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qemu/migration/savevm.c
Dr. David Alan Gilbert f68945d42b Add a protective section footer 
Badly formatted migration streams can go undetected or produce
misleading errors due to a lock of checking at the end of sections.
In particular a section that adds an extra 0x00 at the end
causes what looks like a normal end of stream and thus doesn't produce
any errors, and something that ends in a 0x01..0x04 kind of look
like real section headers and then fail when the section parser tries
to figure out which section they are.  This is made worse by the
choice of 0x00..0x04 being small numbers that are particularly common
in normal section data.

This patch adds a section footer consisting of a marker (0x7e - ~)
followed by the section-id that was also sent in the header.  If
they mismatch then it throws an error explaining which section was
being loaded.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-06-12 06:54:01 +02:00

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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2009-2015 Red Hat Inc
*
* Authors:
* Juan Quintela <quintela@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "config-host.h"
#include "qemu-common.h"
#include "hw/boards.h"
#include "hw/hw.h"
#include "hw/qdev.h"
#include "net/net.h"
#include "monitor/monitor.h"
#include "sysemu/sysemu.h"
#include "qemu/timer.h"
#include "audio/audio.h"
#include "migration/migration.h"
#include "qemu/sockets.h"
#include "qemu/queue.h"
#include "sysemu/cpus.h"
#include "exec/memory.h"
#include "qmp-commands.h"
#include "trace.h"
#include "qemu/iov.h"
#include "block/snapshot.h"
#include "block/qapi.h"
#ifndef ETH_P_RARP
#define ETH_P_RARP 0x8035
#endif
#define ARP_HTYPE_ETH 0x0001
#define ARP_PTYPE_IP 0x0800
#define ARP_OP_REQUEST_REV 0x3
static bool skip_section_footers;
static int announce_self_create(uint8_t *buf,
uint8_t *mac_addr)
{
/* Ethernet header. */
memset(buf, 0xff, 6); /* destination MAC addr */
memcpy(buf + 6, mac_addr, 6); /* source MAC addr */
*(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */
/* RARP header. */
*(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */
*(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */
*(buf + 18) = 6; /* hardware addr length (ethernet) */
*(buf + 19) = 4; /* protocol addr length (IPv4) */
*(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */
memcpy(buf + 22, mac_addr, 6); /* source hw addr */
memset(buf + 28, 0x00, 4); /* source protocol addr */
memcpy(buf + 32, mac_addr, 6); /* target hw addr */
memset(buf + 38, 0x00, 4); /* target protocol addr */
/* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
memset(buf + 42, 0x00, 18);
return 60; /* len (FCS will be added by hardware) */
}
static void qemu_announce_self_iter(NICState *nic, void *opaque)
{
uint8_t buf[60];
int len;
trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr));
len = announce_self_create(buf, nic->conf->macaddr.a);
qemu_send_packet_raw(qemu_get_queue(nic), buf, len);
}
static void qemu_announce_self_once(void *opaque)
{
static int count = SELF_ANNOUNCE_ROUNDS;
QEMUTimer *timer = *(QEMUTimer **)opaque;
qemu_foreach_nic(qemu_announce_self_iter, NULL);
if (--count) {
/* delay 50ms, 150ms, 250ms, ... */
timer_mod(timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) +
self_announce_delay(count));
} else {
timer_del(timer);
timer_free(timer);
}
}
void qemu_announce_self(void)
{
static QEMUTimer *timer;
timer = timer_new_ms(QEMU_CLOCK_REALTIME, qemu_announce_self_once, &timer);
qemu_announce_self_once(&timer);
}
/***********************************************************/
/* savevm/loadvm support */
static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
int ret;
QEMUIOVector qiov;
qemu_iovec_init_external(&qiov, iov, iovcnt);
ret = bdrv_writev_vmstate(opaque, &qiov, pos);
if (ret < 0) {
return ret;
}
return qiov.size;
}
static int block_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
bdrv_save_vmstate(opaque, buf, pos, size);
return size;
}
static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
return bdrv_load_vmstate(opaque, buf, pos, size);
}
static int bdrv_fclose(void *opaque)
{
return bdrv_flush(opaque);
}
static const QEMUFileOps bdrv_read_ops = {
.get_buffer = block_get_buffer,
.close = bdrv_fclose
};
static const QEMUFileOps bdrv_write_ops = {
.put_buffer = block_put_buffer,
.writev_buffer = block_writev_buffer,
.close = bdrv_fclose
};
static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
{
if (is_writable) {
return qemu_fopen_ops(bs, &bdrv_write_ops);
}
return qemu_fopen_ops(bs, &bdrv_read_ops);
}
/* QEMUFile timer support.
* Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
*/
void timer_put(QEMUFile *f, QEMUTimer *ts)
{
uint64_t expire_time;
expire_time = timer_expire_time_ns(ts);
qemu_put_be64(f, expire_time);
}
void timer_get(QEMUFile *f, QEMUTimer *ts)
{
uint64_t expire_time;
expire_time = qemu_get_be64(f);
if (expire_time != -1) {
timer_mod_ns(ts, expire_time);
} else {
timer_del(ts);
}
}
/* VMState timer support.
* Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
*/
static int get_timer(QEMUFile *f, void *pv, size_t size)
{
QEMUTimer *v = pv;
timer_get(f, v);
return 0;
}
static void put_timer(QEMUFile *f, void *pv, size_t size)
{
QEMUTimer *v = pv;
timer_put(f, v);
}
const VMStateInfo vmstate_info_timer = {
.name = "timer",
.get = get_timer,
.put = put_timer,
};
typedef struct CompatEntry {
char idstr[256];
int instance_id;
} CompatEntry;
typedef struct SaveStateEntry {
QTAILQ_ENTRY(SaveStateEntry) entry;
char idstr[256];
int instance_id;
int alias_id;
int version_id;
int section_id;
SaveVMHandlers *ops;
const VMStateDescription *vmsd;
void *opaque;
CompatEntry *compat;
int is_ram;
} SaveStateEntry;
typedef struct SaveState {
QTAILQ_HEAD(, SaveStateEntry) handlers;
int global_section_id;
} SaveState;
static SaveState savevm_state = {
.handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
.global_section_id = 0,
};
static void dump_vmstate_vmsd(FILE *out_file,
const VMStateDescription *vmsd, int indent,
bool is_subsection);
static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
int indent)
{
fprintf(out_file, "%*s{\n", indent, "");
indent += 2;
fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name);
fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
field->version_id);
fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "",
field->field_exists ? "true" : "false");
fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size);
if (field->vmsd != NULL) {
fprintf(out_file, ",\n");
dump_vmstate_vmsd(out_file, field->vmsd, indent, false);
}
fprintf(out_file, "\n%*s}", indent - 2, "");
}
static void dump_vmstate_vmss(FILE *out_file,
const VMStateDescription **subsection,
int indent)
{
if (*subsection != NULL) {
dump_vmstate_vmsd(out_file, *subsection, indent, true);
}
}
static void dump_vmstate_vmsd(FILE *out_file,
const VMStateDescription *vmsd, int indent,
bool is_subsection)
{
if (is_subsection) {
fprintf(out_file, "%*s{\n", indent, "");
} else {
fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description");
}
indent += 2;
fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name);
fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
vmsd->version_id);
fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "",
vmsd->minimum_version_id);
if (vmsd->fields != NULL) {
const VMStateField *field = vmsd->fields;
bool first;
fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, "");
first = true;
while (field->name != NULL) {
if (field->flags & VMS_MUST_EXIST) {
/* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
field++;
continue;
}
if (!first) {
fprintf(out_file, ",\n");
}
dump_vmstate_vmsf(out_file, field, indent + 2);
field++;
first = false;
}
fprintf(out_file, "\n%*s]", indent, "");
}
if (vmsd->subsections != NULL) {
const VMStateDescription **subsection = vmsd->subsections;
bool first;
fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
first = true;
while (*subsection != NULL) {
if (!first) {
fprintf(out_file, ",\n");
}
dump_vmstate_vmss(out_file, subsection, indent + 2);
subsection++;
first = false;
}
fprintf(out_file, "\n%*s]", indent, "");
}
fprintf(out_file, "\n%*s}", indent - 2, "");
}
static void dump_machine_type(FILE *out_file)
{
MachineClass *mc;
mc = MACHINE_GET_CLASS(current_machine);
fprintf(out_file, " \"vmschkmachine\": {\n");
fprintf(out_file, " \"Name\": \"%s\"\n", mc->name);
fprintf(out_file, " },\n");
}
void dump_vmstate_json_to_file(FILE *out_file)
{
GSList *list, *elt;
bool first;
fprintf(out_file, "{\n");
dump_machine_type(out_file);
first = true;
list = object_class_get_list(TYPE_DEVICE, true);
for (elt = list; elt; elt = elt->next) {
DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data,
TYPE_DEVICE);
const char *name;
int indent = 2;
if (!dc->vmsd) {
continue;
}
if (!first) {
fprintf(out_file, ",\n");
}
name = object_class_get_name(OBJECT_CLASS(dc));
fprintf(out_file, "%*s\"%s\": {\n", indent, "", name);
indent += 2;
fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name);
fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
dc->vmsd->version_id);
fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "",
dc->vmsd->minimum_version_id);
dump_vmstate_vmsd(out_file, dc->vmsd, indent, false);
fprintf(out_file, "\n%*s}", indent - 2, "");
first = false;
}
fprintf(out_file, "\n}\n");
fclose(out_file);
}
static int calculate_new_instance_id(const char *idstr)
{
SaveStateEntry *se;
int instance_id = 0;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (strcmp(idstr, se->idstr) == 0
&& instance_id <= se->instance_id) {
instance_id = se->instance_id + 1;
}
}
return instance_id;
}
static int calculate_compat_instance_id(const char *idstr)
{
SaveStateEntry *se;
int instance_id = 0;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->compat) {
continue;
}
if (strcmp(idstr, se->compat->idstr) == 0
&& instance_id <= se->compat->instance_id) {
instance_id = se->compat->instance_id + 1;
}
}
return instance_id;
}
/* TODO: Individual devices generally have very little idea about the rest
of the system, so instance_id should be removed/replaced.
