virtio_net: Use temporary storage for accounting rx stats

The purpose is to keep receive_buf arguments simple when more per-queue
counter items are added later.
Also XDP_TX related sq counters will be updated in the following changes
so create a container struct virtnet_rx_stats which will includes both
rq and sq statistics. For now it only covers rq stats.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index abbd3bc..d03bfc4 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -84,14 +84,22 @@ struct virtnet_sq_stats {
        u64 bytes;
 };
 
-struct virtnet_rq_stats {
-       struct u64_stats_sync syncp;
+struct virtnet_rq_stat_items {
        u64 packets;
        u64 bytes;
 };
 
+struct virtnet_rq_stats {
+       struct u64_stats_sync syncp;
+       struct virtnet_rq_stat_items items;
+};
+
+struct virtnet_rx_stats {
+       struct virtnet_rq_stat_items rx;
+};
+
 #define VIRTNET_SQ_STAT(m)     offsetof(struct virtnet_sq_stats, m)
-#define VIRTNET_RQ_STAT(m)     offsetof(struct virtnet_rq_stats, m)
+#define VIRTNET_RQ_STAT(m)     offsetof(struct virtnet_rq_stat_items, m)
 
 static const struct virtnet_stat_desc virtnet_sq_stats_desc[] = {
        { "packets",    VIRTNET_SQ_STAT(packets) },
@@ -587,7 +595,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
                                     void *buf, void *ctx,
                                     unsigned int len,
                                     unsigned int *xdp_xmit,
-                                    unsigned int *rbytes)
+                                    struct virtnet_rx_stats *stats)
 {
        struct sk_buff *skb;
        struct bpf_prog *xdp_prog;
@@ -602,7 +610,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
        int err;
 
        len -= vi->hdr_len;
-       *rbytes += len;
+       stats->rx.bytes += len;
 
        rcu_read_lock();
        xdp_prog = rcu_dereference(rq->xdp_prog);
@@ -708,12 +716,12 @@ static struct sk_buff *receive_big(struct net_device *dev,
                                   struct receive_queue *rq,
                                   void *buf,
                                   unsigned int len,
-                                  unsigned int *rbytes)
+                                  struct virtnet_rx_stats *stats)
 {
        struct page *page = buf;
        struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
 
-       *rbytes += len - vi->hdr_len;
+       stats->rx.bytes += len - vi->hdr_len;
        if (unlikely(!skb))
                goto err;
 
@@ -732,7 +740,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                                         void *ctx,
                                         unsigned int len,
                                         unsigned int *xdp_xmit,
-                                        unsigned int *rbytes)
+                                        struct virtnet_rx_stats *stats)
 {
        struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
        u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
@@ -745,7 +753,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
        int err;
 
        head_skb = NULL;
-       *rbytes += len - vi->hdr_len;
+       stats->rx.bytes += len - vi->hdr_len;
 
        rcu_read_lock();
        xdp_prog = rcu_dereference(rq->xdp_prog);
@@ -883,7 +891,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                        goto err_buf;
                }
 
-               *rbytes += len;
+               stats->rx.bytes += len;
                page = virt_to_head_page(buf);
 
                truesize = mergeable_ctx_to_truesize(ctx);
@@ -939,7 +947,7 @@ err_skb:
                        dev->stats.rx_length_errors++;
                        break;
                }
-               *rbytes += len;
+               stats->rx.bytes += len;
                page = virt_to_head_page(buf);
                put_page(page);
        }
@@ -952,7 +960,8 @@ xdp_xmit:
 
 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
                        void *buf, unsigned int len, void **ctx,
-                       unsigned int *xdp_xmit, unsigned int *rbytes)
+                       unsigned int *xdp_xmit,
+                       struct virtnet_rx_stats *stats)
 {
        struct net_device *dev = vi->dev;
        struct sk_buff *skb;
@@ -973,11 +982,11 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 
        if (vi->mergeable_rx_bufs)
                skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
-                                       rbytes);
+                                       stats);
        else if (vi->big_packets)
-               skb = receive_big(dev, vi, rq, buf, len, rbytes);
+               skb = receive_big(dev, vi, rq, buf, len, stats);
        else
-               skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, rbytes);
+               skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats);
 
        if (unlikely(!skb))
                return;
@@ -1246,22 +1255,24 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
                           unsigned int *xdp_xmit)
 {
        struct virtnet_info *vi = rq->vq->vdev->priv;
-       unsigned int len, received = 0, bytes = 0;
+       struct virtnet_rx_stats stats = {};
+       unsigned int len;
        void *buf;
+       int i;
 
        if (!vi->big_packets || vi->mergeable_rx_bufs) {
                void *ctx;
 
-               while (received < budget &&
+               while (stats.rx.packets < budget &&
                       (buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
-                       receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &bytes);
-                       received++;
+                       receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &stats);
+                       stats.rx.packets++;
                }
        } else {
-               while (received < budget &&
+               while (stats.rx.packets < budget &&
                       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
-                       receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &bytes);
-                       received++;
+                       receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &stats);
+                       stats.rx.packets++;
                }
        }
 
@@ -1271,11 +1282,16 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
        }
 
        u64_stats_update_begin(&rq->stats.syncp);
-       rq->stats.bytes += bytes;
-       rq->stats.packets += received;
+       for (i = 0; i < VIRTNET_RQ_STATS_LEN; i++) {
+               size_t offset = virtnet_rq_stats_desc[i].offset;
+               u64 *item;
+
+               item = (u64 *)((u8 *)&rq->stats.items + offset);
+               *item += *(u64 *)((u8 *)&stats.rx + offset);
+       }
        u64_stats_update_end(&rq->stats.syncp);
 
-       return received;
+       return stats.rx.packets;
 }
 
 static void free_old_xmit_skbs(struct send_queue *sq)
@@ -1628,8 +1644,8 @@ static void virtnet_stats(struct net_device *dev,
 
                do {
                        start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
-                       rpackets = rq->stats.packets;
-                       rbytes   = rq->stats.bytes;
+                       rpackets = rq->stats.items.packets;
+                       rbytes   = rq->stats.items.bytes;
                } while (u64_stats_fetch_retry_irq(&rq->stats.syncp, start));
 
                tot->rx_packets += rpackets;
@@ -2019,7 +2035,7 @@ static void virtnet_get_ethtool_stats(struct net_device *dev,
        for (i = 0; i < vi->curr_queue_pairs; i++) {
                struct receive_queue *rq = &vi->rq[i];
 
-               stats_base = (u8 *)&rq->stats;
+               stats_base = (u8 *)&rq->stats.items;
                do {
                        start = u64_stats_fetch_begin_irq(&rq->stats.syncp);
                        for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {