Re: [PATCH RFC 0/3] MAP_POPULATE for device memory

From: Christoph Hellwig
Date: Mon Mar 07 2022 - 10:57:17 EST


On Mon, Mar 07, 2022 at 03:29:35PM +0200, Jarkko Sakkinen wrote:
> So what would you suggest to sort out the issue? I'm happy to go with
> ioctl if nothing else is acceptable.

PLenty of drivers treat all mmaps as if MAP_POPULATE was specified,
typically by using (io_)remap_pfn_range. If there any reason to only
optionally have the pre-fault semantics for sgx? If not this should
be really simple. And if we have a real need for it to be optional
we'll just need to find a sane way to pass that information to ->mmap.