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e9ff957ac2
qemu/migration/savevm.c
Denis V. Lunev e9ff957ac2 snapshot: create helper to test that block drivers supports snapshots 
The patch enforces proper locking for this operation.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-19 11:50:00 +01:00

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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 "migration/postcopy-ram.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.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/bitops.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
const unsigned int postcopy_ram_discard_version = 0;
static bool skip_section_footers;
static struct mig_cmd_args {
ssize_t len; /* -1 = variable */
const char *name;
} mig_cmd_args[] = {
[MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" },
[MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" },
[MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" },
[MIG_CMD_POSTCOPY_ADVISE] = { .len = 16, .name = "POSTCOPY_ADVISE" },
[MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" },
[MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
[MIG_CMD_POSTCOPY_RAM_DISCARD] = {
.len = -1, .name = "POSTCOPY_RAM_DISCARD" },
[MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" },
[MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
};
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 ssize_t block_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, size_t size)
{
bdrv_save_vmstate(opaque, buf, pos, size);
return size;
}
static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
size_t 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;
bool skip_configuration;
uint32_t len;
const char *name;
} SaveState;
static SaveState savevm_state = {
.handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
.global_section_id = 0,
.skip_configuration = false,
};
void savevm_skip_configuration(void)
{
savevm_state.skip_configuration = true;
}
static void configuration_pre_save(void *opaque)
{
SaveState *state = opaque;
const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
state->len = strlen(current_name);
state->name = current_name;
}
static int configuration_post_load(void *opaque, int version_id)
{
SaveState *state = opaque;
const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
if (strncmp(state->name, current_name, state->len) != 0) {
error_report("Machine type received is '%s' and local is '%s'",
state->name, current_name);
return -EINVAL;
}
return 0;
}
static const VMStateDescription vmstate_configuration = {
.name = "configuration",
.version_id = 1,
.post_load = configuration_post_load,
.pre_save = configuration_pre_save,
.fields = (VMStateField[]) {
VMSTATE_UINT32(len, SaveState),
VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, 0, len),
VMSTATE_END_OF_LIST()
},
};
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_new0(SaveStateEntry, 1);
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_new0(CompatEntry, 1);
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_new0(SaveVMHandlers, 1);
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);
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_new0(SaveStateEntry, 1);
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_new0(CompatEntry, 1);
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);
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);
}
}
/**
* qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
* command and associated data.
*
* @f: File to send command on
* @command: Command type to send
* @len: Length of associated data
* @data: Data associated with command.
*/
void qemu_savevm_command_send(QEMUFile *f,
enum qemu_vm_cmd command,
uint16_t len,
uint8_t *data)
{
trace_savevm_command_send(command, len);
qemu_put_byte(f, QEMU_VM_COMMAND);
qemu_put_be16(f, (uint16_t)command);
qemu_put_be16(f, len);
qemu_put_buffer(f, data, len);
qemu_fflush(f);
}
void qemu_savevm_send_ping(QEMUFile *f, uint32_t value)
{
uint32_t buf;
trace_savevm_send_ping(value);
buf = cpu_to_be32(value);
qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf);
}
void qemu_savevm_send_open_return_path(QEMUFile *f)
{
trace_savevm_send_open_return_path();
qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
}
/* We have a buffer of data to send; we don't want that all to be loaded
* by the command itself, so the command contains just the length of the
* extra buffer that we then send straight after it.
