Re: [dpdk-dev] [PATCH] net/i40e: do not turn on flexible payload on driver init

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

> -----Original Message-----
> From: Rybalchenko, Kirill
> Sent: Wednesday, November 29, 2017 8:56 PM
> To: dev@dpdk.org
> Cc: Rybalchenko, Kirill <kirill.rybalchenko@intel.com>; Chilikin, Andrey
> <andrey.chilikin@intel.com>; Xing, Beilei <beilei.xing@intel.com>; Wu,
> Jingjing <jingjing.wu@intel.com>
> Subject: [PATCH] net/i40e: do not turn on flexible payload on driver init
> 
> Function i40e_GLQF_reg_init() overwrites global register for flexible payload,
> forcing extraction of first 16 bytes of L2/L3/L4 payload to the field vector
> even if flexible payload is not used by an application. Such unconditional turn
> on of flexible payload effectively disables ability to use outer IP Destination
> address for RSS/FDIR for tunnelled packets, as flexible payload overwrites
> outer IP destination address on the field vector.
> 
> Now flexible payload turned on only when flow director is enabled and
> configured.
> 
> Signed-off-by: Kirill Rybalchenko <kirill.rybalchenko@intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev.c | 11 -----------
>  drivers/net/i40e/i40e_fdir.c   |  8 ++++++++
>  2 files changed, 8 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 811cc9f..de5e2a3 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -701,17 +701,6 @@ RTE_PMD_REGISTER_KMOD_DEP(net_i40e, "*
> igb_uio | uio_pci_generic | vfio-pci");  static inline void
> i40e_GLQF_reg_init(struct i40e_hw *hw)  {
>  	/*
> -	 * Force global configuration for flexible payload
> -	 * to the first 16 bytes of the corresponding L2/L3/L4 paylod.
> -	 * This should be removed from code once proper
> -	 * configuration API is added to avoid configuration conflicts
> -	 * between ports of the same device.
> -	 */
> -	I40E_WRITE_REG(hw, I40E_GLQF_ORT(33), 0x000000E0);
> -	I40E_WRITE_REG(hw, I40E_GLQF_ORT(34), 0x000000E3);
> -	I40E_WRITE_REG(hw, I40E_GLQF_ORT(35), 0x000000E6);
> -
> -	/*
>  	 * Initialize registers for parsing packet type of QinQ
>  	 * This should be removed from code once proper
>  	 * configuration API is added to avoid configuration conflicts diff --git
> a/drivers/net/i40e/i40e_fdir.c b/drivers/net/i40e/i40e_fdir.c index
> 3d7170d..8191f72 100644
> --- a/drivers/net/i40e/i40e_fdir.c
> +++ b/drivers/net/i40e/i40e_fdir.c
> @@ -342,6 +342,14 @@ i40e_init_flx_pld(struct i40e_pf *pf)
>  	uint16_t flow_type;
> 
>  	/*
> +	 * Force global configuration for flexible payload
> +	 * to the first 16 bytes of the corresponding L2/L3/L4 paylod.
> +	 */
> +	I40E_WRITE_REG(hw, I40E_GLQF_ORT(33), 0x000000E0);
> +	I40E_WRITE_REG(hw, I40E_GLQF_ORT(34), 0x000000E3);
> +	I40E_WRITE_REG(hw, I40E_GLQF_ORT(35), 0x000000E6);
> +

In this case, the global registers will be set when enabling flow director, but it won't
be reset to default value unless core reset. So need an alternative mechanism to
configure the global registers.

> +	/*
>  	 * Define the bytes stream extracted as flexible payload in
>  	 * field vector. By default, select 8 words from the beginning
>  	 * of payload as flexible payload.
> --
> 2.5.5