On Sat, Oct 18, 2025 at 04:01:08AM +0200, Louis Chauvet wrote:
> To allows the userspace to test many hardware configuration, introduce a
> new interface to configure the available color ranges per planes. VKMS
> supports multiple color ranges, so the userspace can choose any
> combination.
>
> The supported color ranges are configured by writing a color range bitmask
> to the file `supported_color_ranges` and the default color range is
> chosen by writing a color encoding bitmask to `default_color_range`.
>
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
> Documentation/gpu/vkms.rst | 7 ++-
> drivers/gpu/drm/vkms/vkms_configfs.c | 93 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 99 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
> index 4ff75b53a386..979f8a545498 100644
> --- a/Documentation/gpu/vkms.rst
> +++ b/Documentation/gpu/vkms.rst
> @@ -87,7 +87,7 @@ Start by creating one or more planes::
>
> sudo mkdir /config/vkms/my-vkms/planes/plane0
>
> -Planes have 5 configurable attribute:
> +Planes have 7 configurable attribute:
>
> - type: Plane type: 0 overlay, 1 primary, 2 cursor (same values as those
> exposed by the "type" property of a plane)
> @@ -101,6 +101,11 @@ Planes have 5 configurable attribute:
> by the COLOR_ENCODING property of a plane)
> - default_color_encoding: Default color encoding presented to the userspace, same
> values as supported_color_encoding
> +- supported_color_range: Available color range for a plane, as a bitmask:
> + 0x1 DRM_COLOR_YCBCR_LIMITED_RANGE, 0x2 DRM_COLOR_YCBCR_FULL_RANGE (same values as
> + those exposed by the COLOR_RANGE property of a plane)
> +- default_color_range: Default color range presented to the userspace, same
> + values as supported_color_range
>
> Continue by creating one or more CRTCs::
>
> diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
> index a4e0e054cf2d..0b280c73b0cc 100644
> --- a/drivers/gpu/drm/vkms/vkms_configfs.c
> +++ b/drivers/gpu/drm/vkms/vkms_configfs.c
> @@ -412,6 +412,95 @@ static ssize_t plane_default_rotation_store(struct config_item *item,
> return count;
> }
>
> +static ssize_t plane_supported_color_range_show(struct config_item *item, char *page)
> +{
> + struct vkms_configfs_plane *plane;
> + unsigned int supported_color_range;
> +
> + plane = plane_item_to_vkms_configfs_plane(item);
> +
> + scoped_guard(mutex, &plane->dev->lock) {
> + supported_color_range = vkms_config_plane_get_supported_color_range(plane->config);
> + }
> +
> + return sprintf(page, "%u", supported_color_range);
> +}
> +
> +static ssize_t plane_supported_color_range_store(struct config_item *item,
> + const char *page, size_t count)
> +{
> + struct vkms_configfs_plane *plane = plane_item_to_vkms_configfs_plane(item);
> + int ret, val = 0;
> +
> + ret = kstrtouint(page, 10, &val);
> + if (ret)
> + return ret;
> +
> + /* Should be a supported value */
> + if (val & ~(BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
> + BIT(DRM_COLOR_YCBCR_FULL_RANGE)))
> + return -EINVAL;
> + /* Should at least provide one color range */
> + if ((val & (BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
> + BIT(DRM_COLOR_YCBCR_FULL_RANGE))) == 0)
> + return -EINVAL;
> +
> + scoped_guard(mutex, &plane->dev->lock) {
> + /* Ensures that the default rotation is included in supported rotation */
> + if (plane->dev->enabled ||
> + (val & vkms_config_plane_get_default_color_range(plane->config)) !=
> + vkms_config_plane_get_default_color_range(plane->config))
> + return -EINVAL;
> + vkms_config_plane_set_supported_color_range(plane->config, val);
> + }
> +
> + return count;
> +}
> +
> +static ssize_t plane_default_color_range_show(struct config_item *item, char *page)
> +{
> + struct vkms_configfs_plane *plane;
> + unsigned int default_color_range;
> +
> + plane = plane_item_to_vkms_configfs_plane(item);
> +
> + scoped_guard(mutex, &plane->dev->lock)
> + default_color_range = vkms_config_plane_get_default_color_range(plane->config);
> +
> + return sprintf(page, "%u", default_color_range);
> +}
> +
> +static ssize_t plane_default_color_range_store(struct config_item *item,
> + const char *page, size_t count)
> +{
> + struct vkms_configfs_plane *plane = plane_item_to_vkms_configfs_plane(item);
> + int ret, val = 0;
> +
> + ret = kstrtouint(page, 10, &val);
> + if (ret)
> + return ret;
> +
> + /* Should be a supported value */
> + if (val & ~(BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
> + BIT(DRM_COLOR_YCBCR_FULL_RANGE)))
> + return -EINVAL;
> + /* Should at least provide one color range */
> + if ((val & (BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
> + BIT(DRM_COLOR_YCBCR_FULL_RANGE))) == 0)
> + return -EINVAL;
> +
> + scoped_guard(mutex, &plane->dev->lock) {
> + /* Ensures that the default rotation is included in supported rotation */
> + if (plane->dev->enabled ||
> + (val & vkms_config_plane_get_supported_color_range(plane->config)) !=
> + val)
> + return -EINVAL;
> + vkms_config_plane_set_default_color_range(plane->config, val);
Same comment about the validation here.
> + }
> +
> + return count;
> +}
> +
> static ssize_t plane_supported_color_encoding_show(struct config_item *item, char *page)
> {
> struct vkms_configfs_plane *plane;
> @@ -513,6 +602,8 @@ static ssize_t plane_default_color_encoding_store(struct config_item *item,
> CONFIGFS_ATTR(plane_, type);
> CONFIGFS_ATTR(plane_, supported_rotations);
> CONFIGFS_ATTR(plane_, default_rotation);
> +CONFIGFS_ATTR(plane_, supported_color_range);
> +CONFIGFS_ATTR(plane_, default_color_range);
And the mixed use of singular and plural for supported_*.
> CONFIGFS_ATTR(plane_, supported_color_encoding);
> CONFIGFS_ATTR(plane_, default_color_encoding);
>
> @@ -520,6 +611,8 @@ static struct configfs_attribute *plane_item_attrs[] = {
> &plane_attr_type,
> &plane_attr_supported_rotations,
> &plane_attr_default_rotation,
> + &plane_attr_supported_color_range,
> + &plane_attr_default_color_range,
> &plane_attr_supported_color_encoding,
> &plane_attr_default_color_encoding,
> NULL,
>
> --
> 2.51.0
>