xsk wakeup is used to trigger the logic for xsk xmit by xsk framework or user.
Virtio-Net does not support to actively generate a interruption, so it try to trigger tx NAPI on the tx interrupt cpu. Consider the effect of cache. When interrupt triggers, it is generally fixed on a CPU. It is better to start TX Napi on the same CPU. Signed-off-by: Xuan Zhuo <[email protected]> --- drivers/net/virtio/main.c | 3 ++ drivers/net/virtio/virtio_net.h | 2 ++ drivers/net/virtio/xsk.c | 53 +++++++++++++++++++++++++++++++++ drivers/net/virtio/xsk.h | 1 + 4 files changed, 59 insertions(+) diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c index 02d2f7d21bdf..7259b27f5cba 100644 --- a/drivers/net/virtio/main.c +++ b/drivers/net/virtio/main.c @@ -1613,6 +1613,8 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) int opaque; bool done; + sq->xsk.last_cpu = smp_processor_id(); + if (unlikely(is_xdp_raw_buffer_queue(vi, index))) { /* We don't need to enable cb for XDP */ napi_complete_done(napi, 0); @@ -3197,6 +3199,7 @@ static const struct net_device_ops virtnet_netdev = { .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, .ndo_bpf = virtnet_xdp, .ndo_xdp_xmit = virtnet_xdp_xmit, + .ndo_xsk_wakeup = virtnet_xsk_wakeup, .ndo_features_check = passthru_features_check, .ndo_get_phys_port_name = virtnet_get_phys_port_name, .ndo_set_features = virtnet_set_features, diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h index dd2f7890f8cd..fc7c7a0f3c89 100644 --- a/drivers/net/virtio/virtio_net.h +++ b/drivers/net/virtio/virtio_net.h @@ -174,6 +174,8 @@ struct send_queue { struct xsk_buff_pool __rcu *pool; dma_addr_t hdr_dma_address; + + u32 last_cpu; } xsk; }; diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c index 04db80244dbd..27b7f0bb2d34 100644 --- a/drivers/net/virtio/xsk.c +++ b/drivers/net/virtio/xsk.c @@ -153,6 +153,59 @@ bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, return busy; } +static void xsk_remote_trigger_napi(void *info) +{ + struct send_queue *sq = info; + + virtqueue_napi_schedule(&sq->napi, sq->vq); +} + +static void virtnet_xsk_wakeup_sq(struct send_queue *sq, bool in_napi) +{ + u32 last_cpu, cur_cpu; + + if (napi_if_scheduled_mark_missed(&sq->napi)) + return; + + last_cpu = sq->xsk.last_cpu; + + cur_cpu = get_cpu(); + + /* On remote cpu, softirq will run automatically when ipi irq exit. On + * local cpu, smp_call_xxx will not trigger ipi interrupt, then softirq + * cannot be triggered automatically by ipi irq exit. + */ + if (last_cpu == cur_cpu) { + virtqueue_napi_schedule(&sq->napi, sq->vq); + + /* Not in softirq/irq context, we must raise napi tx manually. */ + if (!in_napi) + napi_tx_raise(); + } else { + smp_call_function_single(last_cpu, xsk_remote_trigger_napi, sq, true); + } + + put_cpu(); +} + +int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag) +{ + struct virtnet_info *vi = netdev_priv(dev); + struct send_queue *sq; + + if (!netif_running(dev)) + return -ENETDOWN; + + if (qid >= vi->curr_queue_pairs) + return -EINVAL; + + sq = &vi->sq[qid]; + + virtnet_xsk_wakeup_sq(sq, false); + + return 0; +} + static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queue *rq, struct xsk_buff_pool *pool, struct net_device *dev) { diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h index 15f1540a5803..5eece0de3310 100644 --- a/drivers/net/virtio/xsk.h +++ b/drivers/net/virtio/xsk.h @@ -22,4 +22,5 @@ static inline u32 ptr_to_xsk(void *ptr) int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp); bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, int budget); +int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag); #endif -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