Meanwhile pass -1 as instance_id if you do not already have a clearly
distinguishing id for all instances of your device class. */
int register_savevm_live(DeviceState *dev,
const char *idstr,
int instance_id,
int version_id,
SaveVMHandlers *ops,
void *opaque)
{
SaveStateEntry *se;
se = g_malloc0(sizeof(SaveStateEntry));
se->version_id = version_id;
se->section_id = savevm_state.global_section_id++;
se->ops = ops;
se->opaque = opaque;
se->vmsd = NULL;
/* if this is a live_savem then set is_ram */
if (ops->save_live_setup != NULL) {
se->is_ram = 1;
}
if (dev) {
char *id = qdev_get_dev_path(dev);
if (id) {
pstrcpy(se->idstr, sizeof(se->idstr), id);
pstrcat(se->idstr, sizeof(se->idstr), "/");
g_free(id);
se->compat = g_malloc0(sizeof(CompatEntry));
pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr);
se->compat->instance_id = instance_id == -1 ?
calculate_compat_instance_id(idstr) : instance_id;
instance_id = -1;
}
}
pstrcat(se->idstr, sizeof(se->idstr), idstr);
if (instance_id == -1) {
se->instance_id = calculate_new_instance_id(se->idstr);
} else {
se->instance_id = instance_id;
}
assert(!se->compat || se->instance_id == 0);
/* add at the end of list */
QTAILQ_INSERT_TAIL(&savevm_state.handlers, se, entry);
return 0;
}
int register_savevm(DeviceState *dev,
const char *idstr,
int instance_id,
int version_id,
SaveStateHandler *save_state,
LoadStateHandler *load_state,
void *opaque)
{
SaveVMHandlers *ops = g_malloc0(sizeof(SaveVMHandlers));
ops->save_state = save_state;
ops->load_state = load_state;
return register_savevm_live(dev, idstr, instance_id, version_id,
ops, opaque);
}
void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque)
{
SaveStateEntry *se, *new_se;
char id[256] = "";
if (dev) {
char *path = qdev_get_dev_path(dev);
if (path) {
pstrcpy(id, sizeof(id), path);
pstrcat(id, sizeof(id), "/");
g_free(path);
}
}
pstrcat(id, sizeof(id), idstr);
QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
QTAILQ_REMOVE(&savevm_state.handlers, se, entry);
if (se->compat) {
g_free(se->compat);
}
g_free(se->ops);
g_free(se);
}
}
}
int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
const VMStateDescription *vmsd,
void *opaque, int alias_id,
int required_for_version)
{
SaveStateEntry *se;
/* If this triggers, alias support can be dropped for the vmsd. */
assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id);
se = g_malloc0(sizeof(SaveStateEntry));
se->version_id = vmsd->version_id;
se->section_id = savevm_state.global_section_id++;
se->opaque = opaque;
se->vmsd = vmsd;
se->alias_id = alias_id;
if (dev) {
char *id = qdev_get_dev_path(dev);
if (id) {
pstrcpy(se->idstr, sizeof(se->idstr), id);
pstrcat(se->idstr, sizeof(se->idstr), "/");
g_free(id);
se->compat = g_malloc0(sizeof(CompatEntry));
pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
se->compat->instance_id = instance_id == -1 ?
