[PATCH v4 5/5] drm/virtio: advertise base userptr feature to userspace

From: Honglei Huang

Date: Thu Jan 15 2026 - 02:59:36 EST


From: Honglei Huang <Honglei1.Huang@xxxxxxx>

Integrate userptr functionality into the blob resource creation path:

- Add userptr flags to VIRTGPU_BLOB_FLAG_USE_MASK for validation
- Route userptr requests to virtio_gpu_userptr_create()
- Pass userptr address from ioctl to params structure

With this change, userspace can create userptr blob resources by setting
VIRTGPU_BLOB_FLAG_USE_USERPTR flag and providing a valid userptr address.

Signed-off-by: Honglei Huang <Honglei1.Huang@xxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index c33c05736..e49f5c89b 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -36,7 +36,9 @@

#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_USERPTR | \
+ VIRTGPU_BLOB_FLAG_USERPTR_RDONLY)

/* Must be called with &virtio_gpu_fpriv.struct_mutex held. */
static void virtio_gpu_create_context_locked(struct virtio_gpu_device *vgdev,
@@ -489,6 +491,7 @@ static int verify_blob(struct virtio_gpu_device *vgdev,
params->size = rc_blob->size;
params->blob = true;
params->blob_flags = rc_blob->blob_flags;
+ params->userptr = rc_blob->userptr;
return 0;
}

@@ -527,8 +530,10 @@ 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_object_create(vgdev, &params, &bo, NULL);
+ else if (guest_blob && params.userptr)
+ ret = virtio_gpu_userptr_create(vgdev, file, &params, &bo);
else if (!guest_blob && host3d_blob)
ret = virtio_gpu_vram_create(vgdev, &params, &bo);
else
--
2.34.1