Re: [PATCH] RDMA/mlx5: return the EFAULT per ibv_advise_mr(3)

Jason Gunthorpe
2021-08-03T18:13:45Z

On Tue, Aug 03, 2021 at 08:56:54PM +0300, Leon Romanovsky wrote:
> On Tue, Aug 03, 2021 at 01:25:07PM -0300, Jason Gunthorpe wrote:
> > On Sun, Aug 01, 2021 at 05:20:50PM +0800, Li Zhijian wrote:
> > > ibv_advise_mr(3) says:
> > > EFAULT In one of the following: o When the range requested is out of the MR bounds,
> > > or when parts of it are not part of the process address space. o One of the
> > > lkeys provided in the scatter gather list is invalid or with wrong write access
> > >
> > > Actually get_prefetchable_mr() will return NULL if it see above conditions
> >
> > No, get_prefetchable_mr() returns NULL if the mkey is invalid
>
> And what is this?
> 1701 static struct mlx5_ib_mr *
> 1702 get_prefetchable_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice,
> 1703 u32 lkey)
>
> ...
>
> 1721 /* prefetch with write-access must be supported by the MR */
> 1722 if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE &&
> 1723 !mr->umem->writable) {
> 1724 mr = NULL;
> 1725 goto end;
> 1726 }

I would say that is an invalid mkey

Jason