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
47struct vmctx;
48
49enum snapshot_req {
50	STRUCT_VMX,
51	STRUCT_VIOAPIC,
52	STRUCT_VM,
53	STRUCT_VLAPIC,
54	VM_MEM,
55	STRUCT_VHPET,
56	STRUCT_VMCX,
57	STRUCT_VATPIC,
58	STRUCT_VATPIT,
59	STRUCT_VPMTMR,
60	STRUCT_VRTC,
61};
62
63struct vm_snapshot_buffer {
64	/*
65	 * R/O for device-specific functions;
66	 * written by generic snapshot functions.
67	 */
68	uint8_t *const buf_start;
69	const size_t buf_size;
70
71	/*
72	 * R/W for device-specific functions used to keep track of buffer
73	 * current position and remaining size.
74	 */
75	uint8_t *buf;
76	size_t buf_rem;
77
78	/*
79	 * Length of the snapshot is either determined as (buf_size - buf_rem)
80	 * or (buf - buf_start) -- the second variation returns a signed value
81	 * so it may not be appropriate.
82	 *
83	 * Use vm_get_snapshot_size(meta).
84	 */
85};
86
87enum vm_snapshot_op {
88	VM_SNAPSHOT_SAVE,
89	VM_SNAPSHOT_RESTORE,
90};
91
92struct vm_snapshot_meta {
93	struct vmctx *ctx;
94	void *dev_data;
95	const char *dev_name;      /* identify userspace devices */
96	enum snapshot_req dev_req; /* identify kernel structs */
97
98	struct vm_snapshot_buffer buffer;
99
100	enum vm_snapshot_op op;
101};
102
103void vm_snapshot_buf_err(const char *bufname, const enum vm_snapshot_op op);
104int vm_snapshot_buf(volatile void *data, size_t data_size,
105		    struct vm_snapshot_meta *meta);
106size_t vm_get_snapshot_size(struct vm_snapshot_meta *meta);
107int vm_snapshot_guest2host_addr(void **addrp, size_t len, bool restore_null,
108				struct vm_snapshot_meta *meta);
109int vm_snapshot_buf_cmp(volatile void *data, size_t data_size,
110			      struct vm_snapshot_meta *meta);
111
112#define	SNAPSHOT_BUF_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
113do {										\
114	(RES) = vm_snapshot_buf((DATA), (LEN), (META));				\
115	if ((RES) != 0) {							\
116		vm_snapshot_buf_err(#DATA, (META)->op);				\
117		goto LABEL;							\
118	}									\
119} while (0)
120
121#define	SNAPSHOT_VAR_OR_LEAVE(DATA, META, RES, LABEL)				\
122	SNAPSHOT_BUF_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
123
124/*
125 * Address variables are pointers to guest memory.
126 *
127 * When RNULL != 0, do not enforce invalid address checks; instead, make the
128 * pointer NULL at restore time.
129 */
130#define	SNAPSHOT_GUEST2HOST_ADDR_OR_LEAVE(ADDR, LEN, RNULL, META, RES, LABEL)	\
131do {										\
132	(RES) = vm_snapshot_guest2host_addr((void **)&(ADDR), (LEN), (RNULL),	\
133			(META));					\
134	if ((RES) != 0) {							\
135		if ((RES) == EFAULT)						\
136			fprintf(stderr, "%s: invalid address: %s\r\n",		\
137				__func__, #ADDR);				\
138		goto LABEL;							\
139	}									\
140} while (0)
141
142/* compare the value in the meta buffer with the data */
143#define	SNAPSHOT_BUF_CMP_OR_LEAVE(DATA, LEN, META, RES, LABEL)			\
144do {										\
145	(RES) = vm_snapshot_buf_cmp((DATA), (LEN), (META));			\
146	if ((RES) != 0) {							\
147		vm_snapshot_buf_err(#DATA, (META)->op);				\
148		goto LABEL;							\
149	}									\
150} while (0)
151
152#define	SNAPSHOT_VAR_CMP_OR_LEAVE(DATA, META, RES, LABEL)			\
153	SNAPSHOT_BUF_CMP_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)
154
155#endif
156