On Sat, Apr 15, 2017 at 12:38:17PM -0400, Vladislav Yasevich wrote:
> This extension allows us to pass vlan ID and vlan protocol data to the
> host hypervisor as part of the vnet header and lets us take advantage
> of HW accelerated vlan tagging in the host. It requires support in the
> host to negotiate the feature. When the extension is enabled, the
> virtio device will enabled HW accelerated vlan features.
>
> Signed-off-by: Vladislav Yasevich <vyasevic@xxxxxxxxxx>
Performance data will be required to justify this.
> ---
> drivers/net/virtio_net.c | 17 ++++++++++++++++-
> include/linux/virtio_net.h | 17 +++++++++++++++++
> include/uapi/linux/virtio_net.h | 7 +++++++
> 3 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 18eb0dd..696ef4a 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -182,6 +182,7 @@ struct virtio_net_hdr_max {
> struct virtio_net_hdr_mrg_rxbuf hdr;
> struct virtio_net_ext_hdr ext_hdr;
> struct virtio_net_ext_ip6frag ip6f_ext;
> + struct virtio_net_ext_vlan vlan_ext;
> };
>
> static inline u8 padded_vnet_hdr(struct virtnet_info *vi)
> @@ -2276,6 +2277,11 @@ static void virtnet_init_extensions(struct virtio_device *vdev)
> vi->hdr_len += sizeof(u32);
> vi->ext_mask |= VIRTIO_NET_EXT_F_IP6FRAG;
> }
> +
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_VLAN_OFFLOAD)) {
> + vi->hdr_len += sizeof(struct virtio_net_ext_vlan);
> + vi->ext_mask |= VIRTIO_NET_EXT_F_VLAN;
> + }
> }
>
> #define MIN_MTU ETH_MIN_MTU
> @@ -2352,6 +2358,14 @@ static int virtnet_probe(struct virtio_device *vdev)
> if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_CSUM))
> dev->features |= NETIF_F_RXCSUM;
>
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_VLAN_OFFLOAD)) {
> + dev->features |= NETIF_F_HW_VLAN_CTAG_TX |
> + NETIF_F_HW_VLAN_CTAG_RX |
> + NETIF_F_HW_VLAN_STAG_TX |
> + NETIF_F_HW_VLAN_STAG_RX;
> + }
> +
> +
> dev->vlan_features = dev->features;
>
> /* MTU range: 68 - 65535 */
> @@ -2395,7 +2409,8 @@ static int virtnet_probe(struct virtio_device *vdev)
> if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
> vi->mergeable_rx_bufs = true;
>
> - if (virtio_has_feature(vdev, VIRTIO_NET_F_IP6_FRAGID))
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_IP6_FRAGID) ||
> + virtio_has_feature(vdev, VIRTIO_NET_F_VLAN_OFFLOAD))
> vi->hdr_ext = true;
>
> if (vi->hdr_ext)
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 3b259dc..e790191 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -113,6 +113,14 @@ static inline int virtio_net_ext_to_skb(struct sk_buff *skb,
> ptr += sizeof(struct virtio_net_ext_ip6frag);
> }
>
> + if (ext->flags & VIRTIO_NET_EXT_F_VLAN) {
> + struct virtio_net_ext_vlan *vhdr =
> + (struct virtio_net_ext_vlan *)ptr;
> +
> + __vlan_hwaccel_put_tag(skb, vhdr->vlan_proto, vhdr->vlan_tci);
> + ptr += sizeof(struct virtio_net_ext_vlan);
> + }
> +
> return 0;
> }
>
> @@ -130,6 +138,15 @@ static inline int virtio_net_ext_from_skb(const struct sk_buff *skb,
> ext->flags |= VIRTIO_NET_EXT_F_IP6FRAG;
> }
>
> + if (ext_mask & VIRTIO_NET_EXT_F_VLAN && skb_vlan_tag_present(skb)) {
> + struct virtio_net_ext_vlan *vhdr =
> + (struct virtio_net_ext_vlan *)ptr;
> +
> + vlan_get_tag(skb, &vhdr->vlan_tci);
> + vhdr->vlan_proto = skb->vlan_proto;
> + ext->flags |= VIRTIO_NET_EXT_F_VLAN;
> + }
> +
> return 0;
> }
> #endif /* _LINUX_VIRTIO_NET_H */
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index eac8d94..6125de7 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -57,6 +57,7 @@
> * Steering */
> #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */
> #define VIRTIO_NET_F_IP6_FRAGID 24 /* Host supports VLAN accleration */
> +#define VIRTIO_NET_F_VLAN_OFFLOAD 25 /* Host supports VLAN accleration */
>
> #ifndef VIRTIO_NET_NO_LEGACY
> #define VIRTIO_NET_F_GSO 6 /* Host handles pkts w/ any GSO type */
> @@ -111,6 +112,7 @@ struct virtio_net_hdr_v1 {
> */
> struct virtio_net_ext_hdr {
> #define VIRTIO_NET_EXT_F_IP6FRAG (1<<0)
> +#define VIRTIO_NET_EXT_F_VLAN (1<<1)
> __u32 flags;
> __u8 extensions[];
> };
> @@ -120,6 +122,11 @@ struct virtio_net_ext_ip6frag {
> __be32 frag_id;
> };
>
> +struct virtio_net_ext_vlan {
> + __be16 vlan_tci;
> + __be16 vlan_proto;
> +};
> +
> #ifndef VIRTIO_NET_NO_LEGACY
> /* This header comes first in the scatter-gather list.
> * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, it must
> --
> 2.7.4
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