Re: [PATCH for-next v2 7/9] RDMA/rxe: Add support for bind MW work requests

[Bob Pearson <rpearsonhpe@gmail.com>]

On 4/20/21 9:32 AM, Zhu Yanjun wrote:
> On Thu, Apr 15, 2021 at 10:55 AM 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>
>> ---
>> v2:
>>   Dropped kernel support for bind_mw in rxe_mw.c
>>   Replaced umw with mw in 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     | 204 ++++++++++++++++++++++++-
>>  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, 232 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..6ced54126b72 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);
>> +               rxe_drop_ref(mr);
>> +       }
>> +
>> +       if (mw->qp) {
>> +               struct rxe_qp *qp = mw->qp;
>> +
>> +               mw->qp = NULL;
>> +               rxe_drop_ref(qp);
>> +       }
>> +
>> +       mw->access = 0;
>> +       mw->addr = 0;
>> +       mw->length = 0;
>> +       mw->state = RXE_MW_STATE_INVALID;
>> +}
>> +
>>  int rxe_dealloc_mw(struct ib_mw *ibmw)
>>  {
>>         struct rxe_mw *mw = to_rmw(ibmw);
>> @@ -36,7 +59,7 @@ int rxe_dealloc_mw(struct ib_mw *ibmw)
>>         unsigned long flags;
>>
>>         spin_lock_irqsave(&mw->lock, flags);
>> -       mw->state = RXE_MW_STATE_INVALID;
>> +       do_dealloc_mw(mw);
>>         spin_unlock_irqrestore(&mw->lock, flags);
>>
>>         rxe_drop_ref(mw);
>> @@ -45,6 +68,185 @@ int rxe_dealloc_mw(struct ib_mw *ibmw)
>>         return 0;
>>  }
>>
>> +static int check_bind_mw(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
>> +                        struct rxe_mw *mw, struct rxe_mr *mr)
>> +{
>> +       if (mw->ibmw.type == IB_MW_TYPE_1) {
>> +               if (unlikely(mw->state != RXE_MW_STATE_VALID)) {
>> +                       pr_err_once(
>> +                               "attempt to bind a type 1 MW not in the valid state\n");
>> +                       return -EINVAL;
>> +               }
>> +
>> +               /* o10-36.2.2 */
>> +               if (unlikely((mw->access & IB_ZERO_BASED))) {
>> +                       pr_err_once("attempt to bind a zero based type 1 MW\n");
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
>> +       if (mw->ibmw.type == IB_MW_TYPE_2) {
>> +               /* o10-37.2.30 */
>> +               if (unlikely(mw->state != RXE_MW_STATE_FREE)) {
>> +                       pr_err_once(
>> +                               "attempt to bind a type 2 MW not in the free state\n");
>> +                       return -EINVAL;
>> +               }
>> +
>> +               /* C10-72 */
>> +               if (unlikely(qp->pd != to_rpd(mw->ibmw.pd))) {
>> +                       pr_err_once(
>> +                               "attempt to bind type 2 MW with qp with different PD\n");
>> +                       return -EINVAL;
>> +               }
>> +
>> +               /* o10-37.2.40 */
>> +               if (unlikely(!mr || wqe->wr.wr.mw.length == 0)) {
>> +                       pr_err_once(
>> +                               "attempt to invalidate type 2 MW by binding with NULL or zero length MR\n");
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
>> +       if (unlikely((wqe->wr.wr.mw.rkey & 0xff) == (mw->ibmw.rkey & 0xff))) {
>> +               pr_err_once("attempt to bind MW with same key\n");
>> +               return -EINVAL;
>> +       }
>> +
>> +       /* remaining checks only apply to a nonzero MR */
>> +       if (!mr)
>> +               return 0;
>> +
>> +       if (unlikely(mr->access & IB_ZERO_BASED)) {
>> +               pr_err_once("attempt to bind MW to zero based MR\n");
>> +               return -EINVAL;
>> +       }
>> +
>> +       /* C10-73 */
>> +       if (unlikely(!(mr->access & IB_ACCESS_MW_BIND))) {
>> +               pr_err_once(
>> +                       "attempt to bind an MW to an MR without bind access\n");
>> +               return -EINVAL;
>> +       }
>> +
>> +       /* C10-74 */
>> +       if (unlikely((mw->access &
>> +                     (IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_ATOMIC)) &&
>> +                    !(mr->access & IB_ACCESS_LOCAL_WRITE))) {
>> +               pr_err_once(
>> +                       "attempt to bind an writeable MW to an MR without local write access\n");
>> +               return -EINVAL;
>> +       }
>> +
>> +       /* C10-75 */
>> +       if (mw->access & IB_ZERO_BASED) {
>> +               if (unlikely(wqe->wr.wr.mw.length > mr->length)) {
>> +                       pr_err_once(
>> +                               "attempt to bind a ZB MW outside of the MR\n");
>> +                       return -EINVAL;
>> +               }
>> +       } else {
>> +               if (unlikely((wqe->wr.wr.mw.addr < mr->iova) ||
>> +                            ((wqe->wr.wr.mw.addr + wqe->wr.wr.mw.length) >
>> +                             (mr->iova + mr->length)))) {
>> +                       pr_err_once(
>> +                               "attempt to bind a VA MW outside of the MR\n");
>> +                       return -EINVAL;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int do_bind_mw(struct rxe_qp *qp, struct rxe_send_wqe *wqe,
>> +                     struct rxe_mw *mw, struct rxe_mr *mr)
>> +{
>> +       u32 rkey;
>> +       u32 new_rkey;
>> +
>> +       rkey = mw->ibmw.rkey;
>> +       new_rkey = (rkey & 0xffffff00) | (wqe->wr.wr.mw.rkey & 0x000000ff);
>> +
>> +       mw->ibmw.rkey = new_rkey;
>> +       mw->access = wqe->wr.wr.mw.access;
>> +       mw->state = RXE_MW_STATE_VALID;
>> +       mw->addr = wqe->wr.wr.mw.addr;
>> +       mw->length = wqe->wr.wr.mw.length;
>> +
>> +       if (mw->mr) {
>> +               rxe_drop_ref(mw->mr);
>> +               atomic_dec(&mw->mr->num_mw);
>> +               mw->mr = NULL;
>> +       }
>> +
>> +       if (mw->length) {
>> +               mw->mr = mr;
>> +               atomic_inc(&mr->num_mw);
>> +               rxe_add_ref(mr);
>> +       }
>> +
>> +       if (mw->ibmw.type == IB_MW_TYPE_2) {
>> +               rxe_add_ref(qp);
>> +               mw->qp = qp;
>> +       }
>> +
>> +       return 0;
> 
> Is it necessary to return 0?
> 
> no others invalid value.
> 
> Zhu Yanjun

Good catch. It was left over from the past. I'll get rid of it.

Bob