kms: Dmabuf Feedback support

src/backend/kms/mod.rs

@@ -6,7 +6,7 @@ use crate::{
     backend::render::{workspace_elements, CLEAR_COLOR},
     config::OutputConfig,
     shell::Shell,
-    state::{BackendData, ClientState, Common, Data, Fps},
+    state::{BackendData, ClientState, Common, Data, Fps, SurfaceDmabufFeedback},
     utils::prelude::*,
     wayland::{
         handlers::screencopy::{render_session, UserdataExt},
@@ -38,7 +38,7 @@ use smithay::{
             glow::GlowRenderer,
             multigpu::{gbm::GbmGlesBackend, Error as MultiError, GpuManager},
             utils::draw_render_elements,
-            Bind, Blit, Offscreen, Renderer, TextureFilter,
+            Bind, Blit, ImportDma, Offscreen, Renderer, TextureFilter,
         },
         session::{libseat::LibSeatSession, Event as SessionEvent, Session},
         udev::{all_gpus, primary_gpu, UdevBackend, UdevEvent},
@@ -58,12 +58,16 @@ use smithay::{
         },
         input::Libinput,
         nix::{fcntl::OFlag, sys::stat::dev_t},
-        wayland_protocols::wp::presentation_time::server::wp_presentation_feedback,
+        wayland_protocols::wp::{
+            linux_dmabuf::zv1::server::zwp_linux_dmabuf_feedback_v1,
+            presentation_time::server::wp_presentation_feedback,
+        },
         wayland_server::{protocol::wl_surface::WlSurface, DisplayHandle, Resource},
     },
     utils::{DeviceFd, Size, Transform},
     wayland::{
-        dmabuf::{get_dmabuf, DmabufGlobal},
+        compositor::with_states,
+        dmabuf::{get_dmabuf, DmabufFeedbackBuilder, DmabufGlobal, SurfaceDmabufFeedbackState},
         relative_pointer::RelativePointerManagerState,
         seat::WaylandFocus,
     },
@@ -119,6 +123,7 @@ pub struct Surface {
     dirty: bool,
     render_timer_token: Option<RegistrationToken>,
     fps: Fps,
+    feedback: Option<SurfaceDmabufFeedback>,
 }
 
 pub type GbmDrmCompositor = DrmCompositor<
@@ -889,6 +894,7 @@ impl Device {
             dirty: false,
             render_timer_token: None,
             fps: Fps::new(renderer.as_mut()),
+            feedback: None,
         };
         self.surfaces.insert(crtc, data);
 
@@ -909,10 +915,18 @@ fn render_node_for_output(
         .unwrap_or_else(|| workspace.windows().collect::<Vec<_>>())
         .into_iter()
         .flat_map(|w| {
+            // has the client requested surface-feedback? If yes it is properly rendering on our target_node
+            if with_states(&w.wl_surface()?, |data| {
+                SurfaceDmabufFeedbackState::from_states(data).is_some()
+            }) {
+                return Some(target_node.clone());
+            }
+            // else lets check the global drm-node the client got either through default-feedback or wl_drm
             let client = dh.get_client(w.wl_surface()?.id()).ok()?;
             if let Some(normal_client) = client.get_data::<ClientState>() {
                 return normal_client.drm_node.clone();
             }
+            // last but not least all xwayland-surfaces should also share a single node
             if let Some(xwayland_client) = client.get_data::<XWaylandClientData>() {
                 return xwayland_client.user_data().get::<DrmNode>().cloned();
             }
@@ -936,6 +950,51 @@ fn render_node_for_output(
     }
 }
 
+fn get_surface_dmabuf_feedback(
+    render_node: DrmNode,
+    renderer: &mut GlMultiRenderer<'_, '_>,
+    compositor: &GbmDrmCompositor,
+) -> Option<SurfaceDmabufFeedback> {
+    let render_formats = renderer.dmabuf_formats().copied().collect::<HashSet<_>>();
+
+    let surface = compositor.surface();
+    let planes = surface.planes().unwrap();
+    // We limit the scan-out trache to formats we can also render from
+    // so that there is always a fallback render path available in case
+    // the supplied buffer can not be scanned out directly
+    let planes_formats = surface
+        .supported_formats(planes.primary.handle)
+        .unwrap()
+        .into_iter()
+        .chain(
+            planes
+                .overlay
+                .iter()
+                .flat_map(|p| surface.supported_formats(p.handle).unwrap()),
+        )
+        .collect::<HashSet<_>>()
+        .intersection(&render_formats)
+        .copied()
+        .collect::<Vec<_>>();
+
+    let builder = DmabufFeedbackBuilder::new(render_node.dev_id(), render_formats);
+    let render_feedback = builder.clone().build().unwrap();
+
+    let scanout_feedback = builder
+        .add_preference_tranche(
+            surface.device_fd().dev_id().unwrap(),
+            Some(zwp_linux_dmabuf_feedback_v1::TrancheFlags::Scanout),
+            planes_formats,
+        )
+        .build()
+        .unwrap();
+
+    Some(SurfaceDmabufFeedback {
+        render_feedback,
+        scanout_feedback,
+    })
+}
+
 impl Surface {
     pub fn render_output(
         &mut self,
@@ -1088,7 +1147,7 @@ impl Surface {
                 } else {
                     None
                 };
-                state.send_frames(&self.output, &frame_result.states);
+                state.send_frames(&self.output, &frame_result.states, self.feedback.as_ref());
                 compositor
                     .queue_frame(feedback)
                     .with_context(|| "Failed to submit result for display")?
@@ -1215,6 +1274,16 @@ impl KmsState {
                                     .unwrap_or_else(|_| String::from("Unknown"))
                             )
                         })?;
+                        surface.feedback =
+                            self.api.single_renderer(&device.render_node).ok().and_then(
+                                |mut renderer| {
+                                    get_surface_dmabuf_feedback(
+                                        device.render_node,
+                                        &mut renderer,
+                                        &target,
+                                    )
+                                },
+                            );
                         surface.surface = Some(target);
                         true
                     };
@@ -1287,8 +1356,6 @@ impl KmsState {
     }
 
     pub fn dmabuf_imported(&mut self, global: &DmabufGlobal, dmabuf: Dmabuf) -> Result<()> {
-        use smithay::backend::renderer::ImportDma;
-
         for device in self.devices.values() {
             if device
                 .socket