Re: [PATCH 3/4] vdpa/mlx5: Add debugfs subtree

[Si-Wei Liu <si-wei.liu@oracle.com>]

On 10/18/2022 4:12 AM, Eli Cohen wrote:
> Add debugfs subtree and expose flow table ID and TIR number. This
> information can be used by external tools to do extended
> troubleshooting.
>
> The information can be retrieved like so:
> $ cat /sys/kernel/debug/mlx5/mlx5_core.sf.1/vdpa-0/rx/table_id
> $ cat /sys/kernel/debug/mlx5/mlx5_core.sf.1/vdpa-0/rx/tirn
>
> Signed-off-by: Eli Cohen <elic@nvidia.com>
LGTM

Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>
> ---
>   drivers/vdpa/mlx5/Makefile        |  2 +-
>   drivers/vdpa/mlx5/net/debug.c     | 66 +++++++++++++++++++++++++++++++
>   drivers/vdpa/mlx5/net/mlx5_vnet.c | 11 ++++++
>   drivers/vdpa/mlx5/net/mlx5_vnet.h |  9 +++++
>   4 files changed, 87 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/vdpa/mlx5/net/debug.c
>
> diff --git a/drivers/vdpa/mlx5/Makefile b/drivers/vdpa/mlx5/Makefile
> index f717978c83bf..e791394c33e3 100644
> --- a/drivers/vdpa/mlx5/Makefile
> +++ b/drivers/vdpa/mlx5/Makefile
> @@ -1,4 +1,4 @@
>   subdir-ccflags-y += -I$(srctree)/drivers/vdpa/mlx5/core
>   
>   obj-$(CONFIG_MLX5_VDPA_NET) += mlx5_vdpa.o
> -mlx5_vdpa-$(CONFIG_MLX5_VDPA_NET) += net/mlx5_vnet.o core/resources.o core/mr.o
> +mlx5_vdpa-$(CONFIG_MLX5_VDPA_NET) += net/mlx5_vnet.o core/resources.o core/mr.o net/debug.o
> diff --git a/drivers/vdpa/mlx5/net/debug.c b/drivers/vdpa/mlx5/net/debug.c
> new file mode 100644
> index 000000000000..95e4801df211
> --- /dev/null
> +++ b/drivers/vdpa/mlx5/net/debug.c
> @@ -0,0 +1,66 @@
> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
> +/* Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
> +
> +#include <linux/debugfs.h>
> +#include <linux/mlx5/fs.h>
> +#include "mlx5_vnet.h"
> +
> +static int tirn_show(struct seq_file *file, void *priv)
> +{
> +	struct mlx5_vdpa_net *ndev = file->private;
> +
> +	seq_printf(file, "0x%x\n", ndev->res.tirn);
> +	return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(tirn);
> +
> +void mlx5_vdpa_remove_tirn(struct mlx5_vdpa_net *ndev)
> +{
> +	if (ndev->debugfs)
> +		debugfs_remove(ndev->res.tirn_dent);
> +}
> +
> +void mlx5_vdpa_add_tirn(struct mlx5_vdpa_net *ndev)
> +{
> +	ndev->res.tirn_dent = debugfs_create_file("tirn", 0444, ndev->rx_dent,
> +						  ndev, &tirn_fops);
> +}
> +
> +static int rx_flow_table_show(struct seq_file *file, void *priv)
> +{
> +	struct mlx5_vdpa_net *ndev = file->private;
> +
> +	seq_printf(file, "0x%x\n", mlx5_flow_table_id(ndev->rxft));
> +	return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(rx_flow_table);
> +
> +void mlx5_vdpa_remove_rx_flow_table(struct mlx5_vdpa_net *ndev)
> +{
> +	if (ndev->debugfs)
> +		debugfs_remove(ndev->rx_table_dent);
> +}
> +
> +void mlx5_vdpa_add_rx_flow_table(struct mlx5_vdpa_net *ndev)
> +{
> +	ndev->rx_table_dent = debugfs_create_file("table_id", 0444, ndev->rx_dent,
> +						  ndev, &rx_flow_table_fops);
> +}
> +
> +void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev)
> +{
> +	struct mlx5_core_dev *mdev;
> +
> +	mdev = ndev->mvdev.mdev;
> +	ndev->debugfs = debugfs_create_dir(dev_name(&ndev->mvdev.vdev.dev),
> +					   mlx5_debugfs_get_dev_root(mdev));
> +	if (!IS_ERR(ndev->debugfs))
