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/*
* 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 "system/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;
/*
* runstate was 100 bytes, zero padded, but we trimmed it to add a
* few fields and maintain backwards compatibility.
*/
uint8_t runstate[32];
uint8_t has_vm_was_suspended;
uint8_t vm_was_suspended;
uint8_t unused[66];
RunState state;
bool received;
} GlobalState;
static GlobalState global_state;
static void global_state_do_store(RunState state)
{
const char *state_str = RunState_str(state);
assert(strlen(state_str) < sizeof(global_state.runstate));
strpadcpy((char *)global_state.runstate, sizeof(global_state.runstate),
state_str, '\0');
global_state.has_vm_was_suspended = true;
global_state.vm_was_suspended = vm_get_suspended();
memset(global_state.unused, 0, sizeof(global_state.unused));
}
void global_state_store(void)
{
global_state_do_store(runstate_get());
}
void global_state_store_running(void)
{
global_state_do_store(RUN_STATE_RUNNING);
}
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)
{
return migrate_get_current()->store_global_state;
}
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 32 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;
/*
* global_state is saved on the outgoing side before forcing a stopped
* state, so it may have saved state=suspended and vm_was_suspended=0.
* Now we are in a paused state, and when we later call vm_start, it must
* restore the suspended state, so we must set vm_was_suspended=1 here.
*/
vm_set_suspended(s->vm_was_suspended || r == RUN_STATE_SUSPENDED);
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 = (const VMStateField[]) {
VMSTATE_UINT32(size, GlobalState),
VMSTATE_BUFFER(runstate, GlobalState),
VMSTATE_UINT8(has_vm_was_suspended, GlobalState),
VMSTATE_UINT8(vm_was_suspended, GlobalState),
VMSTATE_BUFFER(unused, 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);
}
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