Re: [Qemu-devel] [PATCH] net: netmap: probe netmap interface for virtio-net header

[Jason Wang]

On 02/18/2016 09:34 PM, Vincenzo Maffione wrote:
>>>  static void netmap_set_offload(NetClientState *nc, int csum, int tso4, int 
>>> tso6,
>>> >> @@ -376,7 +394,7 @@ static void netmap_set_offload(NetClientState *nc, 
>>> >> int csum, int tso4, int tso6,
>>> >>       * enables the offloadings.
>>> >>       */
>>> >>      if (!s->vnet_hdr_len) {
>>> >> -        netmap_set_vnet_hdr_len(nc, sizeof(struct virtio_net_hdr));
>>> >> +        netmap_do_set_vnet_hdr_len(s, sizeof(struct virtio_net_hdr), 
>>> >> true);
>>> >>      }
>>> >>  }
>>> >>
>>> >> @@ -388,7 +406,7 @@ static NetClientInfo net_netmap_info = {
>>> >>      .receive_iov = netmap_receive_iov,
>>> >>      .poll = netmap_poll,
>>> >>      .cleanup = netmap_cleanup,
>>> >> -    .has_ufo = netmap_has_ufo,
>>> >> +    .has_ufo = netmap_has_vnet_hdr,
>> >
>> > This look suspicious, I'm not sure this is correct for netmap. May need
>> > a comment to explain. Usually vnet hdr does not imply ufo.
>> >
>>> >>      .has_vnet_hdr = netmap_has_vnet_hdr,
>>> >>      .has_vnet_hdr_len = netmap_has_vnet_hdr_len,
>>> >>      .using_vnet_hdr = netmap_using_vnet_hdr,
>> >
> Yes, I know it sounds weird in general, but a netmap port using
> virtio-net headers always provides TCPv4, TCPv6, UDP and ECN
> offloadings (done in software inside netmap).
>
> This patch already provides a little comment about UFO support on the
> netmap_has_vnet_hdr() function. 

Just saw that.

> Do you want me to move it here, or is
> the comment not understandable enough?
>
> Thanks for your review,
>   Vincenzo

Nope, it's ok.

Thanks