Re: [dpdk-dev] [PATCH v4 1/3] vhost: Fix packet length issue

["Xie, Huawei" <huawei.xie@intel.com>]

> -----Original Message-----
> From: Ouyang, Changchun
> Sent: Wednesday, November 05, 2014 12:11 AM
> To: dev@dpdk.org
> Cc: Xie, Huawei; Ananyev, Konstantin; Cao, Waterman; Ouyang, Changchun
> Subject: [PATCH v4 1/3] vhost: Fix packet length issue
> 
> As HW vlan strip will reduce the packet length by minus length of vlan tag,
> so it need restore the packet length by plus it.
> 
> Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
> ---
>  examples/vhost/main.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> index 57ef464..5ca8dce 100644
> --- a/examples/vhost/main.c
> +++ b/examples/vhost/main.c
> @@ -1078,7 +1078,13 @@ virtio_tx_route(struct vhost_dev *vdev, struct
> rte_mbuf *m, uint16_t vlan_tag)
>  					rte_pktmbuf_free(m);
>  					return;
>  				}
> -				offset = 4;
> +
> +				/*
> +				 * HW vlan strip will reduce the packet length
> +				 * by minus length of vlan tag, so need restore
> +				 * the packet length by plus it.
> +				 */
> +				offset = VLAN_HLEN;
>  				vlan_tag =
>  				(uint16_t)
>  				vlan_tags[(uint16_t)dev_ll->vdev->dev-
> >device_fh];
> @@ -1102,8 +1108,10 @@ virtio_tx_route(struct vhost_dev *vdev, struct
> rte_mbuf *m, uint16_t vlan_tag)
>  	len = tx_q->len;
> 
>  	m->ol_flags = PKT_TX_VLAN_PKT;
> -	/*FIXME: offset*/
> +
>  	m->data_len += offset;
> +	m->pkt_len += offset;
> +
>  	m->vlan_tci = vlan_tag;
> 
>  	tx_q->m_table[len] = m;
> --
> 1.8.4.2
Only one thing, I feel "by minus/plus" has grammar problem. :).
Acked-by: Huawei Xie <huawei.xie@intel.com>.