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

[Michael S. Tsirkin]

On Thu, Nov 24, 2016 at 12:31:18PM +0800, Jason Wang wrote:
> 
> 
> 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.

There is a design considerations chapter, it can go there.

-- 
MST