Pull VFIO updates from Alex Williamson:
- Nested IOMMU extension to type1 (Will Deacon)
- Restore MSIx message before enabling (Gavin Shan)
- Fix remove path locking (Alex Williamson)
* tag 'vfio-v3.18-rc1' of git://github.com/awilliam/linux-vfio:
vfio-pci: Fix remove path locking
drivers/vfio: Export vfio_spapr_iommu_eeh_ioctl() with GPL
vfio/pci: Restore MSIx message prior to enabling
PCI: Export MSI message relevant functions
vfio/iommu_type1: add new VFIO_TYPE1_NESTING_IOMMU IOMMU type
iommu: introduce domain attribute for nesting IOMMUs