(XEN) 'S' pressed -> blowing all shadow tables
(XEN) 
(XEN) iommu 0: nr_pt_levels = 3.
(XEN)   Queued Invalidation: not supported.
(XEN)   Interrupt Remapping: not supported.
(XEN) 
(XEN) iommu 1: nr_pt_levels = 3.
(XEN)   Queued Invalidation: not supported.
(XEN)   Interrupt Remapping: not supported.
(XEN) 
(XEN) iommu 2: nr_pt_levels = 3.
(XEN)   Queued Invalidation: not supported.
(XEN)   Interrupt Remapping: not supported.
(XEN) 
(XEN) iommu 3: nr_pt_levels = 3.
(XEN)   Queued Invalidation: not supported.
(XEN)   Interrupt Remapping: not supported.
(XEN) ==== PCI devices ====