> -----Original Message-----
> From: [email protected] <[email protected]>
> Sent: Thursday, November 13, 2025 9:05 AM
> To: Loktionov, Aleksandr <[email protected]>; Nguyen,
> Anthony L <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]
> Cc: [email protected]; [email protected]; linux-
> [email protected]; Gregory Herrero <[email protected]>
> Subject: [PATCH v2 1/1] i40e: validate ring_len parameter against
> hardware-specific values.
> 
Please drop the trailing period from the subject.

> From: Gregory Herrero <[email protected]>
> 
> The maximum number of descriptors supported by the hardware is
> hardware dependent and can be retrieved using
> i40e_get_max_num_descriptors().
> Move this function to a shared header and use it when checking for
> valid ring_len parameter rather than using hardcoded value.
> Cast info->ring_len to u32 in i40e_config_vsi_tx_queue() as it's u16
> in struct virtchnl_txq_info.
> Also cast it in i40e_config_vsi_rx_queue() even if it's u32 in
> virtchnl_rxq_info to ease stable backport in case this changed.
> 
> By fixing an over-acceptance issue, behavior change could be seen
> where ring_len would now be rejected whereas it was not before.
> 
Please add a short “Tested:” explanation (what hw/flows, expected/actual 
before/after).

> Fixes: 55d225670def ("i40e: add validation for ring_len param")
> Signed-off-by: Gregory Herrero <[email protected]>
> ---
>  drivers/net/ethernet/intel/i40e/i40e.h          | 17
> +++++++++++++++++
>  drivers/net/ethernet/intel/i40e/i40e_ethtool.c  | 12 ------------
> .../net/ethernet/intel/i40e/i40e_virtchnl_pf.c  |  4 ++--
>  3 files changed, 19 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h
> b/drivers/net/ethernet/intel/i40e/i40e.h
> index 801a57a925da..a953cce008f4 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e.h
> +++ b/drivers/net/ethernet/intel/i40e/i40e.h
> @@ -1418,4 +1418,21 @@ static inline struct i40e_veb
> *i40e_pf_get_main_veb(struct i40e_pf *pf)
>       return (pf->lan_veb != I40E_NO_VEB) ? pf->veb[pf->lan_veb] :
> NULL;  }
> 
> +/**
> + * i40e_get_max_num_descriptors - get maximum number of descriptors
> for this hardware.
> + * @pf: pointer to a PF
> + *
> + * Return: u32 value corresponding to the maximum number of
> descriptors.
> + **/
> +static inline u32 i40e_get_max_num_descriptors(const struct i40e_pf
> +*pf) {
> +     const struct i40e_hw *hw = &pf->hw;
> +
> +     switch (hw->mac.type) {
> +     case I40E_MAC_XL710:
> +             return I40E_MAX_NUM_DESCRIPTORS_XL710;
> +     default:
> +             return I40E_MAX_NUM_DESCRIPTORS;
> +     }
> +}
>  #endif /* _I40E_H_ */
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> index 86c72596617a..61c39e881b00 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> @@ -2013,18 +2013,6 @@ static void i40e_get_drvinfo(struct net_device
> *netdev,
>               drvinfo->n_priv_flags += I40E_GL_PRIV_FLAGS_STR_LEN;  }
> 
> -static u32 i40e_get_max_num_descriptors(struct i40e_pf *pf) -{
> -     struct i40e_hw *hw = &pf->hw;
> -
> -     switch (hw->mac.type) {
> -     case I40E_MAC_XL710:
> -             return I40E_MAX_NUM_DESCRIPTORS_XL710;
> -     default:
> -             return I40E_MAX_NUM_DESCRIPTORS;
> -     }
> -}
> -
>  static void i40e_get_ringparam(struct net_device *netdev,
>                              struct ethtool_ringparam *ring,
>                              struct kernel_ethtool_ringparam
> *kernel_ring, diff --git
> a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> index 081a4526a2f0..5e058159057b 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> @@ -656,7 +656,7 @@ static int i40e_config_vsi_tx_queue(struct i40e_vf
> *vf, u16 vsi_id,
> 
>       /* ring_len has to be multiple of 8 */
>       if (!IS_ALIGNED(info->ring_len, 8) ||
> -         info->ring_len > I40E_MAX_NUM_DESCRIPTORS_XL710) {
> +         (u32)info->ring_len > i40e_get_max_num_descriptors(pf)) {
>               ret = -EINVAL;
>               goto error_context;
>       }
> @@ -726,7 +726,7 @@ static int i40e_config_vsi_rx_queue(struct i40e_vf
> *vf, u16 vsi_id,
> 
>       /* ring_len has to be multiple of 32 */
>       if (!IS_ALIGNED(info->ring_len, 32) ||
> -         info->ring_len > I40E_MAX_NUM_DESCRIPTORS_XL710) {
> +         (u32)info->ring_len > i40e_get_max_num_descriptors(pf)) {
virtchnl_rxq_info.ring_len is already u32 (as noted in the commit message).
Casting it to u32 before comparison is redundant and adds churn without value 
in mainline.
The (u32) cast on info->ring_len can be dropped in mainline; if you need it 
only for a stable backport, consider keeping the mainline patch minimal and 
adding the backport‑only hunk when submitting to stable.

With the best regards,
Alex

>               ret = -EINVAL;
>               goto error_param;
>       }
> --
> 2.51.0

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