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virtio_net: Fix incosistent received bytes counter

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When received packets are dropped in virtio_net driver, received packets
counter is incremented but bytes counter is not.
As a result, for instance if we drop all packets by XDP, only received
is counted and bytes stays 0, which looks inconsistent.
IMHO received packets/bytes should be counted if packets are produced by
the hypervisor, like what common NICs on physical machines are doing.
So fix the bytes counter.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Toshiaki Makita 2018-07-23 23:36:04 +09:00 committed by David S. Miller
parent 19725496da
commit 7d9d60fd4a
1 changed files with 23 additions and 18 deletions
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41
drivers/net/virtio_net.c
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@ -586,7 +586,8 @@ static struct sk_buff *receive_small(struct net_device *dev,
struct receive_queue *rq,
void *buf, void *ctx,
unsigned int len,
unsigned int *xdp_xmit)
unsigned int *xdp_xmit,
unsigned int *rbytes)
{
struct sk_buff *skb;
struct bpf_prog *xdp_prog;
@ -601,6 +602,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
int err;
len -= vi->hdr_len;
*rbytes += len;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
@ -705,11 +707,13 @@ static struct sk_buff *receive_big(struct net_device *dev,
struct virtnet_info *vi,
struct receive_queue *rq,
void *buf,
unsigned int len)
unsigned int len,
unsigned int *rbytes)
{
struct page *page = buf;
struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
*rbytes += len - vi->hdr_len;
if (unlikely(!skb))
goto err;
@ -727,7 +731,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
void *buf,
void *ctx,
unsigned int len,
unsigned int *xdp_xmit)
unsigned int *xdp_xmit,
unsigned int *rbytes)
{
struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
u16 num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers);
@ -740,6 +745,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
int err;
head_skb = NULL;
*rbytes += len - vi->hdr_len;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
@ -877,6 +883,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
goto err_buf;
}
*rbytes += len;
page = virt_to_head_page(buf);
truesize = mergeable_ctx_to_truesize(ctx);
@ -932,6 +939,7 @@ err_skb:
dev->stats.rx_length_errors++;
break;
}
*rbytes += len;
page = virt_to_head_page(buf);
put_page(page);
}
@ -942,14 +950,13 @@ xdp_xmit:
return NULL;
}
static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
void *buf, unsigned int len, void **ctx,
unsigned int *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)
{
struct net_device *dev = vi->dev;
struct sk_buff *skb;
struct virtio_net_hdr_mrg_rxbuf *hdr;
int ret;
if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
pr_debug("%s: short packet %i\n", dev->name, len);
@ -961,23 +968,22 @@ static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
} else {
put_page(virt_to_head_page(buf));
}
return 0;
return;
}
if (vi->mergeable_rx_bufs)
skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit);
skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
rbytes);
else if (vi->big_packets)
skb = receive_big(dev, vi, rq, buf, len);
skb = receive_big(dev, vi, rq, buf, len, rbytes);
else
skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit);
skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, rbytes);
if (unlikely(!skb))
return 0;
return;
hdr = skb_vnet_hdr(skb);
ret = skb->len;
if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
skb->ip_summed = CHECKSUM_UNNECESSARY;
@ -994,12 +1000,11 @@ static int receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
ntohs(skb->protocol), skb->len, skb->pkt_type);
napi_gro_receive(&rq->napi, skb);
return ret;
return;
frame_err:
dev->stats.rx_frame_errors++;
dev_kfree_skb(skb);
return 0;
}
/* Unlike mergeable buffers, all buffers are allocated to the
@ -1249,13 +1254,13 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
while (received < budget &&
(buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx))) {
bytes += receive_buf(vi, rq, buf, len, ctx, xdp_xmit);
receive_buf(vi, rq, buf, len, ctx, xdp_xmit, &bytes);
received++;
}
} else {
while (received < budget &&
(buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {
bytes += receive_buf(vi, rq, buf, len, NULL, xdp_xmit);
receive_buf(vi, rq, buf, len, NULL, xdp_xmit, &bytes);
received++;
}
}