From 3762ec05a9fbda16aaaa2568df679ab8ad13f38d Mon Sep 17 00:00:00 2001 From: David Wei Date: Tue, 7 May 2024 09:32:27 -0700 Subject: netdevsim: add NAPI support Add NAPI support to netdevim, similar to veth. * Add a nsim_rq rx queue structure to hold a NAPI instance and a skb queue. * During xmit, store the skb in the peer skb queue and schedule NAPI. * During napi_poll(), drain the skb queue and pass up the stack. * Add assoc between rxq and NAPI instance using netif_queue_set_napi(). Signed-off-by: David Wei Link: https://lore.kernel.org/r/20240507163228.2066817-2-dw@davidwei.uk Signed-off-by: Jakub Kicinski --- drivers/net/netdevsim/netdev.c | 209 ++++++++++++++++++++++++++++++++++++-- drivers/net/netdevsim/netdevsim.h | 8 +- 2 files changed, 205 insertions(+), 12 deletions(-) diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c index e3a385a32269..c22897bf5509 100644 --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -28,11 +28,33 @@ #include "netdevsim.h" +#define NSIM_RING_SIZE 256 + +static int nsim_napi_rx(struct nsim_rq *rq, struct sk_buff *skb) +{ + if (skb_queue_len(&rq->skb_queue) > NSIM_RING_SIZE) { + dev_kfree_skb_any(skb); + return NET_RX_DROP; + } + + skb_queue_tail(&rq->skb_queue, skb); + return NET_RX_SUCCESS; +} + +static int nsim_forward_skb(struct net_device *dev, struct sk_buff *skb, + struct nsim_rq *rq) +{ + return __dev_forward_skb(dev, skb) ?: nsim_napi_rx(rq, skb); +} + static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct netdevsim *ns = netdev_priv(dev); + struct net_device *peer_dev; unsigned int len = skb->len; struct netdevsim *peer_ns; + struct nsim_rq *rq; + int rxq; rcu_read_lock(); if (!nsim_ipsec_tx(ns, skb)) @@ -42,10 +64,18 @@ static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev) if (!peer_ns) goto out_drop_free; + peer_dev = peer_ns->netdev; + rxq = skb_get_queue_mapping(skb); + if (rxq >= peer_dev->num_rx_queues) + rxq = rxq % peer_dev->num_rx_queues; + rq = &peer_ns->rq[rxq]; + skb_tx_timestamp(skb); - if (unlikely(dev_forward_skb(peer_ns->netdev, skb) == NET_RX_DROP)) + if (unlikely(nsim_forward_skb(peer_dev, skb, rq) == NET_RX_DROP)) goto out_drop_cnt; + napi_schedule(&rq->napi); + rcu_read_unlock(); u64_stats_update_begin(&ns->syncp); ns->tx_packets++; @@ -300,25 +330,146 @@ static int nsim_get_iflink(const struct net_device *dev) return iflink; } +static int nsim_rcv(struct nsim_rq *rq, int budget) +{ + struct sk_buff *skb; + int i; + + for (i = 0; i < budget; i++) { + if (skb_queue_empty(&rq->skb_queue)) + break; + + skb = skb_dequeue(&rq->skb_queue); + netif_receive_skb(skb); + } + + return i; +} + +static int nsim_poll(struct napi_struct *napi, int budget) +{ + struct nsim_rq *rq = container_of(napi, struct nsim_rq, napi); + int done; + + done = nsim_rcv(rq, budget); + napi_complete(napi); + + return done; +} + +static int nsim_create_page_pool(struct nsim_rq *rq) +{ + struct page_pool_params p = { + .order = 0, + .pool_size = NSIM_RING_SIZE, + .nid = NUMA_NO_NODE, + .dev = &rq->napi.dev->dev, + .napi = &rq->napi, + .dma_dir = DMA_BIDIRECTIONAL, + .netdev = rq->napi.dev, + }; + + rq->page_pool = page_pool_create(&p); + if (IS_ERR(rq->page_pool)) { + int err = PTR_ERR(rq->page_pool); + + rq->page_pool = NULL; + return err; + } + return 0; +} + +static int nsim_init_napi(struct netdevsim *ns) +{ + struct net_device *dev = ns->netdev; + struct nsim_rq *rq; + int err, i; + + for (i = 0; i < dev->num_rx_queues; i++) { + rq = &ns->rq[i]; + + netif_napi_add(dev, &rq->napi, nsim_poll); + } + + for (i = 0; i < dev->num_rx_queues; i++) { + rq = &ns->rq[i]; + + err = nsim_create_page_pool(rq); + if (err) + goto err_pp_destroy; + } + + return 0; + +err_pp_destroy: + while (i--) { + page_pool_destroy(ns->rq[i].page_pool); + ns->rq[i].page_pool = NULL; + } + + for (i = 0; i < dev->num_rx_queues; i++) + __netif_napi_del(&ns->rq[i].napi); + + return err; +} + +static void nsim_enable_napi(struct