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Date:   Mon, 17 Sep 2018 17:08:17 -0600
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     "Howell, Seth" <seth.howell@intel.com>
Cc:     "Walker, Benjamin" <benjamin.walker@intel.com>,
        Doug Ledford <dledford@redhat.com>,
        "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Moni Shoua <monis@mellanox.com>
Subject: Re: [PATCH] rdma: move the ib_wr_opcode enum to include/uapi
Message-ID: <20180917230817.GA10882@ziepe.ca>
References: <20180814223303.83556-1-seth.howell@intel.com>
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> >From e3c1b1b81373601fa6cbad2ba5fadd2c8cfdfaed Mon Sep 17 00:00:00 2001
> From: Seth Howell <seth.howell@intel.com>
> Date: Tue, 14 Aug 2018 15:33:02 -0700
> Subject: [PATCH] IB/rxe: Revise the ib_wr_opcode enum
> 
> This enum has become part of the uABI, as both RXE and the
> ib_uverbs_post_send() command expect userspace to supply values from
> this enum. So it should be properly placed in include/uapi/rdma.
> 
> In userspace this enum is called 'enum ibv_wr_opcode' as part of
> libibverbs.h. That enum defines different values for
> IB_WR_LOCAL_INV, IB_WR_SEND_WITH_INV, and IB_WR_LSO. These were
> introduced (incorrectly, it turns out) into libiberbs in 2015.
> 
> The kernel has changed its mind on the numbering for several of the
> IB_WC values over the years, but has remained stable on
> IB_WR_LOCAL_INV and below.
> 
> Based on this we can conclude that there is no real user space user
> of the values beyond IB_WR_ATOMIC_FETCH_AND_ADD, as they have never
> worked via rdma-core. This is confirmed by inspection, only rxe uses
> the kernel enum and implements the latter operations. rxe has
> clearly never worked with these attributes from userspace. Other
> drivers that support these opcodes implement the functionality
> without calling out to the kernel.
> 
> To make IB_WR_SEND_WITH_INV and related work for RXE in userspace we
> choose to renumber the IB_WR enum in the kernel to match the uABI
> that userspace has bee using since before Soft RoCE was merged. This
> is an overall simpler configuration for the whole software stack,
> and obviously can't break anything existing.
> 
> Reported-by: Seth Howell <seth.howell@intel.com>
> Fixes: 8700e3e7c485 ("Soft RoCE driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
>  include/rdma/ib_verbs.h           | 34 ++++++++++++++++++-------------
>  include/uapi/rdma/ib_user_verbs.h | 20 +++++++++++++++++-
>  2 files changed, 39 insertions(+), 15 deletions(-)

Applied to for-next

Thanks,
Jason