blob: aefe052cd3b691072887b49468c78512d1c967ff [file] [log] [blame]
/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* 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 <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <errno.h>
#include <sys/time.h>
#include <zlib.h>
/* Needed early for CONFIG_BSD etc. */
#include "config-host.h"
#ifndef _WIN32
#include <sys/times.h>
#include <sys/wait.h>
#include <termios.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <dirent.h>
#include <netdb.h>
#include <sys/select.h>
#ifdef CONFIG_BSD
#include <sys/stat.h>
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
#include <libutil.h>
#else
#include <util.h>
#endif
#ifdef __linux__
#include <pty.h>
#include <malloc.h>
#include <linux/rtc.h>
#endif
#endif
#endif
#ifdef _WIN32
#include <windows.h>
#include <malloc.h>
#include <sys/timeb.h>
#include <mmsystem.h>
#define getopt_long_only getopt_long
#define memalign(align, size) malloc(size)
#endif
#include "qemu-common.h"
#include "hw/hw.h"
#include "net.h"
#include "monitor.h"
#include "sysemu.h"
#include "qemu-timer.h"
#include "qemu-char.h"
#include "block.h"
#include "audio/audio.h"
#include "migration.h"
#include "qemu_socket.h"
#include "qemu-queue.h"
/* point to the block driver where the snapshots are managed */
static BlockDriverState *bs_snapshots;
#define SELF_ANNOUNCE_ROUNDS 5
#ifndef ETH_P_RARP
#define ETH_P_RARP 0x0835
#endif
#define ARP_HTYPE_ETH 0x0001
#define ARP_PTYPE_IP 0x0800
#define ARP_OP_REQUEST_REV 0x3
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;
len = announce_self_create(buf, nic->conf->macaddr.a);
qemu_send_packet_raw(&nic->nc, 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, ... */
qemu_mod_timer(timer, qemu_get_clock(rt_clock) +
50 + (SELF_ANNOUNCE_ROUNDS - count - 1) * 100);
} else {
qemu_del_timer(timer);
qemu_free_timer(timer);
}
}
void qemu_announce_self(void)
{
static QEMUTimer *timer;
timer = qemu_new_timer(rt_clock, qemu_announce_self_once, &timer);
qemu_announce_self_once(&timer);
}
/***********************************************************/
/* savevm/loadvm support */
#define IO_BUF_SIZE 32768
struct QEMUFile {
QEMUFilePutBufferFunc *put_buffer;
QEMUFileGetBufferFunc *get_buffer;
QEMUFileCloseFunc *close;
QEMUFileRateLimit *rate_limit;
QEMUFileSetRateLimit *set_rate_limit;
QEMUFileGetRateLimit *get_rate_limit;
void *opaque;
int is_write;
int64_t buf_offset; /* start of buffer when writing, end of buffer
when reading */
int buf_index;
int buf_size; /* 0 when writing */
uint8_t buf[IO_BUF_SIZE];
int has_error;
};
typedef struct QEMUFileStdio
{
FILE *stdio_file;
QEMUFile *file;
} QEMUFileStdio;
typedef struct QEMUFileSocket
{
int fd;
QEMUFile *file;
} QEMUFileSocket;
static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
QEMUFileSocket *s = opaque;
ssize_t len;
do {
len = recv(s->fd, (void *)buf, size, 0);
} while (len == -1 && socket_error() == EINTR);
if (len == -1)
len = -socket_error();
return len;
}
static int socket_close(void *opaque)
{
QEMUFileSocket *s = opaque;
qemu_free(s);
return 0;
}
static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileStdio *s = opaque;
return fwrite(buf, 1, size, s->stdio_file);
}
static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
QEMUFileStdio *s = opaque;
FILE *fp = s->stdio_file;
int bytes;
do {
clearerr(fp);
bytes = fread(buf, 1, size, fp);
} while ((bytes == 0) && ferror(fp) && (errno == EINTR));
return bytes;
}
static int stdio_pclose(void *opaque)
{
QEMUFileStdio *s = opaque;
pclose(s->stdio_file);
qemu_free(s);
return 0;
}
static int stdio_fclose(void *opaque)
{
QEMUFileStdio *s = opaque;
fclose(s->stdio_file);
qemu_free(s);
return 0;
}
QEMUFile *qemu_popen(FILE *stdio_file, const char *mode)
{
QEMUFileStdio *s;
if (stdio_file == NULL || mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
fprintf(stderr, "qemu_popen: Argument validity check failed\n");
return NULL;
}
s = qemu_mallocz(sizeof(QEMUFileStdio));
s->stdio_file = stdio_file;
if(mode[0] == 'r') {
s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_pclose,
NULL, NULL, NULL);
} else {
s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_pclose,
