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 #define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */
  38 #define VIRTIO_BALLOON_F_PAGE_POISON    4 /* Guest is using page poisoning */
  39 #define VIRTIO_BALLOON_F_REPORTING      5 /* Page reporting virtqueue */
  40
  41 /* Size of a PFN in the balloon interface. */
  42 #define VIRTIO_BALLOON_PFN_SHIFT 12
  43
  44 #define VIRTIO_BALLOON_CMD_ID_STOP      0
  45 #define VIRTIO_BALLOON_CMD_ID_DONE      1
  46 struct virtio_balloon_config {
  47         /* Number of pages host wants Guest to give up. */
  48         uint32_t num_pages;
  49         /* Number of pages we've actually got in balloon. */
  50         uint32_t actual;
  51         /*
  52          * Free page hint command id, readonly by guest.
  53          * Was previously named free_page_report_cmd_id so we
  54          * need to carry that name for legacy support.
  55          */
  56         union {
  57                 uint32_t free_page_hint_cmd_id;
  58                 uint32_t free_page_report_cmd_id;       /* deprecated */
  59         };
  60         /* Stores PAGE_POISON if page poisoning is in use */
  61         uint32_t poison_val;
  62 };
  63
  64 #define VIRTIO_BALLOON_S_SWAP_IN  0   /* Amount of memory swapped in */
  65 #define VIRTIO_BALLOON_S_SWAP_OUT 1   /* Amount of memory swapped out */
  66 #define VIRTIO_BALLOON_S_MAJFLT   2   /* Number of major faults */
  67 #define VIRTIO_BALLOON_S_MINFLT   3   /* Number of minor faults */
  68 #define VIRTIO_BALLOON_S_MEMFREE  4   /* Total amount of free memory */
  69 #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
  70 #define VIRTIO_BALLOON_S_AVAIL    6   /* Available memory as in /proc */
  71 #define VIRTIO_BALLOON_S_CACHES   7   /* Disk caches */
  72 #define VIRTIO_BALLOON_S_HTLB_PGALLOC  8  /* Hugetlb page allocations */
  73 #define VIRTIO_BALLOON_S_HTLB_PGFAIL   9  /* Hugetlb page allocation failures */
  74 #define VIRTIO_BALLOON_S_NR       10
  75
  76 #define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \
  77         VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \
  78         VIRTIO_BALLOON_S_NAMES_prefix "swap-out", \
  79         VIRTIO_BALLOON_S_NAMES_prefix "major-faults", \
  80         VIRTIO_BALLOON_S_NAMES_prefix "minor-faults", \
  81         VIRTIO_BALLOON_S_NAMES_prefix "free-memory", \
  82         VIRTIO_BALLOON_S_NAMES_prefix "total-memory", \
  83         VIRTIO_BALLOON_S_NAMES_prefix "available-memory", \
  84         VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \
  85         VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \
  86         VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures" \
  87 }
  88
  89 #define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("")
  90
  91 /*
  92  * Memory statistics structure.
  93  * Driver fills an array of these structures and passes to device.
  94  *
  95  * NOTE: fields are laid out in a way that would make compiler add padding
  96  * between and after fields, so we have to use compiler-specific attributes to
  97  * pack it, to disable this padding. This also often causes compiler to
  98  * generate suboptimal code.
  99  *
 100  * We maintain this statistics structure format for backwards compatibility,
 101  * but don't follow this example.
 102  *
 103  * If implementing a similar structure, do something like the below instead:
 104  *     struct virtio_balloon_stat {
 105  *         __virtio16 tag;
 106  *         uint8_t reserved[6];
 107  *         __virtio64 val;
 108  *     };
 109  *
 110  * In other words, add explicit reserved fields to align field and
 111  * structure boundaries at field size, avoiding compiler padding
 112  * without the packed attribute.
 113  */
 114 struct virtio_balloon_stat {
 115         __virtio16 tag;
 116         __virtio64 val;
 117 } QEMU_PACKED;
 118
 119 #endif /* _LINUX_VIRTIO_BALLOON_H */