[PATCH v10] 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 need to creat 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@xxxxxxxxx>

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index ae46105..c92bc69 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -502,6 +502,36 @@ 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)
+ * Return: 0 on success, -errno on failure.
+ */
+
+struct vfio_device_gfx_plane_info {
+	__u64 start;
+	__u64 drm_format_mod;
+	__u32 drm_format;
+	__u32 width;
+	__u32 height;
+	__u32 stride;
+	__u32 size;
+	__u32 x_pos;
+	__u32 y_pos;
+};
+
+struct vfio_device_query_gfx_plane {
+	__u32 argsz;
+	__u32 flags;
+	struct vfio_device_gfx_plane_info plane_info;
+	__u32 plane_type;
+	__s32 fd; /* dma-buf fd */
+	__u32 plane_id;
+};
+
+#define VFIO_DEVICE_QUERY_GFX_PLANE _IO(VFIO_TYPE, VFIO_BASE + 14)
+
+
 /* -------- API for Type1 VFIO IOMMU -------- */
 
 /**
-- 
2.7.4