NULL, NULL, NULL);
}
return s->file;
}
QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
{
FILE *popen_file;
popen_file = popen(command, mode);
if(popen_file == NULL) {
return NULL;
}
return qemu_popen(popen_file, mode);
}
int qemu_stdio_fd(QEMUFile *f)
{
QEMUFileStdio *p;
int fd;
p = (QEMUFileStdio *)f->opaque;
fd = fileno(p->stdio_file);
return fd;
}
QEMUFile *qemu_fdopen(int fd, const char *mode)
{
QEMUFileStdio *s;
if (mode == NULL ||
(mode[0] != 'r' && mode[0] != 'w') ||
mode[1] != 'b' || mode[2] != 0) {
fprintf(stderr, "qemu_fdopen: Argument validity check failed\n");
return NULL;
}
s = qemu_mallocz(sizeof(QEMUFileStdio));
s->stdio_file = fdopen(fd, mode);
if (!s->stdio_file)
goto fail;
if(mode[0] == 'r') {
s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_fclose,
NULL, NULL, NULL);
} else {
s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_fclose,
NULL, NULL, NULL);
}
return s->file;
fail:
qemu_free(s);
return NULL;
}
QEMUFile *qemu_fopen_socket(int fd)
{
QEMUFileSocket *s = qemu_mallocz(sizeof(QEMUFileSocket));
s->fd = fd;
s->file = qemu_fopen_ops(s, NULL, socket_get_buffer, socket_close,
NULL, NULL, NULL);
return s->file;
}
static int file_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
QEMUFileStdio *s = opaque;
fseek(s->stdio_file, pos, SEEK_SET);
fwrite(buf, 1, size, s->stdio_file);
return size;
}
static int file_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
QEMUFileStdio *s = opaque;
fseek(s->stdio_file, pos, SEEK_SET);
return fread(buf, 1, size, s->stdio_file);
}
QEMUFile *qemu_fopen(const char *filename, const char *mode)
{
QEMUFileStdio *s;
if (mode == NULL ||
(mode[0] != 'r' && mode[0] != 'w') ||
mode[1] != 'b' || mode[2] != 0) {
fprintf(stderr, "qemu_fdopen: Argument validity check failed\n");
return NULL;
}
s = qemu_mallocz(sizeof(QEMUFileStdio));
s->stdio_file = fopen(filename, mode);
if (!s->stdio_file)
goto fail;
if(mode[0] == 'w') {
s->file = qemu_fopen_ops(s, file_put_buffer, NULL, stdio_fclose,
NULL, NULL, NULL);
} else {
s->file = qemu_fopen_ops(s, NULL, file_get_buffer, stdio_fclose,
NULL, NULL, NULL);
}
return s->file;
fail:
qemu_free(s);
return NULL;
}
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 0;
}
static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
{
if (is_writable)
return qemu_fopen_ops(bs, block_put_buffer, NULL, bdrv_fclose,
NULL, NULL, NULL);
return qemu_fopen_ops(bs, NULL, block_get_buffer, bdrv_fclose, NULL, NULL, NULL);
}
QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
QEMUFileGetBufferFunc *get_buffer,
QEMUFileCloseFunc *close,
QEMUFileRateLimit *rate_limit,
QEMUFileSetRateLimit *set_rate_limit,
QEMUFileGetRateLimit *get_rate_limit)
{
QEMUFile *f;
f = qemu_mallocz(sizeof(QEMUFile));
f->opaque = opaque;
f->put_buffer = put_buffer;
f->get_buffer = get_buffer;
f->close = close;
f->rate_limit = rate_limit;
f->set_rate_limit = set_rate_limit;
f->get_rate_limit = get_rate_limit;
f->is_write = 0;
return f;
}
int qemu_file_has_error(QEMUFile *f)
{
return f->has_error;
}
void qemu_file_set_error(QEMUFile *f)
{
f->has_error = 1;
}
void qemu_fflush(QEMUFile *f)
{
if (!f->put_buffer)
return;
if (f->is_write && f->buf_index > 0) {
int len;
len = f->put_buffer(f->opaque, f->buf, f->buf_offset, f->buf_index);
if (len > 0)
f->buf_offset += f->buf_index;
else
f->has_error = 1;
f->buf_index = 0;
}
}
static void qemu_fill_buffer(QEMUFile *f)
{
int len;
if (!f->get_buffer)
return;
if (f->is_write)
abort();
len = f->get_buffer(f->opaque, f->buf, f->buf_offset, IO_BUF_SIZE);
if (len > 0) {
f->buf_index = 0;
f->buf_size = len;
f->buf_offset += len;
} else if (len != -EAGAIN)
f->has_error = 1;
}
int qemu_fclose(QEMUFile *f)
{
int ret = 0;
qemu_fflush(f);
if (f->close)
ret = f->close(f->opaque);
qemu_free(f);
return ret;
}
void qemu_file_put_notify(QEMUFile *f)
{
f->put_buffer(f->opaque, NULL, 0, 0);
}
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
{
int l;
if (!f->has_error && f->is_write == 0 && f->buf_index > 0) {
fprintf(stderr,
"Attempted to write to buffer while read buffer is not empty\n");
abort();
}
while (!f->has_error && size > 0) {
l = IO_BUF_SIZE - f->buf_index;
if (l > size)
l = size;
