| Current File : //usr/include/linux/virtio_balloon.h |
#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.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of IBM nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. */
#include <linux/types.h>
#include <linux/virtio_types.h>
#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 */
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
/* 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. */
__u32 num_pages;
/* Number of pages we've actually got in balloon. */
__u32 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_AVAIL 6 /* Available memory as in /proc */
#define VIRTIO_BALLOON_S_NR 7
/*
* Memory statistics structure.
* Driver fills an array of these structures and passes to device.
*
* NOTE: fields are laid out in a way that would make compiler add padding
* between and after fields, so we have to use compiler-specific attributes to
* pack it, to disable this padding. This also often causes compiler to
* generate suboptimal code.
*
* We maintain this statistics structure format for backwards compatibility,
* but don't follow this example.
*
* If implementing a similar structure, do something like the below instead:
* struct virtio_balloon_stat {
* __virtio16 tag;
* __u8 reserved[6];
* __virtio64 val;
* };
*
* In other words, add explicit reserved fields to align field and
* structure boundaries at field size, avoiding compiler padding
* without the packed attribute.
*/
struct virtio_balloon_stat {
__virtio16 tag;
__virtio64 val;
} __attribute__((packed));
#endif /* _LINUX_VIRTIO_BALLOON_H */