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Date: Tue, 30 Apr 2024 09:57:20 -0300
From: Jason Gunthorpe <jgg@ziepe.ca>
To: Leon Romanovsky <leon@kernel.org>
Cc: Long Li <longli@microsoft.com>,
	Konstantin Taranov <kotaranov@linux.microsoft.com>,
	Konstantin Taranov <kotaranov@microsoft.com>,
	"sharmaajay@microsoft.com" <sharmaajay@microsoft.com>,
	"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH rdma-next 6/6] RDMA/mana_ib: implement uapi for creation
 of rnic cq
Message-ID: <20240430125720.GT231144@ziepe.ca>
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On Tue, Apr 30, 2024 at 03:37:15PM +0300, Leon Romanovsky wrote:
> 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.

Yes, this is the expected method

> 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.

Yes, please don't do that.

Jason