[dpdk-dev] [PATCH 4/4] net/virtio: improve offload check performance
Tiwei Bie
tiwei.bie at intel.com
Mon Jun 4 13:55:07 CEST 2018
On Fri, Jun 01, 2018 at 02:47:58PM +0200, Maxime Coquelin wrote:
> Instead of checking the multiple Virtio features bits for
> every packet, let's do the check once at configure time and
> store it in virtio_hw struct.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> ---
> drivers/net/virtio/virtio_ethdev.c | 19 +++++++++++++++++++
> drivers/net/virtio/virtio_pci.h | 2 ++
> drivers/net/virtio/virtio_rxtx.c | 29 ++++++-----------------------
> 3 files changed, 27 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index d481b282e..981e0994a 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -1790,6 +1790,22 @@ rte_virtio_pmd_init(void)
> rte_pci_register(&rte_virtio_pmd);
> }
>
> +static inline int
Maybe it's better to return bool.
> +rx_offload_enabled(struct virtio_hw *hw)
> +{
> + return vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM) ||
> + vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
> + vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO6);
> +}
> +
> +static inline int
Ditto.
> +tx_offload_enabled(struct virtio_hw *hw)
> +{
> + return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
> + vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
> + vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
> +}
> +
> /*
> * Configure virtio device
> * It returns 0 on success.
> @@ -1869,6 +1885,9 @@ virtio_dev_configure(struct rte_eth_dev *dev)
> return -ENOTSUP;
> }
>
> + hw->has_tx_offload = !!tx_offload_enabled(hw);
> + hw->has_rx_offload = !!rx_offload_enabled(hw);
> +
> if (dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC)
> /* Enable vector (0) for Link State Intrerrupt */
> if (VTPCI_OPS(hw)->set_config_irq(hw, 0) ==
> diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
> index a28ba8339..e0bb871f2 100644
> --- a/drivers/net/virtio/virtio_pci.h
> +++ b/drivers/net/virtio/virtio_pci.h
> @@ -233,6 +233,8 @@ struct virtio_hw {
> uint8_t modern;
> uint8_t use_simple_rx;
> uint8_t use_simple_tx;
> + uint8_t has_tx_offload;
> + uint8_t has_rx_offload;
I think it's better to use spaces, instead of
4 spaces width tabs after uint8_t.
> uint16_t port_id;
> uint8_t mac_addr[ETHER_ADDR_LEN];
> uint32_t notify_off_multiplier;
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index 92fab2174..3f113a118 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -225,13 +225,6 @@ virtio_tso_fix_cksum(struct rte_mbuf *m)
> }
> }
>
> -static inline int
> -tx_offload_enabled(struct virtio_hw *hw)
> -{
> - return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
> - vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
> - vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
> -}
>
> /* avoid write operation when necessary, to lessen cache issues */
> #define ASSIGN_UNLESS_EQUAL(var, val) do { \
> @@ -253,13 +246,15 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
> struct virtio_net_hdr *hdr;
> int offload;
>
> - offload = tx_offload_enabled(vq->hw);
> head_idx = vq->vq_desc_head_idx;
> idx = head_idx;
> dxp = &vq->vq_descx[idx];
> dxp->cookie = (void *)cookie;
> dxp->ndescs = needed;
>
> + offload = vq->hw->has_tx_offload &&
> + (cookie->ol_flags & PKT_TX_OFFLOAD_MASK);
If features aren't negotiated, I think there is no need to
check ol_flags and update the net header.
> +
> start_dp = vq->vq_ring.desc;
>
> if (can_push) {
> @@ -270,7 +265,6 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
> * 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);
> ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
> @@ -686,14 +680,6 @@ virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
> return 0;
> }
[...]
Best regards,
Tiwei Bie
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