drm: Disable the cursor plane on atomic contexts with virtualized drivers

From Zack Rusin
87b3b45ce7b4dd745506f9437b968c5e35b87dda in linux-6.6.y/6.6.15
4e3b70da64a53784683cfcbac2deda5d6e540407 in mainline linux

3 files changed, 34 insertions, 0 deletions

diff --git a/sys/dev/pci/drm/drm_plane.c b/sys/dev/pci/drm/drm_plane.c
index 01fbd3fb7b9..311e179904a 100644
--- a/sys/dev/pci/drm/drm_plane.c
+++ b/sys/dev/pci/drm/drm_plane.c
@@ -678,6 +678,19 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
 		    !file_priv->universal_planes)
 			continue;
 
+		/*
+		 * If we're running on a virtualized driver then,
+		 * unless userspace advertizes support for the
+		 * virtualized cursor plane, disable cursor planes
+		 * because they'll be broken due to missing cursor
+		 * hotspot info.
+		 */
+		if (plane->type == DRM_PLANE_TYPE_CURSOR &&
+		    drm_core_check_feature(dev, DRIVER_CURSOR_HOTSPOT) &&
+		    file_priv->atomic &&
+		    !file_priv->supports_virtualized_cursor_plane)
+			continue;
+
 		if (drm_lease_held(file_priv, plane->base.id)) {
 			if (count < plane_resp->count_planes &&
 			    put_user(plane->base.id, plane_ptr + count))
diff --git a/sys/dev/pci/drm/include/drm/drm_drv.h b/sys/dev/pci/drm/include/drm/drm_drv.h
index 89d7dcb543e..5c855a1bce5 100644
--- a/sys/dev/pci/drm/include/drm/drm_drv.h
+++ b/sys/dev/pci/drm/include/drm/drm_drv.h
@@ -112,6 +112,15 @@ enum drm_driver_feature {
 	 * Driver supports user defined GPU VA bindings for GEM objects.
 	 */
 	DRIVER_GEM_GPUVA		= BIT(8),
+	/**
+	 * @DRIVER_CURSOR_HOTSPOT:
+	 *
+	 * Driver supports and requires cursor hotspot information in the
+	 * cursor plane (e.g. cursor plane has to actually track the mouse
+	 * cursor and the clients are required to set hotspot in order for
+	 * the cursor planes to work correctly).
+	 */
+	DRIVER_CURSOR_HOTSPOT           = BIT(9),
 
 	/* IMPORTANT: Below are all the legacy flags, add new ones above. */
 
diff --git a/sys/dev/pci/drm/include/drm/drm_file.h b/sys/dev/pci/drm/include/drm/drm_file.h
index 7d5259aef50..6e966a8e86b 100644
--- a/sys/dev/pci/drm/include/drm/drm_file.h
+++ b/sys/dev/pci/drm/include/drm/drm_file.h
@@ -232,6 +232,18 @@ struct drm_file {
 	bool is_master;
 
 	/**
+	 * @supports_virtualized_cursor_plane:
+	 *
+	 * This client is capable of handling the cursor plane with the
+	 * restrictions imposed on it by the virtualized drivers.
+	 *
+	 * This implies that the cursor plane has to behave like a cursor
+	 * i.e. track cursor movement. It also requires setting of the
+	 * hotspot properties by the client on the cursor plane.
+	 */
+	bool supports_virtualized_cursor_plane;
+
+	/**
 	 * @master:
 	 *
 	 * Master this node is currently associated with. Protected by struct