net/mlx5: Warn for devlink reload when there are VFs alive

When performing PF reload, VF can't communicate with FW until
it recovers and reloads as well.

Add a warning message when performing devlink reload while
VFs are still present. Thus, giving a notice of an unfavorable
behavior that might occur as a result of a consequential reloads
and cause interruption of VF recovery.
Signed-off-by: Lama Kayal <lkayal@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/devlink.c

@@ -136,6 +136,7 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 				    struct netlink_ext_ack *extack)
 {
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
+	struct pci_dev *pdev = dev->pdev;
 	bool sf_dev_allocated;
 
 	sf_dev_allocated = mlx5_sf_dev_allocated(dev);
@@ -153,6 +154,10 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 		return -EOPNOTSUPP;
 	}
 
+	if (pci_num_vf(pdev)) {
+		NL_SET_ERR_MSG_MOD(extack, "reload while VFs are present is unfavorable");
+	}
+
 	switch (action) {
 	case DEVLINK_RELOAD_ACTION_DRIVER_REINIT:
 		mlx5_unload_one(dev);