[RFC PATCH 13/60] hyper_dmabuf: postponing cleanup of hyper_DMABUF

From: Mateusz Polrola Immediate clean up of buffer is not possible if the buffer is actively used by importer. In this case, we need to postpone freeing hyper_DMABUF until the last consumer unmaps and releases the buffer on impoter VM. New reference count is added for

[RFC PATCH 13/60] hyper_dmabuf: postponing cleanup of hyper_DMABUF

From: Mateusz Polrola Immediate clean up of buffer is not possible if the buffer is actively used by importer. In this case, we need to postpone freeing hyper_DMABUF until the last consumer unmaps and releases the buffer on impoter VM. New reference count is added for tracking usage by