stable/for-linus-3.4-rc4-tag

 - In the low-level assembler code we would jump to check events
   even if none were present. This incorrect behavior had been there
   since 2.6.27 days!
 - When using the fast-path for ACK-ing interrupts we were using the
   Linux IRQ numbers instead of the Xen ones (and they can differ) and
   missing interrupts in process.
 - Fix bootup crashes when ACPI hotplug CPUs were present and they
   would expand past the set number of CPUs we were allocated.
 - Deal with broken BIOSes when uploading C-states to the hypervisor.
 - Disable the cpuid check for MWAIT_LEAF if the ACPI PAD driver is
   loaded. If the ACPI PAD driver is used it will crash, so lets not
   export the functionality so the ACPI PAD driver won't load.