[dpdk-dev] [PATCH 0/3] virtio_user as an alternative exception path

[Jianfeng Tan]

In v16.07, we upstreamed a virtual device, virtio_user (with vhost-user
as the backend). The path to go with a vhost-kernel backend has been
dropped for bad performance comparing to vhost-user and code simplicity.

But after a second thought, virtio_user + vhost-kernel is a good 
candidate as an exceptional path, such as KNI, which exchanges packets
with kernel networking stack.
  - maintenance: vhost-net (kernel) is upstreamed and extensively used 
    kernel module. We don't need any out-of-tree module like KNI.
  - performance: as with KNI, this solution would use one or more
    kthreads to send/receive packets from user space DPDK applications,
    which has little impact on user space polling thread (except that
    it might enter into kernel space to wake up those kthreads if
    necessary.
  - features: vhost-net is born to be a networking solution, which has
    lots of networking related featuers, like multi queue, tso, multi-seg
    mbuf, etc.

Known issues for current version:
  - Multiqueue not supported yet.
  - Offloading is completely enabled yet; to enhance, we will translate
    the virtio header info into mbuf metadata when receiving packets
    from kernel; and translate mbuf metadata info into virtio header
    when sending packets to kernel.

Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>

Jianfeng Tan (3):
  net/virtio_user: add vhost layer
  net/virtio_user: add vhost kernel support
  net/virtio_user: fix wrongly set features

 drivers/net/virtio/Makefile                      |   2 +
 drivers/net/virtio/virtio_user/vhost.c           | 181 ++++++++++
 drivers/net/virtio/virtio_user/vhost.h           |  73 ++--
 drivers/net/virtio/virtio_user/vhost_kernel.c    | 413 +++++++++++++++++++++++
 drivers/net/virtio/virtio_user/vhost_user.c      |  81 +++--
 drivers/net/virtio/virtio_user/virtio_user_dev.c |  49 ++-
 drivers/net/virtio/virtio_user/virtio_user_dev.h |   3 +-
 drivers/net/virtio/virtio_user_ethdev.c          |   4 +-
 8 files changed, 708 insertions(+), 98 deletions(-)
 create mode 100644 drivers/net/virtio/virtio_user/vhost.c
 create mode 100644 drivers/net/virtio/virtio_user/vhost_kernel.c

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2.7.4