Commit 34c9dd8e authored by aliguori's avatar aliguori

Introduce TCP live migration protocol

This patch introduces a tcp protocol for live migration.  It can be used as
follows:

qemu-system-x86_64 -hda ~/images/linux-test.img -monitor stdio
 <vm runs for a while>
(qemu) migrate tcp:localhost:1025

On the same system:

qemu-system-x86_64 -hda ~/images/linux-test.img -incoming 
tcp:localhost:1025

The monitor can be interacted with while waiting for an incoming live 
migration.
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5478 c046a42c-6fe2-441c-8c8c-71466251a162
parent 210f41ba
......@@ -474,7 +474,7 @@ endif #CONFIG_DARWIN_USER
ifndef CONFIG_USER_ONLY
OBJS=vl.o osdep.o monitor.o pci.o loader.o isa_mmio.o machine.o net-checksum.o
OBJS+=fw_cfg.o aio.o buffered_file.o migration.o
OBJS+=fw_cfg.o aio.o buffered_file.o migration.o migration-tcp.o
ifdef CONFIG_WIN32
OBJS+=block-raw-win32.o
else
......
/*
* QEMU live migration
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu-common.h"
#include "qemu_socket.h"
#include "migration.h"
#include "qemu-char.h"
#include "sysemu.h"
#include "console.h"
#include "buffered_file.h"
#include "block.h"
//#define DEBUG_MIGRATION_TCP
typedef struct FdMigrationState
{
MigrationState mig_state;
QEMUFile *file;
int64_t bandwidth_limit;
int fd;
int detach;
int state;
} FdMigrationState;
#ifdef DEBUG_MIGRATION_TCP
#define dprintf(fmt, ...) \
do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
#else
#define dprintf(fmt, ...) \
do { } while (0)
#endif
int debug_me = 0;
static void tcp_cleanup(FdMigrationState *s)
{
if (s->detach == 2) {
monitor_resume();
s->detach = 0;
}
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
if (s->file) {
debug_me = 1;
dprintf("closing file\n");
qemu_fclose(s->file);
}
if (s->fd != -1)
close(s->fd);
s->fd = -1;
}
static void tcp_error(FdMigrationState *s)
{
dprintf("setting error state\n");
s->state = MIG_STATE_ERROR;
tcp_cleanup(s);
}
static void fd_put_notify(void *opaque)
{
FdMigrationState *s = opaque;
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
qemu_file_put_notify(s->file);
}
static ssize_t fd_put_buffer(void *opaque, const void *data, size_t size)
{
FdMigrationState *s = opaque;
ssize_t ret;
do {
ret = write(s->fd, data, size);
} while (ret == -1 && errno == EINTR);
if (ret == -1)
ret = -errno;
if (ret == -EAGAIN)
qemu_set_fd_handler2(s->fd, NULL, NULL, fd_put_notify, s);
return ret;
}
static int fd_close(void *opaque)
{
FdMigrationState *s = opaque;
dprintf("fd_close\n");
if (s->fd != -1) {
close(s->fd);
s->fd = -1;
}
return 0;
}
static void fd_wait_for_unfreeze(void *opaque)
{
FdMigrationState *s = opaque;
int ret;
dprintf("wait for unfreeze\n");
if (s->state != MIG_STATE_ACTIVE)
return;
do {
fd_set wfds;
FD_ZERO(&wfds);
FD_SET(s->fd, &wfds);
ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
} while (ret == -1 && errno == EINTR);
}
static void fd_put_ready(void *opaque)
{
FdMigrationState *s = opaque;
if (s->state != MIG_STATE_ACTIVE) {
dprintf("put_ready returning because of non-active state\n");
return;
}
dprintf("iterate\n");
if (qemu_savevm_state_iterate(s->file) == 1) {
dprintf("done iterating\n");
vm_stop(0);
bdrv_flush_all();
qemu_savevm_state_complete(s->file);
s->state = MIG_STATE_COMPLETED;
tcp_cleanup(s);
}
}
static void tcp_connect_migrate(FdMigrationState *s)
{
int ret;
s->file = qemu_fopen_ops_buffered(s,
s->bandwidth_limit,
fd_put_buffer,
fd_put_ready,
fd_wait_for_unfreeze,
fd_close);
dprintf("beginning savevm\n");
ret = qemu_savevm_state_begin(s->file);
if (ret < 0) {
dprintf("failed, %d\n", ret);
tcp_error(s);
return;
}
fd_put_ready(s);
}
static void tcp_wait_for_connect(void *opaque)
{
FdMigrationState *s = opaque;
int val, ret;
int valsize = sizeof(val);
dprintf("connect completed\n");
do {
ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize);
} while (ret == -1 && errno == EINTR);
if (ret < 0) {
tcp_error(s);
return;
}
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
if (val == 0)
tcp_connect_migrate(s);
else {
dprintf("error connecting %d\n", val);
tcp_error(s);
}
}
static FdMigrationState *to_fms(MigrationState *mig_state)
{
return container_of(mig_state, FdMigrationState, mig_state);
