-----Original Message-----
From: David Miller [mailto:davem@davemloft.net]
Sent: Wednesday, December 3, 2014 12:35 PM
To: Du, Fan
Cc: netdev@vger.kernel.org; fw@strlen.de
Subject: Re: [PATCH net] gso: do GSO for local skb with size bigger than MTU

From: "Du, Fan" <redacted>
Date: Wed, 3 Dec 2014 03:32:46 +0000

quoted

quoted

If guest sees a 1500 byte MTU, that's it's link layer MTU and it had
better be able to send 1500 byte packets onto the "wire".

This patch makes it happens exactly as you putted.

quoted

If you cannot properly propagate the vxlan encapsulation overhead back
into the guest's MTU you must hide this problem from the rest of our stack

somehow.

quoted

Again, this patch hide this problem to make Guest feel it can send packet with

MTU as 1500 bytes.

I said make the guest see the real MTU, not hide the real MTU by fragmenting or
spitting ICMP PMTU messages back.

Do you have any better idea to achieve what you said besides this patch approach
without both fragmentation and ICMP message at the same time to cater for all kinds
tunnel tech?