calculate_compat_instance_id(vmsd->name) : instance_id;
instance_id = -1;
}
}
pstrcat(se->idstr, sizeof(se->idstr), vmsd->name);
if (instance_id == -1) {
se->instance_id = calculate_new_instance_id(se->idstr);
} else {
se->instance_id = instance_id;
}
assert(!se->compat || se->instance_id == 0);
/* add at the end of list */
QTAILQ_INSERT_TAIL(&savevm_state.handlers, se, entry);
return 0;
}
void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd,
void *opaque)
{
SaveStateEntry *se, *new_se;
QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
if (se->vmsd == vmsd && se->opaque == opaque) {
QTAILQ_REMOVE(&savevm_state.handlers, se, entry);
if (se->compat) {
g_free(se->compat);
}
g_free(se);
}
}
}
static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id)
{
trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
if (!se->vmsd) { /* Old style */
return se->ops->load_state(f, se->opaque, version_id);
}
return vmstate_load_state(f, se->vmsd, se->opaque, version_id);
}
static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
{
int64_t old_offset, size;
old_offset = qemu_ftell_fast(f);
se->ops->save_state(f, se->opaque);
size = qemu_ftell_fast(f) - old_offset;
if (vmdesc) {
json_prop_int(vmdesc, "size", size);
json_start_array(vmdesc, "fields");
json_start_object(vmdesc, NULL);
json_prop_str(vmdesc, "name", "data");
json_prop_int(vmdesc, "size", size);
json_prop_str(vmdesc, "type", "buffer");
json_end_object(vmdesc);
json_end_array(vmdesc);
}
}
static void vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
{
trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
if (!se->vmsd) {
vmstate_save_old_style(f, se, vmdesc);
return;
}
vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
}
void savevm_skip_section_footers(void)
{
skip_section_footers = true;
}
/*
* Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
*/
static void save_section_header(QEMUFile *f, SaveStateEntry *se,
uint8_t section_type)
{
qemu_put_byte(f, section_type);
qemu_put_be32(f, se->section_id);
if (section_type == QEMU_VM_SECTION_FULL ||
section_type == QEMU_VM_SECTION_START) {
/* ID string */
size_t len = strlen(se->idstr);
qemu_put_byte(f, len);
qemu_put_buffer(f, (uint8_t *)se->idstr, len);
qemu_put_be32(f, se->instance_id);
qemu_put_be32(f, se->version_id);
}
}
/*
* Write a footer onto device sections that catches cases misformatted device
* sections.
*/
static void save_section_footer(QEMUFile *f, SaveStateEntry *se)
{
if (!skip_section_footers) {
qemu_put_byte(f, QEMU_VM_SECTION_FOOTER);
qemu_put_be32(f, se->section_id);
}
}
/*
* Read a footer off the wire and check that it matches the expected section
*
* Returns: true if the footer was good
* false if there is a problem (and calls error_report to say why)
*/
static bool check_section_footer(QEMUFile *f, SaveStateEntry *se)
{
uint8_t read_mark;
uint32_t read_section_id;
if (skip_section_footers) {
/* No footer to check */
return true;
}
read_mark = qemu_get_byte(f);
if (read_mark != QEMU_VM_SECTION_FOOTER) {
error_report("Missing section footer for %s", se->idstr);
return false;
}
read_section_id = qemu_get_be32(f);
if (read_section_id != se->section_id) {
error_report("Mismatched section id in footer for %s -"
" read 0x%x expected 0x%x",
se->idstr, read_section_id, se->section_id);
return false;
}
/* All good */
return true;
}
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (se->vmsd && se->vmsd->unmigratable) {
error_setg(errp, "State blocked by non-migratable device '%s'",
se->idstr);
return true;
}
}
return false;
}
void qemu_savevm_state_header(QEMUFile *f)
{
trace_savevm_state_header();
qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
qemu_put_be32(f, QEMU_VM_FILE_VERSION);
}
void qemu_savevm_state_begin(QEMUFile *f,
const MigrationParams *params)
{
SaveStateEntry *se;
int ret;
trace_savevm_state_begin();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->set_params) {
continue;
}
se->ops->set_params(params, se->opaque);
}
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_setup) {
continue;
}
if (se->ops && se->ops->is_active) {
if (!se->ops->is_active(se->opaque)) {
continue;
}
}
save_section_header(f, se, QEMU_VM_SECTION_START);
ret = se->ops->save_live_setup(f, se->opaque);
save_section_footer(f, se);
if (ret < 0) {
qemu_file_set_error(f, ret);
break;
}
}
}
/*
* this function has three return values:
* negative: there was one error, and we have -errno.
