Pull Xen features and fixes from David Vrabel:
 "Support PCI devices with multiple MSIs, performance improvement for
  kernel-based backends (by not populated m2p overrides when mapping),
  and assorted minor bug fixes and cleanups"

* tag 'stable/for-linus-3.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/acpi-processor: fix enabling interrupts on syscore_resume
  xen/grant-table: Refactor gnttab_[un]map_refs to avoid m2p_override
  xen: remove XEN_PRIVILEGED_GUEST
  xen: add support for MSI message groups
  xen-pciback: Use pci_enable_msix_exact() instead of pci_enable_msix()
  xen/xenbus: remove unused xenbus_bind_evtchn()
  xen/events: remove unnecessary call to bind_evtchn_to_cpu()
  xen/events: remove the unused resend_irq_on_evtchn()
  drivers:xen-selfballoon:reset 'frontswap_inertia_counter' after frontswap_shrink
  drivers: xen: Include appropriate header file in pcpu.c
  drivers: xen: Mark function as static in platform-pci.c