[PATCH v6 0/5] dcc: Create a stream for non-gl/remote clients that want to use dmabuf (v6)

[Frediano Ziglio]

Il giorno lun 4 mar 2024 alle ore 11:10 Vivek Kasireddy
<vivek.kasireddy at intel.com> ha scritto:
>
> For clients that cannot accept a dmabuf fd directly (such as those
> running on a remote system), this patch series provides a way for
> the Spice server to stream the gl/dmabuf data/buffer instead. This
> is mostly done by enabling the creation of Gst memory using a dmabuf
> fd as the source. This ability is useful given that dmabuf is the
> standard mechanism for sharing buffers between various drivers and
> userspace in many Graphics and Media usecases. Currently, this is
> tested with Qemu and remote-viewer using the x264enc/avdec_h264
> and msdkh264enc/dec plugins to stream the Guest/VM desktop but it
> can be easily extended to other plugins and applications.
>
> Here is roughly how things work:
> - The application (e.g, Qemu) chooses its preferred codec (a Gstreamer
>   one) and calls gl_scanout (to update the fd) followed by gl_draw.
> - In response, the Spice server checks to see if the client is capable
>   of accepting a dmabuf fd directly or not. If yes, the fd is forwarded
>   directly to the client; otherwise, a new stream is created.
> - The Spice server then sends the dmabuf fd to the Gstreamer encoder
>   which uses it as an input for creating an encoded buffer which is then
>   sent to the client.
> - Once the encoding process is done, an async completion cookie is sent
>   to the application.
>
> Here is a link to the previous version that used a drawable to share
> the dmabuf fd with the Gstreamer encoder:
> https://lists.freedesktop.org/archives/spice-devel/2023-January/052948.html
>
> This version is tested together with following (required) patches in qemu:
> https://gitlab.freedesktop.org/Vivek/qemu/-/commits/spice_gl_on_v2
>
> Changelog:
>
> v6: (Frediano)
> - Properly share ownership of the dmabuf fd between stream and scanout
> - Ensure that a newly created stream is associated with all connected clients
>
> v5:
> - Addressed review comments from Frediano mainly regarding adding autoconf
>   support for gstreamer-allocators dependency and not needing to access
>   scanout as part of gl draw operation
>
> v4:
> - Test with Virgl enabled
> - Associate dmabuf's y0_top with stream's top_down variable
>
> v3:
> - Updated the second patch to have a new primary surface created
>   whenever a new stream gets created. This will avoid having to
>   trigger primary surface creation from Qemu. And, this change
>   also fixes the following error seen with v2:
>   ../server/display-channel.cpp:2074:display_channel_create_surface:
>   condition `!display->priv->surfaces[surface_id]' failed
> - Rebase all patches on master
>
> v2:
> - Update all patches to address review comments from Frediano
> - Tested this series with msdkh264enc/dec plugins that will be added
>   in another patch series
>
> Cc: Frediano Ziglio <freddy77 at gmail.com>
> Cc: Gerd Hoffmann <kraxel at redhat.com>
> Cc: Marc-André Lureau <marcandre.lureau at redhat.com>
> Cc: Dongwon Kim <dongwon.kim at intel.com>
>
>
> Vivek Kasireddy (5):
>   dcc: Check to see if the client supports multiple codecs (v2)
>   dcc: Create a stream associated with gl_draw for non-gl clients (v5)
>   dcc-send: Encode and send gl_draw stream data to the remote client
>     (v3)
>   gstreamer-encoder: Add an encoder function that takes dmabuf fd as
>     input (v3)
>   video-stream: Don't stop a stream associated with gl_draw (v2)
>
>  configure.ac                     |   2 +-
>  meson.build                      |   2 +-
>  server/dcc-send.cpp              | 150 ++++++++++++++++++-----
>  server/dcc.cpp                   |  36 ++++--
>  server/dcc.h                     |   6 +
>  server/display-channel-private.h |   1 +
>  server/display-channel.cpp       |   1 +
>  server/gstreamer-encoder.c       | 165 ++++++++++++++++++++-----
>  server/video-encoder.h           |  13 ++
>  server/video-stream.cpp          | 202 ++++++++++++++++++++++++++-----
>  server/video-stream.h            |   5 +
>  11 files changed, 479 insertions(+), 104 deletions(-)
>

Hi,
   I finally managed to try the series. Did it work on your side?
Looks like this series is still WIP/EXP/RFC quality, at this time I
supposed it should be converging to a working state.
By the way, it blinks a lot during boot, then when the machine
switches to the final desktop it gets blank. At that point even if you
close and reopen the client you get a blank screen.

Regards,
   Frediano