Re: [PATCH v1 4/9] iommu/vt-d: Add bounce buffer API for domain map/unmap

[Lu Baolu]

Hi,

On 3/14/19 12:10 AM, Christoph Hellwig wrote:
> On Wed, Mar 13, 2019 at 10:31:52AM +0800, Lu Baolu wrote:
> > Hi again,
> >
> > On 3/13/19 10:04 AM, Lu Baolu wrote:
> > > Hi,
> > >
> > > On 3/13/19 12:38 AM, Christoph Hellwig wrote:
> > > > On Tue, Mar 12, 2019 at 02:00:00PM +0800, Lu Baolu wrote:
> > > > > This adds the APIs for bounce buffer specified domain
> > > > > map() and unmap(). The start and end partial pages will
> > > > > be mapped with bounce buffered pages instead. This will
> > > > > enhance the security of DMA buffer by isolating the DMA
> > > > > attacks from malicious devices.
> > > >
> > > > Please reuse the swiotlb code instead of reinventing it.
> >
> > Just looked into the code again. At least we could reuse below
> > functions:
> >
> > swiotlb_tbl_map_single()
> > swiotlb_tbl_unmap_single()
> > swiotlb_tbl_sync_single()
> >
> > Anything else?
>
> Yes, that is probably about the level you want to reuse, given that the
> next higher layer already has hooks into the direct mapping code.

Okay. Thank you!

I will try to make this happen in v2.

Best regards,
Lu Baolu