Re: [PATCH net-next] rds: rely on IB/core to determine if device is ODP capable

[Leon Romanovsky <leon@kernel.org>]

On Tue, Apr 08, 2025 at 09:23:38AM -0300, Jason Gunthorpe wrote:
> On Tue, Apr 08, 2025 at 02:04:55PM +0300, Leon Romanovsky wrote:
> > diff --git a/net/rds/ib.c b/net/rds/ib.c
> > index 9826fe7f9d00..c62aa2ff4963 100644
> > --- a/net/rds/ib.c
> > +++ b/net/rds/ib.c
> > @@ -153,14 +153,6 @@ static int rds_ib_add_one(struct ib_device *device)
> >  	rds_ibdev->max_wrs = device->attrs.max_qp_wr;
> >  	rds_ibdev->max_sge = min(device->attrs.max_send_sge, RDS_IB_MAX_SGE);
> >  
> > -	rds_ibdev->odp_capable =
> > -		!!(device->attrs.kernel_cap_flags &
> > -		   IBK_ON_DEMAND_PAGING) &&
> > -		!!(device->attrs.odp_caps.per_transport_caps.rc_odp_caps &
> > -		   IB_ODP_SUPPORT_WRITE) &&
> > -		!!(device->attrs.odp_caps.per_transport_caps.rc_odp_caps &
> > -		   IB_ODP_SUPPORT_READ);
> 
> This patch seems to drop the check for WRITE and READ support on the
> ODP.

Right, and they are part of IBK_ON_DEMAND_PAGING support. All ODP
providers support both IB_ODP_SUPPORT_WRITE and IB_ODP_SUPPORT_READ.

RDS doesn't need to check more than general ODP support and can safely
rely on internal driver logic to create right MR.

Thanks

> 
> Jason