Subject: Re: [PATCH v1 3/3] Let host NIC driver to DMA to guest user space.

From: Stephen Hemminger <[email-masked]>
Date: Sat, 6 Mar 2010 09:18:49 -0800

On Sat,  6 Mar 2010 17:38:38 +0800
[email-masked] wrote:

> From: Xin Xiaohui <[email-masked]>
> 
> The patch let host NIC driver to receive user space skb,
> then the driver has chance to directly DMA to guest user
> space buffers thru single ethX interface.
> 
> Signed-off-by: Xin Xiaohui <[email-masked]>
> Signed-off-by: Zhao Yu <[email-masked]>
> Sigend-off-by: Jeff Dike <[email-masked]>
> ---
>  include/linux/netdevice.h |   76 ++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/skbuff.h    |   30 +++++++++++++++--
>  net/core/dev.c            |   32 ++++++++++++++++++
>  net/core/skbuff.c         |   79 +++++++++++++++++++++++++++++++++++++++++----
>  4 files changed, 205 insertions(+), 12 deletions(-)
> 

There are too many ifdef's in this implementation.
I would prefer to see a few functions (with stub for the non-ifdef case),
like the network namespace code.