Re: [PATCH RFC 3/8] memory-provider: dmabuf devmem memory provider

From: Jakub Kicinski
Date: Tue Nov 14 2023 - 17:25:45 EST


On Tue, 14 Nov 2023 16:23:29 +0800 Yunsheng Lin wrote:
> I would expect net stack, page pool, driver still see the 'struct page',
> only memory provider see the specific struct for itself, for the above,
> devmem memory provider sees the 'struct page_pool_iov'.

You can't lie to the driver that an _iov is a page either.
The driver must explicitly "opt-in" to using the _iov variant,
by calling the _iov set of APIs.

Only drivers which can support header-data split can reasonably
use the _iov API, for data pages.