Re: [dpdk-dev] [PATCH v2 6/6] examples/flow_filtering: utilize shared RSS action

[Jerin Jacob <jerinjacobk@gmail.com>]

On Thu, Jul 9, 2020 at 3:09 AM Andrey Vesnovaty <andreyv@mellanox.com> wrote:
>
> This commit gives very first shared RSS action usage example and
> demonstrates shared action capability for in-place update.
>
> First application creates shared action during initialization phase.

What if PMD does not support a shared context, Then this application
fails to run?
if so, have a mode or probe the capability(if capability present then
switches to new mode else fall back to old mode) before changing the
application behavior.


> Later on the flow object created by application uses previously created
> shared RSS action with 1 queue configured instead of queue action in
> original application.
>
> On each RX queue burst shared RSS action reconfigured via
> rte_flow_shared_action_update() API to switch queue 0 to 1 & 1 to 0.
> User supposed to observe consistent queue switches on each packet burst.
>
> Signed-off-by: Andrey Vesnovaty <andreyv@mellanox.com>
> ---
>  doc/guides/sample_app_ug/flow_filtering.rst | 62 +++++++++++++++++----
>  examples/flow_filtering/flow_blocks.c       | 30 +++++-----
>  examples/flow_filtering/main.c              | 41 +++++++++++++-
>  3 files changed, 105 insertions(+), 28 deletions(-)
>
> diff --git a/doc/guides/sample_app_ug/flow_filtering.rst b/doc/guides/sample_app_ug/flow_filtering.rst
> index 5e5a6cd8a0..cfe9334717 100644
> --- a/doc/guides/sample_app_ug/flow_filtering.rst
> +++ b/doc/guides/sample_app_ug/flow_filtering.rst
> @@ -106,7 +106,7 @@ following code:
>  .. code-block:: c
>
>     /* create flow for send packet with */
> -   flow = generate_ipv4_flow(port_id, selected_queue,
> +   flow = generate_ipv4_flow(port_id, shared_action,
>                                  SRC_IP, EMPTY_MASK,
>                                  DEST_IP, FULL_MASK, &error);
>     if (!flow) {
> @@ -242,7 +242,7 @@ The Ethernet port is configured with default settings using the
>     rxq_conf = dev_info.default_rxconf;
>     rxq_conf.offloads = port_conf.rxmode.offloads;
>
> -For this example we are configuring number of rx and tx queues that are connected
> +For this example we are configuring 2 rx and 2 tx queues that are connected
>  to a single port.
>
>  .. code-block:: c
> @@ -270,13 +270,22 @@ to a single port.
>            }
>     }
>
> +Before we create the flow we create shared action in order to send it as
> +actions argument when creating a flow. The action is single queue RSS action
> +similar to action queue with the only difference that shared RSS action
> +provides update capability after action creation.
> +
> +.. code-block:: c
> +
> +   shared_action = rte_flow_shared_action_create(port_id, &action, &error);
> +
>  In the next step we create and apply the flow rule. which is to send packets
>  with destination ip equals to 192.168.1.1 to queue number 1. The detail
>  explanation of the ``generate_ipv4_flow()`` appears later in this document:
>
>  .. code-block:: c
>
> -   flow = generate_ipv4_flow(port_id, selected_queue,
> +   flow = generate_ipv4_flow(port_id, shared_action,
>                               SRC_IP, EMPTY_MASK,
>                               DEST_IP, FULL_MASK, &error);
>
> @@ -339,6 +348,21 @@ looks like the following:
>                                             printf("\n");
>                                             rte_pktmbuf_free(m);
>                                     }
> +                                   if (rss_queue[0] == 0) {
> +                                           printf(">>> switching queue 0 -> 1\n");
> +                                           rss_queue[0] = 1;
> +                                   } else {
> +                                           printf(">>> switching queue 1 -> 0\n");
> +                                           rss_queue[0] = 0;
> +                                   }
> +                                   ret = rte_flow_shared_action_update
> +                                           (port_id, shared_action, &action,
> +                                            &error);
> +                                   if (ret)
> +                                           rte_exit(EXIT_FAILURE,
> +                                                    ":: error: RSS action update "
> +                                                    "failed: %s\n",
> +                                                    rte_strerror(-ret));
>                             }
>                     }
>             }
> @@ -348,6 +372,8 @@ looks like the following:
>             rte_eth_dev_close(port_id);
>     }
>
> +On each loop eteration Rx queue switched using
> +``rte_flow_shared_action_update()`` API.
