1 #ifndef _LINUX_VIRTIO_BALLOON_H
2 #define _LINUX_VIRTIO_BALLOON_H
3 /* This header is BSD licensed so anyone can use the definitions to implement
4  * compatible drivers/servers. */
5 #include <linux/virtio_ids.h>
6 #include <linux/virtio_config.h>
7 
8 /* The feature bitmap for virtio balloon */
9 #define VIRTIO_BALLOON_F_MUST_TELL_HOST	0 /* Tell before reclaiming pages */
10 #define VIRTIO_BALLOON_F_STATS_VQ	1 /* Memory Stats virtqueue */
11 
12 /* Size of a PFN in the balloon interface. */
13 #define VIRTIO_BALLOON_PFN_SHIFT 12
14 
15 struct virtio_balloon_config
16 {
17 	/* Number of pages host wants Guest to give up. */
18 	__le32 num_pages;
19 	/* Number of pages we've actually got in balloon. */
20 	__le32 actual;
21 };
22 
23 #define VIRTIO_BALLOON_S_SWAP_IN  0   /* Amount of memory swapped in */
24 #define VIRTIO_BALLOON_S_SWAP_OUT 1   /* Amount of memory swapped out */
25 #define VIRTIO_BALLOON_S_MAJFLT   2   /* Number of major faults */
26 #define VIRTIO_BALLOON_S_MINFLT   3   /* Number of minor faults */
27 #define VIRTIO_BALLOON_S_MEMFREE  4   /* Total amount of free memory */
28 #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
29 #define VIRTIO_BALLOON_S_NR       6
30 
31 struct virtio_balloon_stat {
32 	u16 tag;
33 	u64 val;
34 } __attribute__((packed));
35 
36 #endif /* _LINUX_VIRTIO_BALLOON_H */
37