/* * Global State configuration * * Copyright (c) 2014-2017 Red Hat Inc * * Authors: * Juan Quintela <quintela@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. */ #include "qemu/osdep.h" #include "qemu/cutils.h" #include "qemu/error-report.h" #include "sysemu/runstate.h" #include "qapi/error.h" #include "migration.h" #include "migration/global_state.h" #include "migration/vmstate.h" #include "trace.h" typedef struct { uint32_t size; uint8_t runstate[100]; RunState state; bool received; } GlobalState; static GlobalState global_state; int global_state_store(void) { if (!runstate_store((char *)global_state.runstate, sizeof(global_state.runstate))) { error_report("runstate name too big: %s", global_state.runstate); trace_migrate_state_too_big(); return -EINVAL; } return 0; } void global_state_store_running(void) { const char *state = RunState_str(RUN_STATE_RUNNING); assert(strlen(state) < sizeof(global_state.runstate)); strncpy((char *)global_state.runstate, state, sizeof(global_state.runstate)); } bool global_state_received(void) { return global_state.received; } RunState global_state_get_runstate(void) { return global_state.state; } static bool global_state_needed(void *opaque) { GlobalState *s = opaque; char *runstate = (char *)s->runstate; /* If it is not optional, it is mandatory */ if (migrate_get_current()->store_global_state) { return true; } /* If state is running or paused, it is not needed */ if (strcmp(runstate, "running") == 0 || strcmp(runstate, "paused") == 0) { return false; } /* for any other state it is needed */ return true; } static int global_state_post_load(void *opaque, int version_id) { GlobalState *s = opaque; Error *local_err = NULL; int r; char *runstate = (char *)s->runstate; s->received = true; trace_migrate_global_state_post_load(runstate); if (strnlen((char *)s->runstate, sizeof(s->runstate)) == sizeof(s->runstate)) { /* * This condition should never happen during migration, because * all runstate names are shorter than 100 bytes (the size of * s->runstate). However, a malicious stream could overflow * the qapi_enum_parse() call, so we force the last character * to a NUL byte. */ s->runstate[sizeof(s->runstate) - 1] = '\0'; } r = qapi_enum_parse(&RunState_lookup, runstate, -1, &local_err); if (r == -1) { if (local_err) { error_report_err(local_err); } return -EINVAL; } s->state = r; return 0; } static int global_state_pre_save(void *opaque) { GlobalState *s = opaque; trace_migrate_global_state_pre_save((char *)s->runstate); s->size = strnlen((char *)s->runstate, sizeof(s->runstate)) + 1; assert(s->size <= sizeof(s->runstate)); return 0; } static const VMStateDescription vmstate_globalstate = { .name = "globalstate", .version_id = 1, .minimum_version_id = 1, .post_load = global_state_post_load, .pre_save = global_state_pre_save, .needed = global_state_needed, .fields = (VMStateField[]) { VMSTATE_UINT32(size, GlobalState), VMSTATE_BUFFER(runstate, GlobalState), VMSTATE_END_OF_LIST() }, }; void register_global_state(void) { /* We would use it independently that we receive it */ strcpy((char *)&global_state.runstate, ""); global_state.received = false; vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); }