From: Vladislav Yasevich <[email protected]>
Date: Fri, 30 Jan 2015 14:27:24 -0500

> commit 3d0ad09412ffe00c9afa201d01effdb6023d09b4
> Author: Ben Hutchings <[email protected]>
> Date:   Thu Oct 30 18:27:12 2014 +0000
> 
>     drivers/net: Disable UFO through virtio
> 
> Turned off UFO support to virtio-net based devices due to issues
> with IPv6 fragment id generation for UFO packets.  The issue
> was that IPv6 UFO/GSO implementation expects the fragment id
> to be supplied in skb_shinfo().  However, for packets generated
> by the VMs, the fragment id is not supplied which causes all
> IPv6 fragments to have the id of 0.
> 
> The problem is that turning off UFO support on tap/macvtap
> as well as virtio devices caused issues with migrations.  
> Migrations would fail when moving a vm from a kernel supporting
> expecting UFO to work to the newer kernels that disabled UFO.
> 
> This series provides a partial solution to address the migration
> issue.  The series allows us to track whether skb_shinfo()->ip6_frag_id
> has been set by treating value of 0 as unset.
> This lets GSO code to generate fragment ids if they are necessary
> (ex: packet was generated by VM or packet socket).
> 
> Since v1:
>   - Removed the skb bit and use value of 0 as tracker.
>   - Used Eric's suggestion to set fragment id as 0x80000000 if id
>     generation procedure yeilded a 0 result.
>   - Consolidated ipv6 id genration code.

Series applied and queued up for -stable.

There was some trailing whitespace in patch #1, which I fixed up.
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