* 0 : We haven't finished, caller have to go again
* 1 : We have finished, we can go to complete phase
*/
int qemu_savevm_state_iterate(QEMUFile *f)
{
SaveStateEntry *se;
int ret = 1;
trace_savevm_state_iterate();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_iterate) {
continue;
}
if (se->ops && se->ops->is_active) {
if (!se->ops->is_active(se->opaque)) {
continue;
}
}
if (qemu_file_rate_limit(f)) {
return 0;
}
trace_savevm_section_start(se->idstr, se->section_id);
save_section_header(f, se, QEMU_VM_SECTION_PART);
ret = se->ops->save_live_iterate(f, se->opaque);
trace_savevm_section_end(se->idstr, se->section_id, ret);
save_section_footer(f, se);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
if (ret <= 0) {
/* Do not proceed to the next vmstate before this one reported
completion of the current stage. This serializes the migration
and reduces the probability that a faster changing state is
synchronized over and over again. */
break;
}
}
return ret;
}
static bool should_send_vmdesc(void)
{
MachineState *machine = MACHINE(qdev_get_machine());
return !machine->suppress_vmdesc;
}
void qemu_savevm_state_complete(QEMUFile *f)
{
QJSON *vmdesc;
int vmdesc_len;
SaveStateEntry *se;
int ret;
trace_savevm_state_complete();
cpu_synchronize_all_states();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_complete) {
continue;
}
if (se->ops && se->ops->is_active) {
if (!se->ops->is_active(se->opaque)) {
continue;
}
}
trace_savevm_section_start(se->idstr, se->section_id);
save_section_header(f, se, QEMU_VM_SECTION_END);
ret = se->ops->save_live_complete(f, se->opaque);
trace_savevm_section_end(se->idstr, se->section_id, ret);
save_section_footer(f, se);
if (ret < 0) {
qemu_file_set_error(f, ret);
return;
}
}
vmdesc = qjson_new();
json_prop_int(vmdesc, "page_size", TARGET_PAGE_SIZE);
json_start_array(vmdesc, "devices");
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
continue;
}
trace_savevm_section_start(se->idstr, se->section_id);
json_start_object(vmdesc, NULL);
json_prop_str(vmdesc, "name", se->idstr);
json_prop_int(vmdesc, "instance_id", se->instance_id);
save_section_header(f, se, QEMU_VM_SECTION_FULL);
vmstate_save(f, se, vmdesc);
json_end_object(vmdesc);
trace_savevm_section_end(se->idstr, se->section_id, 0);
save_section_footer(f, se);
}
qemu_put_byte(f, QEMU_VM_EOF);
json_end_array(vmdesc);
qjson_finish(vmdesc);
vmdesc_len = strlen(qjson_get_str(vmdesc));
if (should_send_vmdesc()) {
qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
qemu_put_be32(f, vmdesc_len);
qemu_put_buffer(f, (uint8_t *)qjson_get_str(vmdesc), vmdesc_len);
}
object_unref(OBJECT(vmdesc));
qemu_fflush(f);
}
uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
{
SaveStateEntry *se;
uint64_t ret = 0;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_pending) {
continue;
}
if (se->ops && se->ops->is_active) {
if (!se->ops->is_active(se->opaque)) {
continue;
}
}
ret += se->ops->save_live_pending(f, se->opaque, max_size);
}
return ret;
}
void qemu_savevm_state_cancel(void)
{
SaveStateEntry *se;
trace_savevm_state_cancel();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (se->ops && se->ops->cancel) {
se->ops->cancel(se->opaque);
}
}
}
static int qemu_savevm_state(QEMUFile *f, Error **errp)
{
int ret;
MigrationParams params = {
.blk = 0,
.shared = 0
};
if (qemu_savevm_state_blocked(errp)) {
return -EINVAL;
}
qemu_mutex_unlock_iothread();
qemu_savevm_state_header(f);
qemu_savevm_state_begin(f, &params);
qemu_mutex_lock_iothread();
while (qemu_file_get_error(f) == 0) {
if (qemu_savevm_state_iterate(f) > 0) {
break;
}
}
ret = qemu_file_get_error(f);
if (ret == 0) {
qemu_savevm_state_complete(f);
ret = qemu_file_get_error(f);
}
if (ret != 0) {
qemu_savevm_state_cancel();
error_setg_errno(errp, -ret, "Error while writing VM state");
}
return ret;
}
static int qemu_save_device_state(QEMUFile *f)
{
SaveStateEntry *se;
qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
qemu_put_be32(f, QEMU_VM_FILE_VERSION);