memcpy(f->buf + f->buf_index, buf, l);
f->is_write = 1;
f->buf_index += l;
buf += l;
size -= l;
if (f->buf_index >= IO_BUF_SIZE)
qemu_fflush(f);
}
}
void qemu_put_byte(QEMUFile *f, int v)
{
if (!f->has_error && f->is_write == 0 && f->buf_index > 0) {
fprintf(stderr,
"Attempted to write to buffer while read buffer is not empty\n");
abort();
}
f->buf[f->buf_index++] = v;
f->is_write = 1;
if (f->buf_index >= IO_BUF_SIZE)
qemu_fflush(f);
}
int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size1)
{
int size, l;
if (f->is_write)
abort();
size = size1;
while (size > 0) {
l = f->buf_size - f->buf_index;
if (l == 0) {
qemu_fill_buffer(f);
l = f->buf_size - f->buf_index;
if (l == 0)
break;
}
if (l > size)
l = size;
memcpy(buf, f->buf + f->buf_index, l);
f->buf_index += l;
buf += l;
size -= l;
}
return size1 - size;
}
int qemu_get_byte(QEMUFile *f)
{
if (f->is_write)
abort();
if (f->buf_index >= f->buf_size) {
qemu_fill_buffer(f);
if (f->buf_index >= f->buf_size)
return 0;
}
return f->buf[f->buf_index++];
}
int64_t qemu_ftell(QEMUFile *f)
{
return f->buf_offset - f->buf_size + f->buf_index;
}
int64_t qemu_fseek(QEMUFile *f, int64_t pos, int whence)
{
if (whence == SEEK_SET) {
/* nothing to do */
} else if (whence == SEEK_CUR) {
pos += qemu_ftell(f);
} else {
/* SEEK_END not supported */
return -1;
}
if (f->put_buffer) {
qemu_fflush(f);
f->buf_offset = pos;
} else {
f->buf_offset = pos;
f->buf_index = 0;
f->buf_size = 0;
}
return pos;
}
int qemu_file_rate_limit(QEMUFile *f)
{
if (f->rate_limit)
return f->rate_limit(f->opaque);
return 0;
}
size_t qemu_file_get_rate_limit(QEMUFile *f)
{
if (f->get_rate_limit)
return f->get_rate_limit(f->opaque);
return 0;
}
size_t qemu_file_set_rate_limit(QEMUFile *f, size_t new_rate)
{
/* any failed or completed migration keeps its state to allow probing of
* migration data, but has no associated file anymore */
if (f && f->set_rate_limit)
return f->set_rate_limit(f->opaque, new_rate);
return 0;
}
void qemu_put_be16(QEMUFile *f, unsigned int v)
{
qemu_put_byte(f, v >> 8);
qemu_put_byte(f, v);
}
void qemu_put_be32(QEMUFile *f, unsigned int v)
{
qemu_put_byte(f, v >> 24);
qemu_put_byte(f, v >> 16);
qemu_put_byte(f, v >> 8);
qemu_put_byte(f, v);
}
void qemu_put_be64(QEMUFile *f, uint64_t v)
{
qemu_put_be32(f, v >> 32);
qemu_put_be32(f, v);
}
unsigned int qemu_get_be16(QEMUFile *f)
{
unsigned int v;
v = qemu_get_byte(f) << 8;
v |= qemu_get_byte(f);
return v;
}
unsigned int qemu_get_be32(QEMUFile *f)
{
unsigned int v;
v = qemu_get_byte(f) << 24;
v |= qemu_get_byte(f) << 16;
v |= qemu_get_byte(f) << 8;
v |= qemu_get_byte(f);
return v;
}
uint64_t qemu_get_be64(QEMUFile *f)
{
uint64_t v;
v = (uint64_t)qemu_get_be32(f) << 32;
v |= qemu_get_be32(f);
return v;
}
/* 8 bit int */
static int get_int8(QEMUFile *f, void *pv, size_t size)
{
int8_t *v = pv;
qemu_get_s8s(f, v);
return 0;
}
static void put_int8(QEMUFile *f, void *pv, size_t size)
{
int8_t *v = pv;
qemu_put_s8s(f, v);
}
const VMStateInfo vmstate_info_int8 = {
.name = "int8",
.get = get_int8,
.put = put_int8,
};
/* 16 bit int */
static int get_int16(QEMUFile *f, void *pv, size_t size)
{
int16_t *v = pv;
qemu_get_sbe16s(f, v);
return 0;
}
static void put_int16(QEMUFile *f, void *pv, size_t size)
{
int16_t *v = pv;
qemu_put_sbe16s(f, v);
}
const VMStateInfo vmstate_info_int16 = {
.name = "int16",
.get = get_int16,
.put = put_int16,
};
/* 32 bit int */
static int get_int32(QEMUFile *f, void *pv, size_t size)
{
int32_t *v = pv;
qemu_get_sbe32s(f, v);
return 0;
}
static void put_int32(QEMUFile *f, void *pv, size_t size)
{
int32_t *v = pv;
qemu_put_sbe32s(f, v);
}
const VMStateInfo vmstate_info_int32 = {
.name = "int32",
.get = get_int32,
.put = put_int32,
};
/* 32 bit int. See that the received value is the same than the one
in the field */
static int get_int32_equal(QEMUFile *f, void *pv, size_t size)
{
int32_t *v = pv;
int32_t v2;
qemu_get_sbe32s(f, &v2);
if (*v == v2)
return 0;
return -EINVAL;
}
const VMStateInfo vmstate_info_int32_equal = {
.name = "int32 equal",
.get = get_int32_equal,
.put = put_int32,
};
/* 32 bit int. See that the received value is the less or the same
than the one in the field */
