Re: [EXTERNAL] Re: [PATCH rdma-next 1/1] RDMA/mana_ib: indicate that inline data is not supported

[Leon Romanovsky <leon@kernel.org>]

On Tue, Jul 16, 2024 at 05:25:22PM +0000, Konstantin Taranov wrote:
> > 
> > Yes, you are. If user asked for specific functionality (max_inline_data != 0) and
> > your device doesn't support it, you should return an error.
> > 
> > pvrdma, mlx4 and rvt are not good examples, they should return an error as
> > well, but because of being legacy code, we won't change them.
> > 
> > Thanks
> > 
> 
> I see. So I guess we can return a larger value, but not smaller. Right?
> I will send v2 that fails QP creation then.
> 
> In this case, may I submit a patch to rdma-core that queries device caps before
> trying to create a qp in rdma_client.c and rdma_server.c? As that code violates
> what you described.

Let's ask Jason, why is that? Do we allow to ignore max_inline_data?

librdmacm/examples/rdma_client.c
  63         memset(&attr, 0, sizeof attr);
  64         attr.cap.max_send_wr = attr.cap.max_recv_wr = 1;
  65         attr.cap.max_send_sge = attr.cap.max_recv_sge = 1;
  66         attr.cap.max_inline_data = 16;
  67         attr.qp_context = id;
  68         attr.sq_sig_all = 1;
  69         ret = rdma_create_ep(&id, res, NULL, &attr);
  70         // Check to see if we got inline data allowed or not
  71         if (attr.cap.max_inline_data >= 16)
  72                 send_flags = IBV_SEND_INLINE;
  73         else
  74                 printf("rdma_client: device doesn't support IBV_SEND_INLINE, "
  75                        "using sge sends\n");

> 
> Thanks
> 
>  
>