-----"Jason Gunthorpe" <jgg@xxxxxxxx> wrote: ----- >To: "Bernard Metzler" <BMT@xxxxxxxxxxxxxx> >From: "Jason Gunthorpe" <jgg@xxxxxxxx> >Date: 08/19/2019 06:05PM >Cc: "Geert Uytterhoeven" <geert@xxxxxxxxxxxxxx>, "Doug Ledford" ><dledford@xxxxxxxxxx>, linux-rdma@xxxxxxxxxxxxxxx, >linux-kernel@xxxxxxxxxxxxxxx >Subject: [EXTERNAL] Re: Re: Re: Re: [PATCH] RDMA/siw: Fix compiler >warnings on 32-bit due to u64/pointer abuse > >On Mon, Aug 19, 2019 at 03:54:56PM +0000, Bernard Metzler wrote: > >> Absolutely. But these addresses are conveyed through the >> API as unsigned 64 during post_send(), and land in the siw >> send queue as is. During send queue processing, these addresses >> must be interpreted according to its context and transformed >> (casted) back to the callers intention. I frankly do not >> know what we can do differently... The representation of >> all addresses as unsigned 64 is given. Sorry for the confusion. > >send work does not have pointers in it, so I'm confused what this is >about. Does siw allow userspace to stick an ordinary pointer for the >SG list? Right a user references a buffer by address and local key it got during reservation of that buffer. The user can provide any VA between start of that buffer and registered length. > >The code paths here must be totally different, so there should be >different types and functions for each case. Yes, there is a function to process application memory (siw_rx_umem), to process a kernel PBL (siw_rx_pbl), and one to process kernel addresses (siw_rx_kva). Before running that function, the API representation of the current SGE gets translated into target buffer representation. Thanks and best regards, Bernard.
