On Thu, May 27, 2021 at 11:57:10AM -0300, Jason Gunthorpe wrote:

quoted

 2) IB_UVERBS_ACCESS_*.  These just get checked using ib_check_mr_access
    and then passed into ->reg_user_mr, ->rereg_user_mr and
    ->reg_user_mr_dmabuf

Yes. Using the kernerl flags for those user marked APIs is intended to
simplify the drivers as the user/kernel MR logic should have shared
elements

I'd rather map between these flags somewhere low done if and when this
actually happens.  Usually the driver will map to their internal flags
somewhere, and I bet not doing a detour will clean this up while also
removing the possibility for stupid errors.

quoted

 3) in-kernel FRWR uses IB_ACCESS_*, but all users seem to hardcode it
    to IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
    IB_ACCESS_REMOTE_WRITE anyway

So when a ULP is processing a READ it doesn't create a FRWR with
read-only rights? Isn't that security wrong?

Probably.  We probably want a helper that does the right thing based
off a enum dma_data_direction parameter.