* TODO: Must be a better way to organise that
*
* Returns:
* 0 on success
* -ve on error
*/
int qemu_savevm_send_packaged(QEMUFile *f, const QEMUSizedBuffer *qsb)
{
size_t cur_iov;
size_t len = qsb_get_length(qsb);
uint32_t tmp;
if (len > MAX_VM_CMD_PACKAGED_SIZE) {
error_report("%s: Unreasonably large packaged state: %zu",
__func__, len);
return -1;
}
tmp = cpu_to_be32(len);
trace_qemu_savevm_send_packaged();
qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp);
/* all the data follows (concatinating the iov's) */
for (cur_iov = 0; cur_iov < qsb->n_iov; cur_iov++) {
/* The iov entries are partially filled */
size_t towrite = MIN(qsb->iov[cur_iov].iov_len, len);
len -= towrite;
if (!towrite) {
break;
}
qemu_put_buffer(f, qsb->iov[cur_iov].iov_base, towrite);
}
return 0;
}
/* Send prior to any postcopy transfer */
void qemu_savevm_send_postcopy_advise(QEMUFile *f)
{
uint64_t tmp[2];
tmp[0] = cpu_to_be64(getpagesize());
tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
trace_qemu_savevm_send_postcopy_advise();
qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 16, (uint8_t *)tmp);
}
/* Sent prior to starting the destination running in postcopy, discard pages
* that have already been sent but redirtied on the source.
* CMD_POSTCOPY_RAM_DISCARD consist of:
* byte version (0)
* byte Length of name field (not including 0)
* n x byte RAM block name
* byte 0 terminator (just for safety)
* n x Byte ranges within the named RAMBlock
* be64 Start of the range
* be64 Length
*
* name: RAMBlock name that these entries are part of
* len: Number of page entries
* start_list: 'len' addresses
* length_list: 'len' addresses
*
*/
void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
uint16_t len,
uint64_t *start_list,
uint64_t *length_list)
{
uint8_t *buf;
uint16_t tmplen;
uint16_t t;
size_t name_len = strlen(name);
trace_qemu_savevm_send_postcopy_ram_discard(name, len);
assert(name_len < 256);
buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len);
buf[0] = postcopy_ram_discard_version;
buf[1] = name_len;
memcpy(buf + 2, name, name_len);
tmplen = 2 + name_len;
buf[tmplen++] = '\0';
for (t = 0; t < len; t++) {
cpu_to_be64w((uint64_t *)(buf + tmplen), start_list[t]);
tmplen += 8;
cpu_to_be64w((uint64_t *)(buf + tmplen), length_list[t]);
tmplen += 8;
}
qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf);
g_free(buf);
}
/* Get the destination into a state where it can receive postcopy data. */
void qemu_savevm_send_postcopy_listen(QEMUFile *f)
{
trace_savevm_send_postcopy_listen();
qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL);
}
/* Kick the destination into running */
void qemu_savevm_send_postcopy_run(QEMUFile *f)
{
trace_savevm_send_postcopy_run();
qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
}
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);
if (!savevm_state.skip_configuration) {
qemu_put_byte(f, QEMU_VM_CONFIGURATION);
vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
}
}
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, bool postcopy)
{
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;
}
}
/*
* In the postcopy phase, any device that doesn't know how to
* do postcopy should have saved it's state in the _complete
* call that's already run, it might get confused if we call
* iterate afterwards.
*/
if (postcopy && !se->ops->save_live_complete_postcopy) {
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());
bool in_postcopy = migration_in_postcopy(migrate_get_current());
return !machine->suppress_vmdesc && !in_postcopy;
}
/*
* Calls the save_live_complete_postcopy methods
* causing the last few pages to be sent immediately and doing any associated
* cleanup.
* Note postcopy also calls qemu_savevm_state_complete_precopy to complete
* all the other devices, but that happens at the point we switch to postcopy.
