Zack Rusin <zack@xxxxxxx> writes:
Hello Zack,
> From: Zack Rusin <zackr@xxxxxxxxxx>
>
> Cursor planes on virtualized drivers have special meaning and require
> that the clients handle them in specific ways, e.g. the cursor plane
> should react to the mouse movement the way a mouse cursor would be
> expected to and the client is required to set hotspot properties on it
> in order for the mouse events to be routed correctly.
>
> This breaks the contract as specified by the "universal planes". Fix it
> by disabling the cursor planes on virtualized drivers while adding
> a foundation on top of which it's possible to special case mouse cursor
> planes for clients that want it.
>
> Disabling the cursor planes makes some kms compositors which were broken,
> e.g. Weston, fallback to software cursor which works fine or at least
> better than currently while having no effect on others, e.g. gnome-shell
> or kwin, which put virtualized drivers on a deny-list when running in
> atomic context to make them fallback to legacy kms and avoid this issue.
>
> Signed-off-by: Zack Rusin <zackr@xxxxxxxxxx>
> Fixes: 681e7ec73044 ("drm: Allow userspace to ask for universal plane list (v2)")
> Cc: <stable@xxxxxxxxxxxxxxx> # v5.4+
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Dave Airlie <airlied@xxxxxxxxxx>
> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
> Cc: Gurchetan Singh <gurchetansingh@xxxxxxxxxxxx>
> Cc: Chia-I Wu <olvaffe@xxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: spice-devel@xxxxxxxxxxxxxxxxxxxxx
> ---
> drivers/gpu/drm/drm_plane.c | 13 +++++++++++++
> drivers/gpu/drm/qxl/qxl_drv.c | 2 +-
> drivers/gpu/drm/vboxvideo/vbox_drv.c | 2 +-
> drivers/gpu/drm/virtio/virtgpu_drv.c | 2 +-
> drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 2 +-
> include/drm/drm_drv.h | 9 +++++++++
> include/drm/drm_file.h | 12 ++++++++++++
> 7 files changed, 38 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 24e7998d1731..a4a39f4834e2 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/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) &&
Nit: you have a tab instead of an space before && but this can just be
fixed when applying.
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
--
Best regards,
Javier Martinez Canillas
Core Platforms
Red Hat