From: Ido Schimmel <idosch@mellanox.com>

The switch periodically sends notifications about learned FDB entries.
Among other things, the notification includes the FID (Filtering
Identifier) and the port on which the MAC was learned.

In case the driver does not have the FID defined on the relevant port,
the following error will be periodically generated:

mlxsw_spectrum2 0000:06:00.0 swp32: Failed to find a matching {Port, VID} following FDB notification

This is not supposed to happen under normal conditions, but can happen
if an ingress tc filter with a redirect action is installed on a bridged
port. The redirect action will cause the packet's FID to be changed to
the dummy FID and a learning notification will be emitted with this FID
- which is not defined on the bridged port.

Fix this by having the driver ignore learning notifications generated
with the dummy FID and delete them from the device.

Another option is to chain an ignore action after the redirect action
which will cause the device to disable learning, but this means that we
need to consume another action whenever a redirect action is used. In
addition, the scenario described above is merely a corner case.

Fixes: cedbb8b25948 ("mlxsw: spectrum_flower: Set dummy FID before forward action")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alex Kushnarov <alexanderk@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Tested-by: Alex Kushnarov <alexanderk@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.h         |  1 +
 drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c     | 10 ++++++++++
 .../net/ethernet/mellanox/mlxsw/spectrum_switchdev.c   |  6 ++++++
 3 files changed, 17 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
index a252b080dda9..131f62ce9297 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -830,6 +830,7 @@ int mlxsw_sp_setup_tc_prio(struct mlxsw_sp_port *mlxsw_sp_port,
 			   struct tc_prio_qopt_offload *p);
 
 /* spectrum_fid.c */
+bool mlxsw_sp_fid_is_dummy(struct mlxsw_sp *mlxsw_sp, u16 fid_index);
 bool mlxsw_sp_fid_lag_vid_valid(const struct mlxsw_sp_fid *fid);
 struct mlxsw_sp_fid *mlxsw_sp_fid_lookup_by_index(struct mlxsw_sp *mlxsw_sp,
 						  u16 fid_index);
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c
index 46baf3b44309..8df3cb21baa6 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_fid.c
@@ -126,6 +126,16 @@ static const int *mlxsw_sp_packet_type_sfgc_types[] = {
 	[MLXSW_SP_FLOOD_TYPE_MC]	= mlxsw_sp_sfgc_mc_packet_types,
 };
 
+bool mlxsw_sp_fid_is_dummy(struct mlxsw_sp *mlxsw_sp, u16 fid_index)
+{
+	enum mlxsw_sp_fid_type fid_type = MLXSW_SP_FID_TYPE_DUMMY;
+	struct mlxsw_sp_fid_family *fid_family;
+
+	fid_family = mlxsw_sp->fid_core->fid_family_arr[fid_type];
+
+	return fid_family->start_index == fid_index;
+}
+
 bool mlxsw_sp_fid_lag_vid_valid(const struct mlxsw_sp_fid *fid)
 {
 	return fid->fid_family->lag_vid_valid;
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index 50111f228d77..5ecb45118400 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -2468,6 +2468,9 @@ static void mlxsw_sp_fdb_notify_mac_process(struct mlxsw_sp *mlxsw_sp,
 		goto just_remove;
 	}
 
+	if (mlxsw_sp_fid_is_dummy(mlxsw_sp, fid))
+		goto just_remove;
+
 	mlxsw_sp_port_vlan = mlxsw_sp_port_vlan_find_by_fid(mlxsw_sp_port, fid);
 	if (!mlxsw_sp_port_vlan) {
 		netdev_err(mlxsw_sp_port->dev, "Failed to find a matching {Port, VID} following FDB notification\n");
@@ -2527,6 +2530,9 @@ static void mlxsw_sp_fdb_notify_mac_lag_process(struct mlxsw_sp *mlxsw_sp,
 		goto just_remove;
 	}
 
+	if (mlxsw_sp_fid_is_dummy(mlxsw_sp, fid))
+		goto just_remove;
+
 	mlxsw_sp_port_vlan = mlxsw_sp_port_vlan_find_by_fid(mlxsw_sp_port, fid);
 	if (!mlxsw_sp_port_vlan) {
 		netdev_err(mlxsw_sp_port->dev, "Failed to find a matching {Port, VID} following FDB notification\n");
-- 
2.21.0

Re: [PATCH net 0/2] mlxsw: Two fixes

[David Miller]

From: Ido Schimmel <idosch@idosch.org>
Date: Wed, 17 Jul 2019 23:29:06 +0300

> From: Ido Schimmel <idosch@mellanox.com>
> 
> This patchset contains two fixes for mlxsw.
> 
> Patch #1 from Petr fixes an issue in which DSCP rewrite can occur even
> if the egress port was switched to Trust L2 mode where priority mapping
> is based on PCP.
> 
> Patch #2 fixes a problem where packets can be learned on a non-existing
> FID if a tc filter with a redirect action is configured on a bridged
> port. The problem and fix are explained in detail in the commit message.

Series applied.

> Please consider both patches for 5.2.y

I'll queue them up for -stable, thanks.