cpu_synchronize_all_states();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (se->is_ram) {
continue;
}
if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
continue;
}
save_section_header(f, se, QEMU_VM_SECTION_FULL);
vmstate_save(f, se, NULL);
save_section_footer(f, se);
}
qemu_put_byte(f, QEMU_VM_EOF);
return qemu_file_get_error(f);
}
static SaveStateEntry *find_se(const char *idstr, int instance_id)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!strcmp(se->idstr, idstr) &&
(instance_id == se->instance_id ||
instance_id == se->alias_id))
return se;
/* Migrating from an older version? */
if (strstr(se->idstr, idstr) && se->compat) {
if (!strcmp(se->compat->idstr, idstr) &&
(instance_id == se->compat->instance_id ||
instance_id == se->alias_id))
return se;
}
}
return NULL;
}
struct LoadStateEntry {
QLIST_ENTRY(LoadStateEntry) entry;
SaveStateEntry *se;
int section_id;
int version_id;
};
void loadvm_free_handlers(MigrationIncomingState *mis)
{
LoadStateEntry *le, *new_le;
QLIST_FOREACH_SAFE(le, &mis->loadvm_handlers, entry, new_le) {
QLIST_REMOVE(le, entry);
g_free(le);
}
}
int qemu_loadvm_state(QEMUFile *f)
{
MigrationIncomingState *mis = migration_incoming_get_current();
Error *local_err = NULL;
uint8_t section_type;
unsigned int v;
int ret;
int file_error_after_eof = -1;
if (qemu_savevm_state_blocked(&local_err)) {
error_report_err(local_err);
return -EINVAL;
}
v = qemu_get_be32(f);
if (v != QEMU_VM_FILE_MAGIC) {
error_report("Not a migration stream");
return -EINVAL;
}
v = qemu_get_be32(f);
if (v == QEMU_VM_FILE_VERSION_COMPAT) {
error_report("SaveVM v2 format is obsolete and don't work anymore");
return -ENOTSUP;
}
if (v != QEMU_VM_FILE_VERSION) {
error_report("Unsupported migration stream version");
return -ENOTSUP;
}
while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
uint32_t instance_id, version_id, section_id;
SaveStateEntry *se;
LoadStateEntry *le;
char idstr[256];
trace_qemu_loadvm_state_section(section_type);
switch (section_type) {
case QEMU_VM_SECTION_START:
case QEMU_VM_SECTION_FULL:
/* Read section start */
section_id = qemu_get_be32(f);
if (!qemu_get_counted_string(f, idstr)) {
error_report("Unable to read ID string for section %u",
section_id);
return -EINVAL;
}
instance_id = qemu_get_be32(f);
version_id = qemu_get_be32(f);
trace_qemu_loadvm_state_section_startfull(section_id, idstr,
instance_id, version_id);
/* Find savevm section */
se = find_se(idstr, instance_id);
if (se == NULL) {
error_report("Unknown savevm section or instance '%s' %d",
idstr, instance_id);
ret = -EINVAL;
goto out;
}
/* Validate version */
if (version_id > se->version_id) {
error_report("savevm: unsupported version %d for '%s' v%d",
version_id, idstr, se->version_id);
ret = -EINVAL;
goto out;
}
/* Add entry */
le = g_malloc0(sizeof(*le));
le->se = se;
le->section_id = section_id;
le->version_id = version_id;
QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
ret = vmstate_load(f, le->se, le->version_id);
if (ret < 0) {
error_report("error while loading state for instance 0x%x of"
" device '%s'", instance_id, idstr);
goto out;
}
if (!check_section_footer(f, le->se)) {
ret = -EINVAL;
goto out;
}
break;
case QEMU_VM_SECTION_PART:
case QEMU_VM_SECTION_END:
section_id = qemu_get_be32(f);
trace_qemu_loadvm_state_section_partend(section_id);
QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
if (le->section_id == section_id) {
break;
}
}
if (le == NULL) {
error_report("Unknown savevm section %d", section_id);
ret = -EINVAL;
goto out;
}
ret = vmstate_load(f, le->se, le->version_id);
if (ret < 0) {
error_report("error while loading state section id %d(%s)",
section_id, le->se->idstr);
goto out;
}
if (!check_section_footer(f, le->se)) {
ret = -EINVAL;
goto out;
}
break;
default:
error_report("Unknown savevm section type %d", section_type);
ret = -EINVAL;
goto out;
}
}
file_error_after_eof = qemu_file_get_error(f);
/*
* Try to read in the VMDESC section as well, so that dumping tools that
* intercept our migration stream have the chance to see it.
