Re: remove dma_virt_ops v2

Jason Gunthorpe
2020-11-12T13:24:03Z

On Thu, Nov 12, 2020 at 10:40:30AM +0100, Christoph Hellwig wrote:
> ping?
>
> On Fri, Nov 06, 2020 at 07:19:31PM +0100, Christoph Hellwig wrote:
> > Hi Jason,
> >
> > this series switches the RDMA core to opencode the special case of
> > devices bypassing the DMA mapping in the RDMA ULPs. The virt ops
> > have caused a bit of trouble due to the P2P code node working with
> > them due to the fact that we'd do two dma mapping iterations for a
> > single I/O, but also are a bit of layering violation and lead to
> > more code than necessary.
> >
> > Tested with nvme-rdma over rxe.
> >
> > Note that the rds changes are untested, as I could not find any
> > simple rds test setup.
> >
> > Changes since v2:
> > - simplify the INFINIBAND_VIRT_DMA dependencies
> > - add a ib_uses_virt_dma helper
> > - use ib_uses_virt_dma in nvmet-rdma to disable p2p for virt_dma devices
> > - use ib_dma_max_seg_size in umem
> > - stop using dmapool in rds
> >
> > Changes since v1:
> > - disable software RDMA drivers for highmem configs
> > - update the PCI commit logs

Santosh can you please check the RDA parts??

Jason