virtio_balloon.h (6070B) - Raw
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 <linux/types.h> 29 #include <linux/virtio_types.h> 30 #include <linux/virtio_ids.h> 31 #include <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 __le32 num_pages; 49 /* Number of pages we've actually got in balloon. */ 50 __le32 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 __le32 free_page_hint_cmd_id; 58 __le32 free_page_report_cmd_id; /* deprecated */ 59 }; 60 /* Stores PAGE_POISON if page poisoning is in use */ 61 __le32 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_OOM_KILL 10 /* OOM killer invocations */ 75 #define VIRTIO_BALLOON_S_ALLOC_STALL 11 /* Stall count of memory allocatoin */ 76 #define VIRTIO_BALLOON_S_ASYNC_SCAN 12 /* Amount of memory scanned asynchronously */ 77 #define VIRTIO_BALLOON_S_DIRECT_SCAN 13 /* Amount of memory scanned directly */ 78 #define VIRTIO_BALLOON_S_ASYNC_RECLAIM 14 /* Amount of memory reclaimed asynchronously */ 79 #define VIRTIO_BALLOON_S_DIRECT_RECLAIM 15 /* Amount of memory reclaimed directly */ 80 #define VIRTIO_BALLOON_S_NR 16 81 82 #define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \ 83 VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \ 84 VIRTIO_BALLOON_S_NAMES_prefix "swap-out", \ 85 VIRTIO_BALLOON_S_NAMES_prefix "major-faults", \ 86 VIRTIO_BALLOON_S_NAMES_prefix "minor-faults", \ 87 VIRTIO_BALLOON_S_NAMES_prefix "free-memory", \ 88 VIRTIO_BALLOON_S_NAMES_prefix "total-memory", \ 89 VIRTIO_BALLOON_S_NAMES_prefix "available-memory", \ 90 VIRTIO_BALLOON_S_NAMES_prefix "disk-caches", \ 91 VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \ 92 VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures", \ 93 VIRTIO_BALLOON_S_NAMES_prefix "oom-kills", \ 94 VIRTIO_BALLOON_S_NAMES_prefix "alloc-stalls", \ 95 VIRTIO_BALLOON_S_NAMES_prefix "async-scans", \ 96 VIRTIO_BALLOON_S_NAMES_prefix "direct-scans", \ 97 VIRTIO_BALLOON_S_NAMES_prefix "async-reclaims", \ 98 VIRTIO_BALLOON_S_NAMES_prefix "direct-reclaims" \ 99 } 100 101 #define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("") 102 103 /* 104 * Memory statistics structure. 105 * Driver fills an array of these structures and passes to device. 106 * 107 * NOTE: fields are laid out in a way that would make compiler add padding 108 * between and after fields, so we have to use compiler-specific attributes to 109 * pack it, to disable this padding. This also often causes compiler to 110 * generate suboptimal code. 111 * 112 * We maintain this statistics structure format for backwards compatibility, 113 * but don't follow this example. 114 * 115 * If implementing a similar structure, do something like the below instead: 116 * struct virtio_balloon_stat { 117 * __virtio16 tag; 118 * __u8 reserved[6]; 119 * __virtio64 val; 120 * }; 121 * 122 * In other words, add explicit reserved fields to align field and 123 * structure boundaries at field size, avoiding compiler padding 124 * without the packed attribute. 125 */ 126 struct virtio_balloon_stat { 127 __virtio16 tag; 128 __virtio64 val; 129 } __attribute__((packed)); 130 131 #endif /* _LINUX_VIRTIO_BALLOON_H */