netdevsim *ns) +{ + struct net_device *dev = ns->netdev; + int i; + + for (i = 0; i < dev->num_rx_queues; i++) { + struct nsim_rq *rq = &ns->rq[i]; + + netif_queue_set_napi(dev, i, NETDEV_QUEUE_TYPE_RX, &rq->napi); + napi_enable(&rq->napi); + } +} + static int nsim_open(struct net_device *dev) { struct netdevsim *ns = netdev_priv(dev); - struct page_pool_params pp = { 0 }; + int err; - pp.pool_size = 128; - pp.dev = &dev->dev; - pp.dma_dir = DMA_BIDIRECTIONAL; - pp.netdev = dev; + err = nsim_init_napi(ns); + if (err) + return err; - ns->pp = page_pool_create(&pp); - return PTR_ERR_OR_ZERO(ns->pp); + nsim_enable_napi(ns); + + return 0; +} + +static void nsim_del_napi(struct netdevsim *ns) +{ + struct net_device *dev = ns->netdev; + int i; + + for (i = 0; i < dev->num_rx_queues; i++) { + struct nsim_rq *rq = &ns->rq[i]; + + napi_disable(&rq->napi); + __netif_napi_del(&rq->napi); + } + synchronize_net(); + + for (i = 0; i < dev->num_rx_queues; i++) { + page_pool_destroy(ns->rq[i].page_pool); + ns->rq[i].page_pool = NULL; + } } static int nsim_stop(struct net_device *dev) { struct netdevsim *ns = netdev_priv(dev); + struct netdevsim *peer; + + netif_carrier_off(dev); + peer = rtnl_dereference(ns->peer); + if (peer) + netif_carrier_off(peer->netdev); - page_pool_destroy(ns->pp); + nsim_del_napi(ns); return 0; } @@ -437,7 +588,7 @@ nsim_pp_hold_write(struct file *file, const char __user *data, if (!netif_running(ns->netdev) && val) { ret = -ENETDOWN; } else if (val) { - ns->page = page_pool_dev_alloc_pages(ns->pp); + ns->page = page_pool_dev_alloc_pages(ns->rq[0].page_pool); if (!ns->page) ret = -ENOMEM; } else { @@ -477,6 +628,35 @@ static void nsim_setup(struct net_device *dev) dev->xdp_features = NETDEV_XDP_ACT_HW_OFFLOAD; } +static int nsim_queue_init(struct netdevsim *ns) +{ + struct net_device *dev = ns->netdev; + int i; + + ns->rq = kvcalloc(dev->num_rx_queues, sizeof(*ns->rq), + GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL); + if (!ns->rq) + return -ENOMEM; + + for (i = 0; i < dev->num_rx_queues; i++) + skb_queue_head_init(&ns->rq[i].skb_queue); + + return 0; +} + +static void nsim_queue_free(struct netdevsim *ns) +{ + struct net_device *dev = ns->netdev; + int i; + + for (i = 0; i < dev->num_rx_queues; i++) + skb_queue_purge_reason(&ns->rq[i].skb_queue, + SKB_DROP_REASON_QUEUE_PURGE); + + kvfree(ns->rq); + ns->rq = NULL; +} + static int nsim_init_netdevsim(struct netdevsim *ns) { struct mock_phc *phc; @@ -495,10 +675,14 @@ static int nsim_init_netdevsim(struct netdevsim *ns) goto err_phc_destroy; rtnl_lock(); - err = nsim_bpf_init(ns); + err = nsim_queue_init(ns); if (err) goto err_utn_destroy; + err = nsim_bpf_init(ns); + if (err) + goto err_rq_destroy; + nsim_macsec_init(ns); nsim_ipsec_init(ns); @@ -512,6 +696,8 @@ err_ipsec_teardown: nsim_ipsec_teardown(ns); nsim_macsec_teardown(ns); nsim_bpf_uninit(ns); +err_rq_destroy: + nsim_queue_free(ns); err_utn_destroy: rtnl_unlock(); nsim_udp_tunnels_info_destroy(ns->netdev); @@ -593,6 +779,7 @@ void nsim_destroy(struct netdevsim *ns) nsim_macsec_teardown(ns); nsim_ipsec_teardown(ns); nsim_bpf_uninit(ns); + nsim_queue_free(ns); } rtnl_unlock(); if (nsim_dev_port_is_pf(ns->nsim_dev_port)) diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h index 7664ab823e29..bf02efa10956 100644 --- a/drivers/net/netdevsim/netdevsim.h +++ b/drivers/net/netdevsim/netdevsim.h @@ -90,11 +90,18 @@ struct nsim_ethtool { struct ethtool_fecparam fec; }; +struct nsim_rq { + struct napi_struct napi; + struct sk_buff_head skb_queue; + struct page_pool *page_pool; +}; + struct netdevsim { struct net_device *netdev; struct nsim_dev *nsim_dev; struct nsim_dev_port *nsim_dev_port; struct mock_phc *phc; + struct nsim_rq *rq; u64 tx_packets; u64 tx_bytes; @@ -125,7 +132,6 @@ struct netdevsim { struct debugfs_u32_array dfs_ports[2]; } udp_ports; - struct page_pool *pp; struct page *page; struct dentry *pp_dfs; -- cgit v1.2.3