[dpdk-dev,v3] net/virtio: fix wrong TX pkt length stats
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Commit Message
In the function virtqueue_enqueue_xmit(), when can_push is true,
vtnet_hdr_size is added to pkt_len by calling rte_pktmbuf_prepend.
which is wrong for pkt stats, virtio header length should be subtracted
before calling stats function.
Fixes: 58169a9c8153 ("net/virtio: support Tx checksum offload")
Cc: stable@dpdk.org
Cc: yliu@fridaylinux.org
Cc: maxime.coquelin@redhat.com
Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
Changes in V3:
Move code inside "if (can_push)" clause and simplify comments.
Changes in V2:
Put code in the function virtqueue_enqueue_xmit() according to
yuanhan's comments.
drivers/net/virtio/virtio_rxtx.c | 4 ++++
1 file changed, 4 insertions(+)
Comments
On Tue, Oct 24, 2017 at 11:06:14AM +0800, Zhiyong Yang wrote:
> In the function virtqueue_enqueue_xmit(), when can_push is true,
> vtnet_hdr_size is added to pkt_len by calling rte_pktmbuf_prepend.
> which is wrong for pkt stats, virtio header length should be subtracted
> before calling stats function.
>
> Fixes: 58169a9c8153 ("net/virtio: support Tx checksum offload")
>
> Cc: stable@dpdk.org
> Cc: yliu@fridaylinux.org
> Cc: maxime.coquelin@redhat.com
> Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Applied to dpdk-next-virtio.
Thanks.
--yliu
@@ -299,6 +299,10 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
/* prepend cannot fail, checked by caller */
hdr = (struct virtio_net_hdr *)
rte_pktmbuf_prepend(cookie, head_size);
+ /* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
+ * which is wrong. Below subtract restores correct pkt size.
+ */
+ cookie->pkt_len -= head_size;
/* if offload disabled, it is not zeroed below, do it now */
if (offload == 0) {
ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);