*/
if (qemu_get_byte(f) == QEMU_VM_VMDESCRIPTION) {
uint32_t size = qemu_get_be32(f);
uint8_t *buf = g_malloc(0x1000);
while (size > 0) {
uint32_t read_chunk = MIN(size, 0x1000);
qemu_get_buffer(f, buf, read_chunk);
size -= read_chunk;
}
g_free(buf);
}
cpu_synchronize_all_post_init();
ret = 0;
out:
if (ret == 0) {
/* We may not have a VMDESC section, so ignore relative errors */
ret = file_error_after_eof;
}
return ret;
}
static BlockDriverState *find_vmstate_bs(void)
{
BlockDriverState *bs = NULL;
while ((bs = bdrv_next(bs))) {
if (bdrv_can_snapshot(bs)) {
return bs;
}
}
return NULL;
}
/*
* Deletes snapshots of a given name in all opened images.
*/
static int del_existing_snapshots(Monitor *mon, const char *name)
{
BlockDriverState *bs;
QEMUSnapshotInfo sn1, *snapshot = &sn1;
Error *err = NULL;
bs = NULL;
while ((bs = bdrv_next(bs))) {
if (bdrv_can_snapshot(bs) &&
bdrv_snapshot_find(bs, snapshot, name) >= 0) {
bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
if (err) {
monitor_printf(mon,
"Error while deleting snapshot on device '%s':"
" %s\n",
bdrv_get_device_name(bs),
error_get_pretty(err));
error_free(err);
return -1;
}
}
}
return 0;
}
void hmp_savevm(Monitor *mon, const QDict *qdict)
{
BlockDriverState *bs, *bs1;
QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
int ret;
QEMUFile *f;
int saved_vm_running;
uint64_t vm_state_size;
qemu_timeval tv;
struct tm tm;
const char *name = qdict_get_try_str(qdict, "name");
Error *local_err = NULL;
/* Verify if there is a device that doesn't support snapshots and is writable */
bs = NULL;
while ((bs = bdrv_next(bs))) {
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
continue;
}
if (!bdrv_can_snapshot(bs)) {
monitor_printf(mon, "Device '%s' is writable but does not support snapshots.\n",
bdrv_get_device_name(bs));
return;
}
}
bs = find_vmstate_bs();
if (!bs) {
monitor_printf(mon, "No block device can accept snapshots\n");
return;
}
saved_vm_running = runstate_is_running();
vm_stop(RUN_STATE_SAVE_VM);
memset(sn, 0, sizeof(*sn));
/* fill auxiliary fields */
qemu_gettimeofday(&tv);
sn->date_sec = tv.tv_sec;
sn->date_nsec = tv.tv_usec * 1000;
sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
if (name) {
ret = bdrv_snapshot_find(bs, old_sn, name);
if (ret >= 0) {
pstrcpy(sn->name, sizeof(sn->name), old_sn->name);
pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str);
} else {
pstrcpy(sn->name, sizeof(sn->name), name);
}
} else {
/* cast below needed for OpenBSD where tv_sec is still 'long' */
localtime_r((const time_t *)&tv.tv_sec, &tm);
strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm);
}
/* Delete old snapshots of the same name */
if (name && del_existing_snapshots(mon, name) < 0) {
goto the_end;
}
/* save the VM state */
f = qemu_fopen_bdrv(bs, 1);
if (!f) {
monitor_printf(mon, "Could not open VM state file\n");
goto the_end;
}
ret = qemu_savevm_state(f, &local_err);
vm_state_size = qemu_ftell(f);
qemu_fclose(f);
if (ret < 0) {
monitor_printf(mon, "%s\n", error_get_pretty(local_err));
error_free(local_err);
goto the_end;
}
/* create the snapshots */
bs1 = NULL;
while ((bs1 = bdrv_next(bs1))) {
if (bdrv_can_snapshot(bs1)) {
/* Write VM state size only to the image that contains the state */
sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
ret = bdrv_snapshot_create(bs1, sn);
if (ret < 0) {
monitor_printf(mon, "Error while creating snapshot on '%s'\n",
bdrv_get_device_name(bs1));
}
}
}
the_end:
if (saved_vm_running) {
vm_start();
}
}
void qmp_xen_save_devices_state(const char *filename, Error **errp)
{
QEMUFile *f;
int saved_vm_running;
int ret;
saved_vm_running = runstate_is_running();
vm_stop(RUN_STATE_SAVE_VM);
f = qemu_fopen(filename, "wb");
if (!f) {
error_setg_file_open(errp, errno, filename);
goto the_end;
}
ret = qemu_save_device_state(f);
qemu_fclose(f);
if (ret < 0) {
error_set(errp, QERR_IO_ERROR);
}
the_end:
if (saved_vm_running) {
vm_start();
}
}
int load_vmstate(const char *name)
{
BlockDriverState *bs, *bs_vm_state;
