[RFC PATCH v9 4/4] drm/virtio: wire blob ioctl creation to userptr objects

[Honglei Huang <honghuan@amd.com>]

Integrate userptr into the blob resource creation ioctl.

- A non-zero userptr selects virtio_gpu_userptr_create()
- Reject userptr unless blob_mem is VIRTGPU_BLOB_MEM_GUEST
- Reject VIRTGPU_BLOB_FLAG_USE_READONLY unless the device
  advertised VIRTIO_GPU_F_BLOB_READONLY
- Advertise VIRTGPU_PARAM_USERPTR and VIRTGPU_PARAM_BLOB_READONLY
- Add VIRTIO_GPU_F_BLOB_READONLY to the driver's features[] array

virtio_has_feature() routes device-specific feature bits through
virtio_check_driver_offered_feature(), which calls BUG() when the
driver queries a bit it never declared in features[]. The
VIRTIO_GPU_F_BLOB_READONLY probe added to virtio_gpu_init() hit
exactly that: every probe crashed regardless of host support because
the bit was missing from features[]. Registering it there fixes the
crash.

Signed-off-by: Honglei Huang <honghuan@amd.com>
---
 drivers/gpu/drm/virtio/virtgpu_debugfs.c |  1 +
 drivers/gpu/drm/virtio/virtgpu_drv.c     |  1 +
 drivers/gpu/drm/virtio/virtgpu_ioctl.c   | 35 ++++++++++++++++++++----
 drivers/gpu/drm/virtio/virtgpu_kms.c     |  8 ++++--
 4 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_debugfs.c b/drivers/gpu/drm/virtio/virtgpu_debugfs.c
index 3a68a16b58..b8b9b40584 100644
--- a/drivers/gpu/drm/virtio/virtgpu_debugfs.c
+++ b/drivers/gpu/drm/virtio/virtgpu_debugfs.c
@@ -55,6 +55,7 @@ static int virtio_gpu_features(struct seq_file *m, void *data)
 			    vgdev->has_resource_assign_uuid);
 
 	virtio_gpu_add_bool(m, "blob resources", vgdev->has_resource_blob);
+	virtio_gpu_add_bool(m, "blob readonly", vgdev->has_blob_readonly);
 	virtio_gpu_add_bool(m, "context init", vgdev->has_context_init);
 	virtio_gpu_add_int(m, "cap sets", vgdev->num_capsets);
 	virtio_gpu_add_int(m, "scanouts", vgdev->num_scanouts);
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index 2aaa7cb080..f1edd20c37 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -182,6 +182,7 @@ static unsigned int features[] = {
 	VIRTIO_GPU_F_RESOURCE_BLOB,
 	VIRTIO_GPU_F_CONTEXT_INIT,
 	VIRTIO_GPU_F_BLOB_ALIGNMENT,
+	VIRTIO_GPU_F_BLOB_READONLY,
 };
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 3d8e4ccdb7..3dc058e50e 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -36,7 +36,10 @@
 
 #define VIRTGPU_BLOB_FLAG_USE_MASK (VIRTGPU_BLOB_FLAG_USE_MAPPABLE | \
 				    VIRTGPU_BLOB_FLAG_USE_SHAREABLE | \
-				    VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE)
+				    VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE | \
+				    VIRTGPU_BLOB_FLAG_USE_READONLY)
+
+#define VIRTGPU_BLOB_HINT_MASK DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING
 
 /* Must be called with &virtio_gpu_fpriv.struct_mutex held. */
 static void virtio_gpu_create_context_locked(struct virtio_gpu_device *vgdev,
@@ -122,6 +125,12 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data,
 			return -ENOENT;
 		value = vgdev->blob_alignment;
 		break;
+	case VIRTGPU_PARAM_USERPTR:
+		value = 1;
+		break;
+	case VIRTGPU_PARAM_BLOB_READONLY:
+		value = vgdev->has_blob_readonly ? 1 : 0;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -453,11 +462,23 @@ static int verify_blob(struct virtio_gpu_device *vgdev,
 	if (rc_blob->blob_flags & ~VIRTGPU_BLOB_FLAG_USE_MASK)
 		return -EINVAL;
 
