[PATCH v12 5/6] vfio: ABI for mdev display dma-buf operation

[Tina Zhang]

Add VFIO_DEVICE_QUERY_GFX_PLANE ioctl command to let user mode query and
get the plan and its related information.

The dma-buf's life cycle is handled by user mode and tracked by kernel.
The returned fd in struct vfio_device_query_gfx_plane can be a new
fd or an old fd of a re-exported dma-buf. Host User mode can check the
value of fd and to see if it needs to create new resource according to
the new fd or just use the existed resource related to the old fd.

Signed-off-by: Tina Zhang <tina.zhang at intel.com>
---
 include/uapi/linux/vfio.h | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index ae46105..827a230 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -502,6 +502,34 @@ struct vfio_pci_hot_reset {
 
 #define VFIO_DEVICE_PCI_HOT_RESET	_IO(VFIO_TYPE, VFIO_BASE + 13)
 
+/**
+ * VFIO_DEVICE_QUERY_GFX_PLANE - _IOW(VFIO_TYPE, VFIO_BASE + 14, struct vfio_device_query_gfx_plane)
+ *
+ * Set the drm_plane_type and retrieve information about the gfx plane.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_device_gfx_plane_info {
+	__u32 argsz;
+	__u32 flags;
+	/* in */
+	__u32 drm_plane_type;	/* type of plane: DRM_PLANE_TYPE_* */
+	/* out */
+	__u32 drm_format;	/* drm format of plane */
+	__u64 drm_format_mod;   /* tiled mode */
+	__u32 width;	/* width of plane */
+	__u32 height;	/* height of plane */
+	__u32 stride;	/* stride of plane */
+	__u32 size;	/* size of plane in bytes, align on page*/
+	__u32 x_pos;	/* horizontal position of cursor plane, upper left corner in pixels */
+	__u32 y_pos;	/* vertical position of cursor plane, upper left corner in lines*/
+	__u32 region_index;
+	__s32 fd;	/* dma-buf fd */
+};
+
+#define VFIO_DEVICE_QUERY_GFX_PLANE _IO(VFIO_TYPE, VFIO_BASE + 14)
+
+
 /* -------- API for Type1 VFIO IOMMU -------- */
 
 /**
-- 
2.7.4