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

David Laight
2022-03-07T22:11:29Z

From: Christoph Hellwig
> Sent: 07 March 2022 15:57
>
> 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.

Is there any space in vma->vm_flags ?

That would be better than an extra argument or function.

David

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