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* [bug report] net/mlx5: Implement devlink total_vfs parameter
@ 2025-09-12 12:47 Dan Carpenter
  2025-09-14 17:04 ` Vlad Dumitrescu
  0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2025-09-12 12:47 UTC (permalink / raw)
  To: Vlad Dumitrescu; +Cc: linux-rdma

Hello Vlad Dumitrescu,

Commit a4c49611cf4f ("net/mlx5: Implement devlink total_vfs
parameter") from Sep 6, 2025 (linux-next), leads to the following
Smatch static checker warning:

	drivers/net/ethernet/mellanox/mlx5/core/lib/nv_param.c:494 mlx5_devlink_total_vfs_set()
	warn: duplicate check 'per_pf_support' (previous on line 479)

drivers/net/ethernet/mellanox/mlx5/core/lib/nv_param.c
    455 static int mlx5_devlink_total_vfs_set(struct devlink *devlink, u32 id,
    456                                       struct devlink_param_gset_ctx *ctx,
    457                                       struct netlink_ext_ack *extack)
    458 {
    459         struct mlx5_core_dev *dev = devlink_priv(devlink);
    460         u32 mnvda[MLX5_ST_SZ_DW(mnvda_reg)];
    461         bool per_pf_support;
    462         void *data;
    463         int err;
    464 
    465         err = mlx5_nv_param_read_global_pci_cap(dev, mnvda, sizeof(mnvda));
    466         if (err) {
    467                 NL_SET_ERR_MSG_MOD(extack, "Failed to read global pci cap");
    468                 return err;
    469         }
    470 
    471         data = MLX5_ADDR_OF(mnvda_reg, mnvda, configuration_item_data);
    472         if (!MLX5_GET(nv_global_pci_cap, data, sriov_support)) {
    473                 NL_SET_ERR_MSG_MOD(extack, "Not configurable on this device");
    474                 return -EOPNOTSUPP;
    475         }
    476 
    477         per_pf_support = MLX5_GET(nv_global_pci_cap, data,
    478                                   per_pf_total_vf_supported);
    479         if (!per_pf_support) {
    480                 /* We don't allow global SRIOV setting on per PF devlink */
    481                 NL_SET_ERR_MSG_MOD(extack,
    482                                    "SRIOV is not per PF on this device");
    483                 return -EOPNOTSUPP;

!per_pf_support is not supported.

    484         }
    485 
    486         memset(mnvda, 0, sizeof(mnvda));
    487         err = mlx5_nv_param_read_global_pci_conf(dev, mnvda, sizeof(mnvda));
    488         if (err)
    489                 return err;
    490 
    491         MLX5_SET(nv_global_pci_conf, data, sriov_valid, 1);
    492         MLX5_SET(nv_global_pci_conf, data, per_pf_total_vf, per_pf_support);
    493 
--> 494         if (!per_pf_support) {
    495                 MLX5_SET(nv_global_pci_conf, data, total_vfs, ctx->val.vu32);
    496                 return mlx5_nv_param_write(dev, mnvda, sizeof(mnvda));

Dead code.

    497         }
    498 
    499         /* SRIOV is per PF */
    500         err = mlx5_nv_param_write(dev, mnvda, sizeof(mnvda));
    501         if (err)
    502                 return err;
    503 
    504         memset(mnvda, 0, sizeof(mnvda));
    505         err = mlx5_nv_param_read_per_host_pf_conf(dev, mnvda, sizeof(mnvda));
    506         if (err)
    507                 return err;
    508 
    509         data = MLX5_ADDR_OF(mnvda_reg, mnvda, configuration_item_data);
    510         MLX5_SET(nv_pf_pci_conf, data, total_vf, ctx->val.vu32);
    511         return mlx5_nv_param_write(dev, mnvda, sizeof(mnvda));
    512 }

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [bug report] net/mlx5: Implement devlink total_vfs parameter
  2025-09-12 12:47 [bug report] net/mlx5: Implement devlink total_vfs parameter Dan Carpenter
@ 2025-09-14 17:04 ` Vlad Dumitrescu
  0 siblings, 0 replies; 2+ messages in thread
From: Vlad Dumitrescu @ 2025-09-14 17:04 UTC (permalink / raw)
  To: Saeed Mahameed; +Cc: linux-rdma, Dan Carpenter

