fate#314663 hyper-v memory ballooning support
    - mm: Export a function to get vm committed memory.
    - Drivers: hv: Add Hyper-V balloon driver.
    - Drivers: hv: balloon: Fix a bug in the definition of struct
      dm_info_msg.
    - Update config files.
    fate#314665 hyper-v: Update the Vmbus protocol
    - Drivers: hv: Implement routines for read side signaling
      optimization.
    - Drivers: hv: Add state to manage batched reading.
    - Drivers: hv: Turn off batched reading for util drivers.
    - Drivers: hv: Optimize signaling in the read path.
    - Drivers: hv: Optimize the signaling on the write path.
    - Drivers: hv: Get rid of hv_get_ringbuffer_interrupt_mask().
    - Drivers: hv: Support handling multiple VMBUS versions.
    - Drivers: hv: Update the ring buffer structure to match win8
      functionality.
    - Drivers: hv: Extend/modify vmbus_channel_offer_channel for
      win7 and beyond.
    - Drivers: hv: Save and export negotiated vmbus version.
    - Drivers: hv: Change the signature for hv_signal_event().
    - Drivers: hv: Change the signature of vmbus_set_event().
    - Drivers: hv: Move vmbus version definitions to hyperv.h.
    - Drivers: hv: Manage signaling state on a per-connection basis.
    - Drivers: hv: Cleanup vmbus_set_event() to support win7 and
      beyond.
    - Drivers: hv: Setup a mapping for Hyper-V's notion cpu ID.
    - Drivers: hv: Add state to manage incoming channel interrupt
      load.
    - Drivers: hv: Modify the interrupt handling code to support
      win8 and beyond.
    - Drivers: hv: Add code to distribute channel interrupt load.
    - Drivers: hv: Get rid of the unused global signaling state.
    - Drivers: hv: Get rid of unnecessary request for offers.
    - Drivers: hv: Manage event tasklets on per-cpu basis.
    - Drivers: hv: Handle vmbus interrupts concurrently on all cpus.
    - Drivers: hv: Add a check to deal with spurious interrupts.
    - Drivers: hv: Enable protocol negotiation with win8 hosts.
    - Drivers: hv: Implement flow management on the send side.
    - Drivers: hv: Capture the host build information.
    - Drivers: hv: Cleanup and consolidate reporting of build/version
      info.