*/
void qemu_savevm_state_complete_postcopy(QEMUFile *f)
{
SaveStateEntry *se;
int ret;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_complete_postcopy) {
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);
/* Section type */
qemu_put_byte(f, QEMU_VM_SECTION_END);
qemu_put_be32(f, se->section_id);
ret = se->ops->save_live_complete_postcopy(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;
}
}
qemu_put_byte(f, QEMU_VM_EOF);
qemu_fflush(f);
}
void qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only)
{
QJSON *vmdesc;
int vmdesc_len;
SaveStateEntry *se;
int ret;
bool in_postcopy = migration_in_postcopy(migrate_get_current());
trace_savevm_state_complete_precopy();
cpu_synchronize_all_states();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops ||
(in_postcopy && se->ops->save_live_complete_postcopy) ||
(in_postcopy && !iterable_only) ||
!se->ops->save_live_complete_precopy) {
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_precopy(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;
}
}
if (iterable_only) {
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;
}
if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
trace_savevm_section_skip(se->idstr, se->section_id);
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);
}
if (!in_postcopy) {
/* Postcopy stream will still be going */
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);
}
/* Give an estimate of the amount left to be transferred,
* the result is split into the amount for units that can and
* for units that can't do postcopy.
*/
void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
uint64_t *res_non_postcopiable,
uint64_t *res_postcopiable)
{
SaveStateEntry *se;
*res_non_postcopiable = 0;
*res_postcopiable = 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;
}
}
se->ops->save_live_pending(f, se->opaque, max_size,
res_non_postcopiable, res_postcopiable);
}
}
void qemu_savevm_state_cleanup(void)
{
SaveStateEntry *se;
trace_savevm_state_cleanup();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (se->ops && se->ops->cleanup) {
se->ops->cleanup(se->opaque);
}
}
}
static int qemu_savevm_state(QEMUFile *f, Error **errp)
{
int ret;
MigrationParams params = {
.blk = 0,
.shared = 0
};
MigrationState *ms = migrate_init(&params);
ms->file = f;
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, false) > 0) {
break;
}
}
ret = qemu_file_get_error(f);
if (ret == 0) {
qemu_savevm_state_complete_precopy(f, false);
ret = qemu_file_get_error(f);
}
qemu_savevm_state_cleanup();
if (ret != 0) {
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;
}
if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
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;
}
enum LoadVMExitCodes {
/* Allow a command to quit all layers of nested loadvm loops */
LOADVM_QUIT = 1,
};
static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
/* ------ incoming postcopy messages ------ */
/* 'advise' arrives before any transfers just to tell us that a postcopy
* *might* happen - it might be skipped if precopy transferred everything
* quickly.
*/
static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
{
PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
uint64_t remote_hps, remote_tps;
trace_loadvm_postcopy_handle_advise();
if (ps != POSTCOPY_INCOMING_NONE) {
error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps);
return -1;
}
if (!postcopy_ram_supported_by_host()) {
return -1;
}
remote_hps = qemu_get_be64(mis->from_src_file);
if (remote_hps != getpagesize()) {
/*
* Some combinations of mismatch are probably possible but it gets
* a bit more complicated. In particular we need to place whole
* host pages on the dest at once, and we need to ensure that we
* handle dirtying to make sure we never end up sending part of
* a hostpage on it's own.
*/
error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
(int)remote_hps, getpagesize());
return -1;
}
remote_tps = qemu_get_be64(mis->from_src_file);
if (remote_tps != (1ul << qemu_target_page_bits())) {
/*
* Again, some differences could be dealt with, but for now keep it
* simple.
*/
error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
(int)remote_tps, 1 << qemu_target_page_bits());
return -1;
}
if (ram_postcopy_incoming_init(mis)) {
return -1;
}
postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
return 0;
}
/* After postcopy we will be told to throw some pages away since they're
* dirty and will have to be demand fetched. Must happen before CPU is
* started.
* There can be 0..many of these messages, each encoding multiple pages.
