483 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			483 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * QEMU live migration
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|  *
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|  * Copyright IBM, Corp. 2008
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|  *
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|  * Authors:
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|  *  Anthony Liguori   <aliguori@us.ibm.com>
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|  *
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|  * This work is licensed under the terms of the GNU GPL, version 2.  See
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|  * the COPYING file in the top-level directory.
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|  *
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|  */
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| 
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| #include "qemu-common.h"
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| #include "migration.h"
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| #include "monitor.h"
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| #include "buffered_file.h"
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| #include "sysemu.h"
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| #include "block.h"
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| #include "qemu_socket.h"
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| #include "block-migration.h"
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| #include "qemu-objects.h"
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| 
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| //#define DEBUG_MIGRATION
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| 
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| #ifdef DEBUG_MIGRATION
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| #define DPRINTF(fmt, ...) \
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|     do { printf("migration: " fmt, ## __VA_ARGS__); } while (0)
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| #else
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| #define DPRINTF(fmt, ...) \
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|     do { } while (0)
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| #endif
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| 
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| /* Migration speed throttling */
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| static int64_t max_throttle = (32 << 20);
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| 
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| static MigrationState *current_migration;
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| 
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| static NotifierList migration_state_notifiers =
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|     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
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| 
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| int qemu_start_incoming_migration(const char *uri)
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| {
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|     const char *p;
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|     int ret;
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| 
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|     if (strstart(uri, "tcp:", &p))
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|         ret = tcp_start_incoming_migration(p);
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| #if !defined(WIN32)
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|     else if (strstart(uri, "exec:", &p))
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|         ret =  exec_start_incoming_migration(p);
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|     else if (strstart(uri, "unix:", &p))
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|         ret = unix_start_incoming_migration(p);
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|     else if (strstart(uri, "fd:", &p))
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|         ret = fd_start_incoming_migration(p);
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| #endif
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|     else {
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|         fprintf(stderr, "unknown migration protocol: %s\n", uri);
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|         ret = -EPROTONOSUPPORT;
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|     }
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|     return ret;
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| }
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| 
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| void process_incoming_migration(QEMUFile *f)
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| {
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|     if (qemu_loadvm_state(f) < 0) {
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|         fprintf(stderr, "load of migration failed\n");
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|         exit(0);
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|     }
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|     qemu_announce_self();
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|     DPRINTF("successfully loaded vm state\n");
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| 
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|     incoming_expected = false;
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| 
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|     if (autostart)
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|         vm_start();
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| }
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| 
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| int do_migrate(Monitor *mon, const QDict *qdict, QObject **ret_data)
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| {
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|     MigrationState *s = NULL;
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|     const char *p;
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|     int detach = qdict_get_try_bool(qdict, "detach", 0);
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|     int blk = qdict_get_try_bool(qdict, "blk", 0);
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|     int inc = qdict_get_try_bool(qdict, "inc", 0);
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|     const char *uri = qdict_get_str(qdict, "uri");
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| 
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|     if (current_migration &&
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|         current_migration->get_status(current_migration) == MIG_STATE_ACTIVE) {
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|         monitor_printf(mon, "migration already in progress\n");
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|         return -1;
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|     }
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| 
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|     if (qemu_savevm_state_blocked(mon)) {
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|         return -1;
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|     }
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| 
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|     if (strstart(uri, "tcp:", &p)) {
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|         s = tcp_start_outgoing_migration(mon, p, max_throttle, detach,
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|                                          blk, inc);
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| #if !defined(WIN32)
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|     } else if (strstart(uri, "exec:", &p)) {
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|         s = exec_start_outgoing_migration(mon, p, max_throttle, detach,
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|                                           blk, inc);
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|     } else if (strstart(uri, "unix:", &p)) {
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|         s = unix_start_outgoing_migration(mon, p, max_throttle, detach,
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|                                           blk, inc);
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|     } else if (strstart(uri, "fd:", &p)) {
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|         s = fd_start_outgoing_migration(mon, p, max_throttle, detach, 
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|                                         blk, inc);
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| #endif
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|     } else {
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|         monitor_printf(mon, "unknown migration protocol: %s\n", uri);
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|         return -1;
