Re: [PATCH 4.4 01/27] netvsc: reduce maximum GSO size

[Greg Kroah-Hartman]

On Thu, Feb 09, 2017 at 07:37:35PM +0000, Ben Hutchings wrote:
> On Fri, 2017-01-13 at 12:38 +0100, Greg Kroah-Hartman wrote:
> > 4.4-stable review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: stephen hemminger <stephen@xxxxxxxxxxxxxxxxxx>
> > 
> > 
> > [ Upstream commit a50af86dd49ee1851d1ccf06dd0019c05b95e297 ]
> > 
> > Hyper-V (and Azure) support using NVGRE which requires some extra space
> > for encapsulation headers. Because of this the largest allowed TSO
> > packet is reduced.
> > 
> > For older releases, hard code a fixed reduced value.  For next release,
> > there is a better solution which uses result of host offload
> > negotiation.
> > 
> > Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
> > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/net/hyperv/netvsc_drv.c |    3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > --- a/drivers/net/hyperv/netvsc_drv.c
> > +++ b/drivers/net/hyperv/netvsc_drv.c
> > @@ -40,6 +40,8 @@
> >  
> >  #include "hyperv_net.h"
> >  
> > +/* Restrict GSO size to account for NVGRE */
> > +#define NETVSC_GSO_MAX_SIZE	62768
> >  
> >  #define RING_SIZE_MIN 64
> >  static int ring_size = 128;
> > @@ -852,6 +854,7 @@ static int netvsc_set_channels(struct ne
> >  		}
> >  		goto recover;
> >  	}
> > +	netif_set_gso_max_size(net, NETVSC_GSO_MAX_SIZE);
> >  
> >   out:
> >  	netvsc_open(net);
> > 
> 
> This has been wrongly backported.  Please apply the patch below.
> 
> Ben.

Many thanks for this, now applied.

greg k-h