*/
static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
uint16_t len)
{
int tmp;
char ramid[256];
PostcopyState ps = postcopy_state_get();
trace_loadvm_postcopy_ram_handle_discard();
switch (ps) {
case POSTCOPY_INCOMING_ADVISE:
/* 1st discard */
tmp = postcopy_ram_prepare_discard(mis);
if (tmp) {
return tmp;
}
break;
case POSTCOPY_INCOMING_DISCARD:
/* Expected state */
break;
default:
error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
ps);
return -1;
}
/* We're expecting a
* Version (0)
* a RAM ID string (length byte, name, 0 term)
* then at least 1 16 byte chunk
*/
if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
return -1;
}
tmp = qemu_get_byte(mis->from_src_file);
if (tmp != postcopy_ram_discard_version) {
error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
return -1;
}
if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
return -1;
}
tmp = qemu_get_byte(mis->from_src_file);
if (tmp != 0) {
error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
return -1;
}
len -= 3 + strlen(ramid);
if (len % 16) {
error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
return -1;
}
trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
while (len) {
uint64_t start_addr, block_length;
start_addr = qemu_get_be64(mis->from_src_file);
block_length = qemu_get_be64(mis->from_src_file);
len -= 16;
int ret = ram_discard_range(mis, ramid, start_addr,
block_length);
if (ret) {
return ret;
}
}
trace_loadvm_postcopy_ram_handle_discard_end();
return 0;
}
/*
* Triggered by a postcopy_listen command; this thread takes over reading
* the input stream, leaving the main thread free to carry on loading the rest
* of the device state (from RAM).
* (TODO:This could do with being in a postcopy file - but there again it's
* just another input loop, not that postcopy specific)
*/
static void *postcopy_ram_listen_thread(void *opaque)
{
QEMUFile *f = opaque;
MigrationIncomingState *mis = migration_incoming_get_current();
int load_res;
qemu_sem_post(&mis->listen_thread_sem);
trace_postcopy_ram_listen_thread_start();
/*
* Because we're a thread and not a coroutine we can't yield
* in qemu_file, and thus we must be blocking now.
*/
qemu_file_set_blocking(f, true);
load_res = qemu_loadvm_state_main(f, mis);
/* And non-blocking again so we don't block in any cleanup */
qemu_file_set_blocking(f, false);
trace_postcopy_ram_listen_thread_exit();
if (load_res < 0) {
error_report("%s: loadvm failed: %d", __func__, load_res);
qemu_file_set_error(f, load_res);
} else {
/*
* This looks good, but it's possible that the device loading in the
* main thread hasn't finished yet, and so we might not be in 'RUN'
* state yet; wait for the end of the main thread.
*/
qemu_event_wait(&mis->main_thread_load_event);
}
postcopy_ram_incoming_cleanup(mis);
/*
* If everything has worked fine, then the main thread has waited
* for us to start, and we're the last use of the mis.
* (If something broke then qemu will have to exit anyway since it's
* got a bad migration state).
*/
migration_incoming_state_destroy();
if (load_res < 0) {
/*
* If something went wrong then we have a bad state so exit;
* depending how far we got it might be possible at this point
* to leave the guest running and fire MCEs for pages that never
* arrived as a desperate recovery step.
*/
exit(EXIT_FAILURE);
}
return NULL;
}
/* After this message we must be able to immediately receive postcopy data */
static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
{
PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
trace_loadvm_postcopy_handle_listen();
if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
return -1;
}
if (ps == POSTCOPY_INCOMING_ADVISE) {
/*
* A rare case, we entered listen without having to do any discards,
* so do the setup that's normally done at the time of the 1st discard.
