On 10/22/2015 10:45 AM, Jianfeng wrote:
> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Huawei Xie
> Sent: Tuesday, October 20, 2015 11:30 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH v3 7/7] virtio: pick simple rx/tx func
>
> simple rx/tx func is enabled when user specifies single segment and no
> offload support.
> merge-able should be disabled to use simple rxtx.
>
> Signed-off-by: Huawei Xie <huawei.xie at intel.com>
> ---
> drivers/net/virtio/virtio_rxtx.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/net/virtio/virtio_rxtx.c
> b/drivers/net/virtio/virtio_rxtx.c
> index 947fc46..71f8cd4 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -62,6 +62,10 @@
> #define VIRTIO_DUMP_PACKET(m, len) do { } while (0) #endif
>
> +
> +#define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS
> | \
> + ETH_TXQ_FLAGS_NOOFFLOADS)
> +
> static int use_simple_rxtx;
>
> static void
> @@ -471,6 +475,14 @@ virtio_dev_tx_queue_setup(struct rte_eth_dev
> *dev,
> return -EINVAL;
> }
>
> + /* Use simple rx/tx func if single segment and no offloads */
> + if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) ==
> VIRTIO_SIMPLE_FLAGS) {
> + PMD_INIT_LOG(INFO, "Using simple rx/tx path");
> + dev->tx_pkt_burst = virtio_xmit_pkts_simple;
> + dev->rx_pkt_burst = virtio_recv_pkts_vec;
Whether recv side mergeable is supported is controlled by
virtio_negotiate_feature().
So "dev->rx_pkt_burst = virtio_recv_pkts_vec" should be restricted by
hw->guest_features & VIRTIO_NET_F_MRG_RXBUF, right?
> + use_simple_rxtx = 1;
> + }
> +
> ret = virtio_dev_queue_setup(dev, VTNET_TQ, queue_idx,
> vtpci_queue_idx,
> nb_desc, socket_id, &vq);
> if (ret < 0) {
> --
> 1.8.1.4
