net/mlx5: fix init with zero Rx queue

Recent patch [1] added, at the end of mlx5_dev_configure(), a call to
mlx5_proc_priv_init(), initializing process_private data of eth_dev.
This call is not reached if PMD is started with zero Rx queues.
In this case mlx5_dev_configure() returns earlier due to the check:
	if (rxqs_n == priv->rxqs_n)
		return 0;
In such a scenario, later references to uninitialized process_private
data will result in segmentation fault.
For example see in function txq_uar_init().

This patch changes the check logic. The following code is executed
if (rxqs_n != priv->rxqs_n), and skipped otherwise.
Function mlx5_proc_priv_init() is always invoked, to ensure
process_private data is initialized.

[1] http://patches.dpdk.org/patch/52629/

Fixes: 120dc4a7dcd3 ("net/mlx5: remove device register remap")
Cc: stable@dpdk.org
Signed-off-by: Dekel Peled <dekelp@mellanox.com>
Acked-by: Yongseok Koh <yskoh@mellanox.com>

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index d1a70fc..80ee98f 100644 (file)
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -428,27 +428,31 @@ mlx5_dev_configure(struct rte_eth_dev *dev)
                rte_errno = EINVAL;
                return -rte_errno;
        }
-       if (rxqs_n == priv->rxqs_n)
-               return 0;
-       DRV_LOG(INFO, "port %u Rx queues number update: %u -> %u",
-               dev->data->port_id, priv->rxqs_n, rxqs_n);
-       priv->rxqs_n = rxqs_n;
-       /* If the requested number of RX queues is not a power of two, use the
-        * maximum indirection table size for better balancing.
-        * The result is always rounded to the next power of two. */
-       reta_idx_n = (1 << log2above((rxqs_n & (rxqs_n - 1)) ?
-                                    priv->config.ind_table_max_size :
-                                    rxqs_n));
-       ret = mlx5_rss_reta_index_resize(dev, reta_idx_n);
-       if (ret)
-               return ret;
-       /* When the number of RX queues is not a power of two, the remaining
-        * table entries are padded with reused WQs and hashes are not spread
-        * uniformly. */
-       for (i = 0, j = 0; (i != reta_idx_n); ++i) {
-               (*priv->reta_idx)[i] = j;
-               if (++j == rxqs_n)
-                       j = 0;
+       if (rxqs_n != priv->rxqs_n) {
+               DRV_LOG(INFO, "port %u Rx queues number update: %u -> %u",
+                       dev->data->port_id, priv->rxqs_n, rxqs_n);
+               priv->rxqs_n = rxqs_n;
+               /*
+                * If the requested number of RX queues is not a power of two,
+                * use the maximum indirection table size for better balancing.
+                * The result is always rounded to the next power of two.
+                */
+               reta_idx_n = (1 << log2above((rxqs_n & (rxqs_n - 1)) ?
+                                            priv->config.ind_table_max_size :
+                                            rxqs_n));
+               ret = mlx5_rss_reta_index_resize(dev, reta_idx_n);
+               if (ret)
+                       return ret;
+               /*
+                * When the number of RX queues is not a power of two,
+                * the remaining table entries are padded with reused WQs
+                * and hashes are not spread uniformly.
+                */
+               for (i = 0, j = 0; (i != reta_idx_n); ++i) {
+                       (*priv->reta_idx)[i] = j;
+                       if (++j == rxqs_n)
+                               j = 0;
+               }
        }
        ret = mlx5_proc_priv_init(dev);
        if (ret)