net/mlx4_core: Don't fail reg/unreg vlan for older guests

In upstream kernels under SRIOV, the vlan register/unregister calls
were NOPs (doing nothing and returning OK). We detect these old
calls from guests (via the comm channel), since previously the
port number in mlx4_register_vlan was passed (improperly) in the
out_param. This has been corrected so that the port number is now
passed in bits 8..15 of the in_modifier field.

For old calls, these bits will be zero, so if the passed port
number is zero, we can still look at the out_param field to see
if it contains a valid port number. If yes, the VM is running
an old driver.

Since for old drivers, the register/unregister_vlan wrappers were
NOPs, we continue this policy -- the reason being that upstream
had an additional bug in eth driver running on guests (where
procedure mlx4_en_vlan_rx_kill_vid() had the following code:

if (!mlx4_find_cached_vlan(mdev->dev, priv->port, vid, &idx))
        mlx4_unregister_vlan(mdev->dev, priv->port, idx);
else
        en_err(priv, "could not find vid %d in cache\n", vid);

On a VM, mlx4_find_cached_vlan() will always fail, since the
vlan cache is located on the Hypervisor; on guests it is empty.

Therefore, if we allow upstream guests to register vlans, we will
have vlan leakage since the unregister will never be performed.
Leaving vlan reg/unreg for old guest drivers as a NOP is not a
feature regression, since in upstream the register/unregister
vlan wrapper is a NOP.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c
index 887d625..65d41b7 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c
@@ -1718,6 +1718,7 @@ static void mlx4_master_do_cmd(struct mlx4_dev *dev, int slave, u8 cmd,
        if (cmd == MLX4_COMM_CMD_RESET) {
                mlx4_warn(dev, "Received reset from slave:%d\n", slave);
                slave_state[slave].active = false;
+               slave_state[slave].old_vlan_api = false;
                mlx4_master_deactivate_admin_state(priv, slave);
                for (i = 0; i < MLX4_EVENT_TYPES_NUM; ++i) {
                                slave_state[slave].event_eq[i].eqn = -1;

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4.h b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
index f2ad4f6..9794126 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
@@ -455,6 +455,7 @@ struct mlx4_slave_state {
        u8 last_cmd;
        u8 init_port_mask;
        bool active;
+       bool old_vlan_api;
        u8 function;
        dma_addr_t vhcr_dma;
        u16 mtu[MLX4_MAX_PORTS + 1];

diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index e18bfff..3586388 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -1555,15 +1555,26 @@ static void rem_slave_vlans(struct mlx4_dev *dev, int slave)
 }
 
 static int vlan_alloc_res(struct mlx4_dev *dev, int slave, int op, int cmd,
-                         u64 in_param, u64 *out_param, int port)
+                         u64 in_param, u64 *out_param, int in_port)
 {
+       struct mlx4_priv *priv = mlx4_priv(dev);
+       struct mlx4_slave_state *slave_state = priv->mfunc.master.slave_state;
        int err;
        u16 vlan;
        int vlan_index;
+       int port;
+
+       port = !in_port ? get_param_l(out_param) : in_port;
 
        if (!port || op != RES_OP_RESERVE_AND_MAP)
                return -EINVAL;
 
+       /* upstream kernels had NOP for reg/unreg vlan. Continue this. */
+       if (!in_port && port > 0 && port <= dev->caps.num_ports) {
+               slave_state[slave].old_vlan_api = true;
+               return 0;
+       }
+
        vlan = (u16) in_param;
 
        err = __mlx4_register_vlan(dev, port, vlan, &vlan_index);
@@ -1856,10 +1867,14 @@ static int mac_free_res(struct mlx4_dev *dev, int slave, int op, int cmd,
 static int vlan_free_res(struct mlx4_dev *dev, int slave, int op, int cmd,
                            u64 in_param, u64 *out_param, int port)
 {
+       struct mlx4_priv *priv = mlx4_priv(dev);
+       struct mlx4_slave_state *slave_state = priv->mfunc.master.slave_state;
        int err = 0;
 
        switch (op) {
        case RES_OP_RESERVE_AND_MAP:
+               if (slave_state[slave].old_vlan_api)
+                       return 0;
                if (!port)
                        return -EINVAL;
                vlan_del_from_slave(dev, slave, in_param, port);