Re: [RFC PATCH v9 3/4] drm/virtio: implement userptr resource support

[Huang, Honglei]

On 10/10/2026 2:32 AM, Dmitry Osipenko wrote:
> 24.09.2026 12:55, Honglei Huang пишет:
> > +static struct dma_buf *
> > +virtio_gpu_userptr_prime_export(struct drm_gem_object *obj, int flags)
> > +{
> > +	return ERR_PTR(-EINVAL);
> > +}
> > +
> > +static const struct drm_gem_object_funcs virtio_gpu_userptr_funcs = {
> > +	.open = virtio_gpu_gem_object_open,
> > +	.close = virtio_gpu_gem_object_close,
> > +	.free = virtio_gpu_userptr_free,
> > +	.export = virtio_gpu_userptr_prime_export,
> > +};
>
> Is virtio_gpu_userptr_prime_export() optional?
Yes it is optional, but if not set this callback then .export will 
fallback to  drm_gem_prime_export, userptr can not support the export
feature, to prevent silent failure, an explicit registration method is 
used here to ensure it is not supported.

Regards,
Honglei