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

[Jason Wang]

On 2016年11月24日 12:26, Michael S. Tsirkin wrote:
> On Thu, Nov 24, 2016 at 12:17:21PM +0800, Jason Wang wrote:
> > > diff --git a/include/standard-headers/linux/virtio_net.h 
> > > b/include/standard-headers/linux/virtio_net.h
> > > index 30ff249..e67b36e 100644
> > > --- a/include/standard-headers/linux/virtio_net.h
> > > +++ b/include/standard-headers/linux/virtio_net.h
> > > @@ -57,6 +57,9 @@
> > >                                          * Steering */
> > >    #define VIRTIO_NET_F_CTRL_MAC_ADDR 23        /* Set MAC address */
> > > +/* Guest can handle coalesced ipv4-tcp packets */
> > > +#define VIRTIO_NET_F_GUEST_RSC4    41
> > Why not use 24?
> I think we should use features >31 (virtio 1 only) for
> nice-to-have features like RSC. Feature bits <31 are
> easy to backport, so it makes more sense to use
> them for fundamental things like the MTU
> (which for some setups help fix broken networking).

Ok, I believe we need clarify this in the spec or somewhere else.