Re: [dpdk-dev] [RFC 06/10] virtio: use software vlan stripping

["Ouyang, Changchun" <changchun.ouyang@intel.com>]

Hi Stephen,

Would you please describe the use scenario for the front end rx vlan strip and tx vlan insertion?
In our current implementation, backend will strip vlan tag for RX, and insert vlan tag for TX.
  
Thanks
Changchun

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Tuesday, August 26, 2014 10:08 AM
> To: Ouyang, Changchun
> Cc: dev@dpdk.org; Stephen Hemminger
> Subject: [RFC 06/10] virtio: use software vlan stripping
> 
> Implement VLAN stripping in software. This allows application to be device
> independent.
> 
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> 
> 
> ---
>  lib/librte_pmd_virtio/virtio_ethdev.c |    2 ++
>  lib/librte_pmd_virtio/virtio_pci.h    |    1 +
>  lib/librte_pmd_virtio/virtio_rxtx.c   |   20 ++++++++++++++++++--
>  3 files changed, 21 insertions(+), 2 deletions(-)
> 
> --- a/lib/librte_pmd_virtio/virtio_ethdev.c	2014-08-25
> 19:00:07.574537243 -0700
> +++ b/lib/librte_pmd_virtio/virtio_ethdev.c	2014-08-25
> 19:00:07.574537243 -0700
> @@ -976,6 +976,8 @@ virtio_dev_configure(struct rte_eth_dev
>  		return (-EINVAL);
>  	}
> 
> +	hw->vlan_strip = rxmode->hw_vlan_strip;
> +
>  	ret = vtpci_irq_config(hw, 0);
>  	if (ret != 0)
>  		PMD_DRV_LOG(ERR, "failed to set config vector");
> --- a/lib/librte_pmd_virtio/virtio_pci.h	2014-08-25 19:00:07.574537243 -0700
> +++ b/lib/librte_pmd_virtio/virtio_pci.h	2014-08-25
> 19:00:07.574537243 -0700
> @@ -168,6 +168,7 @@ struct virtio_hw {
>  	uint32_t    max_tx_queues;
>  	uint32_t    max_rx_queues;
>  	uint16_t    vtnet_hdr_size;
> +	uint8_t	    vlan_strip;
>  	uint8_t	    use_msix;
>  	uint8_t     mac_addr[ETHER_ADDR_LEN];
>  };
> --- a/lib/librte_pmd_virtio/virtio_rxtx.c	2014-08-25 19:00:07.574537243 -0700
> +++ b/lib/librte_pmd_virtio/virtio_rxtx.c	2014-08-25
> 19:00:07.574537243 -0700
> @@ -49,6 +49,7 @@
>  #include <rte_prefetch.h>
>  #include <rte_string_fns.h>
>  #include <rte_errno.h>
> +#include <rte_byteorder.h>
> 
>  #include "virtio_logs.h"
>  #include "virtio_ethdev.h"
> @@ -406,8 +407,8 @@ virtio_dev_tx_queue_setup(struct rte_eth
> 
>  	PMD_INIT_FUNC_TRACE();
> 
> -	if ((tx_conf->txq_flags & ETH_TXQ_FLAGS_NOOFFLOADS)
> -	    != ETH_TXQ_FLAGS_NOOFFLOADS) {
> +	if ((tx_conf->txq_flags & ETH_TXQ_FLAGS_NOXSUMS)
> +	    != ETH_TXQ_FLAGS_NOXSUMS) {
>  		PMD_INIT_LOG(ERR, "TX checksum offload not
> supported\n");
>  		return -EINVAL;
>  	}
> @@ -444,6 +445,7 @@ uint16_t
>  virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t
> nb_pkts)  {
>  	struct virtqueue *rxvq = rx_queue;
> +	struct virtio_hw *hw = rxvq->hw;
>  	struct rte_mbuf *rxm, *new_mbuf;
>  	uint16_t nb_used, num, nb_rx = 0;
>  	uint32_t len[VIRTIO_MBUF_BURST_SZ];
> @@ -487,6 +489,9 @@ virtio_recv_pkts(void *rx_queue, struct
>  		rxm->pkt.pkt_len = (uint32_t)(len[i] - hdr_size);
>  		rxm->pkt.data_len = (uint16_t)(len[i] - hdr_size);
> 
> +		if (hw->vlan_strip)
> +			rte_vlan_strip(rxm);
> +
>  		VIRTIO_DUMP_PACKET(rxm, rxm->pkt.data_len);
> 
>  		rx_pkts[nb_rx++] = rxm;
> @@ -711,6 +716,17 @@ virtio_xmit_pkts(void *tx_queue, struct
> 
>  		if (tx_pkts[nb_tx]->pkt.nb_segs <= txvq->vq_free_cnt) {
>  			txm = tx_pkts[nb_tx];
> +
> +			/* Do VLAN tag insertion */
> +			if (txm->ol_flags & PKT_TX_VLAN_PKT) {
> +				error = rte_vlan_insert(txm);
> +				if (unlikely(error)) {
> +					rte_pktmbuf_free(txm);
> +					++nb_tx;
> +					continue;
> +				}
> +			}
> +
>  			/* Enqueue Packet buffers */
>  			error = virtqueue_enqueue_xmit(txvq, txm);
>  			if (unlikely(error)) {