Re: [Qemu-devel] [PATCH v2 2/6] net: removing tap_using_vnet_hdr() function

[Stefan Hajnoczi]

On Thu, Jan 16, 2014 at 11:29:34AM +0200, Michael S. Tsirkin wrote:
> On Tue, Jan 14, 2014 at 11:59:46AM +0100, Vincenzo Maffione wrote:
> > This function was used to set the using_vnet_hdr field into the
> > TAPState struct. However, it is always called immediately before
> > (see virtio-net.c) or immediately after (see vmxnet3.c) the function
> > tap_set_vnet_hdr_len(). It's therefore possible to set the
> > using_vnet_hdr field directly in tap_set_vnet_hdr_len() and remove
> > tap_using_vnet_hdr(), making the code simpler.
> > 
> > Signed-off-by: Vincenzo Maffione <address@hidden>
> 
> 
> virtio net only calls tap_set_vnet_hdr_len if tap_has_vnet_hdr_len
> returns true.
> I think this patch will break old linux hosts which don't support
> modifying vnet_hdr_len.

This is a good point.  Let's leave the API alone then.

Stefan