Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost fixes from Michael Tsirkin:

 - Fixes in the iommu and balloon devices.

 - Disable the meta-data optimization for now - I hope we can get it
   fixed shortly, but there's no point in making users suffer crashes
   while we are working on that.

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: disable metadata prefetch optimization
  iommu/virtio: Update to most recent specification
  balloon: fix up comments
  mm/balloon_compaction: avoid duplicate page removal