xref: /freebsd/sys/amd64/include/vmm_snapshot.h (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
36 #ifndef _VMM_SNAPSHOT_
37 #define _VMM_SNAPSHOT_
38 
39 #include <sys/errno.h>
40 #include <sys/types.h>
41 #ifndef _KERNEL
42 #include <stdbool.h>
43 #endif
44 
45 enum snapshot_req {
46 	STRUCT_VIOAPIC = 1,
47 	STRUCT_VM,
48 	STRUCT_VLAPIC,
49 	VM_MEM,
50 	STRUCT_VHPET,
51 	STRUCT_VMCX,
52 	STRUCT_VATPIC,
53 	STRUCT_VATPIT,
54 	STRUCT_VPMTMR,
55 	STRUCT_VRTC,
56 };
57 
58 struct vm_snapshot_buffer {
59 	/*
60 	 * R/O for device-specific functions;
61 	 * written by generic snapshot functions.
62 	 */
63 	uint8_t *const buf_start;
64 	const size_t buf_size;
65 
66 	/*
67 	 * R/W for device-specific functions used to keep track of buffer
68 	 * current position and remaining size.
69 	 */
70 	uint8_t *buf;
71 	size_t buf_rem;
72 
73 	/*
74 	 * Length of the snapshot is either determined as (buf_size - buf_rem)
75 	 * or (buf - buf_start) -- the second variation returns a signed value
76 	 * so it may not be appropriate.
77 	 *
78 	 * Use vm_get_snapshot_size(meta).
79 	 */
80 };
81 
82 enum vm_snapshot_op {
83 	VM_SNAPSHOT_SAVE,
84 	VM_SNAPSHOT_RESTORE,
85 };
86 
87 struct vm_snapshot_meta {
88 	void *dev_data;
89 	const char *dev_name;      /* identify userspace devices */
90 	enum snapshot_req dev_req; /* identify kernel structs */
91 
92 	struct vm_snapshot_buffer buffer;
93 
94 	enum vm_snapshot_op op;
95 };
96 
97 void vm_snapshot_buf_err(const char *bufname, const enum vm_snapshot_op op);
98 int vm_snapshot_buf(void *data, size_t data_size,
99     struct vm_snapshot_meta *meta);
100 size_t vm_get_snapshot_size(struct vm_snapshot_meta *meta);
101 int vm_snapshot_buf_cmp(void *data, size_t data_size,
102     struct vm_snapshot_meta *meta);
103 
104 #define	SNAPSHOT_BUF_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
105 do {										\
106 	(RES) = vm_snapshot_buf((DATA), (LEN), (META));				\
107 	if ((RES) != 0) {							\
108 		vm_snapshot_buf_err(#DATA, (META)->op);				\
109 		goto LABEL;							\
110 	}									\
111 } while (0)
112 
113 #define	SNAPSHOT_VAR_OR_LEAVE(DATA, META, RES, LABEL)				\
114 	SNAPSHOT_BUF_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
115 
116 /* compare the value in the meta buffer with the data */
117 #define	SNAPSHOT_BUF_CMP_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
118 do {										\
119 	(RES) = vm_snapshot_buf_cmp((DATA), (LEN), (META));			\
120 	if ((RES) != 0) {							\
121 		vm_snapshot_buf_err(#DATA, (META)->op);				\
122 		goto LABEL;							\
123 	}									\
124 } while (0)
125 
126 #define	SNAPSHOT_VAR_CMP_OR_LEAVE(DATA, META, RES, LABEL)			\
127 	SNAPSHOT_BUF_CMP_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
128 
129 #endif
130