[Spice-devel] [PATCH v1 0/5] dcc: Create a stream for non-gl/remote clients that want to use dmabuf

Kasireddy, Vivek vivek.kasireddy at intel.com
Mon Mar 27 06:53:04 UTC 2023


Hi Frediano,

>    I was trying the patch series but the client keeps crashing. I
> tried different versions of remote-viewer (from Fedora and from
> Ubuntu) and they both crashed.
> On host I installed Intel VA drivers , Gstreamer VAAPIs and forced
> gstreamer:h264 as encoder.
[Kasireddy, Vivek] I don't think any of these packages are needed if we are testing
with a software (i.e, CPU-based) encoder/decoder (i.e, using x264enc/x264dec plugins).
On my Fedora 37, these relevant plugins are provided by:
# rpm -q --whatprovides /usr/lib64/gstreamer-1.0/libgstx264.so
gstreamer1-plugins-ugly-1.20.5-1.fc37.x86_64
# rpm -q --whatprovides /usr/lib64/gstreamer-1.0/libgstlibav.so
gstreamer1-plugin-libav-1.20.5-1.fc37.x86_64

The former provides x264enc and the latter provides x264dec. You can either choose
the ones provided by your distro or build Gstreamer with -Dgst-plugins-ugly:x264=enabled 
and -Dlibav=enabled. However, note that one of our eventual goals is to cleanly add a
new Gstreamer pipeline to Spice to provide users an option for hardware-based
(i.e, GPU assisted) H.264 encoding/decoding using msdkh264enc/msdkh264dec plugins:
https://gstreamer.freedesktop.org/documentation/msdk/msdkh264enc.html?gi-language=c

> Anything else you need to do?
[Kasireddy, Vivek] Sorry, I was not expecting anyone would test the Spice server
patches and therefore did not provide all the required information to test them.
Anyway, I suspect the reason for your remote-viewer crash is because there is no
(primary) surface created. Here is the tentative Qemu patch that does just that:

Author: Vivek Kasireddy <vivek.kasireddy at intel.com>
Date:   Wed Mar 15 22:18:00 2023 -0700

    spice: Create a primary surface for a streaming non-gl client

    When gl=on option is enabled and a client that cannot accept
    dmabuf fds is connected, create a primary surface so that
    the server can start streaming the dmabuf data.

    Signed-off-by: Vivek Kasireddy <vivek.kasireddy at intel.com>

diff --git a/include/ui/spice-display.h b/include/ui/spice-display.h
index e271e011da..121fb0caf8 100644
--- a/include/ui/spice-display.h
+++ b/include/ui/spice-display.h
@@ -153,6 +153,7 @@ struct SimpleSpiceCursor {
 };

 extern bool spice_opengl;
+extern bool streaming_client;

 int qemu_spice_rect_is_empty(const QXLRect* r);
 void qemu_spice_rect_union(QXLRect *dest, const QXLRect *r);
diff --git a/ui/spice-core.c b/ui/spice-core.c
index 6e00211e3a..e5822b41ef 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -845,9 +845,7 @@ static void qemu_spice_init(void)
 #ifdef HAVE_SPICE_GL
     if (qemu_opt_get_bool(opts, "gl", 0)) {
         if ((port != 0) || (tls_port != 0)) {
-            error_report("SPICE GL support is local-only for now and "
-                         "incompatible with -spice port/tls-port");
-            exit(1);
+            streaming_client = 1;
         }
         if (egl_rendernode_init(qemu_opt_get(opts, "rendernode"),
                                 DISPLAYGL_MODE_ON) != 0) {
diff --git a/ui/spice-display.c b/ui/spice-display.c
index 494168e7fe..fe85604c2e 100644
--- a/ui/spice-display.c
+++ b/ui/spice-display.c
@@ -28,6 +28,7 @@
 #include "ui/spice-display.h"

 bool spice_opengl;
+bool streaming_client;

 int qemu_spice_rect_is_empty(const QXLRect* r)
 {
@@ -891,6 +892,9 @@ static void spice_gl_switch(DisplayChangeListener *dcl,
     }
     ssd->ds = new_surface;
     if (ssd->ds) {
+        if (streaming_client) {
+            qemu_spice_create_host_primary(ssd);
+        }
         surface_gl_create_texture(ssd->gls, ssd->ds);
         fd = egl_get_fd_for_texture(ssd->ds->texture,

