xref: /qemu/migration/global_state.c (revision 6402cbbb) 
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.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_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 static bool global_state_needed(void *opaque)
61 {
62     GlobalState *s = opaque;
63     char *runstate = (char *)s->runstate;
64 
65     /* If it is not optional, it is mandatory */
66 
67     if (migrate_get_current()->store_global_state) {
68         return true;
69     }
70 
71     /* If state is running or paused, it is not needed */
72 
73     if (strcmp(runstate, "running") == 0 ||
74         strcmp(runstate, "paused") == 0) {
75         return false;
76     }
77 
78     /* for any other state it is needed */
79     return true;
80 }
81 
82 static int global_state_post_load(void *opaque, int version_id)
83 {
84     GlobalState *s = opaque;
85     Error *local_err = NULL;
86     int r;
87     char *runstate = (char *)s->runstate;
88 
89     s->received = true;
90     trace_migrate_global_state_post_load(runstate);
91 
92     r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE__MAX,
93                                 -1, &local_err);
94 
95     if (r == -1) {
96         if (local_err) {
97             error_report_err(local_err);
98         }
99         return -EINVAL;
100     }
101     s->state = r;
102 
103     return 0;
104 }
105 
106 static void global_state_pre_save(void *opaque)
107 {
108     GlobalState *s = opaque;
109 
110     trace_migrate_global_state_pre_save((char *)s->runstate);
111     s->size = strlen((char *)s->runstate) + 1;
112 }
113 
114 static const VMStateDescription vmstate_globalstate = {
115     .name = "globalstate",
116     .version_id = 1,
117     .minimum_version_id = 1,
118     .post_load = global_state_post_load,
119     .pre_save = global_state_pre_save,
120     .needed = global_state_needed,
121     .fields = (VMStateField[]) {
122         VMSTATE_UINT32(size, GlobalState),
123         VMSTATE_BUFFER(runstate, GlobalState),
124         VMSTATE_END_OF_LIST()
125     },
126 };
127 
128 void register_global_state(void)
129 {
130     /* We would use it independently that we receive it */
131     strcpy((char *)&global_state.runstate, "");
132     global_state.received = false;
133     vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
134 }
135