On Wed, Nov 30, 2022 at 11:05:04PM -0600, Bob Pearson wrote: > On 11/30/22 18:41, Jason Gunthorpe wrote: > > On Wed, Nov 30, 2022 at 06:36:56PM -0600, Bob Pearson wrote: > >> I'm not looking at my patch you responded to but the one you posted to replace maps > >> by xarrays. > > > > I see, I botched that part > > > >> The existing rxe driver assumes that if ibmr->type == IB_MR_TYPE_DMA > >> that the iova is just a kernel (virtual) address that is already > >> mapped. > > > > No, it is not correct > > > >> Maybe this is not correct but it has always worked this way. These > >> are heavily used by storage stacks (e.g. Lustre) which always use > >> DMA mr's. Since we don't actually do any DMAs we don't need to setup > >> the iommu for these and just do memcpy's without dealing with pages. > > > > You still should be doing the kmap > > > > Jason > > Does this have to do with 32 bit machines? I have always tested on 64 bit machines and > dma mr's are always already mapped. Originally, but people are making 64 bit machines require kmap for security purposes Jason
