[RFC RESEND 00/16] Split IOMMU DMA mapping operation to two steps

[Christoph Hellwig]

On Wed, Mar 13, 2024 at 09:46:36AM +0200, Leon Romanovsky wrote:
> On Tue, Mar 12, 2024 at 10:28:44PM +0100, Christoph Hellwig wrote:
> > On Sun, Mar 10, 2024 at 11:35:13AM +0200, Leon Romanovsky wrote:
> > > And you will need to have a way to instruct that pin_user_pages() variant
> > > to continue anyway, because you asked for FOLL_PCI_P2PDMA. Without that
> > > force, you will have !FOLL_PCI_P2PDMA behaviour.
> > 
> > I don't understand what you mean.
> 
> Jason talked about the need to call to pin_user_pages(..., gup_flags | FOLL_PCI_P2PDMA, ...),
> but in your proposal this call won't be possible anymore.

Why?