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1 | #ifndef _LINUX_VIRTIO_BALLOON_H |
2 | #define _LINUX_VIRTIO_BALLOON_H | |
674bfc23 | 3 | /* This header is BSD licensed so anyone can use the definitions to implement |
a1b38387 RR |
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. */ | |
df81b29c | 28 | #include <linux/types.h> |
e95646c3 | 29 | #include <linux/virtio_ids.h> |
6b35e407 RR |
30 | #include <linux/virtio_config.h> |
31 | ||
6b35e407 RR |
32 | /* The feature bitmap for virtio balloon */ |
33 | #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ | |
9564e138 | 34 | #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */ |
5a10b7db | 35 | #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */ |
6b35e407 | 36 | |
1b4aa2fa HB |
37 | /* Size of a PFN in the balloon interface. */ |
38 | #define VIRTIO_BALLOON_PFN_SHIFT 12 | |
39 | ||
25e65e4e | 40 | struct virtio_balloon_config { |
6b35e407 | 41 | /* Number of pages host wants Guest to give up. */ |
df81b29c | 42 | __u32 num_pages; |
6b35e407 | 43 | /* Number of pages we've actually got in balloon. */ |
df81b29c | 44 | __u32 actual; |
6b35e407 | 45 | }; |
9564e138 AL |
46 | |
47 | #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ | |
48 | #define VIRTIO_BALLOON_S_SWAP_OUT 1 /* Amount of memory swapped out */ | |
49 | #define VIRTIO_BALLOON_S_MAJFLT 2 /* Number of major faults */ | |
50 | #define VIRTIO_BALLOON_S_MINFLT 3 /* Number of minor faults */ | |
51 | #define VIRTIO_BALLOON_S_MEMFREE 4 /* Total amount of free memory */ | |
52 | #define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of memory */ | |
53 | #define VIRTIO_BALLOON_S_NR 6 | |
54 | ||
df81b29c MT |
55 | /* |
56 | * Memory statistics structure. | |
57 | * Driver fills an array of these structures and passes to device. | |
58 | * | |
59 | * NOTE: fields are laid out in a way that would make compiler add padding | |
60 | * between and after fields, so we have to use compiler-specific attributes to | |
61 | * pack it, to disable this padding. This also often causes compiler to | |
62 | * generate suboptimal code. | |
63 | * | |
64 | * We maintain this statistics structure format for backwards compatibility, | |
65 | * but don't follow this example. | |
66 | * | |
67 | * If implementing a similar structure, do something like the below instead: | |
68 | * struct virtio_balloon_stat { | |
69 | * __virtio16 tag; | |
70 | * __u8 reserved[6]; | |
71 | * __virtio64 val; | |
72 | * }; | |
73 | * | |
74 | * In other words, add explicit reserved fields to align field and | |
75 | * structure boundaries at field size, avoiding compiler padding | |
76 | * without the packed attribute. | |
77 | */ | |
9564e138 | 78 | struct virtio_balloon_stat { |
df81b29c MT |
79 | __virtio16 tag; |
80 | __virtio64 val; | |
9564e138 AL |
81 | } __attribute__((packed)); |
82 | ||
6b35e407 | 83 | #endif /* _LINUX_VIRTIO_BALLOON_H */ |