[RFC v1 11/22] net: allocate per-queue config structs and pass them thru the queue API
From: Pavel Begunkov <asml.silence@gmail.com>
Date: 2025-07-28 11:03:29
Also in:
io-uring
Subsystem:
broadcom bnxt_en 50 gigabit ethernet driver, netdevsim, networking drivers, networking [general], the rest · Maintainers:
Michael Chan, Pavan Chebbi, Jakub Kicinski, Andrew Lunn, "David S. Miller", Eric Dumazet, Paolo Abeni, Linus Torvalds
From: Jakub Kicinski <kuba@kernel.org> Create an array of config structs to store per-queue config. Pass these structs in the queue API. Drivers can also retrieve the config for a single queue calling netdev_queue_config() directly. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 8 ++- drivers/net/ethernet/google/gve/gve_main.c | 9 ++-- drivers/net/netdevsim/netdev.c | 6 ++- include/net/netdev_queues.h | 19 +++++++ net/core/dev.h | 3 ++ net/core/netdev_config.c | 58 ++++++++++++++++++++++ net/core/netdev_rx_queue.c | 11 ++-- 7 files changed, 104 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 55685ed60519..c3195be0ac26 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c@@ -15820,7 +15820,9 @@ static const struct netdev_stat_ops bnxt_stat_ops = { .get_base_stats = bnxt_get_base_stats, }; -static int bnxt_queue_mem_alloc(struct net_device *dev, void *qmem, int idx) +static int bnxt_queue_mem_alloc(struct net_device *dev, + struct netdev_queue_config *qcfg, + void *qmem, int idx) { struct bnxt_rx_ring_info *rxr, *clone; struct bnxt *bp = netdev_priv(dev);
@@ -15988,7 +15990,9 @@ static void bnxt_copy_rx_ring(struct bnxt *bp, dst->rx_agg_bmap = src->rx_agg_bmap; } -static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx) +static int bnxt_queue_start(struct net_device *dev, + struct netdev_queue_config *qcfg, + void *qmem, int idx) { struct bnxt *bp = netdev_priv(dev); struct bnxt_rx_ring_info *rxr, *clone;
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index dc35a23ec47f..dffe3ebc456b 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c@@ -2429,8 +2429,9 @@ static void gve_rx_queue_mem_free(struct net_device *dev, void *per_q_mem) gve_rx_free_ring_dqo(priv, gve_per_q_mem, &cfg); } -static int gve_rx_queue_mem_alloc(struct net_device *dev, void *per_q_mem, - int idx) +static int gve_rx_queue_mem_alloc(struct net_device *dev, + struct netdev_queue_config *qcfg, + void *per_q_mem, int idx) { struct gve_priv *priv = netdev_priv(dev); struct gve_rx_alloc_rings_cfg cfg = {0};
@@ -2451,7 +2452,9 @@ static int gve_rx_queue_mem_alloc(struct net_device *dev, void *per_q_mem, return err; } -static int gve_rx_queue_start(struct net_device *dev, void *per_q_mem, int idx) +static int gve_rx_queue_start(struct net_device *dev, + struct netdev_queue_config *qcfg, + void *per_q_mem, int idx) { struct gve_priv *priv = netdev_priv(dev); struct gve_rx_ring *gve_per_q_mem;
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index fa5fbd97ad69..03003adc41fb 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c@@ -664,7 +664,8 @@ struct nsim_queue_mem { }; static int -nsim_queue_mem_alloc(struct net_device *dev, void *per_queue_mem, int idx) +nsim_queue_mem_alloc(struct net_device *dev, struct netdev_queue_config *qcfg, + void *per_queue_mem, int idx) { struct nsim_queue_mem *qmem = per_queue_mem; struct netdevsim *ns = netdev_priv(dev);
@@ -713,7 +714,8 @@ static void nsim_queue_mem_free(struct net_device *dev, void *per_queue_mem) } static int -nsim_queue_start(struct net_device *dev, void *per_queue_mem, int idx) +nsim_queue_start(struct net_device *dev, struct netdev_queue_config *qcfg, + void *per_queue_mem, int idx) { struct nsim_queue_mem *qmem = per_queue_mem; struct netdevsim *ns = netdev_priv(dev);
diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
index 070a1150241d..e3e7ecf91bac 100644
--- a/include/net/netdev_queues.h
+++ b/include/net/netdev_queues.h@@ -31,6 +31,13 @@ struct netdev_config { /** @hds_config: HDS enabled (ETHTOOL_A_RINGS_TCP_DATA_SPLIT). */ u8 hds_config; + + /** @qcfg: per-queue configuration */ + struct netdev_queue_config *qcfg; +}; + +/* Same semantics as fields in struct netdev_config */ +struct netdev_queue_config { }; /* See the netdev.yaml spec for definition of each statistic */
@@ -135,6 +142,10 @@ void netdev_stat_queue_sum(struct net_device *netdev, * * @ndo_queue_mem_size: Size of the struct that describes a queue's memory. * + * @ndo_queue_cfg_defaults: (Optional) Populate queue config struct with + * defaults. Queue config structs are passed to this + * helper before the user-requested settings are applied. + * * @ndo_queue_mem_alloc: Allocate memory for an RX queue at the specified index. * The new memory is written at the specified address. *
@@ -152,12 +163,17 @@ void netdev_stat_queue_sum(struct net_device *netdev, */ struct netdev_queue_mgmt_ops { size_t ndo_queue_mem_size; + void (*ndo_queue_cfg_defaults)(struct net_device *dev, + int idx, + struct netdev_queue_config *qcfg); int (*ndo_queue_mem_alloc)(struct net_device *dev, + struct netdev_queue_config *qcfg, void *per_queue_mem, int idx); void (*ndo_queue_mem_free)(struct net_device *dev, void *per_queue_mem); int (*ndo_queue_start)(struct net_device *dev, + struct netdev_queue_config *qcfg, void *per_queue_mem, int idx); int (*ndo_queue_stop)(struct net_device *dev,
@@ -165,6 +181,9 @@ struct netdev_queue_mgmt_ops { int idx); }; +void netdev_queue_config(struct net_device *dev, int rxq, + struct netdev_queue_config *qcfg); + /** * DOC: Lockless queue stopping / waking helpers. *
diff --git a/net/core/dev.h b/net/core/dev.h
index c8971c6f1fcd..6d7f5e920018 100644
--- a/net/core/dev.h
+++ b/net/core/dev.h@@ -9,6 +9,7 @@ #include <net/netdev_lock.h> struct net; +struct netdev_queue_config; struct netlink_ext_ack; struct cpumask;
@@ -96,6 +97,8 @@ int netdev_alloc_config(struct net_device *dev); void __netdev_free_config(struct netdev_config *cfg); void netdev_free_config(struct net_device *dev); int netdev_reconfig_start(struct net_device *dev); +void __netdev_queue_config(struct net_device *dev, int rxq, + struct netdev_queue_config *qcfg, bool pending); /* netdev management, shared between various uAPI entry points */ struct netdev_name_node {
diff --git a/net/core/netdev_config.c b/net/core/netdev_config.c
index 270b7f10a192..bad2d53522f0 100644
--- a/net/core/netdev_config.c
+++ b/net/core/netdev_config.c@@ -8,18 +8,29 @@ int netdev_alloc_config(struct net_device *dev) { struct netdev_config *cfg; + unsigned int maxqs; cfg = kzalloc(sizeof(*dev->cfg), GFP_KERNEL_ACCOUNT); if (!cfg) return -ENOMEM; + maxqs = max(dev->num_rx_queues, dev->num_tx_queues); + cfg->qcfg = kcalloc(maxqs, sizeof(*cfg->qcfg), GFP_KERNEL_ACCOUNT); + if (!cfg->qcfg) + goto err_free_cfg; + dev->cfg = cfg; dev->cfg_pending = cfg; return 0; + +err_free_cfg: + kfree(cfg); + return -ENOMEM; } void __netdev_free_config(struct netdev_config *cfg) { + kfree(cfg->qcfg); kfree(cfg); }