*/
postcopy_ram_prepare_discard(mis);
}
/*
* Sensitise RAM - can now generate requests for blocks that don't exist
* However, at this point the CPU shouldn't be running, and the IO
* shouldn't be doing anything yet so don't actually expect requests
*/
if (postcopy_ram_enable_notify(mis)) {
return -1;
}
if (mis->have_listen_thread) {
error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
return -1;
}
mis->have_listen_thread = true;
/* Start up the listening thread and wait for it to signal ready */
qemu_sem_init(&mis->listen_thread_sem, 0);
qemu_thread_create(&mis->listen_thread, "postcopy/listen",
postcopy_ram_listen_thread, mis->from_src_file,
QEMU_THREAD_JOINABLE);
qemu_sem_wait(&mis->listen_thread_sem);
qemu_sem_destroy(&mis->listen_thread_sem);
return 0;
}
/* After all discards we can start running and asking for pages */
static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
{
PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
Error *local_err = NULL;
trace_loadvm_postcopy_handle_run();
if (ps != POSTCOPY_INCOMING_LISTENING) {
error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
return -1;
}
/* TODO we should move all of this lot into postcopy_ram.c or a shared code
* in migration.c
*/
cpu_synchronize_all_post_init();
qemu_announce_self();
/* Make sure all file formats flush their mutable metadata */
bdrv_invalidate_cache_all(&local_err);
if (local_err) {
error_report_err(local_err);
return -1;
}
trace_loadvm_postcopy_handle_run_cpu_sync();
cpu_synchronize_all_post_init();
trace_loadvm_postcopy_handle_run_vmstart();
if (autostart) {
/* Hold onto your hats, starting the CPU */
vm_start();
} else {
/* leave it paused and let management decide when to start the CPU */
runstate_set(RUN_STATE_PAUSED);
}
/* We need to finish reading the stream from the package
* and also stop reading anything more from the stream that loaded the
* package (since it's now being read by the listener thread).
* LOADVM_QUIT will quit all the layers of nested loadvm loops.
*/
return LOADVM_QUIT;
}
/**
* Immediately following this command is a blob of data containing an embedded
* chunk of migration stream; read it and load it.
*
* @mis: Incoming state
* @length: Length of packaged data to read
*
* Returns: Negative values on error
*
*/
static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
{
int ret;
uint8_t *buffer;
uint32_t length;
QEMUSizedBuffer *qsb;
length = qemu_get_be32(mis->from_src_file);
trace_loadvm_handle_cmd_packaged(length);
if (length > MAX_VM_CMD_PACKAGED_SIZE) {
error_report("Unreasonably large packaged state: %u", length);
return -1;
}
buffer = g_malloc0(length);
ret = qemu_get_buffer(mis->from_src_file, buffer, (int)length);
if (ret != length) {
g_free(buffer);
error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%d\n",
ret, length);
return (ret < 0) ? ret : -EAGAIN;
}
trace_loadvm_handle_cmd_packaged_received(ret);
/* Setup a dummy QEMUFile that actually reads from the buffer */
qsb = qsb_create(buffer, length);
g_free(buffer); /* Because qsb_create copies */
if (!qsb) {
error_report("Unable to create qsb");
}
QEMUFile *packf = qemu_bufopen("r", qsb);
ret = qemu_loadvm_state_main(packf, mis);
trace_loadvm_handle_cmd_packaged_main(ret);
qemu_fclose(packf);
qsb_free(qsb);
return ret;
}
/*
* Process an incoming 'QEMU_VM_COMMAND'
* 0 just a normal return
* LOADVM_QUIT All good, but exit the loop
* <0 Error
*/
static int loadvm_process_command(QEMUFile *f)
{
MigrationIncomingState *mis = migration_incoming_get_current();
uint16_t cmd;
uint16_t len;
uint32_t tmp32;
cmd = qemu_get_be16(f);
len = qemu_get_be16(f);
trace_loadvm_process_command(cmd, len);
if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) {
error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len);
return -EINVAL;
}
if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) {
error_report("%s received with bad length - expecting %zu, got %d",
mig_cmd_args[cmd].name,
(size_t)mig_cmd_args[cmd].len, len);
return -ERANGE;
}
switch (cmd) {
case MIG_CMD_OPEN_RETURN_PATH:
if (mis->to_src_file) {
error_report("CMD_OPEN_RETURN_PATH called when RP already open");
/* Not really a problem, so don't give up */
return 0;
}
mis->to_src_file = qemu_file_get_return_path(f);