+	if (rc_blob->blob_hints & ~VIRTGPU_BLOB_HINT_MASK)
+		return -EINVAL;
+
 	if (rc_blob->blob_flags & VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE) {
 		if (!vgdev->has_resource_assign_uuid)
 			return -EINVAL;
 	}
 
+	if (rc_blob->blob_flags & VIRTGPU_BLOB_FLAG_USE_READONLY) {
+		if (!vgdev->has_blob_readonly)
+			return -EINVAL;
+	}
+
+	if (rc_blob->userptr &&
+	    rc_blob->blob_mem != VIRTGPU_BLOB_MEM_GUEST)
+		return -EINVAL;
+
 	switch (rc_blob->blob_mem) {
 	case VIRTGPU_BLOB_MEM_GUEST:
 		*guest_blob = true;
@@ -495,6 +516,7 @@ static int verify_blob(struct virtio_gpu_device *vgdev,
 	params->blob = true;
 	params->blob_flags = rc_blob->blob_flags;
 	params->blob_hints = rc_blob->blob_hints;
+	params->userptr = rc_blob->userptr;
 
 	if (vgdev->has_blob_alignment &&
 	    !IS_ALIGNED(params->size, vgdev->blob_alignment))
@@ -518,9 +540,10 @@ static int virtio_gpu_resource_create_blob_ioctl(struct drm_device *dev,
 	struct virtio_gpu_fpriv *vfpriv = file->driver_priv;
 	struct drm_virtgpu_resource_create_blob *rc_blob = data;
 
-	if (verify_blob(vgdev, vfpriv, &params, rc_blob,
-			&guest_blob, &host3d_blob))
-		return -EINVAL;
+	ret = verify_blob(vgdev, vfpriv, &params, rc_blob,
+			  &guest_blob, &host3d_blob);
+	if (ret)
+		return ret;
 
 	if (vgdev->has_virgl_3d)
 		virtio_gpu_create_context(dev, file);
@@ -538,7 +561,9 @@ static int virtio_gpu_resource_create_blob_ioctl(struct drm_device *dev,
 				      vfpriv->ctx_id, NULL, NULL);
 	}
 
-	if (guest_blob)
+	if (guest_blob && params.userptr)
+		ret = virtio_gpu_userptr_create(vgdev, file, &params, &bo);
+	else if (guest_blob)
 		ret = virtio_gpu_object_create(vgdev, &params, &bo, NULL);
 	else if (!guest_blob && host3d_blob)
 		ret = virtio_gpu_vram_create(vgdev, &params, &bo);
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 1d4d3bf46a..06c2bded49 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -249,15 +249,19 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 		vgdev->blob_alignment = blob_alignment;
 	}
 
+	if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_BLOB_READONLY))
+		vgdev->has_blob_readonly = true;
+
 	DRM_INFO("features: %cvirgl %cedid %cresource_blob %chost_visible",
 		 vgdev->has_virgl_3d    ? '+' : '-',
 		 vgdev->has_edid        ? '+' : '-',
 		 vgdev->has_resource_blob ? '+' : '-',
 		 vgdev->has_host_visible ? '+' : '-');
 
-	DRM_INFO("features: %ccontext_init %cblob_alignment\n",
+	DRM_INFO("features: %ccontext_init %cblob_alignment %cblob_readonly\n",
 		 vgdev->has_context_init ? '+' : '-',
-		 vgdev->has_blob_alignment ? '+' : '-');
+		 vgdev->has_blob_alignment ? '+' : '-',
+		 vgdev->has_blob_readonly ? '+' : '-');
 
 	ret = virtio_gpu_find_vqs(vgdev);
 	if (ret) {
-- 
2.34.1