VT-d suspend/resume bug

[Nickolai Zeldovich]

Enabling VT-d support, as of the latest git kernel, breaks
suspend-to-RAM on my laptop, I'm guessing because the IOMMU isn't
being re-initialized on resume; see comments #3, 4 of
http://bugzilla.kernel.org/show_bug.cgi?id=11963.

I have a workaround for now (disable VT-d in BIOS) but it would be
great if this worked, or at least warned me and refused to suspend.

Nickolai.