Re: [Patch v8 12/12] RDMA/mana_ib: Add a driver for Microsoft Azure Network Adapter

[Tom Talpey]

On 10/20/2022 4:42 PM, Long Li wrote:
> > [Bernard wrote...]

> > > +	props->max_qp_wr = MAX_SEND_BUFFERS_PER_QUEUE;
> > > +
> > > +	/*
> > > +	 * max_cqe could be potentially much bigger.
> > > +	 * As this version of driver only support RAW QP, set it to the same
> > > +	 * value as max_qp_wr
> > > +	 */
> > > +	props->max_cqe = MAX_SEND_BUFFERS_PER_QUEUE;
> > > +
> > > +	props->max_mr_size = MANA_IB_MAX_MR_SIZE;
> > > +	props->max_mr = INT_MAX;
> >
> > How the 24 bit wide MR keys can handle INT_MAX unique
> > MR's?
>
> Not sure if I understand this correctly, lkey and rkey are u32 in ib_mr.

The upper 8 bits of an ib_mr remote token are reserved for use as a
rotating key, this allows a consumer to more safely reuse an ib_mr
without having to overallocate large region pools.

Tom.