15/10/2020 07:35, Bing Zhao:
> To support two ports hairpin mode and keep the backward compatibility
> for the application, two new attribute members of the hairpin queue
> configuration structure will be added.
>
> `tx_explicit` means if the application itself will insert the TX part
> flow rules. If not set, PMD will insert the rules implicitly.
> `manual_bind` means if the hairpin TX queue and peer RX queue will be
> bound automatically during the device start stage.
>
> Different TX and RX queue pairs could have different values, but it
> is highly recommended that all paired queues between one egress and
> its peer ingress ports have the same values, in order not to bring
> any chaos to the system. The actual support of these attribute
> parameters will be checked and decided by the PMD drivers.
>
> In the single port hairpin, if both are zero without any setting, the
> behavior will remain the same as before. It means that no bind API
> needs to be called and no TX flow rules need to be inserted manually
> by the application.
>
> Signed-off-by: Bing Zhao <bi...@nvidia.com>
> Acked-by: Ori Kam <or...@nvidia.com>
> ---
> v4: squash document update and more info for the two new attributes
> v2: optimize the structure and remove unused macros
> ---
Acked-by: Thomas Monjalon <tho...@monjalon.net>
Minor comments below.
> struct rte_eth_hairpin_conf {
> - uint16_t peer_count; /**< The number of peers. */
> + uint32_t peer_count:16; /**< The number of peers. */
> +
> + /**
> + * Explicit TX flow rule mode. One hairpin pair of queues should have
> + * the same attribute. The actual support depends on the PMD.
The second sentence should be on a separate line.
About the third sentence, implementation is always PMD-specific.
PMD will reject the not supported conf, as usual.
I think this comment is not needed in the API description.
> + *
> + * - When set, the user should be responsible for inserting the hairpin
> + * TX part flows and removing them.
> + * - When clear, the PMD will try to handle the TX part of the flows,
> + * e.g., by splitting one flow into two parts.
> + */
> + uint32_t tx_explicit:1;
> +
> + /**
> + * Manually bind hairpin queues. One hairpin pair of queues should have
> + * the same attribute. The actual support depends on the PMD.
Same here
> + *
> + * - When set, to enable hairpin, the user should call the hairpin bind
> + * API after all the queues are set up properly and the ports are
> + * started. Also, the hairpin unbind API should be called accordingly
> + * before stopping a port that with hairpin configured.
> + * - When clear, the PMD will try to enable the hairpin with the queues
> + * configured automatically during port start.
> + */
> + uint32_t manual_bind:1;
> + uint32_t reserved:14; /**< Reserved bits. */
> struct rte_eth_hairpin_peer peers[RTE_ETH_MAX_HAIRPIN_PEERS];
> };