static int get_int32_le(QEMUFile *f, void *pv, size_t size)
{
int32_t *old = pv;
int32_t new;
qemu_get_sbe32s(f, &new);
if (*old <= new)
return 0;
return -EINVAL;
}
const VMStateInfo vmstate_info_int32_le = {
.name = "int32 equal",
.get = get_int32_le,
.put = put_int32,
};
/* 64 bit int */
static int get_int64(QEMUFile *f, void *pv, size_t size)
{
int64_t *v = pv;
qemu_get_sbe64s(f, v);
return 0;
}
static void put_int64(QEMUFile *f, void *pv, size_t size)
{
int64_t *v = pv;
qemu_put_sbe64s(f, v);
}
const VMStateInfo vmstate_info_int64 = {
.name = "int64",
.get = get_int64,
.put = put_int64,
};
/* 8 bit unsigned int */
static int get_uint8(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_get_8s(f, v);
return 0;
}
static void put_uint8(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_put_8s(f, v);
}
const VMStateInfo vmstate_info_uint8 = {
.name = "uint8",
.get = get_uint8,
.put = put_uint8,
};
/* 16 bit unsigned int */
static int get_uint16(QEMUFile *f, void *pv, size_t size)
{
uint16_t *v = pv;
qemu_get_be16s(f, v);
return 0;
}
static void put_uint16(QEMUFile *f, void *pv, size_t size)
{
uint16_t *v = pv;
qemu_put_be16s(f, v);
}
const VMStateInfo vmstate_info_uint16 = {
.name = "uint16",
.get = get_uint16,
.put = put_uint16,
};
/* 32 bit unsigned int */
static int get_uint32(QEMUFile *f, void *pv, size_t size)
{
uint32_t *v = pv;
qemu_get_be32s(f, v);
return 0;
}
static void put_uint32(QEMUFile *f, void *pv, size_t size)
{
uint32_t *v = pv;
qemu_put_be32s(f, v);
}
const VMStateInfo vmstate_info_uint32 = {
.name = "uint32",
.get = get_uint32,
.put = put_uint32,
};
/* 64 bit unsigned int */
static int get_uint64(QEMUFile *f, void *pv, size_t size)
{
uint64_t *v = pv;
qemu_get_be64s(f, v);
return 0;
}
static void put_uint64(QEMUFile *f, void *pv, size_t size)
{
uint64_t *v = pv;
qemu_put_be64s(f, v);
}
const VMStateInfo vmstate_info_uint64 = {
.name = "uint64",
.get = get_uint64,
.put = put_uint64,
};
/* 8 bit int. See that the received value is the same than the one
in the field */
static int get_uint8_equal(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
uint8_t v2;
qemu_get_8s(f, &v2);
if (*v == v2)
return 0;
return -EINVAL;
}
const VMStateInfo vmstate_info_uint8_equal = {
.name = "uint8 equal",
.get = get_uint8_equal,
.put = put_uint8,
};
/* 16 bit unsigned int int. See that the received value is the same than the one
in the field */
static int get_uint16_equal(QEMUFile *f, void *pv, size_t size)
{
uint16_t *v = pv;
uint16_t v2;
qemu_get_be16s(f, &v2);
if (*v == v2)
return 0;
return -EINVAL;
}
const VMStateInfo vmstate_info_uint16_equal = {
.name = "uint16 equal",
.get = get_uint16_equal,
.put = put_uint16,
};
/* timers */
static int get_timer(QEMUFile *f, void *pv, size_t size)
{
QEMUTimer *v = pv;
qemu_get_timer(f, v);
return 0;
}
static void put_timer(QEMUFile *f, void *pv, size_t size)
{
QEMUTimer *v = pv;
qemu_put_timer(f, v);
}
const VMStateInfo vmstate_info_timer = {
.name = "timer",
.get = get_timer,
.put = put_timer,
};
/* uint8_t buffers */
static int get_buffer(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_get_buffer(f, v, size);
return 0;
}
static void put_buffer(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_put_buffer(f, v, size);
}
const VMStateInfo vmstate_info_buffer = {
.name = "buffer",
.get = get_buffer,
.put = put_buffer,
};
/* unused buffers: space that was used for some fields that are
not usefull anymore */
static int get_unused_buffer(QEMUFile *f, void *pv, size_t size)
{
uint8_t buf[1024];
int block_len;
while (size > 0) {
block_len = MIN(sizeof(buf), size);
size -= block_len;
qemu_get_buffer(f, buf, block_len);
}
return 0;
}
static void put_unused_buffer(QEMUFile *f, void *pv, size_t size)
{
static const uint8_t buf[1024];
int block_len;
while (size > 0) {
block_len = MIN(sizeof(buf), size);
size -= block_len;
qemu_put_buffer(f, buf, block_len);
}
}
const VMStateInfo vmstate_info_unused_buffer = {
.name = "unused_buffer",
.get = get_unused_buffer,
.put = put_unused_buffer,
};
typedef struct SaveStateEntry {
QTAILQ_ENTRY(SaveStateEntry) entry;
char idstr[256];
int instance_id;
int version_id;
int section_id;