>  The main work of the application is reading the packets from all
>  queues and printing for each packet the destination queue:
>
> @@ -365,6 +391,21 @@ queues and printing for each packet the destination queue:
>                               printf(" - queue=0x%x", (unsigned int)i);
>                               printf("\n");
>                               rte_pktmbuf_free(m);
> +                             if (rss_queue[0] == 0) {
> +                                     printf(">>> switching queue 0 -> 1\n");
> +                                     rss_queue[0] = 1;
> +                             } else {
> +                                     printf(">>> switching queue 1 -> 0\n");
> +                                     rss_queue[0] = 0;
> +                             }
> +                             ret = rte_flow_shared_action_update
> +                                     (port_id, shared_action, &action,
> +                                      &error);
> +                             if (ret)
> +                                     rte_exit(EXIT_FAILURE,
> +                                              ":: error: RSS action update "
> +                                              "failed: %s\n",
> +                                              rte_strerror(-ret));
>                          }
>                  }
>             }
> @@ -378,13 +419,15 @@ The forwarding loop can be interrupted and the application closed using
>  The generate_ipv4_flow function
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> +
>  The generate_ipv4_flow function is responsible for creating the flow rule.
>  This function is located in the ``flow_blocks.c`` file.
>
>  .. code-block:: c
>
>     static struct rte_flow *
> -   generate_ipv4_flow(uint8_t port_id, uint16_t rx_q,
> +   generate_ipv4_flow(uint8_t port_id,
> +                   cstructrte_flow_shared_action *shared_action,
>                     uint32_t src_ip, uint32_t src_mask,
>                     uint32_t dest_ip, uint32_t dest_mask,
>                     struct rte_flow_error *error)
> @@ -393,7 +436,6 @@ This function is located in the ``flow_blocks.c`` file.
>             struct rte_flow_item pattern[MAX_PATTERN_NUM];
>             struct rte_flow_action action[MAX_ACTION_NUM];
>             struct rte_flow *flow = NULL;
> -           struct rte_flow_action_queue queue = { .index = rx_q };
>             struct rte_flow_item_ipv4 ip_spec;
>             struct rte_flow_item_ipv4 ip_mask;
>
> @@ -411,8 +453,8 @@ This function is located in the ``flow_blocks.c`` file.
>              * create the action sequence.
>              * one action only,  move packet to queue
>              */
> -           action[0].type = RTE_FLOW_ACTION_TYPE_QUEUE;
> -           action[0].conf = &queue;
> +           action[0].type = RTE_FLOW_ACTION_TYPE_SHARED;
> +           action[0].conf = shared_action;
>             action[1].type = RTE_FLOW_ACTION_TYPE_END;
>
>             /*
> @@ -468,12 +510,12 @@ The following part create the flow attributes, in our case ingress.
>     attr.ingress = 1;
>
>  The third part defines the action to be taken when a packet matches
> -the rule. In this case send the packet to queue.
> +the rule. In this case send the packet to single RSS queue.
>
>  .. code-block:: c
>
> -   action[0].type = RTE_FLOW_ACTION_TYPE_QUEUE;
> -   action[0].conf = &queue;
> +   action[0].type = RTE_FLOW_ACTION_TYPE_SHARED;
> +   action[0].conf = shared_action;
>     action[1].type = RTE_FLOW_ACTION_TYPE_END;
>
>  The fourth part is responsible for creating the pattern and is built from
> diff --git a/examples/flow_filtering/flow_blocks.c b/examples/flow_filtering/flow_blocks.c
> index 575d792810..99bfed3172 100644
> --- a/examples/flow_filtering/flow_blocks.c
> +++ b/examples/flow_filtering/flow_blocks.c
> @@ -6,11 +6,11 @@
>  #define MAX_ACTION_NUM         2
>
>  struct rte_flow *
> -generate_ipv4_flow(uint16_t port_id, uint16_t rx_q,
> -               uint32_t src_ip, uint32_t src_mask,
> -               uint32_t dest_ip, uint32_t dest_mask,
> -               struct rte_flow_error *error);
> -
> +generate_ipv4_flow(uint16_t port_id,
> +                  struct rte_flow_shared_action *shared_action,
> +                  uint32_t src_ip, uint32_t src_mask,
> +                  uint32_t dest_ip, uint32_t dest_mask,
> +                  struct rte_flow_error *error);
>
>  /**
>   * create a flow rule that sends packets with matching src and dest ip
> @@ -18,8 +18,8 @@ generate_ipv4_flow(uint16_t port_id, uint16_t rx_q,
>   *
>   * @param port_id
>   *   The selected port.
> - * @param rx_q
> - *   The selected target queue.
> + * @param shared_action
> + *   The shared RSS action with single queue
>   * @param src_ip
>   *   The src ip value to match the input packet.
>   * @param src_mask
> @@ -35,16 +35,16 @@ generate_ipv4_flow(uint16_t port_id, uint16_t rx_q,
>   *   A flow if the rule could be created else return NULL.
