[openib-general] CMA and device removal

[Sean Hefty]

I'd like to get some feedback about the following design change to the CMA.

Currently, a user receives a device GUID and port number as part of address
resolution.  The user matches the GUID to an existing device and creates a
cma_id associated with that device.

I'm considering the following alternative:

On creation, a cma_id is not bound to a particular device.  It gets bound to a
device as part of address resolution.  The CMA tracks device references.  When a
device is removed, the CMA will generate an event on all associated cma_id's.
Users must destroy cma_id's and associated device resources after receiving the
event.

A couple of notes: the CMA already performs reference counting on devices.
Also, with some additional work, this would permit a single listen request to
span multiple devices.

Comments?

- Sean