[ofw] RE: [owf][patch] user multicast offload support

[Fab Tillier]

Hi Slava,

>Please review the code that adds support for user mode component
>performing multicast offload for applications.
>The idea is to allow host to issue IGMP messages through IPoIB. No data
>flow on IPoIB since there is no ATTACH in case of using user mcast
>offload. This prevents data duplicating on receive path.
>IB leave will send always if issued from user mode application, and when
>reference count reaches 0 if leave has been requested from IPoIB.

Is there anything in the WinOF SVN that will use this capability?

Are you going to solve the issue where the first client to leave a MC group will tell the SA to remove the port from the MC group so that other clients using the MC group will not get 'disconnected'?  I would think this would be an important first step.

Maybe it's just that I don't understand how the applications work.  Do they create their own UD QPs, and attach them to the MC group?  Who issues the MC join/leave to the SA?  Who issues the attach/detach of the user-mode UD QPs to the HCA, and how?

Once I understand the above better I'll be able to provide meaningful comments on the patch.

Thanks,
-Fab