if (!mis->to_src_file) {
error_report("CMD_OPEN_RETURN_PATH failed");
return -1;
}
break;
case MIG_CMD_PING:
tmp32 = qemu_get_be32(f);
trace_loadvm_process_command_ping(tmp32);
if (!mis->to_src_file) {
error_report("CMD_PING (0x%x) received with no return path",
tmp32);
return -1;
}
migrate_send_rp_pong(mis, tmp32);
break;
case MIG_CMD_PACKAGED:
return loadvm_handle_cmd_packaged(mis);
case MIG_CMD_POSTCOPY_ADVISE:
return loadvm_postcopy_handle_advise(mis);
case MIG_CMD_POSTCOPY_LISTEN:
return loadvm_postcopy_handle_listen(mis);
case MIG_CMD_POSTCOPY_RUN:
return loadvm_postcopy_handle_run(mis);
case MIG_CMD_POSTCOPY_RAM_DISCARD:
return loadvm_postcopy_ram_handle_discard(mis, len);
}
return 0;
}
struct LoadStateEntry {
QLIST_ENTRY(LoadStateEntry) entry;
SaveStateEntry *se;
int section_id;
int version_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, LoadStateEntry *le)
{
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", le->se->idstr);
return false;
}
read_section_id = qemu_get_be32(f);
if (read_section_id != le->section_id) {
error_report("Mismatched section id in footer for %s -"
" read 0x%x expected 0x%x",
le->se->idstr, read_section_id, le->section_id);
return false;
}
/* All good */
return true;
}
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);
}
}
static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
{
uint8_t section_type;
int ret;
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);
return -EINVAL;
}
/* Validate version */
if (version_id > se->version_id) {
error_report("savevm: unsupported version %d for '%s' v%d",
version_id, idstr, se->version_id);
return -EINVAL;
}
/* 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);
return ret;
}
if (!check_section_footer(f, le)) {
return -EINVAL;
}
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);
return -EINVAL;
}
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);
return ret;
}
if (!check_section_footer(f, le)) {
return -EINVAL;
}
break;
case QEMU_VM_COMMAND:
ret = loadvm_process_command(f);
trace_qemu_loadvm_state_section_command(ret);
if ((ret < 0) || (ret & LOADVM_QUIT)) {
return ret;
}
break;
default:
error_report("Unknown savevm section type %d", section_type);
return -EINVAL;
}
}
return 0;
}
int qemu_loadvm_state(QEMUFile *f)
{
MigrationIncomingState *mis = migration_incoming_get_current();
Error *local_err = NULL;
unsigned int v;
int ret;
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;
}
if (!savevm_state.skip_configuration) {
if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
error_report("Configuration section missing");
return -EINVAL;
}
ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
if (ret) {
return ret;
}
}
ret = qemu_loadvm_state_main(f, mis);
qemu_event_set(&mis->main_thread_load_event);
trace_qemu_loadvm_state_post_main(ret);
if (mis->have_listen_thread) {
/* Listen thread still going, can't clean up yet */
return ret;
}
if (ret == 0) {
ret = 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.
*/
/* We've got to be careful; if we don't read the data and just shut the fd
* then the sender can error if we close while it's still sending.
* We also mustn't read data that isn't there; some transports (RDMA)
* will stall waiting for that data when the source has already closed.
*/
if (ret == 0 && should_send_vmdesc()) {
uint8_t *buf;
uint32_t size;
uint8_t section_type = qemu_get_byte(f);
if (section_type != QEMU_VM_VMDESCRIPTION) {
error_report("Expected vmdescription section, but got %d",
section_type);
/*
* It doesn't seem worth failing at this point since
* we apparently have an otherwise valid VM state
*/
} else {
buf = g_malloc(0x1000);
size = qemu_get_be32(f);
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();
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;
if (!bdrv_all_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();
ret = global_state_store();
if (ret) {
monitor_printf(mon, "Error saving global state\n");
return;
}
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);
global_state_store_running();
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_setg(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_new0(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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