include/standard-headers/linux/virtio_balloon.h

   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  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of IBM nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE. */
  28 #include "standard-headers/linux/types.h"
  29 #include "standard-headers/linux/virtio_types.h"
  30 #include "standard-headers/linux/virtio_ids.h"
  31 #include "standard-headers/linux/virtio_config.h"
  32
  33 /* The feature bitmap for virtio balloon */
  34 #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
  35 #define VIRTIO_BALLOON_F_STATS_VQ       1 /* Memory Stats virtqueue */
  36 #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
  37
  38 /* Size of a PFN in the balloon interface. */
  39 #define VIRTIO_BALLOON_PFN_SHIFT 12
  40
  41 struct virtio_balloon_config {
  42         /* Number of pages host wants Guest to give up. */
  43         uint32_t num_pages;
  44         /* Number of pages we've actually got in balloon. */
  45         uint32_t actual;
  46 };
  47
  48 #define VIRTIO_BALLOON_S_SWAP_IN  0   /* Amount of memory swapped in */
  49 #define VIRTIO_BALLOON_S_SWAP_OUT 1   /* Amount of memory swapped out */
  50 #define VIRTIO_BALLOON_S_MAJFLT   2   /* Number of major faults */
  51 #define VIRTIO_BALLOON_S_MINFLT   3   /* Number of minor faults */
  52 #define VIRTIO_BALLOON_S_MEMFREE  4   /* Total amount of free memory */
  53 #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
  54 #define VIRTIO_BALLOON_S_AVAIL    6   /* Available memory as in /proc */
  55 #define VIRTIO_BALLOON_S_CACHES   7   /* Disk caches */
  56 #define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Hugetlb page allocations */
  57 #define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Hugetlb page allocation failures */
  58 #define VIRTIO_BALLOON_S_NR       10
  59
  60 #define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \
  61         VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \
  62         VIRTIO_BALLOON_S_NAMES_prefix "swap-out", \
  63         VIRTIO_BALLOON_S_NAMES_prefix "major-faults", \
  64         VIRTIO_BALLOON_S_NAMES_prefix "minor-faults", \
  65         VIRTIO_BALLOON_S_NAMES_prefix "free-memory", \
  66         VIRTIO_BALLOON_S_NAMES_prefix "total-memory", \
  67         VIRTIO_BALLOON_S_NAMES_prefix "available-memory", \
  68         VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \
  69         VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \
  70         VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures" \
  71 }
  72
  73 #define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("")
  74
  75 /*
  76  * Memory statistics structure.
  77  * Driver fills an array of these structures and passes to device.
  78  *
  79  * NOTE: fields are laid out in a way that would make compiler add padding
  80  * between and after fields, so we have to use compiler-specific attributes to
  81  * pack it, to disable this padding. This also often causes compiler to
  82  * generate suboptimal code.
  83  *
  84  * We maintain this statistics structure format for backwards compatibility,
  85  * but don't follow this example.
  86  *
  87  * If implementing a similar structure, do something like the below instead:
  88  *     struct virtio_balloon_stat {
  89  *         __virtio16 tag;
  90  *         uint8_t reserved[6];
  91  *         __virtio64 val;
  92  *     };
  93  *
  94  * In other words, add explicit reserved fields to align field and
  95  * structure boundaries at field size, avoiding compiler padding
  96  * without the packed attribute.
  97  */
  98 struct virtio_balloon_stat {
  99         __virtio16 tag;
 100         __virtio64 val;
 101 } QEMU_PACKED;
 102
 103 #endif /* _LINUX_VIRTIO_BALLOON_H */