Re: [RFC PATCH 3/4] drivers/net/virtio_net: Added basic RSS support.

[Willem de Bruijn]

> > +               hdr_hash = (struct virtio_net_hdr_v1_hash *)(hdr);
> > +
> > +               switch (hdr_hash->hash_report) {
> > +               case VIRTIO_NET_HASH_REPORT_TCPv4:
> > +               case VIRTIO_NET_HASH_REPORT_UDPv4:
> > +               case VIRTIO_NET_HASH_REPORT_TCPv6:
> > +               case VIRTIO_NET_HASH_REPORT_UDPv6:
> > +               case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
> > +               case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
> > +                       rss_hash_type = PKT_HASH_TYPE_L4;
> > +                       break;
> > +               case VIRTIO_NET_HASH_REPORT_IPv4:
> > +               case VIRTIO_NET_HASH_REPORT_IPv6:
> > +               case VIRTIO_NET_HASH_REPORT_IPv6_EX:
> > +                       rss_hash_type = PKT_HASH_TYPE_L3;
> > +                       break;
> > +               case VIRTIO_NET_HASH_REPORT_NONE:
> > +               default:
> > +                       rss_hash_type = PKT_HASH_TYPE_NONE;
> > +               }
>
> Is this detailed protocol typing necessary? Most devices only pass a bit is_l4.
> > +static void virtnet_init_default_rss(struct virtnet_info *vi)
> > +{
> > +       u32 indir_val = 0;
> > +       int i = 0;
> > +
> > +       vi->ctrl->rss.table_info.hash_types = vi->rss_hash_types_supported;
>
> Similar to above, and related to the next patch: is this very detailed
> specification of supported hash types needed? When is this useful? It
> is not customary to specify RSS to that degree.

My bad. This is also implemented by bnxt, for one. I was unaware of
this feature.