Re: [RFC PATCH 1/2] x86: Don't let pgprot_modify() change the page encryption bit

From: Christoph Hellwig
Date: Thu Sep 05 2019 - 11:24:43 EST


On Thu, Sep 05, 2019 at 05:21:24PM +0200, Thomas Hellström (VMware) wrote:
> On 9/5/19 4:15 PM, Dave Hansen wrote:
> > Hi Thomas,
> >
> > Thanks for the second batch of patches! These look much improved on all
> > fronts.
>
> Yes, although the TTM functionality isn't in yet. Hopefully we won't have to
> bother you with those though, since this assumes TTM will be using the dma
> API.

Please take a look at dma_mmap_prepare and dma_mmap_fault in this
branch:

http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/dma-mmap-improvements

they should allow to fault dma api pages in the page fault handler. But
this is totally hot off the press and not actually tested for the last
few patches. Note that I've also included your two patches from this
series to handle SEV.