Hi, Should we split this commit into two ones? For rte and for the driver? Should we add tracing to the rte_eth_get_queue_rate_limit() getter like we have in the rte_eth_set_queue_rate_limit() ?
With best regards, Slava > -----Original Message----- > From: Vincent Jardin <[email protected]> > Sent: Friday, March 13, 2026 12:01 AM > To: [email protected] > Cc: Raslan Darawsheh <[email protected]>; NBU-Contact-Thomas Monjalon > (EXTERNAL) <[email protected]>; [email protected]; > Dariusz Sosnowski <[email protected]>; Slava Ovsiienko > <[email protected]>; Bing Zhao <[email protected]>; Ori Kam > <[email protected]>; Suanming Mou <[email protected]>; Matan Azrad > <[email protected]>; [email protected]; Vincent Jardin > <[email protected]> > Subject: [PATCH v3 08/9] ethdev: add getter for per-queue Tx rate limit > > The existing rte_eth_set_queue_rate_limit() API allows setting a per-queue Tx > rate but provides no way to read it back. Applications such as grout are > forced > to maintain a shadow copy of the rate to be able to report it. > > Add rte_eth_get_queue_rate_limit() as the symmetric getter, following the > established DPDK pattern (e.g. rte_eth_dev_set_mtu/get_mtu, > rte_eth_dev_set_vlan_offload/get_vlan_offload). > > This adds: > - eth_get_queue_rate_limit_t driver callback in ethdev_driver.h > - rte_eth_get_queue_rate_limit() public experimental API (26.07) > - mlx5 PMD implementation reading from the existing per-queue > rate_mbps tracking field > > Signed-off-by: Vincent Jardin <[email protected]> > --- > app/test-pmd/cmdline.c | 69 > +++++++++++++++++++++++++++++++++++++ > drivers/net/mlx5/mlx5.c | 2 ++ > drivers/net/mlx5/mlx5_tx.h | 2 ++ > drivers/net/mlx5/mlx5_txq.c | 30 ++++++++++++++++ > lib/ethdev/ethdev_driver.h | 7 ++++ > lib/ethdev/rte_ethdev.c | 28 +++++++++++++++ > lib/ethdev/rte_ethdev.h | 24 +++++++++++++ > 7 files changed, 162 insertions(+) > > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index > c33c66f327..ee532984e8 100644 > --- a/app/test-pmd/cmdline.c > +++ b/app/test-pmd/cmdline.c > @@ -8912,6 +8912,74 @@ static cmdline_parse_inst_t cmd_queue_rate_limit > = { > }, > }; > > +/* *** SHOW RATE LIMIT FOR A QUEUE OF A PORT *** */ struct > +cmd_show_queue_rate_limit_result { > + cmdline_fixed_string_t show; > + cmdline_fixed_string_t port; > + uint16_t port_num; > + cmdline_fixed_string_t queue; > + uint16_t queue_num; > + cmdline_fixed_string_t rate; > +}; > + > +static void cmd_show_queue_rate_limit_parsed(void *parsed_result, > + __rte_unused struct cmdline *cl, > + __rte_unused void *data) > +{ > + struct cmd_show_queue_rate_limit_result *res = parsed_result; > + uint32_t tx_rate = 0; > + int ret; > + > + ret = rte_eth_get_queue_rate_limit(res->port_num, res->queue_num, > + &tx_rate); > + if (ret) { > + fprintf(stderr, "Get queue rate limit failed: %s\n", > + rte_strerror(-ret)); > + return; > + } > + if (tx_rate) > + printf("Port %u Queue %u rate limit: %u Mbps\n", > + res->port_num, res->queue_num, tx_rate); > + else > + printf("Port %u Queue %u rate limit: disabled\n", > + res->port_num, res->queue_num); } > + > +static cmdline_parse_token_string_t cmd_show_queue_rate_limit_show = > + TOKEN_STRING_INITIALIZER(struct > cmd_show_queue_rate_limit_result, > + show, "show"); > +static cmdline_parse_token_string_t cmd_show_queue_rate_limit_port = > + TOKEN_STRING_INITIALIZER(struct > cmd_show_queue_rate_limit_result, > + port, "port"); > +static cmdline_parse_token_num_t cmd_show_queue_rate_limit_portnum = > + TOKEN_NUM_INITIALIZER(struct cmd_show_queue_rate_limit_result, > + port_num, RTE_UINT16); > +static cmdline_parse_token_string_t cmd_show_queue_rate_limit_queue = > + TOKEN_STRING_INITIALIZER(struct > cmd_show_queue_rate_limit_result, > + queue, "queue"); > +static cmdline_parse_token_num_t cmd_show_queue_rate_limit_queuenum > = > + TOKEN_NUM_INITIALIZER(struct cmd_show_queue_rate_limit_result, > + queue_num, RTE_UINT16); > +static cmdline_parse_token_string_t cmd_show_queue_rate_limit_rate = > + TOKEN_STRING_INITIALIZER(struct > cmd_show_queue_rate_limit_result, > + rate, "rate"); > + > +static cmdline_parse_inst_t cmd_show_queue_rate_limit = { > + .f = cmd_show_queue_rate_limit_parsed, > + .data = NULL, > + .help_str = "show port <port_id> queue <queue_id> rate: " > + "Show rate limit for a queue on port_id", > + .tokens = { > + (void *)&cmd_show_queue_rate_limit_show, > + (void *)&cmd_show_queue_rate_limit_port, > + (void *)&cmd_show_queue_rate_limit_portnum, > + (void *)&cmd_show_queue_rate_limit_queue, > + (void *)&cmd_show_queue_rate_limit_queuenum, > + (void *)&cmd_show_queue_rate_limit_rate, > + NULL, > + }, > +}; > + > /* *** SET RATE LIMIT FOR A VF OF A PORT *** */ struct > cmd_vf_rate_limit_result { > cmdline_fixed_string_t set; > @@ -14198,6 +14266,7 @@ static cmdline_parse_ctx_t builtin_ctx[] = { > &cmd_set_uc_all_hash_filter, > &cmd_vf_mac_addr_filter, > &cmd_queue_rate_limit, > + &cmd_show_queue_rate_limit, > &cmd_tunnel_udp_config, > &cmd_showport_rss_hash, > &cmd_showport_rss_hash_key, > diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c index > f399e0d5c9..6e21ed31f3 100644 > --- a/drivers/net/mlx5/mlx5.c > +++ b/drivers/net/mlx5/mlx5.c > @@ -2721,6 +2721,7 @@ const struct eth_dev_ops mlx5_dev_ops = { > .rx_metadata_negotiate = mlx5_flow_rx_metadata_negotiate, > .get_restore_flags = mlx5_get_restore_flags, > .set_queue_rate_limit = mlx5_set_queue_rate_limit, > + .get_queue_rate_limit = mlx5_get_queue_rate_limit, > }; > > /* Available operations from secondary process. */ @@ -2815,6 +2816,7 @@ > const struct eth_dev_ops mlx5_dev_ops_isolate = { > .map_aggr_tx_affinity = mlx5_map_aggr_tx_affinity, > .get_restore_flags = mlx5_get_restore_flags, > .set_queue_rate_limit = mlx5_set_queue_rate_limit, > + .get_queue_rate_limit = mlx5_get_queue_rate_limit, > }; > > /** > diff --git a/drivers/net/mlx5/mlx5_tx.h b/drivers/net/mlx5/mlx5_tx.h index > 3a37f5bb4d..46e199d93e 100644 > --- a/drivers/net/mlx5/mlx5_tx.h > +++ b/drivers/net/mlx5/mlx5_tx.h > @@ -224,6 +224,8 @@ int mlx5_txq_releasable(struct rte_eth_dev *dev, > uint16_t idx); int mlx5_txq_verify(struct rte_eth_dev *dev); int > mlx5_set_queue_rate_limit(struct rte_eth_dev *dev, uint16_t queue_idx, > uint32_t tx_rate); > +int mlx5_get_queue_rate_limit(struct rte_eth_dev *dev, uint16_t queue_idx, > + uint32_t *tx_rate); > int mlx5_txq_get_sqn(struct mlx5_txq_ctrl *txq); void > mlx5_txq_alloc_elts(struct mlx5_txq_ctrl *txq_ctrl); void > mlx5_txq_free_elts(struct mlx5_txq_ctrl *txq_ctrl); diff --git > a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c index > f0881f3560..c81542113e 100644 > --- a/drivers/net/mlx5/mlx5_txq.c > +++ b/drivers/net/mlx5/mlx5_txq.c > @@ -1473,6 +1473,36 @@ mlx5_set_queue_rate_limit(struct rte_eth_dev > *dev, uint16_t queue_idx, > return 0; > } > > +/** > + * Get per-queue packet pacing rate limit. > + * > + * @param dev > + * Pointer to Ethernet device. > + * @param queue_idx > + * TX queue index. > + * @param[out] tx_rate > + * Pointer to store the TX rate in Mbps, 0 if rate limiting is disabled. > + * > + * @return > + * 0 on success, a negative errno value otherwise and rte_errno is set. > + */ > +int > +mlx5_get_queue_rate_limit(struct rte_eth_dev *dev, uint16_t queue_idx, > + uint32_t *tx_rate) > +{ > + struct mlx5_priv *priv = dev->data->dev_private; > + struct mlx5_txq_ctrl *txq_ctrl; > + > + if (priv->txqs == NULL || (*priv->txqs)[queue_idx] == NULL) { > + rte_errno = EINVAL; > + return -rte_errno; > + } > + txq_ctrl = container_of((*priv->txqs)[queue_idx], > + struct mlx5_txq_ctrl, txq); > + *tx_rate = txq_ctrl->rl.rate_mbps; > + return 0; > +} > + > /** > * Verify if the queue can be released. > * > diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h index > 1255cd6f2c..0f336f9567 100644 > --- a/lib/ethdev/ethdev_driver.h > +++ b/lib/ethdev/ethdev_driver.h > @@ -762,6 +762,11 @@ typedef int (*eth_set_queue_rate_limit_t)(struct > rte_eth_dev *dev, > uint16_t queue_idx, > uint32_t tx_rate); > > +/** @internal Get queue Tx rate. */ > +typedef int (*eth_get_queue_rate_limit_t)(struct rte_eth_dev *dev, > + uint16_t queue_idx, > + uint32_t *tx_rate); > + > /** @internal Add tunneling UDP port. */ typedef int > (*eth_udp_tunnel_port_add_t)(struct rte_eth_dev *dev, > struct rte_eth_udp_tunnel > *tunnel_udp); @@ -1522,6 +1527,8 @@ struct eth_dev_ops { > > /** Set queue rate limit */ > eth_set_queue_rate_limit_t set_queue_rate_limit; > + /** Get queue rate limit */ > + eth_get_queue_rate_limit_t get_queue_rate_limit; > > /** Configure RSS hash protocols and hashing key */ > rss_hash_update_t rss_hash_update; > diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c index > 2edc7a362e..c6ad399033 100644 > --- a/lib/ethdev/rte_ethdev.c > +++ b/lib/ethdev/rte_ethdev.c > @@ -5694,6 +5694,34 @@ int rte_eth_set_queue_rate_limit(uint16_t > port_id, uint16_t queue_idx, > return ret; > } > > +RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_eth_get_queue_rate_limit, 26.07) > int > +rte_eth_get_queue_rate_limit(uint16_t port_id, uint16_t queue_idx, > + uint32_t *tx_rate) > +{ > + struct rte_eth_dev *dev; > + > + RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV); > + dev = &rte_eth_devices[port_id]; > + > + if (tx_rate == NULL) { > + RTE_ETHDEV_LOG_LINE(ERR, > + "Get queue rate limit:port %u: NULL tx_rate pointer", > + port_id); > + return -EINVAL; > + } > + > + if (queue_idx >= dev->data->nb_tx_queues) { > + RTE_ETHDEV_LOG_LINE(ERR, > + "Get queue rate limit:port %u: invalid queue ID=%u", > + port_id, queue_idx); > + return -EINVAL; > + } > + > + if (dev->dev_ops->get_queue_rate_limit == NULL) > + return -ENOTSUP; > + return eth_err(port_id, dev->dev_ops->get_queue_rate_limit(dev, > +queue_idx, tx_rate)); } > + > RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_eth_rx_avail_thresh_set, 22.07) > int rte_eth_rx_avail_thresh_set(uint16_t port_id, uint16_t queue_id, > uint8_t avail_thresh) > diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index > 0d8e2d0236..e525217b77 100644 > --- a/lib/ethdev/rte_ethdev.h > +++ b/lib/ethdev/rte_ethdev.h > @@ -4817,6 +4817,30 @@ int rte_eth_dev_uc_all_hash_table_set(uint16_t > port_id, uint8_t on); int rte_eth_set_queue_rate_limit(uint16_t port_id, > uint16_t queue_idx, > uint32_t tx_rate); > > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change, or be removed, without prior > notice. > + * > + * Get the rate limitation for a queue on an Ethernet device. > + * > + * @param port_id > + * The port identifier of the Ethernet device. > + * @param queue_idx > + * The queue ID. > + * @param[out] tx_rate > + * A pointer to retrieve the Tx rate in Mbps. > + * 0 means rate limiting is disabled. > + * @return > + * - (0) if successful. > + * - (-ENOTSUP) if hardware doesn't support this feature. > + * - (-ENODEV) if *port_id* invalid. > + * - (-EIO) if device is removed. > + * - (-EINVAL) if bad parameter. > + */ > +__rte_experimental > +int rte_eth_get_queue_rate_limit(uint16_t port_id, uint16_t queue_idx, > + uint32_t *tx_rate); > + > /** > * Configuration of Receive Side Scaling hash computation of Ethernet device. > * > -- > 2.43.0