}
static int tcp_get_status(MigrationState *mig_state)
{
FdMigrationState *s = to_fms(mig_state);
return s->state;
}
static void tcp_cancel(MigrationState *mig_state)
{
FdMigrationState *s = to_fms(mig_state);
if (s->state != MIG_STATE_ACTIVE)
return;
dprintf("cancelling migration\n");
s->state = MIG_STATE_CANCELLED;
tcp_cleanup(s);
}
static void tcp_release(MigrationState *mig_state)
{
FdMigrationState *s = to_fms(mig_state);
dprintf("releasing state\n");
if (s->state == MIG_STATE_ACTIVE) {
s->state = MIG_STATE_CANCELLED;
tcp_cleanup(s);
}
free(s);
}
MigrationState *tcp_start_outgoing_migration(const char *host_port,
int64_t bandwidth_limit,
int async)
{
struct sockaddr_in addr;
FdMigrationState *s;
int ret;
if (parse_host_port(&addr, host_port) < 0)
return NULL;
s = qemu_mallocz(sizeof(*s));
if (s == NULL)
return NULL;
s->mig_state.cancel = tcp_cancel;
s->mig_state.get_status = tcp_get_status;
s->mig_state.release = tcp_release;
s->state = MIG_STATE_ACTIVE;
s->detach = !async;
s->bandwidth_limit = bandwidth_limit;
s->fd = socket(PF_INET, SOCK_STREAM, 0);
if (s->fd == -1) {
qemu_free(s);
return NULL;
}
fcntl(s->fd, F_SETFL, O_NONBLOCK);
if (s->detach == 1) {
dprintf("detaching from monitor\n");
monitor_suspend();
s->detach = 2;
}
do {
ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
if (ret == -1)
ret = -errno;
if (ret == -EINPROGRESS)
qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
} while (ret == -EINTR);
if (ret < 0 && ret != -EINPROGRESS) {
dprintf("connect failed\n");
close(s->fd);
qemu_free(s);
s = NULL;
} else if (ret >= 0)
tcp_connect_migrate(s);
return &s->mig_state;
}
static void tcp_accept_incoming_migration(void *opaque)
{
struct sockaddr_in addr;
socklen_t addrlen = sizeof(addr);
int s = (unsigned long)opaque;
QEMUFile *f;
int c, ret;
do {
c = accept(s, (struct sockaddr *)&addr, &addrlen);
} while (c == -1 && errno == EINTR);
dprintf("accepted migration\n");
if (c == -1) {
fprintf(stderr, "could not accept migration connection\n");
return;
}
f = qemu_fopen_fd(c);
if (f == NULL) {
fprintf(stderr, "could not qemu_fopen socket\n");
goto out;
}
vm_stop(0); /* just in case */
ret = qemu_loadvm_state(f);
if (ret < 0) {
fprintf(stderr, "load of migration failed\n");
goto out_fopen;
}
qemu_announce_self();
dprintf("successfully loaded vm state\n");
/* we've successfully migrated, close the server socket */
qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
close(s);
vm_start();
out_fopen:
qemu_fclose(f);
out:
close(c);
}
int tcp_start_incoming_migration(const char *host_port)
{
struct sockaddr_in addr;
int val;
int s;
if (parse_host_port(&addr, host_port) < 0) {
fprintf(stderr, "invalid host/port combination: %s\n", host_port);
return -EINVAL;
}
s = socket(PF_INET, SOCK_STREAM, 0);
if (s == -1)
return -errno;
val = 1;
setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
goto err;
if (listen(s, 1) == -1)
goto err;
qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
(void *)(unsigned long)s);
return 0;
err:
close(s);
return -errno;
}
......@@ -22,12 +22,32 @@ static MigrationState *current_migration;
void qemu_start_incoming_migration(const char *uri)
{
fprintf(stderr, "unknown migration protocol: %s\n", uri);
const char *p;
if (strstart(uri, "tcp:", &p))
tcp_start_incoming_migration(p);
else
fprintf(stderr, "unknown migration protocol: %s\n", uri);
}
void do_migrate(int detach, const char *uri)
{
term_printf("unknown migration protocol: %s\n", uri);
MigrationState *s = NULL;
const char *p;
if (strstart(uri, "tcp:", &p))
s = tcp_start_outgoing_migration(p, max_throttle, detach);
else
term_printf("unknown migration protocol: %s\n", uri);
if (s == NULL)
term_printf("migration failed\n");
else {
if (current_migration)
current_migration->release(current_migration);
current_migration = s;
}
}
void do_migrate_cancel(void)
......
......@@ -39,5 +39,11 @@ void do_migrate_set_speed(const char *value);
void do_info_migrate(void);
int tcp_start_incoming_migration(const char *host_port);
MigrationState *tcp_start_outgoing_migration(const char *host_port,
int64_t bandwidth_limit,
int detach);
#endif
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