Re: [dpdk-dev] [PATCH] vhost: fix off-by-one error on nr_desc check

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-07-25 23:24, Yuanhan Liu:
> On Mon, Jul 25, 2016 at 04:09:58PM +0200, Maxime Coquelin wrote:
> > nr_desc is not an index but the number of descriptors,
> > so can be equal to the virtqueue size.
> > 
> > Fixes: a436f53ebfeb ("vhost: avoid dead loop chain")
> > 
> > Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> > Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> Thanks for catching it!
> 
> > ---
> > Hi Yuanhan,
> > 
> > I faced the bug while testing my indirect descriptor patch, it happens
> > as soon as the number of chained descritors is above 2.
> > 
> > But the bug may in theory also be faced with normal descriptors,
> 
> In theory, yes, and only in one case, that there is a Tx has 256
> descriptors chained. If that happens, I doubt things work well.
> So I would say it just happens __in theory__.
> 
> > so it might
> > be good to have it 16.07?
> 
> Even though, it apparently fixes a bug, so I think we could have it
> for 16.07.
> 
> Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

Applied, thanks