Comment 15 for bug 238118

I have put up two -xen kernels at http://people.ubuntu.com/~smb/bug238118/
While they won't fix the problem I'd really like to see what the driver tries to settle for dma size (the messages should prefix xxx).
Also I saw that the xen iommu implementation seems to support swiotlb=<nrpages> and dma_bits=<bits (default 32)> which might be options to play around with.