Re: [Qemu-devel] [ Patch 1/2] virtio-net rsc: support coalescing ipv4 tcp traffic

[Wei Xu <wexu@redhat.com>]

On 2016年03月18日 13:20, Jason Wang wrote:
>
> On 03/18/2016 12:17 PM, Wei Xu wrote:
>>>>>> +static ssize_t virtio_net_receive(NetClientState *nc,
>>>>>> +                                  const uint8_t *buf, size_t size)
>>>>>> +{
>>>>>> +    if (virtio_net_rsc_bypass) {
>>>>>> +        return virtio_net_do_receive(nc, buf, size);
>>>>> You need a feature bit for this and compat it for older machine types.
>>>>> And also need some work on virtio spec I think.
>>>> yes, not sure which way is good to support this, hmp/qmp/ethtool, this
>>>> is gonna to support win guest,
>>>> so need a well-compatible interface, any comments?
>>> I think this should be implemented through feature bits/negotiation
>>> instead of something like ethtool.
>> Looks this feature should be turn on/off dynamically due to the spec,
>> so maybe this should be managed from the guest, is there any reference
>> code for this?
> Then you may want to look at implementation of
> VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.
Have a short look at it, do you know how to control the feature bit?  
both when lauching vm and changing it during runtime?