SaveSetParamsHandler *set_params;
SaveLiveStateHandler *save_live_state;
SaveStateHandler *save_state;
LoadStateHandler *load_state;
const VMStateDescription *vmsd;
void *opaque;
} SaveStateEntry;
static QTAILQ_HEAD(savevm_handlers, SaveStateEntry) savevm_handlers =
QTAILQ_HEAD_INITIALIZER(savevm_handlers);
static int global_section_id;
static int calculate_new_instance_id(const char *idstr)
{
SaveStateEntry *se;
int instance_id = 0;
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if (strcmp(idstr, se->idstr) == 0
&& instance_id <= se->instance_id) {
instance_id = se->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(const char *idstr,
int instance_id,
int version_id,
SaveSetParamsHandler *set_params,
SaveLiveStateHandler *save_live_state,
SaveStateHandler *save_state,
LoadStateHandler *load_state,
void *opaque)
{
SaveStateEntry *se;
se = qemu_mallocz(sizeof(SaveStateEntry));
pstrcpy(se->idstr, sizeof(se->idstr), idstr);
se->version_id = version_id;
se->section_id = global_section_id++;
se->set_params = set_params;
se->save_live_state = save_live_state;
se->save_state = save_state;
se->load_state = load_state;
se->opaque = opaque;
se->vmsd = NULL;
if (instance_id == -1) {
se->instance_id = calculate_new_instance_id(idstr);
} else {
se->instance_id = instance_id;
}
/* add at the end of list */
QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
return 0;
}
int register_savevm(const char *idstr,
int instance_id,
int version_id,
SaveStateHandler *save_state,
LoadStateHandler *load_state,
void *opaque)
{
return register_savevm_live(idstr, instance_id, version_id,
NULL, NULL, save_state, load_state, opaque);
}
void unregister_savevm(const char *idstr, void *opaque)
{
SaveStateEntry *se, *new_se;
QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
if (strcmp(se->idstr, idstr) == 0 && se->opaque == opaque) {
QTAILQ_REMOVE(&savevm_handlers, se, entry);
qemu_free(se);
}
}
}
int vmstate_register(int instance_id, const VMStateDescription *vmsd,
void *opaque)
{
SaveStateEntry *se;
se = qemu_mallocz(sizeof(SaveStateEntry));
pstrcpy(se->idstr, sizeof(se->idstr), vmsd->name);
se->version_id = vmsd->version_id;
se->section_id = global_section_id++;
se->save_live_state = NULL;
se->save_state = NULL;
se->load_state = NULL;
se->opaque = opaque;
se->vmsd = vmsd;
if (instance_id == -1) {
se->instance_id = calculate_new_instance_id(vmsd->name);
} else {
se->instance_id = instance_id;
}
/* add at the end of list */
QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
return 0;
}
void vmstate_unregister(const VMStateDescription *vmsd, void *opaque)
{
SaveStateEntry *se, *new_se;
QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
if (se->vmsd == vmsd && se->opaque == opaque) {
QTAILQ_REMOVE(&savevm_handlers, se, entry);
qemu_free(se);
}
}
}
int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque, int version_id)
{
VMStateField *field = vmsd->fields;
if (version_id > vmsd->version_id) {
return -EINVAL;
}
if (version_id < vmsd->minimum_version_id_old) {
return -EINVAL;
}
if (version_id < vmsd->minimum_version_id) {
return vmsd->load_state_old(f, opaque, version_id);
}
if (vmsd->pre_load) {
int ret = vmsd->pre_load(opaque);
if (ret)
return ret;
}
while(field->name) {
if ((field->field_exists &&
field->field_exists(opaque, version_id)) ||
(!field->field_exists &&
field->version_id <= version_id)) {
void *base_addr = opaque + field->offset;
int ret, i, n_elems = 1;
int size = field->size;
if (field->flags & VMS_VBUFFER) {
size = *(int32_t *)(opaque+field->size_offset);
if (field->flags & VMS_MULTIPLY) {
size *= field->size;
}
}
if (field->flags & VMS_ARRAY) {
n_elems = field->num;
} else if (field->flags & VMS_VARRAY_INT32) {
n_elems = *(int32_t *)(opaque+field->num_offset);
} else if (field->flags & VMS_VARRAY_UINT16) {
n_elems = *(uint16_t *)(opaque+field->num_offset);
}
if (field->flags & VMS_POINTER) {
base_addr = *(void **)base_addr + field->start;
}
for (i = 0; i < n_elems; i++) {
void *addr = base_addr + size * i;
if (field->flags & VMS_ARRAY_OF_POINTER) {
addr = *(void **)addr;
}
if (field->flags & VMS_STRUCT) {
ret = vmstate_load_state(f, field->vmsd, addr, field->vmsd->version_id);