> +		ndev->rx_dent = debugfs_create_dir("rx", ndev->debugfs);
> +}
> +
> +void mlx5_vdpa_remove_debugfs(struct dentry *dbg)
> +{
> +	debugfs_remove_recursive(dbg);
> +}
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 64fdb940380f..ee50da33e25b 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1388,11 +1388,16 @@ static int create_tir(struct mlx5_vdpa_net *ndev)
>   
>   	err = mlx5_vdpa_create_tir(&ndev->mvdev, in, &ndev->res.tirn);
>   	kfree(in);
> +	if (err)
> +		return err;
> +
> +	mlx5_vdpa_add_tirn(ndev);
>   	return err;
>   }
>   
>   static void destroy_tir(struct mlx5_vdpa_net *ndev)
>   {
> +	mlx5_vdpa_remove_tirn(ndev);
>   	mlx5_vdpa_destroy_tir(&ndev->mvdev, ndev->res.tirn);
>   }
>   
> @@ -1576,6 +1581,7 @@ static int setup_steering(struct mlx5_vdpa_net *ndev)
>   		mlx5_vdpa_warn(&ndev->mvdev, "failed to create flow table\n");
>   		return PTR_ERR(ndev->rxft);
>   	}
> +	mlx5_vdpa_add_rx_flow_table(ndev);
>   
>   	err = mac_vlan_add(ndev, ndev->config.mac, 0, false);
>   	if (err)
> @@ -1584,6 +1590,7 @@ static int setup_steering(struct mlx5_vdpa_net *ndev)
>   	return 0;
>   
>   err_add:
> +	mlx5_vdpa_remove_rx_flow_table(ndev);
>   	mlx5_destroy_flow_table(ndev->rxft);
>   	return err;
>   }
> @@ -1591,6 +1598,7 @@ static int setup_steering(struct mlx5_vdpa_net *ndev)
>   static void teardown_steering(struct mlx5_vdpa_net *ndev)
>   {
>   	clear_mac_vlan_table(ndev);
> +	mlx5_vdpa_remove_rx_flow_table(ndev);
>   	mlx5_destroy_flow_table(ndev->rxft);
>   }
>   
> @@ -3167,6 +3175,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>   	if (err)
>   		goto err_reg;
>   
> +	mlx5_vdpa_add_debugfs(ndev);
>   	mgtdev->ndev = ndev;
>   	return 0;
>   
> @@ -3193,6 +3202,8 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device *
>   	struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
>   	struct workqueue_struct *wq;
>   
> +	mlx5_vdpa_remove_debugfs(ndev->debugfs);
> +	ndev->debugfs = NULL;
>   	if (ndev->nb_registered) {
>   		mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);
>   		ndev->nb_registered = false;
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.h b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> index 6691c879a6ca..f2cef3925e5b 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.h
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> @@ -16,6 +16,7 @@ struct mlx5_vdpa_net_resources {
>   	u32 tirn;
>   	u32 rqtn;
>   	bool valid;
> +	struct dentry *tirn_dent;
>   };
>   
>   #define MLX5V_MACVLAN_SIZE 256
> @@ -43,6 +44,7 @@ struct mlx5_vdpa_net {
>   	struct vdpa_callback config_cb;
>   	struct mlx5_vdpa_wq_ent cvq_ent;
>   	struct hlist_head macvlan_hash[MLX5V_MACVLAN_SIZE];
> +	struct dentry *debugfs;
>   };
>   
>   struct macvlan_node {
> @@ -52,4 +54,11 @@ struct macvlan_node {
>   	u64 macvlan;
>   };
>   
> +void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev);
> +void mlx5_vdpa_remove_debugfs(struct dentry *dbg);
> +void mlx5_vdpa_add_rx_flow_table(struct mlx5_vdpa_net *ndev);
> +void mlx5_vdpa_remove_rx_flow_table(struct mlx5_vdpa_net *ndev);
> +void mlx5_vdpa_add_tirn(struct mlx5_vdpa_net *ndev);
> +void mlx5_vdpa_remove_tirn(struct mlx5_vdpa_net *ndev);
> +
>   #endif /* __MLX5_VNET_H__ */