xref: /freebsd/sys/amd64/vmm/vmm_snapshot.c (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c)
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 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/types.h>
40 #include <sys/systm.h>
41 
42 #include <machine/vmm_snapshot.h>
43 
44 void
45 vm_snapshot_buf_err(const char *bufname, const enum vm_snapshot_op op)
46 {
47 	const char *opstr;
48 
49 	if (op == VM_SNAPSHOT_SAVE)
50 		opstr = "save";
51 	else if (op == VM_SNAPSHOT_RESTORE)
52 		opstr = "restore";
53 	else
54 		opstr = "unknown";
55 
56 	printf("%s: snapshot-%s failed for %s\r\n", __func__, opstr, bufname);
57 }
58 
59 int
60 vm_snapshot_buf(volatile void *data, size_t data_size,
61 	     struct vm_snapshot_meta *meta)
62 {
63 	struct vm_snapshot_buffer *buffer;
64 	int op;
65 	void *nv_data;
66 
67 	nv_data = __DEVOLATILE(void *, data);
68 	buffer = &meta->buffer;
69 	op = meta->op;
70 
71 	if (buffer->buf_rem < data_size) {
72 		printf("%s: buffer too small\r\n", __func__);
73 		return (E2BIG);
74 	}
75 
76 	if (op == VM_SNAPSHOT_SAVE)
77 		copyout(nv_data, buffer->buf, data_size);
78 	else if (op == VM_SNAPSHOT_RESTORE)
79 		copyin(buffer->buf, nv_data, data_size);
80 	else
81 		return (EINVAL);
82 
83 	buffer->buf += data_size;
84 	buffer->buf_rem -= data_size;
85 
86 	return (0);
87 }
88 
89 size_t
90 vm_get_snapshot_size(struct vm_snapshot_meta *meta)
91 {
92 	size_t length;
93 	struct vm_snapshot_buffer *buffer;
94 
95 	buffer = &meta->buffer;
96 
97 	if (buffer->buf_size < buffer->buf_rem) {
98 		printf("%s: Invalid buffer: size = %zu, rem = %zu\r\n",
99 		       __func__, buffer->buf_size, buffer->buf_rem);
100 		length = 0;
101 	} else {
102 		length = buffer->buf_size - buffer->buf_rem;
103 	}
104 
105 	return (length);
106 }
107 
108 int
109 vm_snapshot_buf_cmp(volatile void *data, size_t data_size,
110 		    struct vm_snapshot_meta *meta)
111 {
112 	struct vm_snapshot_buffer *buffer;
113 	int op;
114 	int ret;
115 	void *_data = *(void **)(void *)&data;
116 
117 	buffer = &meta->buffer;
118 	op = meta->op;
119 
120 	if (buffer->buf_rem < data_size) {
121 		printf("%s: buffer too small\r\n", __func__);
122 		ret = E2BIG;
123 		goto done;
124 	}
125 
126 	if (op == VM_SNAPSHOT_SAVE) {
127 		ret = 0;
128 		copyout(_data, buffer->buf, data_size);
129 	} else if (op == VM_SNAPSHOT_RESTORE) {
130 		ret = memcmp(_data, buffer->buf, data_size);
131 	} else {
132 		ret = EINVAL;
133 		goto done;
134 	}
135 
136 	buffer->buf += data_size;
137 	buffer->buf_rem -= data_size;
138 
139 done:
140 	return (ret);
141 }
142