Subject: Re: [PATCH net-next 2/9] ice: devlink PF MSI-X max and min parameter

From: David Laight <[email-masked]>
Date: Mon, 3 Feb 2025 21:48:08 +0000

On Mon,  3 Feb 2025 13:09:31 -0800
Tony Nguyen <[email-masked]> wrote:

> From: Michal Swiatkowski <[email-masked]>
> 
> Use generic devlink PF MSI-X parameter to allow user to change MSI-X
> range.
> 
> Add notes about this parameters into ice devlink documentation.
> 
> Tested-by: Pucha Himasekhar Reddy <[email-masked]>
> Signed-off-by: Michal Swiatkowski <[email-masked]>
> ---
>  Documentation/networking/devlink/ice.rst      | 11 +++
>  .../net/ethernet/intel/ice/devlink/devlink.c  | 88 +++++++++++++++++++
>  drivers/net/ethernet/intel/ice/ice.h          |  7 ++
>  drivers/net/ethernet/intel/ice/ice_irq.c      |  7 ++
>  4 files changed, 113 insertions(+)
> 
> diff --git a/Documentation/networking/devlink/ice.rst b/Documentation/networking/devlink/ice.rst
> index e3972d03cea0..792e9f8c846a 100644
> --- a/Documentation/networking/devlink/ice.rst
> +++ b/Documentation/networking/devlink/ice.rst
> @@ -69,6 +69,17 @@ Parameters
>  
>         To verify that value has been set:
>         $ devlink dev param show pci/0000:16:00.0 name tx_scheduling_layers
> +   * - ``msix_vec_per_pf_max``
> +     - driverinit
> +     - Set the max MSI-X that can be used by the PF, rest can be utilized for
> +       SRIOV. The range is from min value set in msix_vec_per_pf_min to
> +       2k/number of ports.
> +   * - ``msix_vec_per_pf_min``
> +     - driverinit
> +     - Set the min MSI-X that will be used by the PF. This value inform how many
> +       MSI-X will be allocated statically. The range is from 2 to value set
> +       in msix_vec_per_pf_max.
> +
>  .. list-table:: Driver specific parameters implemented
>      :widths: 5 5 90
>  
> diff --git a/drivers/net/ethernet/intel/ice/devlink/devlink.c b/drivers/net/ethernet/intel/ice/devlink/devlink.c
> index d116e2b10bce..c53baecf8a90 100644
> --- a/drivers/net/ethernet/intel/ice/devlink/devlink.c
> +++ b/drivers/net/ethernet/intel/ice/devlink/devlink.c
> @@ -1202,6 +1202,25 @@ static int ice_devlink_set_parent(struct devlink_rate *devlink_rate,
>  	return status;
>  }
>  
> +static void ice_set_min_max_msix(struct ice_pf *pf)
> +{
> +	struct devlink *devlink = priv_to_devlink(pf);
> +	union devlink_param_value val;
> +	int err;
> +
> +	err = devl_param_driverinit_value_get(devlink,
> +					      DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MIN,
> +					      &val);
> +	if (!err)
> +		pf->msix.min = val.vu32;
> +
> +	err = devl_param_driverinit_value_get(devlink,
> +					      DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MAX,
> +					      &val);
> +	if (!err)
> +		pf->msix.max = val.vu32;
> +}
> +
>  /**
>   * ice_devlink_reinit_up - do reinit of the given PF
>   * @pf: pointer to the PF struct
> @@ -1217,6 +1236,9 @@ static int ice_devlink_reinit_up(struct ice_pf *pf)
>  		return err;
>  	}
>  
> +	/* load MSI-X values */
> +	ice_set_min_max_msix(pf);
> +
>  	err = ice_init_dev(pf);
>  	if (err)
>  		goto unroll_hw_init;
> @@ -1530,6 +1552,37 @@ static int ice_devlink_local_fwd_validate(struct devlink *devlink, u32 id,
>  	return 0;
>  }
>  
> +static int
> +ice_devlink_msix_max_pf_validate(struct devlink *devlink, u32 id,
> +				 union devlink_param_value val,
> +				 struct netlink_ext_ack *extack)
> +{
> +	struct ice_pf *pf = devlink_priv(devlink);
> +
> +	if (val.vu32 > pf->hw.func_caps.common_cap.num_msix_vectors ||
> +	    val.vu32 < pf->msix.min) {
> +		NL_SET_ERR_MSG_MOD(extack, "Value is invalid");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +ice_devlink_msix_min_pf_validate(struct devlink *devlink, u32 id,
> +				 union devlink_param_value val,
> +				 struct netlink_ext_ack *extack)
> +{
> +	struct ice_pf *pf = devlink_priv(devlink);
> +
> +	if (val.vu32 < ICE_MIN_MSIX || val.vu32 > pf->msix.max) {
> +		NL_SET_ERR_MSG_MOD(extack, "Value is invalid");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}

Don't those checks make it difficult to set the min and max together?
I think you need to create the new min/max pair and check they are
valid together.
Which probably requires one parameter with two values.