>   */
>  struct rte_flow *
> -generate_ipv4_flow(uint16_t port_id, uint16_t rx_q,
> -               uint32_t src_ip, uint32_t src_mask,
> -               uint32_t dest_ip, uint32_t dest_mask,
> -               struct rte_flow_error *error)
> +generate_ipv4_flow(uint16_t port_id,
> +                  struct rte_flow_shared_action *shared_action,
> +                  uint32_t src_ip, uint32_t src_mask,
> +                  uint32_t dest_ip, uint32_t dest_mask,
> +                  struct rte_flow_error *error)
>  {
>         struct rte_flow_attr attr;
>         struct rte_flow_item pattern[MAX_PATTERN_NUM];
>         struct rte_flow_action action[MAX_ACTION_NUM];
>         struct rte_flow *flow = NULL;
> -       struct rte_flow_action_queue queue = { .index = rx_q };
>         struct rte_flow_item_ipv4 ip_spec;
>         struct rte_flow_item_ipv4 ip_mask;
>         int res;
> @@ -61,10 +61,10 @@ generate_ipv4_flow(uint16_t port_id, uint16_t rx_q,
>
>         /*
>          * create the action sequence.
> -        * one action only,  move packet to queue
> +        * one action only,  move packet to shared RSS queue
>          */
> -       action[0].type = RTE_FLOW_ACTION_TYPE_QUEUE;
> -       action[0].conf = &queue;
> +       action[0].type = RTE_FLOW_ACTION_TYPE_SHARED;
> +       action[0].conf = shared_action;
>         action[1].type = RTE_FLOW_ACTION_TYPE_END;
>
>         /*
> diff --git a/examples/flow_filtering/main.c b/examples/flow_filtering/main.c
> index cc9e7e7808..d6b18d95fc 100644
> --- a/examples/flow_filtering/main.c
> +++ b/examples/flow_filtering/main.c
> @@ -32,8 +32,7 @@
>  static volatile bool force_quit;
>
>  static uint16_t port_id;
> -static uint16_t nr_queues = 5;
> -static uint8_t selected_queue = 1;
> +static uint16_t nr_queues = 2;
>  struct rte_mempool *mbuf_pool;
>  struct rte_flow *flow;
>
> @@ -42,6 +41,24 @@ struct rte_flow *flow;
>  #define FULL_MASK 0xffffffff /* full mask */
>  #define EMPTY_MASK 0x0 /* empty mask */
>
> +struct rte_flow_shared_action *shared_action;
> +uint16_t rss_queue[1] = {0};
> +
> +struct rte_flow_action_rss action_rss = {
> +               .func = RTE_ETH_HASH_FUNCTION_DEFAULT,
> +               .level = 0,
> +               .types = 0,
> +               .key_len = 0,
> +               .key = NULL,
> +               .queue = rss_queue,
> +               .queue_num = 1,
> +};
> +
> +struct rte_flow_action action = {
> +       .type = RTE_FLOW_ACTION_TYPE_RSS,
> +       .conf = &action_rss,
> +};
> +
>  #include "flow_blocks.c"
>
>  static inline void
> @@ -61,6 +78,7 @@ main_loop(void)
>         uint16_t nb_rx;
>         uint16_t i;
>         uint16_t j;
> +       int ret;
>
>         while (!force_quit) {
>                 for (i = 0; i < nr_queues; i++) {
> @@ -82,6 +100,21 @@ main_loop(void)
>
>                                         rte_pktmbuf_free(m);
>                                 }
> +                               if (rss_queue[0] == 0) {
> +                                       printf(">>> switching queue 0 -> 1\n");
> +                                       rss_queue[0] = 1;
> +                               } else {
> +                                       printf(">>> switching queue 1 -> 0\n");
> +                                       rss_queue[0] = 0;
> +                               }
> +                               ret = rte_flow_shared_action_update
> +                                       (port_id, shared_action, &action,
> +                                        &error);
> +                               if (ret)
> +                                       rte_exit(EXIT_FAILURE,
> +                                                ":: error: RSS action update "
> +                                                "failed: %s\n",
> +                                                rte_strerror(-ret));
>                         }
>                 }
>         }
> @@ -243,8 +276,10 @@ main(int argc, char **argv)
>
>         init_port();
>
> +       shared_action = rte_flow_shared_action_create(port_id, &action, &error);
> +
>         /* create flow for send packet with */
> -       flow = generate_ipv4_flow(port_id, selected_queue,
> +       flow = generate_ipv4_flow(port_id, shared_action,
>                                 SRC_IP, EMPTY_MASK,
>                                 DEST_IP, FULL_MASK, &error);
>         if (!flow) {
> --
> 2.26.2
>