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 static void global_state_do_store(RunState state) 33 { 34 const char *state_str = RunState_str(state); 35 assert(strlen(state_str) < sizeof(global_state.runstate)); 36 strpadcpy((char *)global_state.runstate, sizeof(global_state.runstate), 37 state_str, '\0'); 38 } 39 40 void global_state_store(void) 41 { 42 global_state_do_store(runstate_get()); 43 } 44 45 void global_state_store_running(void) 46 { 47 global_state_do_store(RUN_STATE_RUNNING); 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 if (strnlen((char *)s->runstate, 93 sizeof(s->runstate)) == sizeof(s->runstate)) { 94 /* 95 * This condition should never happen during migration, because 96 * all runstate names are shorter than 100 bytes (the size of 97 * s->runstate). However, a malicious stream could overflow 98 * the qapi_enum_parse() call, so we force the last character 99 * to a NUL byte. 100 */ 101 s->runstate[sizeof(s->runstate) - 1] = '\0'; 102 } 103 r = qapi_enum_parse(&RunState_lookup, runstate, -1, &local_err); 104 105 if (r == -1) { 106 if (local_err) { 107 error_report_err(local_err); 108 } 109 return -EINVAL; 110 } 111 s->state = r; 112 113 return 0; 114 } 115 116 static int global_state_pre_save(void *opaque) 117 { 118 GlobalState *s = opaque; 119 120 trace_migrate_global_state_pre_save((char *)s->runstate); 121 s->size = strnlen((char *)s->runstate, sizeof(s->runstate)) + 1; 122 assert(s->size <= sizeof(s->runstate)); 123 124 return 0; 125 } 126 127 static const VMStateDescription vmstate_globalstate = { 128 .name = "globalstate", 129 .version_id = 1, 130 .minimum_version_id = 1, 131 .post_load = global_state_post_load, 132 .pre_save = global_state_pre_save, 133 .needed = global_state_needed, 134 .fields = (VMStateField[]) { 135 VMSTATE_UINT32(size, GlobalState), 136 VMSTATE_BUFFER(runstate, GlobalState), 137 VMSTATE_END_OF_LIST() 138 }, 139 }; 140 141 void register_global_state(void) 142 { 143 /* We would use it independently that we receive it */ 144 strcpy((char *)&global_state.runstate, ""); 145 global_state.received = false; 146 vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); 147 } 148