	David

> +
>  enum ice_param_id {
>  	ICE_DEVLINK_PARAM_ID_BASE = DEVLINK_PARAM_GENERIC_ID_MAX,
>  	ICE_DEVLINK_PARAM_ID_TX_SCHED_LAYERS,
> @@ -1547,6 +1600,15 @@ static const struct devlink_param ice_dvl_rdma_params[] = {
>  			      ice_devlink_enable_iw_validate),
>  };
>  
> +static const struct devlink_param ice_dvl_msix_params[] = {
> +	DEVLINK_PARAM_GENERIC(MSIX_VEC_PER_PF_MAX,
> +			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
> +			      NULL, NULL, ice_devlink_msix_max_pf_validate),
> +	DEVLINK_PARAM_GENERIC(MSIX_VEC_PER_PF_MIN,
> +			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
> +			      NULL, NULL, ice_devlink_msix_min_pf_validate),
> +};
> +
>  static const struct devlink_param ice_dvl_sched_params[] = {
>  	DEVLINK_PARAM_DRIVER(ICE_DEVLINK_PARAM_ID_TX_SCHED_LAYERS,
>  			     "tx_scheduling_layers",
> @@ -1648,6 +1710,7 @@ void ice_devlink_unregister(struct ice_pf *pf)
>  int ice_devlink_register_params(struct ice_pf *pf)
>  {
>  	struct devlink *devlink = priv_to_devlink(pf);
> +	union devlink_param_value value;
>  	struct ice_hw *hw = &pf->hw;
>  	int status;
>  
> @@ -1656,10 +1719,33 @@ int ice_devlink_register_params(struct ice_pf *pf)
>  	if (status)
>  		return status;
>  
> +	status = devl_params_register(devlink, ice_dvl_msix_params,
> +				      ARRAY_SIZE(ice_dvl_msix_params));
> +	if (status)
> +		goto unregister_rdma_params;
> +
>  	if (hw->func_caps.common_cap.tx_sched_topo_comp_mode_en)
>  		status = devl_params_register(devlink, ice_dvl_sched_params,
>  					      ARRAY_SIZE(ice_dvl_sched_params));
> +	if (status)
> +		goto unregister_msix_params;
> +
> +	value.vu32 = pf->msix.max;
> +	devl_param_driverinit_value_set(devlink,
> +					DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MAX,
> +					value);
> +	value.vu32 = pf->msix.min;
> +	devl_param_driverinit_value_set(devlink,
> +					DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MIN,
> +					value);
> +	return 0;
>  
> +unregister_msix_params:
> +	devl_params_unregister(devlink, ice_dvl_msix_params,
> +			       ARRAY_SIZE(ice_dvl_msix_params));
> +unregister_rdma_params:
> +	devl_params_unregister(devlink, ice_dvl_rdma_params,
> +			       ARRAY_SIZE(ice_dvl_rdma_params));
>  	return status;
>  }
>  
> @@ -1670,6 +1756,8 @@ void ice_devlink_unregister_params(struct ice_pf *pf)
>  
>  	devl_params_unregister(devlink, ice_dvl_rdma_params,
>  			       ARRAY_SIZE(ice_dvl_rdma_params));
> +	devl_params_unregister(devlink, ice_dvl_msix_params,
> +			       ARRAY_SIZE(ice_dvl_msix_params));
>  
>  	if (hw->func_caps.common_cap.tx_sched_topo_comp_mode_en)
>  		devl_params_unregister(devlink, ice_dvl_sched_params,
> diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
> index 71e05d30f0fd..d041b04ff324 100644
> --- a/drivers/net/ethernet/intel/ice/ice.h
> +++ b/drivers/net/ethernet/intel/ice/ice.h
> @@ -542,6 +542,12 @@ struct ice_agg_node {
>  	u8 valid;
>  };
>  
> +struct ice_pf_msix {
> +	u32 cur;
> +	u32 min;
> +	u32 max;
> +};
> +
>  struct ice_pf {
>  	struct pci_dev *pdev;
>  	struct ice_adapter *adapter;
> @@ -612,6 +618,7 @@ struct ice_pf {
>  	struct msi_map ll_ts_irq;	/* LL_TS interrupt MSIX vector */
>  	u16 max_pf_txqs;	/* Total Tx queues PF wide */
>  	u16 max_pf_rxqs;	/* Total Rx queues PF wide */
> +	struct ice_pf_msix msix;
>  	u16 num_lan_msix;	/* Total MSIX vectors for base driver */
>  	u16 num_lan_tx;		/* num LAN Tx queues setup */
>  	u16 num_lan_rx;		/* num LAN Rx queues setup */
> diff --git a/drivers/net/ethernet/intel/ice/ice_irq.c b/drivers/net/ethernet/intel/ice/ice_irq.c
> index ad82ff7d1995..0659b96b9b8c 100644
> --- a/drivers/net/ethernet/intel/ice/ice_irq.c
> +++ b/drivers/net/ethernet/intel/ice/ice_irq.c
> @@ -254,6 +254,13 @@ int ice_init_interrupt_scheme(struct ice_pf *pf)
>  	int total_vectors = pf->hw.func_caps.common_cap.num_msix_vectors;
>  	int vectors, max_vectors;
>  
> +	/* load default PF MSI-X range */
> +	if (!pf->msix.min)
> +		pf->msix.min = ICE_MIN_MSIX;
> +
> +	if (!pf->msix.max)
> +		pf->msix.max = total_vectors / 2;
> +
>  	vectors = ice_ena_msix_range(pf);
>  
>  	if (vectors < 0)