[PATCH v8 2/4] drm/virtgpu api: add blob userptr resource

[Honglei Huang <honghuan@amd.com>]

Add DRM ioctl hints and a userptr address field so userspace can
request a blob backed by an existing process mapping.

UAPI changes:
- Add guest-only DRM_VIRTGPU_BLOB_FLAG_HINT_USERPTR and
  DRM_VIRTGPU_BLOB_FLAG_HINT_USERPTR_RDONLY to blob_hints
- Add a userptr field to drm_virtgpu_resource_create_blob

These hints select guest pin behavior in the ioctl. They are not
part of the virtio CREATE_BLOB wire ABI.

Signed-off-by: Honglei Huang <honghuan@amd.com>
---
 include/uapi/drm/virtgpu_drm.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h
index 95587e12ae..aa8abef8f9 100644
--- a/include/uapi/drm/virtgpu_drm.h
+++ b/include/uapi/drm/virtgpu_drm.h
@@ -203,8 +203,17 @@ struct drm_virtgpu_resource_create_blob {
 	__u64 blob_id;
 
 #define DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING        0x0001
+/* Guest-only: pin an existing process mapping as blob backing. */
+#define DRM_VIRTGPU_BLOB_FLAG_HINT_USERPTR              0x0002
+#define DRM_VIRTGPU_BLOB_FLAG_HINT_USERPTR_RDONLY       0x0004
 	__u32 blob_hints;
 	__u32 pad2;
+
+	/*
+	 * userptr: guest userspace memory address for
+	 * DRM_VIRTGPU_BLOB_FLAG_HINT_USERPTR. Must be 0 if that hint is not set.
+	 */
+	__u64 userptr;
 };
 
 #define VIRTGPU_CONTEXT_PARAM_CAPSET_ID       0x0001
-- 
2.34.1