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|     }
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| 
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|     if (s == NULL) {
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|         monitor_printf(mon, "migration failed\n");
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|         return -1;
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|     }
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| 
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|     if (current_migration) {
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|         current_migration->release(current_migration);
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|     }
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| 
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|     current_migration = s;
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|     notifier_list_notify(&migration_state_notifiers);
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|     return 0;
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| }
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| 
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| int do_migrate_cancel(Monitor *mon, const QDict *qdict, QObject **ret_data)
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| {
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|     MigrationState *s = current_migration;
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| 
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|     if (s)
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|         s->cancel(s);
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| 
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|     return 0;
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| }
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| 
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| int do_migrate_set_speed(Monitor *mon, const QDict *qdict, QObject **ret_data)
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| {
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|     int64_t d;
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|     FdMigrationState *s;
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| 
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|     d = qdict_get_int(qdict, "value");
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|     if (d < 0) {
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|         d = 0;
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|     }
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|     max_throttle = d;
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| 
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|     s = migrate_to_fms(current_migration);
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|     if (s && s->file) {
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|         qemu_file_set_rate_limit(s->file, max_throttle);
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|     }
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| 
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|     return 0;
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| }
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| 
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| /* amount of nanoseconds we are willing to wait for migration to be down.
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|  * the choice of nanoseconds is because it is the maximum resolution that
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|  * get_clock() can achieve. It is an internal measure. All user-visible
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|  * units must be in seconds */
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| static uint64_t max_downtime = 30000000;
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| 
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| uint64_t migrate_max_downtime(void)
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| {
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|     return max_downtime;
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| }
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| 
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| int do_migrate_set_downtime(Monitor *mon, const QDict *qdict,
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|                             QObject **ret_data)
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| {
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|     double d;
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| 
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|     d = qdict_get_double(qdict, "value") * 1e9;
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|     d = MAX(0, MIN(UINT64_MAX, d));
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|     max_downtime = (uint64_t)d;
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| 
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|     return 0;
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| }
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| 
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| static void migrate_print_status(Monitor *mon, const char *name,
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|                                  const QDict *status_dict)
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| {
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|     QDict *qdict;
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| 
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|     qdict = qobject_to_qdict(qdict_get(status_dict, name));
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| 
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|     monitor_printf(mon, "transferred %s: %" PRIu64 " kbytes\n", name,
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|                         qdict_get_int(qdict, "transferred") >> 10);
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|     monitor_printf(mon, "remaining %s: %" PRIu64 " kbytes\n", name,
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|                         qdict_get_int(qdict, "remaining") >> 10);
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|     monitor_printf(mon, "total %s: %" PRIu64 " kbytes\n", name,
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|                         qdict_get_int(qdict, "total") >> 10);
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| }
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| 
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| void do_info_migrate_print(Monitor *mon, const QObject *data)
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| {
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|     QDict *qdict;
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| 
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|     qdict = qobject_to_qdict(data);
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| 
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|     monitor_printf(mon, "Migration status: %s\n",
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|                    qdict_get_str(qdict, "status"));
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| 
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|     if (qdict_haskey(qdict, "ram")) {
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|         migrate_print_status(mon, "ram", qdict);
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|     }
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| 
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|     if (qdict_haskey(qdict, "disk")) {
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|         migrate_print_status(mon, "disk", qdict);
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|     }
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| }
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| 
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| static void migrate_put_status(QDict *qdict, const char *name,
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|                                uint64_t trans, uint64_t rem, uint64_t total)
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| {
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|     QObject *obj;
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| 
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|     obj = qobject_from_jsonf("{ 'transferred': %" PRId64 ", "
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|                                "'remaining': %" PRId64 ", "
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|                                "'total': %" PRId64 " }", trans, rem, total);
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|     qdict_put_obj(qdict, name, obj);
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| }
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| 
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| void do_info_migrate(Monitor *mon, QObject **ret_data)
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| {
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|     QDict *qdict;
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|     MigrationState *s = current_migration;
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| 