} else {
ret = field->info->get(f, addr, size);
}
if (ret < 0) {
return ret;
}
}
}
field++;
}
if (vmsd->post_load) {
return vmsd->post_load(opaque, version_id);
}
return 0;
}
void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque)
{
VMStateField *field = vmsd->fields;
if (vmsd->pre_save) {
vmsd->pre_save(opaque);
}
while(field->name) {
if (!field->field_exists ||
field->field_exists(opaque, vmsd->version_id)) {
void *base_addr = opaque + field->offset;
int i, n_elems = 1;
int size = field->size;
if (field->flags & VMS_VBUFFER) {
size = *(int32_t *)(opaque+field->size_offset);
if (field->flags & VMS_MULTIPLY) {
size *= field->size;
}
}
if (field->flags & VMS_ARRAY) {
n_elems = field->num;
} else if (field->flags & VMS_VARRAY_INT32) {
n_elems = *(int32_t *)(opaque+field->num_offset);
} else if (field->flags & VMS_VARRAY_UINT16) {
n_elems = *(uint16_t *)(opaque+field->num_offset);
}
if (field->flags & VMS_POINTER) {
base_addr = *(void **)base_addr + field->start;
}
for (i = 0; i < n_elems; i++) {
void *addr = base_addr + size * i;
if (field->flags & VMS_ARRAY_OF_POINTER) {
addr = *(void **)addr;
}
if (field->flags & VMS_STRUCT) {
vmstate_save_state(f, field->vmsd, addr);
} else {
field->info->put(f, addr, size);
}
}
}
field++;
}
if (vmsd->post_save) {
vmsd->post_save(opaque);
}
}
static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id)
{
if (!se->vmsd) { /* Old style */
return se->load_state(f, se->opaque, version_id);
}
return vmstate_load_state(f, se->vmsd, se->opaque, version_id);
}
static void vmstate_save(QEMUFile *f, SaveStateEntry *se)
{
if (!se->vmsd) { /* Old style */
se->save_state(f, se->opaque);
return;
}
vmstate_save_state(f,se->vmsd, se->opaque);
}
#define QEMU_VM_FILE_MAGIC 0x5145564d
#define QEMU_VM_FILE_VERSION_COMPAT 0x00000002
#define QEMU_VM_FILE_VERSION 0x00000003
#define QEMU_VM_EOF 0x00
#define QEMU_VM_SECTION_START 0x01
#define QEMU_VM_SECTION_PART 0x02
#define QEMU_VM_SECTION_END 0x03
#define QEMU_VM_SECTION_FULL 0x04
int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
int shared)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if(se->set_params == NULL) {
continue;
}
se->set_params(blk_enable, shared, se->opaque);
}
qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
qemu_put_be32(f, QEMU_VM_FILE_VERSION);
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
int len;
if (se->save_live_state == NULL)
continue;
/* Section type */
qemu_put_byte(f, QEMU_VM_SECTION_START);
qemu_put_be32(f, se->section_id);
/* ID string */
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);
se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
}
if (qemu_file_has_error(f)) {
qemu_savevm_state_cancel(mon, f);
return -EIO;
}
return 0;
}
int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
{
SaveStateEntry *se;
int ret = 1;
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if (se->save_live_state == NULL)
continue;
/* Section type */
qemu_put_byte(f, QEMU_VM_SECTION_PART);
qemu_put_be32(f, se->section_id);
ret = se->save_live_state(mon, f, QEMU_VM_SECTION_PART, se->opaque);
if (!ret) {
/* 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;
}
}
if (ret)
return 1;
if (qemu_file_has_error(f)) {
qemu_savevm_state_cancel(mon, f);
return -EIO;
}
return 0;
}
int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if (se->save_live_state == NULL)
continue;
/* Section type */
qemu_put_byte(f, QEMU_VM_SECTION_END);
qemu_put_be32(f, se->section_id);
se->save_live_state(mon, f, QEMU_VM_SECTION_END, se->opaque);
}
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
int len;
if (se->save_state == NULL && se->vmsd == NULL)
continue;
/* Section type */
qemu_put_byte(f, QEMU_VM_SECTION_FULL);
qemu_put_be32(f, se->section_id);
/* ID string */
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);
vmstate_save(f, se);
}
qemu_put_byte(f, QEMU_VM_EOF);
if (qemu_file_has_error(f))
return -EIO;
return 0;
}
void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if (se->save_live_state) {
se->save_live_state(mon, f, -1, se->opaque);
}
}
}
static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
{
int saved_vm_running;
int ret;