On 9/12/25 05:47, Dan Carpenter wrote:
> Hello Vlad Dumitrescu,
> 
> Commit a4c49611cf4f ("net/mlx5: Implement devlink total_vfs
> parameter") from Sep 6, 2025 (linux-next), leads to the following
> Smatch static checker warning:
> 
> 	drivers/net/ethernet/mellanox/mlx5/core/lib/nv_param.c:494 mlx5_devlink_total_vfs_set()
> 	warn: duplicate check 'per_pf_support' (previous on line 479)
> 
> drivers/net/ethernet/mellanox/mlx5/core/lib/nv_param.c
>     455 static int mlx5_devlink_total_vfs_set(struct devlink *devlink, u32 id,
>     456                                       struct devlink_param_gset_ctx *ctx,
>     457                                       struct netlink_ext_ack *extack)
>     458 {
>     459         struct mlx5_core_dev *dev = devlink_priv(devlink);
>     460         u32 mnvda[MLX5_ST_SZ_DW(mnvda_reg)];
>     461         bool per_pf_support;
>     462         void *data;
>     463         int err;
>     464 
>     465         err = mlx5_nv_param_read_global_pci_cap(dev, mnvda, sizeof(mnvda));
>     466         if (err) {
>     467                 NL_SET_ERR_MSG_MOD(extack, "Failed to read global pci cap");
>     468                 return err;
>     469         }
>     470 
>     471         data = MLX5_ADDR_OF(mnvda_reg, mnvda, configuration_item_data);
>     472         if (!MLX5_GET(nv_global_pci_cap, data, sriov_support)) {
>     473                 NL_SET_ERR_MSG_MOD(extack, "Not configurable on this device");
>     474                 return -EOPNOTSUPP;
>     475         }
>     476 
>     477         per_pf_support = MLX5_GET(nv_global_pci_cap, data,
>     478                                   per_pf_total_vf_supported);
>     479         if (!per_pf_support) {
>     480                 /* We don't allow global SRIOV setting on per PF devlink */
>     481                 NL_SET_ERR_MSG_MOD(extack,
>     482                                    "SRIOV is not per PF on this device");
>     483                 return -EOPNOTSUPP;
> 
> !per_pf_support is not supported.
> 
>     484         }
>     485 
>     486         memset(mnvda, 0, sizeof(mnvda));
>     487         err = mlx5_nv_param_read_global_pci_conf(dev, mnvda, sizeof(mnvda));
>     488         if (err)
>     489                 return err;
>     490 
>     491         MLX5_SET(nv_global_pci_conf, data, sriov_valid, 1);
>     492         MLX5_SET(nv_global_pci_conf, data, per_pf_total_vf, per_pf_support);
>     493 
> --> 494         if (!per_pf_support) {
>     495                 MLX5_SET(nv_global_pci_conf, data, total_vfs, ctx->val.vu32);
>     496                 return mlx5_nv_param_write(dev, mnvda, sizeof(mnvda));
> 
> Dead code.
> 
>     497         }
>     498 
>     499         /* SRIOV is per PF */
>     500         err = mlx5_nv_param_write(dev, mnvda, sizeof(mnvda));
>     501         if (err)
>     502                 return err;
>     503 
>     504         memset(mnvda, 0, sizeof(mnvda));
>     505         err = mlx5_nv_param_read_per_host_pf_conf(dev, mnvda, sizeof(mnvda));
>     506         if (err)
>     507                 return err;
>     508 
>     509         data = MLX5_ADDR_OF(mnvda_reg, mnvda, configuration_item_data);
>     510         MLX5_SET(nv_pf_pci_conf, data, total_vf, ctx->val.vu32);
>     511         return mlx5_nv_param_write(dev, mnvda, sizeof(mnvda));
>     512 }

Dan, thank you for the report!

Saeed, it seems like this was introduced all the way back in v2.

Vlad

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2025-09-14 17:04 UTC | newest]

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2025-09-12 12:47 [bug report] net/mlx5: Implement devlink total_vfs parameter Dan Carpenter
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