Re: [dpdk-dev] [PATCH 0/4] Add external contiguous memory support to Virtio-user

[David Marchand <david.marchand@redhat.com>]

On Fri, Dec 13, 2019 at 3:13 PM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> Somme applications/frameworks using DPDK allocate their own memory
> for its buffers. This is the case of Seastar, and also VPP.
>
> It is currently not possible to use Virtio-user PMD with these
> applications because Virtio-user requires file descriptor for this
> memory to be shared with the vhost-user backend (vDPA in our case [0]).
>
> This series introduces a new API in EAL to register external memory
> that is contiguous in both the VA and the IOVA space.
>
> It also enables VDEVs to implement the DMA map/unmap callback, and
> implement it in Virtio-user PMD.
>
> Please note that extmem unit tests are missing. I'm working on it
> and it will be in v2. Just share this v1 for early reviews.
>
> Maxime Coquelin (4):
>   eal: add new API to register contiguous external memory
>   eal: allow getting memory segment FD with external memory
>   bus/vdev: add DMA mapping supprt
>   net/virtio: add DMA mapping callback to virtio-user
>
>  drivers/bus/vdev/rte_bus_vdev.h               | 24 +++++
>  drivers/bus/vdev/vdev.c                       | 50 +++++++++++
>  .../net/virtio/virtio_user/virtio_user_dev.c  | 10 +--
>  .../net/virtio/virtio_user/virtio_user_dev.h  |  3 +
>  drivers/net/virtio/virtio_user_ethdev.c       | 58 +++++++++++++
>  lib/librte_eal/common/eal_common_memory.c     | 87 ++++++++++++++++---
>  lib/librte_eal/common/include/rte_memory.h    | 46 ++++++++++
>  lib/librte_eal/common/malloc_heap.c           | 17 +++-
>  lib/librte_eal/common/malloc_heap.h           |  2 +-
>  lib/librte_eal/common/rte_malloc.c            |  2 +-
>  lib/librte_eal/rte_eal_version.map            |  3 +
>  11 files changed, 278 insertions(+), 24 deletions(-)

I am not sure this feature is still needed as there was no activity
for a long time.

There was some feedback from Anatoly and the series needs a rebase in any case.
I marked the series as Changes requested so it is clear it can't be
considered for merging in its current state.

Thanks.

-- 
David Marchand