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

[Wei Xu]

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?