diff options
| -rw-r--r-- | drivers/net/virtio_net.c | 155 |
1 files changed, 85 insertions, 70 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fb5e68ed3ec2..1a309cfb4976 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -545,6 +545,87 @@ ok: return skb; } +static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi) +{ + unsigned int len; + unsigned int packets = 0; + unsigned int bytes = 0; + void *ptr; + + while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) { + if (likely(!is_xdp_frame(ptr))) { + struct sk_buff *skb = ptr; + + pr_debug("Sent skb %p\n", skb); + + bytes += skb->len; + napi_consume_skb(skb, in_napi); + } else { + struct xdp_frame *frame = ptr_to_xdp(ptr); + + bytes += xdp_get_frame_len(frame); + xdp_return_frame(frame); + } + packets++; + } + + /* Avoid overhead when no packets have been processed + * happens when called speculatively from start_xmit. + */ + if (!packets) + return; + + u64_stats_update_begin(&sq->stats.syncp); + sq->stats.bytes += bytes; + sq->stats.packets += packets; + u64_stats_update_end(&sq->stats.syncp); +} + +static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q) +{ + if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) + return false; + else if (q < vi->curr_queue_pairs) + return true; + else + return false; +} + +static void check_sq_full_and_disable(struct virtnet_info *vi, + struct net_device *dev, + struct send_queue *sq) +{ + bool use_napi = sq->napi.weight; + int qnum; + + qnum = sq - vi->sq; + + /* If running out of space, stop queue to avoid getting packets that we + * are then unable to transmit. + * An alternative would be to force queuing layer to requeue the skb by + * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be + * returned in a normal path of operation: it means that driver is not + * maintaining the TX queue stop/start state properly, and causes + * the stack to do a non-trivial amount of useless work. + * Since most packets only take 1 or 2 ring slots, stopping the queue + * early means 16 slots are typically wasted. + */ + if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { + netif_stop_subqueue(dev, qnum); + if (use_napi) { + if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) + virtqueue_napi_schedule(&sq->napi, sq->vq); + } else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { + /* More just got used, free them then recheck. */ + free_old_xmit_skbs(sq, false); + if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { + netif_start_subqueue(dev, qnum); + virtqueue_disable_cb(sq->vq); + } + } + } +} + static int __virtnet_xdp_xmit_one(struct virtnet_info *vi, struct send_queue *sq, struct xdp_frame *xdpf) @@ -686,6 +767,9 @@ static int virtnet_xdp_xmit(struct net_device *dev, } ret = nxmit; + if (!is_xdp_raw_buffer_queue(vi, sq - vi->sq)) + check_sq_full_and_disable(vi, dev, sq); + if (flags & XDP_XMIT_FLUSH) { if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) kicks = 1; @@ -1714,52 +1798,6 @@ static int virtnet_receive(struct receive_queue *rq, int budget, return stats.packets; } -static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi) -{ - unsigned int len; - unsigned int packets = 0; - unsigned int bytes = 0; - void *ptr; - - while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) { - if (likely(!is_xdp_frame(ptr))) { - struct sk_buff *skb = ptr; - - pr_debug("Sent skb %p\n", skb); - - bytes += skb->len; - napi_consume_skb(skb, in_napi); - } else { - struct xdp_frame *frame = ptr_to_xdp(ptr); - - bytes += xdp_get_frame_len(frame); - xdp_return_frame(frame); - } - packets++; - } - - /* Avoid overhead when no packets have been processed - * happens when called speculatively from start_xmit. - */ - if (!packets) - return; - - u64_stats_update_begin(&sq->stats.syncp); - sq->stats.bytes += bytes; - sq->stats.packets += packets; - u64_stats_update_end(&sq->stats.syncp); -} - -static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q) -{ - if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) - return false; - else if (q < vi->curr_queue_pairs) - return true; - else - return false; -} - static void virtnet_poll_cleantx(struct receive_queue *rq) { struct virtnet_info *vi = rq->vq->vdev->priv; @@ -1989,30 +2027,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) nf_reset_ct(skb); } - /* If running out of space, stop queue to avoid getting packets that we - * are then unable to transmit. - * An alternative would be to force queuing layer to requeue the skb by - * returning NETDEV_TX_BUSY. However, NETDEV_TX_BUSY should not be - * returned in a normal path of operation: it means that driver is not - * maintaining the TX queue stop/start state properly, and causes - * the stack to do a non-trivial amount of useless work. - * Since most packets only take 1 or 2 ring slots, stopping the queue - * early means 16 slots are typically wasted. - */ - if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { - netif_stop_subqueue(dev, qnum); - if (use_napi) { - if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) - virtqueue_napi_schedule(&sq->napi, sq->vq); - } else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { - /* More just got used, free them then recheck. */ - free_old_xmit_skbs(sq, false); - if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { - netif_start_subqueue(dev, qnum); - virtqueue_disable_cb(sq->vq); - } - } - } + check_sq_full_and_disable(vi, dev, sq); if (kick || netif_xmit_stopped(txq)) { if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) { |