QEMUSnapshotInfo sn;
QEMUFile *f;
int ret;
bs_vm_state = find_vmstate_bs();
if (!bs_vm_state) {
error_report("No block device supports snapshots");
return -ENOTSUP;
}
/* Don't even try to load empty VM states */
ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
if (ret < 0) {
return ret;
} else if (sn.vm_state_size == 0) {
error_report("This is a disk-only snapshot. Revert to it offline "
"using qemu-img.");
return -EINVAL;
}
/* Verify if there is any device that doesn't support snapshots and is
writable and check if the requested snapshot is available too. */
bs = NULL;
while ((bs = bdrv_next(bs))) {
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
continue;
}
if (!bdrv_can_snapshot(bs)) {
error_report("Device '%s' is writable but does not support snapshots.",
bdrv_get_device_name(bs));
return -ENOTSUP;
}
ret = bdrv_snapshot_find(bs, &sn, name);
if (ret < 0) {
error_report("Device '%s' does not have the requested snapshot '%s'",
bdrv_get_device_name(bs), name);
return ret;
}
}
/* Flush all IO requests so they don't interfere with the new state. */
bdrv_drain_all();
bs = NULL;
while ((bs = bdrv_next(bs))) {
if (bdrv_can_snapshot(bs)) {
ret = bdrv_snapshot_goto(bs, name);
if (ret < 0) {
error_report("Error %d while activating snapshot '%s' on '%s'",
ret, name, bdrv_get_device_name(bs));
return ret;
}
}
}
/* restore the VM state */
f = qemu_fopen_bdrv(bs_vm_state, 0);
if (!f) {
error_report("Could not open VM state file");
return -EINVAL;
}
qemu_system_reset(VMRESET_SILENT);
migration_incoming_state_new(f);
ret = qemu_loadvm_state(f);
qemu_fclose(f);
migration_incoming_state_destroy();
if (ret < 0) {
error_report("Error %d while loading VM state", ret);
return ret;
}
return 0;
}
void hmp_delvm(Monitor *mon, const QDict *qdict)
{
BlockDriverState *bs;
Error *err;
const char *name = qdict_get_str(qdict, "name");
if (!find_vmstate_bs()) {
monitor_printf(mon, "No block device supports snapshots\n");
return;
}
bs = NULL;
while ((bs = bdrv_next(bs))) {
if (bdrv_can_snapshot(bs)) {
err = NULL;
bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
if (err) {
monitor_printf(mon,
"Error while deleting snapshot on device '%s':"
" %s\n",
bdrv_get_device_name(bs),
error_get_pretty(err));
error_free(err);
}
}
}
}
void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
{
BlockDriverState *bs, *bs1;
QEMUSnapshotInfo *sn_tab, *sn, s, *sn_info = &s;
int nb_sns, i, ret, available;
int total;
int *available_snapshots;
bs = find_vmstate_bs();
if (!bs) {
monitor_printf(mon, "No available block device supports snapshots\n");
return;
}
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns < 0) {
monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns);
return;
}
if (nb_sns == 0) {
monitor_printf(mon, "There is no snapshot available.\n");
return;
}
available_snapshots = g_malloc0(sizeof(int) * nb_sns);
total = 0;
for (i = 0; i < nb_sns; i++) {
sn = &sn_tab[i];
available = 1;
bs1 = NULL;
while ((bs1 = bdrv_next(bs1))) {
if (bdrv_can_snapshot(bs1) && bs1 != bs) {
ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str);
if (ret < 0) {
available = 0;
break;
}
}
}
if (available) {
available_snapshots[total] = i;
total++;
}
}
if (total > 0) {
bdrv_snapshot_dump((fprintf_function)monitor_printf, mon, NULL);
monitor_printf(mon, "\n");
for (i = 0; i < total; i++) {
sn = &sn_tab[available_snapshots[i]];
bdrv_snapshot_dump((fprintf_function)monitor_printf, mon, sn);
monitor_printf(mon, "\n");
}
} else {
monitor_printf(mon, "There is no suitable snapshot available\n");
}
g_free(sn_tab);
g_free(available_snapshots);
}
void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
{
qemu_ram_set_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK,
memory_region_name(mr), dev);
}
void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
{
qemu_ram_unset_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
}
void vmstate_register_ram_global(MemoryRegion *mr)
{
vmstate_register_ram(mr, NULL);
}
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