Re: [dpdk-dev] [PATCH 0/8] Introduce emudev library and iavf emudev driver

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 18 Dec 2020 15:47:28 +0800
Chenbo Xia <chenbo.xia@intel.com> wrote:

> This series introduces a new device abstraction called emudev for emulated
> devices. A new library (librte_emudev) is implemented. The first emudev
> driver is also introduced, which emulates Intel Adaptive Virtual Function
> (iavf) as a software network device.
> 
> This series has a dependency on librte_vfio_user patch series:
> http://patchwork.dpdk.org/cover/85389/
> 
> Background & Motivation 
> -----------------------
> The disaggregated/multi-process QEMU is using VFIO-over-socket/vfio-user
> as the main transport mechanism to disaggregate IO services from QEMU.
> Therefore, librte_vfio_user is introduced in DPDK to accommodate
> emulated devices for high performance I/O. Although vfio-user library
> provides possibility of emulating devices in DPDK, DPDK does not have
> a device abstraction for emulated devices. A good device abstraction will
> be useful for applications or high performance data path driver. With
> this consideration, emudev library is designed and implemented. It also
> make it possbile to keep modular design on emulated devices by implementing
> data path related logic in a standalone driver (e.g., an ethdev driver)
> and keeps the unrelated logic in the emudev driver.
> 
> Design overview
> ---------------
> 
>                     +---------------------------------------+
>                     |   +---------------+    +-----------+  |
>                     |   |  iavf_emudev  |<-->| data path |  |
>                     |   |    driver     |    |   driver  |  |
>                     |   +---------------+    +-----------+  |
>                     |           |                           |
>                     | --------------------------- VDEV BUS  |
>                     |           |                           |
>                     |   +---------------+                   |
> +--------------+    |   | vdev:         |                   |
> | +----------+ |    |   | /path/to/vfio |                   |
> | | Generic  | |    |   +---------------+                   |
> | | vfio-dev | |    |           |                           |
> | +----------+ |    |           |                           |
> | +----------+ |    |      +----------+                     |
> | | vfio-user| |    |      | vfio-user|                     |
> | | client   | |<---|----->| server   |                     |
> | +----------+ |    |      +----------+                     |
> | QEMU/DPDK    |    | DPDK                                  |
> +--------------+    +---------------------------------------+
> 
> - Generic vfio-dev/vfio-user client/vfio-user server
>   Above concepts are all introduced in librte_vfio_user patch series:
>   http://patchwork.dpdk.org/cover/85389/
> 
> - vdev:/path/to/vfio.
>   It binds to vdev bus driver. The vdev device is defined by DPDK applications
>   through command line as '--vdev=emu_iavf, path=/path/to/socket' in iavf_emudev
>   case. Parameters in command line include device name (emu_iavf) which is used
>   to identify corresponding driver (in this case, iavf_emudev driver),
>   path=/path/to/socket which is used to open the transport interface to vfio-user
>   client in QEMU/DPDK.
> 
> - data path driver.
>   The data path handling is splited to another standalone driver for modular
>   design.
> 
> 
> Chenbo Xia (8):
>   lib: introduce emudev library
>   doc: add emudev library guide
>   emu: introduce emulated iavf driver
>   emu/iavf: add vfio-user device register and unregister
>   emu/iavf: add resource management and internal logic of iavf
>   emu/iavf: add emudev operations to fit in emudev framework
>   test/emudev: introduce functional test
>   doc: update release notes for iavf emudev driver
> 
>  MAINTAINERS                            |   12 +
>  app/test/meson.build                   |    5 +-
>  app/test/test_emudev.c                 |   29 +
>  doc/guides/prog_guide/emudev.rst       |  122 +++
>  doc/guides/prog_guide/index.rst        |    1 +
>  doc/guides/rel_notes/release_21_02.rst |   16 +
>  drivers/emu/iavf/iavf_emu.c            |  250 ++++++
>  drivers/emu/iavf/iavf_emu_internal.h   |   69 ++
>  drivers/emu/iavf/iavf_emu_test.c       |  174 ++++
>  drivers/emu/iavf/iavf_emudev.c         |  237 ++++++
>  drivers/emu/iavf/iavf_vfio_user.c      | 1053 ++++++++++++++++++++++++
>  drivers/emu/iavf/iavf_vfio_user.h      |   57 ++
>  drivers/emu/iavf/meson.build           |   17 +
>  drivers/emu/iavf/rte_iavf_emu.h        |  119 +++
>  drivers/emu/iavf/version.map           |    3 +
>  drivers/emu/meson.build                |    6 +
>  drivers/meson.build                    |    1 +
>  lib/librte_emudev/meson.build          |    5 +
>  lib/librte_emudev/rte_emudev.c         |  486 +++++++++++
>  lib/librte_emudev/rte_emudev.h         |  410 +++++++++
>  lib/librte_emudev/rte_emudev_vdev.h    |   53 ++
>  lib/librte_emudev/version.map          |   27 +
>  lib/meson.build                        |    2 +-
>  23 files changed, 3152 insertions(+), 2 deletions(-)
>  create mode 100644 app/test/test_emudev.c
>  create mode 100644 doc/guides/prog_guide/emudev.rst
>  create mode 100644 drivers/emu/iavf/iavf_emu.c
>  create mode 100644 drivers/emu/iavf/iavf_emu_internal.h
>  create mode 100644 drivers/emu/iavf/iavf_emu_test.c
>  create mode 100644 drivers/emu/iavf/iavf_emudev.c
>  create mode 100644 drivers/emu/iavf/iavf_vfio_user.c
>  create mode 100644 drivers/emu/iavf/iavf_vfio_user.h
>  create mode 100644 drivers/emu/iavf/meson.build
>  create mode 100644 drivers/emu/iavf/rte_iavf_emu.h
>  create mode 100644 drivers/emu/iavf/version.map
>  create mode 100644 drivers/emu/meson.build
>  create mode 100644 lib/librte_emudev/meson.build
>  create mode 100644 lib/librte_emudev/rte_emudev.c
>  create mode 100644 lib/librte_emudev/rte_emudev.h
>  create mode 100644 lib/librte_emudev/rte_emudev_vdev.h
>  create mode 100644 lib/librte_emudev/version.map
> 

This patchset seems to have a dependency on a recent version of QEMU.
Was it merged? The patchset would need to be rebased and retested on current
DPDK. If still relevant please do that and resubmit.