saved_vm_running = vm_running;
vm_stop(0);
bdrv_flush_all();
ret = qemu_savevm_state_begin(mon, f, 0, 0);
if (ret < 0)
goto out;
do {
ret = qemu_savevm_state_iterate(mon, f);
if (ret < 0)
goto out;
} while (ret == 0);
ret = qemu_savevm_state_complete(mon, f);
out:
if (qemu_file_has_error(f))
ret = -EIO;
if (!ret && saved_vm_running)
vm_start();
return ret;
}
static SaveStateEntry *find_se(const char *idstr, int instance_id)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if (!strcmp(se->idstr, idstr) &&
instance_id == se->instance_id)
return se;
}
return NULL;
}
typedef struct LoadStateEntry {
QLIST_ENTRY(LoadStateEntry) entry;
SaveStateEntry *se;
int section_id;
int version_id;
} LoadStateEntry;
int qemu_loadvm_state(QEMUFile *f)
{
QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
QLIST_HEAD_INITIALIZER(loadvm_handlers);
LoadStateEntry *le, *new_le;
uint8_t section_type;
unsigned int v;
int ret;
v = qemu_get_be32(f);
if (v != QEMU_VM_FILE_MAGIC)
return -EINVAL;
v = qemu_get_be32(f);
if (v == QEMU_VM_FILE_VERSION_COMPAT) {
fprintf(stderr, "SaveVM v2 format is obsolete and don't work anymore\n");
return -ENOTSUP;
}
if (v != QEMU_VM_FILE_VERSION)
return -ENOTSUP;
while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
uint32_t instance_id, version_id, section_id;
SaveStateEntry *se;
char idstr[257];
int len;
switch (section_type) {
case QEMU_VM_SECTION_START:
case QEMU_VM_SECTION_FULL:
/* Read section start */
section_id = qemu_get_be32(f);
len = qemu_get_byte(f);
qemu_get_buffer(f, (uint8_t *)idstr, len);
idstr[len] = 0;
instance_id = qemu_get_be32(f);
version_id = qemu_get_be32(f);
/* Find savevm section */
se = find_se(idstr, instance_id);
if (se == NULL) {
fprintf(stderr, "Unknown savevm section or instance '%s' %d\n", idstr, instance_id);
ret = -EINVAL;
goto out;
}
/* Validate version */
if (version_id > se->version_id) {
fprintf(stderr, "savevm: unsupported version %d for '%s' v%d\n",
version_id, idstr, se->version_id);
ret = -EINVAL;
goto out;
}
/* Add entry */
le = qemu_mallocz(sizeof(*le));
le->se = se;
le->section_id = section_id;
le->version_id = version_id;
QLIST_INSERT_HEAD(&loadvm_handlers, le, entry);
ret = vmstate_load(f, le->se, le->version_id);
if (ret < 0) {
fprintf(stderr, "qemu: warning: error while loading state for instance 0x%x of device '%s'\n",
instance_id, idstr);
goto out;
}
break;
case QEMU_VM_SECTION_PART:
case QEMU_VM_SECTION_END:
section_id = qemu_get_be32(f);
QLIST_FOREACH(le, &loadvm_handlers, entry) {
if (le->section_id == section_id) {
break;
}
}
if (le == NULL) {
fprintf(stderr, "Unknown savevm section %d\n", section_id);
ret = -EINVAL;
goto out;
}
ret = vmstate_load(f, le->se, le->version_id);
if (ret < 0) {
fprintf(stderr, "qemu: warning: error while loading state section id %d\n",
section_id);
goto out;
}
break;
default:
fprintf(stderr, "Unknown savevm section type %d\n", section_type);
ret = -EINVAL;
goto out;
}
}
ret = 0;
out:
QLIST_FOREACH_SAFE(le, &loadvm_handlers, entry, new_le) {
QLIST_REMOVE(le, entry);
qemu_free(le);
}
if (qemu_file_has_error(f))
ret = -EIO;
return ret;
}
/* device can contain snapshots */
static int bdrv_can_snapshot(BlockDriverState *bs)
{
return (bs &&
!bdrv_is_removable(bs) &&
!bdrv_is_read_only(bs));
}
/* device must be snapshots in order to have a reliable snapshot */
static int bdrv_has_snapshot(BlockDriverState *bs)
{
return (bs &&
!bdrv_is_removable(bs) &&
!bdrv_is_read_only(bs));
}
static BlockDriverState *get_bs_snapshots(void)
{
BlockDriverState *bs;
DriveInfo *dinfo;
if (bs_snapshots)
return bs_snapshots;
QTAILQ_FOREACH(dinfo, &drives, next) {
bs = dinfo->bdrv;
if (bdrv_can_snapshot(bs))
goto ok;
}
return NULL;
ok:
bs_snapshots = bs;
return bs;
}
static int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
const char *name)
{
QEMUSnapshotInfo *sn_tab, *sn;
int nb_sns, i, ret;
ret = -ENOENT;
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns < 0)
return ret;
for(i = 0; i < nb_sns; i++) {
sn = &sn_tab[i];
if (!strcmp(sn->id_str, name) || !strcmp(sn->name, name)) {
*sn_info = *sn;
ret = 0;
break;
}
}
qemu_free(sn_tab);
return ret;
}
/*
* Deletes snapshots of a given name in all opened images.
