1 | /* |
2 | * Global State configuration |
3 | * |
4 | * Copyright (c) 2014-2017 Red Hat Inc |
5 | * |
6 | * Authors: |
7 | * Juan Quintela <quintela@redhat.com> |
8 | * |
9 | * This work is licensed under the terms of the GNU GPL, version 2 or later. |
10 | * See the COPYING file in the top-level directory. |
11 | */ |
12 | |
13 | #include "qemu/osdep.h" |
14 | #include "qemu/cutils.h" |
15 | #include "qemu/error-report.h" |
16 | #include "sysemu/runstate.h" |
17 | #include "qapi/error.h" |
18 | #include "migration.h" |
19 | #include "migration/global_state.h" |
20 | #include "migration/vmstate.h" |
21 | #include "trace.h" |
22 | |
23 | typedef struct { |
24 | uint32_t size; |
25 | uint8_t runstate[100]; |
26 | RunState state; |
27 | bool received; |
28 | } GlobalState; |
29 | |
30 | static GlobalState global_state; |
31 | |
32 | int global_state_store(void) |
33 | { |
34 | if (!runstate_store((char *)global_state.runstate, |
35 | sizeof(global_state.runstate))) { |
36 | error_report("runstate name too big: %s" , global_state.runstate); |
37 | trace_migrate_state_too_big(); |
38 | return -EINVAL; |
39 | } |
40 | return 0; |
41 | } |
42 | |
43 | void global_state_store_running(void) |
44 | { |
45 | const char *state = RunState_str(RUN_STATE_RUNNING); |
46 | assert(strlen(state) < sizeof(global_state.runstate)); |
47 | strncpy((char *)global_state.runstate, |
48 | state, sizeof(global_state.runstate)); |
49 | } |
50 | |
51 | bool global_state_received(void) |
52 | { |
53 | return global_state.received; |
54 | } |
55 | |
56 | RunState global_state_get_runstate(void) |
57 | { |
58 | return global_state.state; |
59 | } |
60 | |
61 | static bool global_state_needed(void *opaque) |
62 | { |
63 | GlobalState *s = opaque; |
64 | char *runstate = (char *)s->runstate; |
65 | |
66 | /* If it is not optional, it is mandatory */ |
67 | |
68 | if (migrate_get_current()->store_global_state) { |
69 | return true; |
70 | } |
71 | |
72 | /* If state is running or paused, it is not needed */ |
73 | |
74 | if (strcmp(runstate, "running" ) == 0 || |
75 | strcmp(runstate, "paused" ) == 0) { |
76 | return false; |
77 | } |
78 | |
79 | /* for any other state it is needed */ |
80 | return true; |
81 | } |
82 | |
83 | static int global_state_post_load(void *opaque, int version_id) |
84 | { |
85 | GlobalState *s = opaque; |
86 | Error *local_err = NULL; |
87 | int r; |
88 | char *runstate = (char *)s->runstate; |
89 | |
90 | s->received = true; |
91 | trace_migrate_global_state_post_load(runstate); |
92 | |
93 | if (strnlen((char *)s->runstate, |
94 | sizeof(s->runstate)) == sizeof(s->runstate)) { |
95 | /* |
96 | * This condition should never happen during migration, because |
97 | * all runstate names are shorter than 100 bytes (the size of |
98 | * s->runstate). However, a malicious stream could overflow |
99 | * the qapi_enum_parse() call, so we force the last character |
100 | * to a NUL byte. |
101 | */ |
102 | s->runstate[sizeof(s->runstate) - 1] = '\0'; |
103 | } |
104 | r = qapi_enum_parse(&RunState_lookup, runstate, -1, &local_err); |
105 | |
106 | if (r == -1) { |
107 | if (local_err) { |
108 | error_report_err(local_err); |
109 | } |
110 | return -EINVAL; |
111 | } |
112 | s->state = r; |
113 | |
114 | return 0; |
115 | } |
116 | |
117 | static int global_state_pre_save(void *opaque) |
118 | { |
119 | GlobalState *s = opaque; |
120 | |
121 | trace_migrate_global_state_pre_save((char *)s->runstate); |
122 | s->size = strnlen((char *)s->runstate, sizeof(s->runstate)) + 1; |
123 | assert(s->size <= sizeof(s->runstate)); |
124 | |
125 | return 0; |
126 | } |
127 | |
128 | static const VMStateDescription vmstate_globalstate = { |
129 | .name = "globalstate" , |
130 | .version_id = 1, |
131 | .minimum_version_id = 1, |
132 | .post_load = global_state_post_load, |
133 | .pre_save = global_state_pre_save, |
134 | .needed = global_state_needed, |
135 | .fields = (VMStateField[]) { |
136 | VMSTATE_UINT32(size, GlobalState), |
137 | VMSTATE_BUFFER(runstate, GlobalState), |
138 | VMSTATE_END_OF_LIST() |
139 | }, |
140 | }; |
141 | |
142 | void register_global_state(void) |
143 | { |
144 | /* We would use it independently that we receive it */ |
145 | strcpy((char *)&global_state.runstate, "" ); |
146 | global_state.received = false; |
147 | vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); |
148 | } |
149 | |