@@ -32,12 +43,59 @@ void netdev_free_config(struct net_device *dev) int netdev_reconfig_start(struct net_device *dev) { struct netdev_config *cfg; + unsigned int maxqs; WARN_ON(dev->cfg != dev->cfg_pending); cfg = kmemdup(dev->cfg, sizeof(*dev->cfg), GFP_KERNEL_ACCOUNT); if (!cfg) return -ENOMEM; + maxqs = max(dev->num_rx_queues, dev->num_tx_queues); + cfg->qcfg = kmemdup_array(dev->cfg->qcfg, maxqs, sizeof(*cfg->qcfg), + GFP_KERNEL_ACCOUNT); + if (!cfg->qcfg) + goto err_free_cfg; + dev->cfg_pending = cfg; return 0; + +err_free_cfg: + kfree(cfg); + return -ENOMEM; +} + +void __netdev_queue_config(struct net_device *dev, int rxq, + struct netdev_queue_config *qcfg, bool pending) +{ + memset(qcfg, 0, sizeof(*qcfg)); + + /* Get defaults from the driver, in case user config not set */ + if (dev->queue_mgmt_ops->ndo_queue_cfg_defaults) + dev->queue_mgmt_ops->ndo_queue_cfg_defaults(dev, rxq, qcfg); +} + +/** + * netdev_queue_config() - get configuration for a given queue + * @dev: net_device instance + * @rxq: index of the queue of interest + * @qcfg: queue configuration struct (output) + * + * Render the configuration for a given queue. This helper should be used + * by drivers which support queue configuration to retrieve config for + * a particular queue. + * + * @qcfg is an output parameter and is always fully initialized by this + * function. Some values may not be set by the user, drivers may either + * deal with the "unset" values in @qcfg, or provide the callback + * to populate defaults in queue_management_ops. + * + * Note that this helper returns pending config, as it is expected that + * "old" queues are retained until config is successful so they can + * be restored directly without asking for the config. + */ +void netdev_queue_config(struct net_device *dev, int rxq, + struct netdev_queue_config *qcfg) +{ + __netdev_queue_config(dev, rxq, qcfg, true); } +EXPORT_SYMBOL(netdev_queue_config);
diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
index d126f10197bf..d8a710db21cd 100644
--- a/net/core/netdev_rx_queue.c
+++ b/net/core/netdev_rx_queue.c@@ -7,12 +7,14 @@ #include <net/netdev_rx_queue.h> #include <net/page_pool/memory_provider.h> +#include "dev.h" #include "page_pool_priv.h" int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) { struct netdev_rx_queue *rxq = __netif_get_rx_queue(dev, rxq_idx); const struct netdev_queue_mgmt_ops *qops = dev->queue_mgmt_ops; + struct netdev_queue_config qcfg; void *new_mem, *old_mem; int err;
@@ -32,7 +34,9 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) goto err_free_new_mem; } - err = qops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx); + netdev_queue_config(dev, rxq_idx, &qcfg); + + err = qops->ndo_queue_mem_alloc(dev, &qcfg, new_mem, rxq_idx); if (err) goto err_free_old_mem;
@@ -45,7 +49,7 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) if (err) goto err_free_new_queue_mem; - err = qops->ndo_queue_start(dev, new_mem, rxq_idx); + err = qops->ndo_queue_start(dev, &qcfg, new_mem, rxq_idx); if (err) goto err_start_queue; } else {
@@ -60,6 +64,7 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) return 0; err_start_queue: + __netdev_queue_config(dev, rxq_idx, &qcfg, false); /* Restarting the queue with old_mem should be successful as we haven't * changed any of the queue configuration, and there is not much we can * do to recover from a failure here.
@@ -67,7 +72,7 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) * WARN if we fail to recover the old rx queue, and at least free * old_mem so we don't also leak that. */ - if (qops->ndo_queue_start(dev, old_mem, rxq_idx)) { + if (qops->ndo_queue_start(dev, &qcfg, old_mem, rxq_idx)) { WARN(1, "Failed to restart old queue in error path. RX queue %d may be unhealthy.", rxq_idx);
--
2.49.0