1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * This header is BSD licensed so anyone can use the definitions to implement
5  * compatible drivers/servers.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of IBM nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD: head/sys/dev/virtio/balloon/virtio_balloon.h 326022 2017-11-20 19:36:21Z pfg $
31  */
32 /*
33  * Copyright (c) 2018 The DragonFly Project.  All rights reserved.
34  *
35  * This code is derived from software contributed to The DragonFly Project
36  * by Diederik de Groot <info@talon.nl>
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  *
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in
46  *    the documentation and/or other materials provided with the
47  *    distribution.
48  * 3. Neither the name of The DragonFly Project nor the names of its
49  *    contributors may be used to endorse or promote products derived
50  *    from this software without specific, prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
53  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
54  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
55  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
56  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
57  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
58  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
59  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
60  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
61  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
62  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  */
65 
66 /* Driver for VirtIO memory balloon devices. */
67 
68 #ifndef _VIRTIO_BALLOON_H
69 #define _VIRTIO_BALLOON_H
70 
71 /* Feature bits. */
72 #define VIRTIO_BALLOON_F_MUST_TELL_HOST	0x1 /* Tell before reclaiming pages */
73 #define VIRTIO_BALLOON_F_STATS_VQ	0x2 /* Memory stats virtqueue */
74 #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 0x3 /* Deflate on Out Of Memory */
75 
76 /* Size of a PFN in the balloon interface. */
77 #define VIRTIO_BALLOON_PFN_SHIFT 12
78 
79 struct virtio_balloon_config {
80 	/* Number of pages host wants Guest to give up. */
81 	uint32_t num_pages;
82 
83 	/* Number of pages we've actually got in balloon. */
84 	uint32_t actual;
85 };
86 
87 #define VTBALLOON_S_SWAP_IN	 0	/* The amount of memory that has been swapped in (in bytes) */
88 #define VTBALLOON_S_SWAP_OUT	 1	/* The amount of memory that has been swapped out to disk (in bytes). */
89 #define VTBALLOON_S_MAJFLT	 2	/* The number of major page faults that have occurred. */
90 #define VTBALLOON_S_MINFLT	 3	/* The number of minor page faults that have occurred. */
91 #define VTBALLOON_S_MEMFREE	 4	/* The amount of memory not being used for any purpose (in bytes). */
92 #define VTBALLOON_S_MEMTOT	 5	/* The total amount of memory available (in bytes). */
93 #define VTBALLOON_S_AVAIL	 6	/* The amount of availabe memory (in bytes) as in linux-proc */
94 #define VTBALLOON_S_CACHES	 7	/* Disk-File caches */
95 #define VTBALLOON_S_HTLB_PGALLOC 8	/* Hugetlb page allocations */
96 #define VTBALLOON_S_HTLB_PGFAIL	 9	/* Hugetlb page allocation failures */
97 #define VTBALLOON_S_NR		10
98 
99 #define VTBALLOON_S_NAMES_WITH_PREFIX(VTBALLOON_S_NAMES_prefix) { \
100 	VTBALLOON_S_NAMES_prefix "swap-in", \
101 	VTBALLOON_S_NAMES_prefix "swap-out", \
102 	VTBALLOON_S_NAMES_prefix "major-faults", \
103 	VTBALLOON_S_NAMES_prefix "minor-faults", \
104 	VTBALLOON_S_NAMES_prefix "free-memory", \
105 	VTBALLOON_S_NAMES_prefix "total-memory", \
106 	VTBALLOON_S_NAMES_prefix "available-memory", \
107 	VTBALLOON_S_NAMES_prefix "disk-file-caches", \
108 	VTBALLOON_S_NAMES_prefix "hugetlb-allocations", \
109 	VTBALLOON_S_NAMES_prefix "hugetlb-failures" \
110 }
111 #define VTBALLOON_S_NAMES VTBALLOON_S_NAMES_WITH_PREFIX("")
112 
113 /*
114  * Memory statistics structure.
115  * Driver fills an array of these structures and passes to device.
116  *
117  * NOTE: fields are laid out in a way that would make compiler add padding
118  * between and after fields, but the virtio specification does not allow
119  * for this. So the struct has to be packed.
120  */
121 struct vtballoon_stat {
122 	uint16_t tag;
123 	uint64_t val;
124 } __packed;
125 
126 #endif /* _VIRTIO_BALLOON_H */
127