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

[Christoph Hellwig]

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.