How to put multiple DxgkDdiBuildPagingBuffer into same DMA buffer(paging buffer) and call DxgkDdiSubmit together

Question

I notice "the driver's DxgkDdiBuildPagingBuffer should update pDmaBuffer to point past the last byte that is written to the paging buffer" in detail of DXGKDDI_BUILDPAGINGBUFFER callback function (d3dkmddi.h). But if move pDmaBuffer to the last byte of buffer, DxgkDdiBuildPagingBuffer will be called and the next DxgkDdiBuildPagingBuffer will use a new DMA buffer. How can i put multiple DxgkDdiBuildPagingBuffer into same DMA buffer and call DxgkDdiSubmit together.