> -----Original Message-----
> From: Robert Malz <[email protected]>
> Sent: Tuesday, October 21, 2025 8:45 AM
> To: [email protected]; [email protected]
> Cc: Nguyen, Anthony L <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; Andrew Lunn <[email protected]>; David
> S . Miller <[email protected]>; Eric Dumazet <[email protected]>;
> Jakub Kicinski <[email protected]>; Paolo Abeni <[email protected]>; Simon
> Horman <[email protected]>; Loktionov, Aleksandr
> <[email protected]>; Czapnik, Lukasz <[email protected]>;
> Robert Malz <[email protected]>; Jamie Bainbridge
> <[email protected]>; Jay Vosburgh <[email protected]>;
> Dennis Chen <[email protected]>; Keller, Jacob E <[email protected]>;
> Michal Swiatkowski <[email protected]>
> Subject: [PATCH] i40e: avoid redundant VF link state updates
>
> From: Jay Vosburgh <[email protected]>
>
> Multiple sources can request VF link state changes with identical
> parameters. For example, Neutron may request to set the VF link state to
> IFLA_VF_LINK_STATE_AUTO during every initialization or user can issue:
> `ip link set <ifname> vf 0 state auto` multiple times. Currently, the i40e
> driver processes each of these requests, even if the requested state is
> the same as the current one. This leads to unnecessary VF resets and can
> cause performance degradation or instability in the VF driver - particularly
> in DPDK environment.
>
> With this patch i40e will skip VF link state change requests when the
> desired link state matches the current configuration. This prevents
> unnecessary VF resets and reduces PF-VF communication overhead.
>
> Co-developed-by: Robert Malz <[email protected]>
> Signed-off-by: Robert Malz <[email protected]>
> Signed-off-by: Jay Vosburgh <[email protected]>
> ---
> drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> index 081a4526a2f0..0fe0d52c796b 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> @@ -4788,6 +4788,7 @@ int i40e_ndo_set_vf_link_state(struct net_device
> *netdev, int vf_id, int link)
> unsigned long q_map;
> struct i40e_vf *vf;
> int abs_vf_id;
> + int old_link;
> int ret = 0;
> int tmp;
>
> @@ -4806,6 +4807,17 @@ int i40e_ndo_set_vf_link_state(struct net_device
> *netdev, int vf_id, int link)
> vf = &pf->vf[vf_id];
> abs_vf_id = vf->vf_id + hw->func_caps.vf_base_id;
>
> + /* skip VF link state change if requested state is already set */
> + if (!vf->link_forced)
> + old_link = IFLA_VF_LINK_STATE_AUTO;
> + else if (vf->link_up)
> + old_link = IFLA_VF_LINK_STATE_ENABLE;
> + else
> + old_link = IFLA_VF_LINK_STATE_DISABLE;
> +
> + if (link == old_link)
> + goto error_out;
> +
This seems reasonable to me. We should check if ice needs something similar as
well.
Thanks,
Jake
> pfe.event = VIRTCHNL_EVENT_LINK_CHANGE;
> pfe.severity = PF_EVENT_SEVERITY_INFO;
>
> --
> 2.34.1
