[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] Question about TCP checksum offload in Xen



On 5 Dec 2013, at 12:47, Paul Durrant wrote:

...
>>>> On Tue, Dec 03, 2013 at 01:00:23PM +0000, Balraj Singh wrote:
>>>> 
...
>>>>> It should ideally be for every packet since chksum
>> offload
>>>>> can be turned off and on on the VIF and existing tcp connections should
>>>>> continue.  If not every packet, I need to get a notification or 
>>>>> efficiently
>>>>> detect right away that the setting is changed on the VIF.

...

> earlier today, i wrote:
> 
>> i think balraj's question arises because the status of checksum offload can
>> change mid-tcp-flow. how does he know whether it's on or off for a given
>> packet?
> 
> Why do you assert that it can change mid-flow? The configuration is decided 
> at ring connect time. Nothing should change after that. If, at that time, the 
> frontend declares it can handle packets with no checksum then clearly it may 
> get some packets that do have checksum as well as ones that don't, depending 
> on where they originated.

i didn't mean to :) i was just trying to point out to ian the reason for 
balraj's question -- i'll leave it to balraj from here...

-- 
Cheers,

R.




This message and any attachment are intended solely for the addressee and may 
contain confidential information. If you have received this message in error, 
please send it back to me, and immediately delete it.   Please do not use, copy 
or disclose the information contained in this message or in any attachment.  
Any views or opinions expressed by the author of this email do not necessarily 
reflect the views of the University of Nottingham.

This message has been checked for viruses but the contents of an attachment
may still contain software viruses which could damage your computer system, you 
are advised to perform your own checks. Email communications with the 
University of Nottingham may be monitored as permitted by UK legislation.







 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.