Re: [Intel-wired-lan] [PATCH net-next v7 1/2] ethtool: Add GTP RSS hash options to ethtool.h

[Marcin Szycik <marcin.szycik@linux.intel.com>]

On 01.02.2024 04:33, Takeru Hayasaka wrote:
> This is a patch that enables RSS functionality for GTP packets using ethtool.
> 
> A user can include TEID and make RSS work for GTP-U over IPv4 by doing the
> following:`ethtool -N ens3 rx-flow-hash gtpu4 sde`
> 
> In addition to gtpu(4|6), we now support gtpc(4|6),gtpc(4|6)t,gtpu(4|6)e,
> gtpu(4|6)u, and gtpu(4|6)d.
> 
> gtpc(4|6): Used for GTP-C in IPv4 and IPv6, where the GTP header format does
> not include a TEID.
> gtpc(4|6)t: Used for GTP-C in IPv4 and IPv6, with a GTP header format that
> includes a TEID.
> gtpu(4|6): Used for GTP-U in both IPv4 and IPv6 scenarios.
> gtpu(4|6)e: Used for GTP-U with extended headers in both IPv4 and IPv6.
> gtpu(4|6)u: Used when the PSC (PDU session container) in the GTP-U extended
> header includes Uplink, applicable to both IPv4 and IPv6.
> gtpu(4|6)d: Used when the PSC in the GTP-U extended header includes Downlink,
> for both IPv4 and IPv6.
> 
> GTP generates a flow that includes an ID called TEID to identify the tunnel.
> This tunnel is created for each UE (User Equipment).By performing RSS based on
> this flow, it is possible to apply RSS for each communication unit from the UE.
> Without this, RSS would only be effective within the range of IP addresses. For
> instance, the PGW can only perform RSS within the IP range of the SGW.
> Problematic from a load distribution perspective, especially if there's a bias
> in the terminals connected to a particular base station.This case can be
> solved by using this patch.

Reviewed-by: Marcin Szycik <marcin.szycik@linux.intel.com>

> Signed-off-by: Takeru Hayasaka <hayatake396@gmail.com>
> ---
> v2->v3: Based on Harald-san's review, I added documentation and comments to
> ethtool.h and ice.rst.
> v3->v4: Based on Marcin-san's review, I added the missing code for GTPC and
> GTPC_TEID, and revised the documentation and comments.
> v4->v5: Based on Marcin-san's review, I fixed rename and wrong code regarding
> GTPC
> v5->v6: Based on Marcin-san's review, Undoing the addition of unnecessary
> blank lines.Minor fixes.
> v6->v7 Based on Jakub-san's review, Split the patch.
>  include/uapi/linux/ethtool.h | 48 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
> 
> diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
> index 06ef6b78b7de..11fc18988bc2 100644
> --- a/include/uapi/linux/ethtool.h
> +++ b/include/uapi/linux/ethtool.h
> @@ -2023,6 +2023,53 @@ static inline int ethtool_validate_duplex(__u8 duplex)
>  #define	IPV4_FLOW	0x10	/* hash only */
>  #define	IPV6_FLOW	0x11	/* hash only */
>  #define	ETHER_FLOW	0x12	/* spec only (ether_spec) */
> +
> +/* Used for GTP-U IPv4 and IPv6.
> + * The format of GTP packets only includes
> + * elements such as TEID and GTP version.
> + * It is primarily intended for data communication of the UE.
> + */
> +#define GTPU_V4_FLOW 0x13	/* hash only */
> +#define GTPU_V6_FLOW 0x14	/* hash only */
> +
> +/* Use for GTP-C IPv4 and v6.
> + * The format of these GTP packets does not include TEID.
> + * Primarily expected to be used for communication
> + * to create sessions for UE data communication,
> + * commonly referred to as CSR (Create Session Request).
> + */
> +#define GTPC_V4_FLOW 0x15	/* hash only */
> +#define GTPC_V6_FLOW 0x16	/* hash only */
> +
> +/* Use for GTP-C IPv4 and v6.
> + * Unlike GTPC_V4_FLOW, the format of these GTP packets includes TEID.
> + * After session creation, it becomes this packet.
> + * This is mainly used for requests to realize UE handover.
> + */
> +#define GTPC_TEID_V4_FLOW 0x17	/* hash only */
> +#define GTPC_TEID_V6_FLOW 0x18	/* hash only */
> +
> +/* Use for GTP-U and extended headers for the PSC (PDU Session Container).
> + * The format of these GTP packets includes TEID and QFI.
> + * In 5G communication using UPF (User Plane Function),
> + * data communication with this extended header is performed.
> + */
> +#define GTPU_EH_V4_FLOW 0x19	/* hash only */
> +#define GTPU_EH_V6_FLOW 0x1a	/* hash only */
> +
> +/* Use for GTP-U IPv4 and v6 PSC (PDU Session Container) extended headers.
> + * This differs from GTPU_EH_V(4|6)_FLOW in that it is distinguished by
> + * UL/DL included in the PSC.
> + * There are differences in the data included based on Downlink/Uplink,
> + * and can be used to distinguish packets.
> + * The functions described so far are useful when you want to
> + * handle communication from the mobile network in UPF, PGW, etc.
> + */
> +#define GTPU_UL_V4_FLOW 0x1b	/* hash only */
> +#define GTPU_UL_V6_FLOW 0x1c	/* hash only */
> +#define GTPU_DL_V4_FLOW 0x1d	/* hash only */
> +#define GTPU_DL_V6_FLOW 0x1e	/* hash only */
> +
>  /* Flag to enable additional fields in struct ethtool_rx_flow_spec */
>  #define	FLOW_EXT	0x80000000
>  #define	FLOW_MAC_EXT	0x40000000
> @@ -2037,6 +2084,7 @@ static inline int ethtool_validate_duplex(__u8 duplex)
>  #define	RXH_IP_DST	(1 << 5)
>  #define	RXH_L4_B_0_1	(1 << 6) /* src port in case of TCP/UDP/SCTP */
>  #define	RXH_L4_B_2_3	(1 << 7) /* dst port in case of TCP/UDP/SCTP */
> +#define	RXH_GTP_TEID	(1 << 8) /* teid in case of GTP */
>  #define	RXH_DISCARD	(1 << 31)
>  
>  #define	RX_CLS_FLOW_DISC	0xffffffffffffffffULL