Re: [PATCH rdma-next 6/6] RDMA/mana_ib: implement uapi for creation of rnic cq

Leon Romanovsky
2024-04-30T12:37:20Z

On Tue, Apr 23, 2024 at 11:57:53PM +0000, Long Li wrote:
> > Subject: [PATCH rdma-next 6/6] RDMA/mana_ib: implement uapi for creation
> > of rnic cq
> >
> > From: Konstantin Taranov <kotaranov@microsoft.com>
> >
> > Enable users to create RNIC CQs.
> > With the previous request size, an ethernet CQ is created.
> > Use the cq_buf_size from the user to create an RNIC CQ and return its ID.
> >
> > Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
> > ---
> > drivers/infiniband/hw/mana/cq.c | 56 ++++++++++++++++++++++++++++++---
> > include/uapi/rdma/mana-abi.h | 7 +++++
> > 2 files changed, 59 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/mana/cq.c
> > b/drivers/infiniband/hw/mana/cq.c index 8323085..a62bda7 100644
> > --- a/drivers/infiniband/hw/mana/cq.c
> > +++ b/drivers/infiniband/hw/mana/cq.c
> > @@ -9,17 +9,25 @@ int mana_ib_create_cq(struct ib_cq *ibcq, const struct
> > ib_cq_init_attr *attr,
> > struct ib_udata *udata)
> > {
> > struct mana_ib_cq *cq = container_of(ibcq, struct mana_ib_cq, ibcq);
> > + struct mana_ib_create_cq_resp resp = {};
> > + struct mana_ib_ucontext *mana_ucontext;
> > struct ib_device *ibdev = ibcq->device;
> > struct mana_ib_create_cq ucmd = {};
> > struct mana_ib_dev *mdev;
> > + bool is_rnic_cq = true;
> > + u32 doorbell;
> > int err;
> >
> > mdev = container_of(ibdev, struct mana_ib_dev, ib_dev);
> >
> > - if (udata->inlen < sizeof(ucmd))
> > + cq->comp_vector = attr->comp_vector % ibdev->num_comp_vectors;
> > + cq->cq_handle = INVALID_MANA_HANDLE;
> > +
> > + if (udata->inlen < offsetof(struct mana_ib_create_cq, cq_buf_size))
> > return -EINVAL;
> >
> > - cq->comp_vector = attr->comp_vector % ibdev->num_comp_vectors;
> > + if (udata->inlen == offsetof(struct mana_ib_create_cq, cq_buf_size))
> > + is_rnic_cq = false;
>
> I think it's okay with checking on offset in uapi message to decide if this is a newer/updated RNIC uverb.
>
> But increasing MANA_IB_UVERBS_ABI_VERSION may make the code simpler. I have a feeling that you may need to increase it anyway, because a new uapi message "mana_ib_create_cq_resp" is introduced.
>
> Jason or Leon may have a better idea on this.

You should really try to avoid changing MANA_IB_UVERBS_ABI_VERSION as it
usually means that backward compatibility will be broken after such change.

Thanks