Re: [Qemu-devel] [PATCH 05/13] iommu: Make sglists and dma_bdrv helpers use new universal DMA helpers

[Benjamin Herrenschmidt]

On Wed, 2012-06-20 at 16:21 -0500, Anthony Liguori wrote:

> Again, you return an error but ignore it now.
> 
> In the very least, on error you should scrub the passed in buffer to avoid 
> leaking data to the guest.
> 
> You can imagine a malicious guest programming the IOMMU with invalid mappings 
> and then doing DMA operations in order to read memory from the host QEMU 
> process.

Cleaning the buffer is easy, I'll add that. Returning an error sounds
non-trivial with the current interface.

Cheers,
Ben.