I did not yet post this patch to the Qemu mailing list because I still need to implement
feature negotiation between Qemu and Spice to auto-detect this capability. And,
in addition to this patch, you also need the patch that adds the "preferred-codec"
option to Qemu, unless you are hardcoding it in Spice:
https://lists.nongnu.org/archive/html/qemu-devel/2023-01/msg04999.html

Lastly, not sure if it makes a difference, but here are the relevant options I am
using to launch Qemu:
-device virtio-gpu-pci,max_outputs=1,blob=true,xres=1920,yres=1080
-spice port=3001,gl=on,disable-ticketing=on,preferred-codec=gstreamer:h264
-object memory-backend-memfd,id=mem1,size=4096M
-machine memory-backend=mem1 -usb -device usb-tablet -serial stdio

Thanks,
Vivek

> 
> On the logs I find:
> 
> 2023-03-25T19:31:36.034007Z qemu-system-x86_64: warning: Spice:
> ../server/dcc-send.cpp:1786:red_marshall_gl_draw_stream: bad return
> value (0) from VideoEncoder::encode_dmabuf
> 2023-03-25T19:31:37.064219Z qemu-system-x86_64: warning: spice: no
> gl-draw-done within one second
> 2023-03-25T19:31:58.214387Z qemu-system-x86_64: warning: Spice:
> Connection reset by peer
> 2023-03-25T19:31:58.214482Z qemu-system-x86_64: warning: Spice:
> Connection reset by peer
> 2023-03-25T19:31:58.214580Z qemu-system-x86_64: warning: Spice:
> Connection reset by peer
> 2023-03-25T19:31:58.214642Z 2023-03-25T19:31:58.214636Z
> qemu-system-x86_64:qemu-system-x86_64:  warning: Spice: Connection
> reset by peer
> warning: Spice: display:0 (0x55947e76fd10): Connection reset by peer
> 2023-03-25T19:31:58.214721Z qemu-system-x86_64: warning: Spice:
> Connection reset by peer
> 2023-03-25T19:31:58.214841Z qemu-system-x86_64: warning: Spice:
> Connection reset by peer
> 2023-03-25T19:31:58.215057Z qemu-system-x86_64: warning: Spice:
> Connection reset by peer
> 
> 0 value from encode_dmabuf should mean VIDEO_ENCODER_FRAME_DROP.
> 
> Regards,
>    Frediano
> 
> Il giorno gio 16 mar 2023 alle ore 06:05 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
> > only used/tested with Qemu and remote-viewer using the x264enc/dec
> > codec 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
> >
> > 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
> >   dcc: Create a stream associated with gl_draw for non-gl clients
> >   dcc-send: Encode and send gl_draw stream data to the remote client
> >   gstreamer-encoder: Add an encoder function that takes dmabuf fd as
> >     input
> >   video-stream: Don't stop a stream if a gl_draw operation is pending
> >
> >  meson.build                      |   2 +-
> >  server/dcc-private.h             |   4 ++
> >  server/dcc-send.cpp              |  89 ++++++++++++++++++++++-
> >  server/dcc.cpp                   |  36 +++++++---
> >  server/display-channel-private.h |   6 ++
> >  server/gstreamer-encoder.c       | 119 ++++++++++++++++++++++++++++++-
> >  server/video-encoder.h           |  13 ++++
> >  server/video-stream.cpp          |  65 ++++++++++++++++-
> >  server/video-stream.h            |   2 +
> >  9 files changed, 319 insertions(+), 17 deletions(-)
> >
> > --
> > 2.37.2
> >


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