#ifndef _LINUX_VIRTIO_BALLOON_H
  #define _LINUX_VIRTIO_BALLOON_H

  /* This header is BSD licensed so anyone can use the definitions to implement
   * compatible drivers/servers. */

  #include <linux/virtio_ids.h>

  #include <linux/virtio_config.h>

  /* The feature bitmap for virtio balloon */
  #define VIRTIO_BALLOON_F_MUST_TELL_HOST	0 /* Tell before reclaiming pages */

  #define VIRTIO_BALLOON_F_STATS_VQ	1 /* Memory Stats virtqueue */

  /* Size of a PFN in the balloon interface. */
  #define VIRTIO_BALLOON_PFN_SHIFT 12

  struct virtio_balloon_config
  {
  	/* Number of pages host wants Guest to give up. */
  	__le32 num_pages;
  	/* Number of pages we've actually got in balloon. */
  	__le32 actual;
  };

  
  #define VIRTIO_BALLOON_S_SWAP_IN  0   /* Amount of memory swapped in */
  #define VIRTIO_BALLOON_S_SWAP_OUT 1   /* Amount of memory swapped out */
  #define VIRTIO_BALLOON_S_MAJFLT   2   /* Number of major faults */
  #define VIRTIO_BALLOON_S_MINFLT   3   /* Number of minor faults */
  #define VIRTIO_BALLOON_S_MEMFREE  4   /* Total amount of free memory */
  #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
  #define VIRTIO_BALLOON_S_NR       6
  
  struct virtio_balloon_stat {
  	u16 tag;
  	u64 val;
  } __attribute__((packed));

  #endif /* _LINUX_VIRTIO_BALLOON_H */