*/
static int del_existing_snapshots(Monitor *mon, const char *name)
{
BlockDriverState *bs;
DriveInfo *dinfo;
QEMUSnapshotInfo sn1, *snapshot = &sn1;
int ret;
QTAILQ_FOREACH(dinfo, &drives, next) {
bs = dinfo->bdrv;
if (bdrv_can_snapshot(bs) &&
bdrv_snapshot_find(bs, snapshot, name) >= 0)
{
ret = bdrv_snapshot_delete(bs, name);
if (ret < 0) {
monitor_printf(mon,
"Error while deleting snapshot on '%s'\n",
bdrv_get_device_name(bs));
return -1;
}
}
}
return 0;
}
void do_savevm(Monitor *mon, const QDict *qdict)
{
DriveInfo *dinfo;
BlockDriverState *bs, *bs1;
QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
int ret;
QEMUFile *f;
int saved_vm_running;
uint32_t vm_state_size;
#ifdef _WIN32
struct _timeb tb;
#else
struct timeval tv;
#endif
const char *name = qdict_get_try_str(qdict, "name");
bs = get_bs_snapshots();
if (!bs) {
monitor_printf(mon, "No block device can accept snapshots\n");
return;
}
/* ??? Should this occur after vm_stop? */
qemu_aio_flush();
saved_vm_running = vm_running;
vm_stop(0);
memset(sn, 0, sizeof(*sn));
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);
}
}
/* fill auxiliary fields */
#ifdef _WIN32
_ftime(&tb);
sn->date_sec = tb.time;
sn->date_nsec = tb.millitm * 1000000;
#else
gettimeofday(&tv, NULL);
sn->date_sec = tv.tv_sec;
sn->date_nsec = tv.tv_usec * 1000;
#endif
sn->vm_clock_nsec = qemu_get_clock(vm_clock);
/* Delete old snapshots of the same name */
if (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(mon, f);
vm_state_size = qemu_ftell(f);
qemu_fclose(f);
if (ret < 0) {
monitor_printf(mon, "Error %d while writing VM\n", ret);
goto the_end;
}
/* create the snapshots */
QTAILQ_FOREACH(dinfo, &drives, next) {
bs1 = dinfo->bdrv;
if (bdrv_has_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();
}
int load_vmstate(Monitor *mon, const char *name)
{
DriveInfo *dinfo;
BlockDriverState *bs, *bs1;
QEMUSnapshotInfo sn;
QEMUFile *f;
int ret;
bs = get_bs_snapshots();
if (!bs) {
monitor_printf(mon, "No block device supports snapshots\n");
return -EINVAL;
}
/* Flush all IO requests so they don't interfere with the new state. */
qemu_aio_flush();
QTAILQ_FOREACH(dinfo, &drives, next) {
bs1 = dinfo->bdrv;
if (bdrv_has_snapshot(bs1)) {
ret = bdrv_snapshot_goto(bs1, name);
if (ret < 0) {
if (bs != bs1)
monitor_printf(mon, "Warning: ");
switch(ret) {
case -ENOTSUP:
monitor_printf(mon,
"Snapshots not supported on device '%s'\n",
bdrv_get_device_name(bs1));
break;
case -ENOENT:
monitor_printf(mon, "Could not find snapshot '%s' on "
"device '%s'\n",
name, bdrv_get_device_name(bs1));
break;
default:
monitor_printf(mon, "Error %d while activating snapshot on"
" '%s'\n", ret, bdrv_get_device_name(bs1));
break;
}
/* fatal on snapshot block device */
if (bs == bs1)
return 0;
}
}
}
/* Don't even try to load empty VM states */
ret = bdrv_snapshot_find(bs, &sn, name);
if ((ret >= 0) && (sn.vm_state_size == 0))
return -EINVAL;
/* restore the VM state */
f = qemu_fopen_bdrv(bs, 0);
if (!f) {
monitor_printf(mon, "Could not open VM state file\n");
return -EINVAL;
}
ret = qemu_loadvm_state(f);
qemu_fclose(f);
if (ret < 0) {
monitor_printf(mon, "Error %d while loading VM state\n", ret);
return ret;
}
return 0;
}
void do_delvm(Monitor *mon, const QDict *qdict)
{
DriveInfo *dinfo;
BlockDriverState *bs, *bs1;
int ret;
const char *name = qdict_get_str(qdict, "name");
bs = get_bs_snapshots();
if (!bs) {
monitor_printf(mon, "No block device supports snapshots\n");
return;
}
QTAILQ_FOREACH(dinfo, &drives, next) {
bs1 = dinfo->bdrv;
if (bdrv_has_snapshot(bs1)) {
ret = bdrv_snapshot_delete(bs1, name);
if (ret < 0) {
if (ret == -ENOTSUP)
monitor_printf(mon,
"Snapshots not supported on device '%s'\n",
bdrv_get_device_name(bs1));
else
monitor_printf(mon, "Error %d while deleting snapshot on "
"'%s'\n", ret, bdrv_get_device_name(bs1));
}
}
}
}
void do_info_snapshots(Monitor *mon)
{
DriveInfo *dinfo;
BlockDriverState *bs, *bs1;
QEMUSnapshotInfo *sn_tab, *sn;
int nb_sns, i;
char buf[256];
bs = get_bs_snapshots();
if (!bs) {
monitor_printf(mon, "No available block device supports snapshots\n");
return;
}
monitor_printf(mon, "Snapshot devices:");
QTAILQ_FOREACH(dinfo, &drives, next) {
bs1 = dinfo->bdrv;
if (bdrv_has_snapshot(bs1)) {
if (bs == bs1)
monitor_printf(mon, " %s", bdrv_get_device_name(bs1));
}
}
monitor_printf(mon, "\n");
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns < 0) {
monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns);
return;
}
monitor_printf(mon, "Snapshot list (from %s):\n",
bdrv_get_device_name(bs));
monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
for(i = 0; i < nb_sns; i++) {
sn = &sn_tab[i];
monitor_printf(mon, "%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
}
qemu_free(sn_tab);
}