Re: [PATCH for-next v3 7/9] RDMA/rxe: Add support for bind MW work requests

[Bob Pearson <rpearsonhpe@gmail.com>]

On 4/21/21 4:36 AM, Zhu Yanjun wrote:
> On Wed, Apr 21, 2021 at 1:20 PM Bob Pearson <rpearsonhpe@gmail.com> wrote:
>>
>> Add support for bind MW work requests from user space.
>> Since rdma/core does not support bind mw in ib_send_wr
>> there is no way to support bind mw in kernel space.
>>
>> Added bind_mw local operation in rxe_req.c
>> Added bind_mw WR operation in rxe_opcode.c
>> Added bind_mw WC in rxe_comp.c
>> Added additional fields to rxe_mw in rxe_verbs.h
>> Added do_dealloc_mw() subroutine to cleanup an mw
>> when rxe_dealloc_mw is called.
>> Added code to implement bind_mw operation in rxe_mw.c
>>
>> Signed-off-by: Bob Pearson <rpearson@hpe.com>
>> ---
>> v3:
>>   do_bind_mw() in rxe_mw.c is changed to be a void instead of
>>   returning an int.
>> v2:
>>   Dropped kernel support for bind_mw in rxe_mw.c
>>   Replaced umw with mw in struct rxe_send_wr
>> ---
>>  drivers/infiniband/sw/rxe/rxe_comp.c   |   1 +
>>  drivers/infiniband/sw/rxe/rxe_loc.h    |   1 +
>>  drivers/infiniband/sw/rxe/rxe_mw.c     | 202 ++++++++++++++++++++++++-
>>  drivers/infiniband/sw/rxe/rxe_opcode.c |   7 +
>>  drivers/infiniband/sw/rxe/rxe_req.c    |   9 ++
>>  drivers/infiniband/sw/rxe/rxe_verbs.h  |  15 +-
>>  6 files changed, 230 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c
>> index 2af26737d32d..bc5488af5f55 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_comp.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_comp.c
>> @@ -103,6 +103,7 @@ static enum ib_wc_opcode wr_to_wc_opcode(enum ib_wr_opcode opcode)
>>         case IB_WR_RDMA_READ_WITH_INV:          return IB_WC_RDMA_READ;
>>         case IB_WR_LOCAL_INV:                   return IB_WC_LOCAL_INV;
>>         case IB_WR_REG_MR:                      return IB_WC_REG_MR;
>> +       case IB_WR_BIND_MW:                     return IB_WC_BIND_MW;
>>
>>         default:
>>                 return 0xff;
>> diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h
>> index edf575930a98..e6f574973298 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_loc.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_loc.h
>> @@ -110,6 +110,7 @@ int advance_dma_data(struct rxe_dma_info *dma, unsigned int length);
>>  /* rxe_mw.c */
>>  int rxe_alloc_mw(struct ib_mw *ibmw, struct ib_udata *udata);
>>  int rxe_dealloc_mw(struct ib_mw *ibmw);
>> +int rxe_bind_mw(struct rxe_qp *qp, struct rxe_send_wqe *wqe);
>>  void rxe_mw_cleanup(struct rxe_pool_entry *arg);
>>
>>  /* rxe_net.c */
>> diff --git a/drivers/infiniband/sw/rxe/rxe_mw.c b/drivers/infiniband/sw/rxe/rxe_mw.c
>> index 69128e298d44..c018e8865876 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_mw.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_mw.c
>> @@ -29,6 +29,29 @@ int rxe_alloc_mw(struct ib_mw *ibmw, struct ib_udata *udata)
>>         return 0;
>>  }
>>
>> +static void do_dealloc_mw(struct rxe_mw *mw)
>> +{
>> +       if (mw->mr) {
>> +               struct rxe_mr *mr = mw->mr;
>> +
>> +               mw->mr = NULL;
>> +               atomic_dec(&mr->num_mw);
> 
> What is the usage of this num_mw?
> 
> Zhu Yanjun
> 

I added a 10th patch to the series as v4 to address this. The other 9 are identical to v3.

Just checked if mr->num_mw > 0 and return -EINVAL if so for dereg MR and invalidate MR.

Bob