xref: /freebsd/sys/amd64/include/vmm_snapshot.h (revision a50d73d5782a351ad83e8d1f84d11720a12e70d3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2016 Flavius Anton
5  * Copyright (c) 2016 Mihai Tiganus
6  * Copyright (c) 2016-2019 Mihai Carabas
7  * Copyright (c) 2017-2019 Darius Mihai
8  * Copyright (c) 2017-2019 Elena Mihailescu
9  * Copyright (c) 2018-2019 Sergiu Weisz
10  * All rights reserved.
11  * The bhyve-snapshot feature was developed under sponsorships
12  * from Matthew Grooms.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD$
36  */
37 
38 #ifndef _VMM_SNAPSHOT_
39 #define _VMM_SNAPSHOT_
40 
41 #include <sys/errno.h>
42 #include <sys/types.h>
43 #ifndef _KERNEL
44 #include <stdbool.h>
45 #endif
46 
47 enum snapshot_req {
48 	STRUCT_VIOAPIC = 1,
49 	STRUCT_VM,
50 	STRUCT_VLAPIC,
51 	VM_MEM,
52 	STRUCT_VHPET,
53 	STRUCT_VMCX,
54 	STRUCT_VATPIC,
55 	STRUCT_VATPIT,
56 	STRUCT_VPMTMR,
57 	STRUCT_VRTC,
58 };
59 
60 struct vm_snapshot_buffer {
61 	/*
62 	 * R/O for device-specific functions;
63 	 * written by generic snapshot functions.
64 	 */
65 	uint8_t *const buf_start;
66 	const size_t buf_size;
67 
68 	/*
69 	 * R/W for device-specific functions used to keep track of buffer
70 	 * current position and remaining size.
71 	 */
72 	uint8_t *buf;
73 	size_t buf_rem;
74 
75 	/*
76 	 * Length of the snapshot is either determined as (buf_size - buf_rem)
77 	 * or (buf - buf_start) -- the second variation returns a signed value
78 	 * so it may not be appropriate.
79 	 *
80 	 * Use vm_get_snapshot_size(meta).
81 	 */
82 };
83 
84 enum vm_snapshot_op {
85 	VM_SNAPSHOT_SAVE,
86 	VM_SNAPSHOT_RESTORE,
87 };
88 
89 struct vm_snapshot_meta {
90 	void *dev_data;
91 	const char *dev_name;      /* identify userspace devices */
92 	enum snapshot_req dev_req; /* identify kernel structs */
93 
94 	struct vm_snapshot_buffer buffer;
95 
96 	enum vm_snapshot_op op;
97 };
98 
99 void vm_snapshot_buf_err(const char *bufname, const enum vm_snapshot_op op);
100 int vm_snapshot_buf(void *data, size_t data_size,
101     struct vm_snapshot_meta *meta);
102 size_t vm_get_snapshot_size(struct vm_snapshot_meta *meta);
103 int vm_snapshot_buf_cmp(void *data, size_t data_size,
104     struct vm_snapshot_meta *meta);
105 
106 #define	SNAPSHOT_BUF_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
107 do {										\
108 	(RES) = vm_snapshot_buf((DATA), (LEN), (META));				\
109 	if ((RES) != 0) {							\
110 		vm_snapshot_buf_err(#DATA, (META)->op);				\
111 		goto LABEL;							\
112 	}									\
113 } while (0)
114 
115 #define	SNAPSHOT_VAR_OR_LEAVE(DATA, META, RES, LABEL)				\
116 	SNAPSHOT_BUF_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
117 
118 /* compare the value in the meta buffer with the data */
119 #define	SNAPSHOT_BUF_CMP_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
120 do {										\
121 	(RES) = vm_snapshot_buf_cmp((DATA), (LEN), (META));			\
122 	if ((RES) != 0) {							\
123 		vm_snapshot_buf_err(#DATA, (META)->op);				\
124 		goto LABEL;							\
125 	}									\
126 } while (0)
127 
128 #define	SNAPSHOT_VAR_CMP_OR_LEAVE(DATA, META, RES, LABEL)			\
129 	SNAPSHOT_BUF_CMP_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
130 
131 #endif
132