xref: /freebsd/sys/dev/virtio/balloon/virtio_balloon.h (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
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  * $FreeBSD$
31  */
32 
33 #ifndef _VIRTIO_BALLOON_H
34 #define _VIRTIO_BALLOON_H
35 
36 /* Feature bits. */
37 #define VIRTIO_BALLOON_F_MUST_TELL_HOST	0x1 /* Tell before reclaiming pages */
38 #define VIRTIO_BALLOON_F_STATS_VQ	0x2 /* Memory stats virtqueue */
39 
40 /* Size of a PFN in the balloon interface. */
41 #define VIRTIO_BALLOON_PFN_SHIFT 12
42 
43 struct virtio_balloon_config {
44 	/* Number of pages host wants Guest to give up. */
45 	uint32_t num_pages;
46 
47 	/* Number of pages we've actually got in balloon. */
48 	uint32_t actual;
49 };
50 
51 #define VIRTIO_BALLOON_S_SWAP_IN  0   /* Amount of memory swapped in */
52 #define VIRTIO_BALLOON_S_SWAP_OUT 1   /* Amount of memory swapped out */
53 #define VIRTIO_BALLOON_S_MAJFLT   2   /* Number of major faults */
54 #define VIRTIO_BALLOON_S_MINFLT   3   /* Number of minor faults */
55 #define VIRTIO_BALLOON_S_MEMFREE  4   /* Total amount of free memory */
56 #define VIRTIO_BALLOON_S_MEMTOT   5   /* Total amount of memory */
57 #define VIRTIO_BALLOON_S_NR       6
58 
59 struct virtio_balloon_stat {
60 	uint16_t tag;
61 	uint64_t val;
62 } __packed;
63 
64 #endif /* _VIRTIO_BALLOON_H */
65