xref: /qemu/migration/global_state.c (revision 01b2ffce) 
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 "qapi/error.h"
17 #include "qapi/util.h"
18 #include "migration/global_state.h"
19 #include "migration/vmstate.h"
20 #include "trace.h"
21 
22 typedef struct {
23     bool optional;
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_lookup[RUN_STATE_RUNNING];
46     strncpy((char *)global_state.runstate,
47            state, sizeof(global_state.runstate));
48 }
49 
50 bool global_state_received(void)
51 {
52     return global_state.received;
53 }
54 
55 RunState global_state_get_runstate(void)
56 {
57     return global_state.state;
58 }
59 
60 void global_state_set_optional(void)
61 {
62     global_state.optional = true;
63 }
64 
65 static bool global_state_needed(void *opaque)
66 {
67     GlobalState *s = opaque;
68     char *runstate = (char *)s->runstate;
69 
70     /* If it is not optional, it is mandatory */
71 
72     if (s->optional == false) {
73         return true;
74     }
75 
76     /* If state is running or paused, it is not needed */
77 
78     if (strcmp(runstate, "running") == 0 ||
79         strcmp(runstate, "paused") == 0) {
80         return false;
81     }
82 
83     /* for any other state it is needed */
84     return true;
85 }
86 
87 static int global_state_post_load(void *opaque, int version_id)
88 {
89     GlobalState *s = opaque;
90     Error *local_err = NULL;
91     int r;
92     char *runstate = (char *)s->runstate;
93 
94     s->received = true;
95     trace_migrate_global_state_post_load(runstate);
96 
97     r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE__MAX,
98                                 -1, &local_err);
99 
100     if (r == -1) {
101         if (local_err) {
102             error_report_err(local_err);
103         }
104         return -EINVAL;
105     }
106     s->state = r;
107 
108     return 0;
109 }
110 
111 static void global_state_pre_save(void *opaque)
112 {
113     GlobalState *s = opaque;
114 
115     trace_migrate_global_state_pre_save((char *)s->runstate);
116     s->size = strlen((char *)s->runstate) + 1;
117 }
118 
119 static const VMStateDescription vmstate_globalstate = {
120     .name = "globalstate",
121     .version_id = 1,
122     .minimum_version_id = 1,
123     .post_load = global_state_post_load,
124     .pre_save = global_state_pre_save,
125     .needed = global_state_needed,
126     .fields = (VMStateField[]) {
127         VMSTATE_UINT32(size, GlobalState),
128         VMSTATE_BUFFER(runstate, GlobalState),
129         VMSTATE_END_OF_LIST()
130     },
131 };
132 
133 void register_global_state(void)
134 {
135     /* We would use it independently that we receive it */
136     strcpy((char *)&global_state.runstate, "");
137     global_state.received = false;
138     vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
139 }
140