[ofa-general] Re: [PATCH 2/3] mcast loopback block

[Roland Dreier]

 > In the sockets world the sender sets the IP_MULTICAST_LOOP socket
 > option which ip(7) says that it "Sets or reads a boolean integer
 > argument whether sent multicast packets should be looped back to the
 > local sockets." so one more point here is that the suggested
 > implementation of setting this at the qp creation is one that brings
 > the API closer to the socket one, which can be easier for users to
 > understand.

OK, that is a reasonably convincing argument.

 > Roland, can you please comment on your preferences, that is on the cap
 > bit vs hint and where you want the app to direct the HW how to behave,
 > in the qp creation time as we suggest or on the time of attach. If you
 > want to go the changing the qp attach verb way, can please provide us
 > with some implementation directions regarding backward compatibility
 > with apps that are built against versions of libibverbs which have
 > different API for this verb, thanks.

I guess the implementation you posted is OK.  But I don't know how to
expose this to userspace anyway, since no one has figured out the QP
flags issues as far as I know.

 - R.