RE: [PATCH v4] net/i40e: restore disable double VLAN by default

["Xing, Beilei" <beilei.xing@intel.com>]

> -----Original Message-----
> From: Liu, KevinX <kevinx.liu@intel.com>
> Sent: Friday, July 8, 2022 1:05 AM
> To: dev@dpdk.org
> Cc: Xing, Beilei <beilei.xing@intel.com>; Zhang, Yuying
> <yuying.zhang@intel.com>; Yang, SteveX <stevex.yang@intel.com>; Liu, KevinX
> <kevinx.liu@intel.com>
> Subject: [PATCH v4] net/i40e: restore disable double VLAN by default
> 
> Previously, QinQ is enabled by default and can't be disabled, but there'll be
> performance drop if QinQ is enabled.
> 
> So, disable QinQ by default.
> 
> Fixes: ae97b8b89826 ("net/i40e: fix error disable double VLAN")
> Signed-off-by: Kevin Liu <kevinx.liu@intel.com>
> 
> ---
> v2: update doc and refine commit log
> ---
> v3: refine commit log
> ---
> v4: update doc
> ---
>  doc/guides/nics/i40e.rst       | 13 ++++++++-----
>  drivers/net/i40e/i40e_ethdev.c | 12 ------------
>  2 files changed, 8 insertions(+), 17 deletions(-)
> 
> diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst index
> 85fdc4944d..d5938fa8e4 100644
> --- a/doc/guides/nics/i40e.rst
> +++ b/doc/guides/nics/i40e.rst
> @@ -969,11 +969,14 @@ it will fail and return the info "Conflict with the first
> rule's input set",  which means the current rule's input set conflicts with the first
> rule's.
>  Remove the first rule if want to change the input set of the PCTYPE.
> 
> -Disable QinQ is not supported when FW >= 8.4 -
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> -
> -If upgrade FW to version 8.4 and higher, enable QinQ by default and disable
> QinQ is not supported.
> -
> +Vlan related Features miss when FW >= 8.4
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +If FW version >= 8.4, there'll be some Vlan related issues:
> +1. TCI input set for QinQ  is invalid.
> +2. Fail to configure TPID for QinQ.
> +3. Need to enable QinQ before enabling Vlan filter.
> +4. Fail to strip outer Vlan.
> 
>  Example of getting best performance with l3fwd example
>  ------------------------------------------------------
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 684e095026..117dd85c11 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -4027,12 +4027,6 @@ i40e_vlan_offload_set(struct rte_eth_dev *dev, int
> mask)
>  	}
> 
>  	if (mask & RTE_ETH_VLAN_EXTEND_MASK) {
> -		/* Double VLAN not allowed to be disabled.*/
> -		if (pf->fw8_3gt && !(rxmode->offloads &
> RTE_ETH_RX_OFFLOAD_VLAN_EXTEND)) {
> -			PMD_DRV_LOG(WARNING,
> -				"Disable double VLAN is not allowed after
> firmwarev8.3!");
> -			return 0;
> -		}
>  		i = 0;
>  		num = vsi->mac_num;
>  		mac_filter = rte_zmalloc("mac_filter_info_data",
> @@ -6296,7 +6290,6 @@ int i40e_vsi_cfg_inner_vlan_stripping(struct i40e_vsi
> *vsi, bool on)  static int  i40e_dev_init_vlan(struct rte_eth_dev *dev)  {
> -	struct i40e_pf *pf = I40E_DEV_PRIVATE_TO_PF(dev->data-
> >dev_private);
>  	struct rte_eth_dev_data *data = dev->data;
>  	int ret;
>  	int mask = 0;
> @@ -6307,11 +6300,6 @@ i40e_dev_init_vlan(struct rte_eth_dev *dev)
>  	       RTE_ETH_VLAN_FILTER_MASK |
>  	       RTE_ETH_VLAN_EXTEND_MASK;
> 
> -	/* Double VLAN be enabled by default.*/
> -	if (pf->fw8_3gt) {
> -		struct rte_eth_rxmode *rxmode = &dev->data-
> >dev_conf.rxmode;
> -		rxmode->offloads |= RTE_ETH_RX_OFFLOAD_VLAN_EXTEND;
> -	}
>  	ret = i40e_vlan_offload_set(dev, mask);
>  	if (ret) {
>  		PMD_DRV_LOG(INFO, "Failed to update vlan offload");
> --
> 2.34.1

Acked-by: Beilei Xing <beilei.xing@intel.com>