xref: /freebsd/sys/amd64/include/vmm_snapshot.h (revision 4d3fc8b0)
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 struct vmctx;
48 
49 enum snapshot_req {
50 	STRUCT_VIOAPIC = 1,
51 	STRUCT_VM,
52 	STRUCT_VLAPIC,
53 	VM_MEM,
54 	STRUCT_VHPET,
55 	STRUCT_VMCX,
56 	STRUCT_VATPIC,
57 	STRUCT_VATPIT,
58 	STRUCT_VPMTMR,
59 	STRUCT_VRTC,
60 };
61 
62 struct vm_snapshot_buffer {
63 	/*
64 	 * R/O for device-specific functions;
65 	 * written by generic snapshot functions.
66 	 */
67 	uint8_t *const buf_start;
68 	const size_t buf_size;
69 
70 	/*
71 	 * R/W for device-specific functions used to keep track of buffer
72 	 * current position and remaining size.
73 	 */
74 	uint8_t *buf;
75 	size_t buf_rem;
76 
77 	/*
78 	 * Length of the snapshot is either determined as (buf_size - buf_rem)
79 	 * or (buf - buf_start) -- the second variation returns a signed value
80 	 * so it may not be appropriate.
81 	 *
82 	 * Use vm_get_snapshot_size(meta).
83 	 */
84 };
85 
86 enum vm_snapshot_op {
87 	VM_SNAPSHOT_SAVE,
88 	VM_SNAPSHOT_RESTORE,
89 };
90 
91 struct vm_snapshot_meta {
92 	struct vmctx *ctx;
93 	void *dev_data;
94 	const char *dev_name;      /* identify userspace devices */
95 	enum snapshot_req dev_req; /* identify kernel structs */
96 
97 	struct vm_snapshot_buffer buffer;
98 
99 	enum vm_snapshot_op op;
100 };
101 
102 void vm_snapshot_buf_err(const char *bufname, const enum vm_snapshot_op op);
103 int vm_snapshot_buf(void *data, size_t data_size,
104     struct vm_snapshot_meta *meta);
105 size_t vm_get_snapshot_size(struct vm_snapshot_meta *meta);
106 int vm_snapshot_guest2host_addr(void **addrp, size_t len, bool restore_null,
107     struct vm_snapshot_meta *meta);
108 int vm_snapshot_buf_cmp(void *data, size_t data_size,
109     struct vm_snapshot_meta *meta);
110 
111 #define	SNAPSHOT_BUF_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
112 do {										\
113 	(RES) = vm_snapshot_buf((DATA), (LEN), (META));				\
114 	if ((RES) != 0) {							\
115 		vm_snapshot_buf_err(#DATA, (META)->op);				\
116 		goto LABEL;							\
117 	}									\
118 } while (0)
119 
120 #define	SNAPSHOT_VAR_OR_LEAVE(DATA, META, RES, LABEL)				\
121 	SNAPSHOT_BUF_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
122 
123 /*
124  * Address variables are pointers to guest memory.
125  *
126  * When RNULL != 0, do not enforce invalid address checks; instead, make the
127  * pointer NULL at restore time.
128  */
129 #define	SNAPSHOT_GUEST2HOST_ADDR_OR_LEAVE(ADDR, LEN, RNULL, META, RES, LABEL)	\
130 do {										\
131 	(RES) = vm_snapshot_guest2host_addr((void **)&(ADDR), (LEN), (RNULL),	\
132 			(META));					\
133 	if ((RES) != 0) {							\
134 		if ((RES) == EFAULT)						\
135 			fprintf(stderr, "%s: invalid address: %s\r\n",		\
136 				__func__, #ADDR);				\
137 		goto LABEL;							\
138 	}									\
139 } while (0)
140 
141 /* compare the value in the meta buffer with the data */
142 #define	SNAPSHOT_BUF_CMP_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
143 do {										\
144 	(RES) = vm_snapshot_buf_cmp((DATA), (LEN), (META));			\
145 	if ((RES) != 0) {							\
146 		vm_snapshot_buf_err(#DATA, (META)->op);				\
147 		goto LABEL;							\
148 	}									\
149 } while (0)
150 
151 #define	SNAPSHOT_VAR_CMP_OR_LEAVE(DATA, META, RES, LABEL)			\
152 	SNAPSHOT_BUF_CMP_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
153 
154 #endif
155