Re: [RFC PATCH 0/2] RDMA/rxe: Add RDMA Atomic Write operation

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Jan 05, 2022 at 01:00:42AM +0000, yangx.jy@fujitsu.com wrote:

> 1) In kernel, current SoftRoCE copies the content of struct rdma to RETH 
> and copies the content of struct atomic to AtomicETH.
> 2) IBTA defines that RDMA Atomic Write uses RETH + payload.
> According to these two reasons, I perfer to tweak the existing struct rdma.

No this is basically meaningless

The wr struct is designed as a 'tagged union' where the op specified
which union is in effect.

It turns out that the op generally specifies the network headers as
well, but that is just a side effect.

> >> How about adding a member in struct rdma? for example:
> >> struct {
> >>       uint64_t    remote_addr;
> >>       uint32_t    rkey;
> >>       uint64_t    wr_value:
> >> } rdma;
> >
> > Yes, that's what Tomasz and I were suggesting - a new template for the
> > ATOMIC_WRITE request payload. The three fields are to be supplied by
> > the verb consumer when posting the work request.
> 
> OK, I will update the patch in this way.

We are not extending the ib_send_wr anymore anyhow.

You should implement new ops inside struct ibv_qp_ex as function
calls.

Jason