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 } > > The above is talking about the address, which is checked inside > pagefault_mr() and does return EFAULT for all the cases I can see? > > Jason