Hi, Thomas
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> Sent: Tuesday, October 28, 2014 12:58 AM
> To: Wu, Jingjing
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v4 04/21] ethdev: define structures for
> adding/deleting flow director
>
> 2014-10-22 09:01, Jingjing Wu:
> > +/**
> > + * A structure used to define the input for IPV4 UDP flow */ struct
> > +rte_eth_udpv4_flow {
> > + uint32_t src_ip; /**< IPv4 source address to match. */
> > + uint32_t dst_ip; /**< IPv4 destination address to match. */
> > + uint16_t src_port; /**< UDP Source port to match. */
> > + uint16_t dst_port; /**< UDP Destination port to match. */
> > +};
> > +
> > +/**
> > + * A structure used to define the input for IPV4 TCP flow */ struct
> > +rte_eth_tcpv4_flow {
> > + uint32_t src_ip; /**< IPv4 source address to match. */
> > + uint32_t dst_ip; /**< IPv4 destination address to match. */
> > + uint16_t src_port; /**< TCP Source port to match. */
> > + uint16_t dst_port; /**< TCP Destination port to match. */
> > +};
> > +
> > +/**
> > + * A structure used to define the input for IPV4 SCTP flow */ struct
> > +rte_eth_sctpv4_flow {
> > + uint32_t src_ip; /**< IPv4 source address to match. */
> > + uint32_t dst_ip; /**< IPv4 destination address to match. */
> > + uint32_t verify_tag; /**< verify tag to match */
> > +};
> > +
> > +/**
> > + * A structure used to define the input for IPV4 flow */ struct
> > +rte_eth_ipv4_flow {
> > + uint32_t src_ip; /**< IPv4 source address to match. */
> > + uint32_t dst_ip; /**< IPv4 destination address to match. */
> > +};
>
> Why not defining only 1 structure?
> struct rte_eth_ipv4_flow {
> uint32_t src_ip;
> uint32_t dst_ip;
> uint16_t src_port;
> uint16_t dst_port;
> uint32_t sctp_tag;
> };
>
> I think the same structure could be used for many filters (not only flow
> director).
>
Yes, one structure can contain all the elements we need, but I think it will be
clearer that each kind of flow type has its key words.
> > +#define RTE_ETH_FDIR_MAX_FLEXWORD_LEN 8
> > +/**
> > + * A structure used to contain extend input of flow */ struct
> > +rte_eth_fdir_flow_ext {
> > + uint16_t vlan_tci;
> > + uint8_t num_flexwords; /**< number of flexwords */
> > + uint16_t flexwords[RTE_ETH_FDIR_MAX_FLEXWORD_LEN];
> > + uint16_t dest_id; /**< destination vsi or pool id*/
> > +};
>
> Flexword should be explained.
>
The flexword means the application can choose a part of packet's payload as key
words to compare match. It is flexible. In Ixgbe, the flexwords is 1 word (2
bytes), while Fortville extend it to 8 words.
> > +/**
> > + * A structure used to define the input for an flow director filter
> > +entry
>
> typo: for *a* flow director
Yes, will change.
>
> > + */
> > +struct rte_eth_fdir_input {
> > + enum rte_eth_flow_type flow_type; /**< type of flow */
> > + union rte_eth_fdir_flow flow; /**< specific flow structure */
> > + struct rte_eth_fdir_flow_ext flow_ext; /**< specific flow info */ };
>
> I don't understand the logic behind flow/flow_ext.
> Why flow_ext is not merged into flow ?
>
The flow defines the key words for each flow_type, while the flow_ext has other
elements which have little to do with flow_type. For example the flexword,
dst_id (can used as pool id), I think it is not reasonable to make it as an
element in the flow.
> > +/**
> > + * Flow director report status
> > + */
> > +enum rte_eth_fdir_status {
> > + RTE_ETH_FDIR_NO_REPORT_STATUS = 0, /**< no report FDIR. */
> > + RTE_ETH_FDIR_REPORT_FD_ID, /**< only report FD ID. */
> > + RTE_ETH_FDIR_REPORT_FD_ID_FLEX_4, /**< report FD ID and 4 flex
> bytes. */
> > + RTE_ETH_FDIR_REPORT_FLEX_8, /**< report 8 flex bytes. */
> > +};
>
> The names and explanations are cryptics.
The enum defines what will be reported when FIR match. Can be FD_ID or flex
bytes
> Is FD redundant with FDIR?
Yes, good point. Will remove FD.
>
> > +/**
> > + * A structure used to define an action when match FDIR packet filter.
> > + */
> > +struct rte_eth_fdir_action {
> > + uint16_t rx_queue; /**< queue assigned to if fdir match. */
> > + uint16_t cnt_idx; /**< statistic counter index */
>
> what is the action of "statistic counter index"?
When FD match happened, the counter will increase. Fortville can support to
configure the different counter for filter entries. The action is a part of a
filter entry, so this element means which counter the entry will use.
>
> > + uint8_t drop; /**< accept or reject */
> > + uint8_t flex_off; /**< offset used define words to report */
>
> still difficult to understand the flex logic
Just as mentioned above, Fortville can support 8 flex words comparing. But for
reporting, only 4 or 8 bytes in the flex words can be reported. So need to
specify the offset to choose the 4 or 8 bytes.
>
> > + enum rte_eth_fdir_status report_status; /**< status report option
> > +*/ };
>
> > +/**
> > + * A structure used to define the flow director filter entry by
> > +filter_ctl API
> > + * to support RTE_ETH_FILTER_FDIR with RTE_ETH_FILTER_ADD and
> > + * RTE_ETH_FILTER_DELETE operations.
> > + */
> > +struct rte_eth_fdir_filter {
> > + uint32_t soft_id; /**< id */
>
> Should the application handle the id numbering?
> Why is it soft_id instead of id?
Yes, the soft_id is just id, is also reported id when entry match. The id is
specified by user, and can be used to identify this entry, application should
handle it.
>
> > + struct rte_eth_fdir_input input; /**< input set */
> > + struct rte_eth_fdir_action action; /**< action taken when match */
> > +};
>
> It's really a hard job to define a clear and easy to use API.
> It would be really interesting to have more people involved in this
> discussion.
Agree too.
Thank you!
> Thanks
> --
> Thomas