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|     if (s) {
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|         switch (s->get_status(s)) {
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|         case MIG_STATE_ACTIVE:
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|             qdict = qdict_new();
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|             qdict_put(qdict, "status", qstring_from_str("active"));
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| 
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|             migrate_put_status(qdict, "ram", ram_bytes_transferred(),
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|                                ram_bytes_remaining(), ram_bytes_total());
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| 
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|             if (blk_mig_active()) {
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|                 migrate_put_status(qdict, "disk", blk_mig_bytes_transferred(),
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|                                    blk_mig_bytes_remaining(),
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|                                    blk_mig_bytes_total());
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|             }
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| 
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|             *ret_data = QOBJECT(qdict);
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|             break;
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|         case MIG_STATE_COMPLETED:
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|             *ret_data = qobject_from_jsonf("{ 'status': 'completed' }");
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|             break;
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|         case MIG_STATE_ERROR:
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|             *ret_data = qobject_from_jsonf("{ 'status': 'failed' }");
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|             break;
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|         case MIG_STATE_CANCELLED:
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|             *ret_data = qobject_from_jsonf("{ 'status': 'cancelled' }");
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|             break;
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|         }
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|     }
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| }
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| 
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| /* shared migration helpers */
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| 
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| void migrate_fd_monitor_suspend(FdMigrationState *s, Monitor *mon)
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| {
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|     s->mon = mon;
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|     if (monitor_suspend(mon) == 0) {
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|         DPRINTF("suspending monitor\n");
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|     } else {
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|         monitor_printf(mon, "terminal does not allow synchronous "
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|                        "migration, continuing detached\n");
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|     }
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| }
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| 
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| void migrate_fd_error(FdMigrationState *s)
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| {
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|     DPRINTF("setting error state\n");
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|     s->state = MIG_STATE_ERROR;
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|     notifier_list_notify(&migration_state_notifiers);
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|     migrate_fd_cleanup(s);
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| }
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| 
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| int migrate_fd_cleanup(FdMigrationState *s)
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| {
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|     int ret = 0;
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| 
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|     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
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| 
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|     if (s->file) {
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|         DPRINTF("closing file\n");
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|         if (qemu_fclose(s->file) != 0) {
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|             ret = -1;
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|         }
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|         s->file = NULL;
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|     }
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| 
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|     if (s->fd != -1)
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|         close(s->fd);
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| 
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|     /* Don't resume monitor until we've flushed all of the buffers */
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|     if (s->mon) {
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|         monitor_resume(s->mon);
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|     }
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| 
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|     s->fd = -1;
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| 
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|     return ret;
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| }
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| 
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| void migrate_fd_put_notify(void *opaque)
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| {
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|     FdMigrationState *s = opaque;
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| 
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|     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
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|     qemu_file_put_notify(s->file);
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| }
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| 
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| ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
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| {
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|     FdMigrationState *s = opaque;
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|     ssize_t ret;
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| 
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|     do {
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|         ret = s->write(s, data, size);
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|     } while (ret == -1 && ((s->get_error(s)) == EINTR));
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| 
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|     if (ret == -1)
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|         ret = -(s->get_error(s));
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| 
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|     if (ret == -EAGAIN) {
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|         qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
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|     } else if (ret < 0) {
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|         if (s->mon) {
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|             monitor_resume(s->mon);
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|         }
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|         s->state = MIG_STATE_ERROR;
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|         notifier_list_notify(&migration_state_notifiers);
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|     }
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| 
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|     return ret;
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| }
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| 
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| void migrate_fd_connect(FdMigrationState *s)
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| {
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|     int ret;
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| 
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|     s->file = qemu_fopen_ops_buffered(s,
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|                                       s->bandwidth_limit,
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|                                       migrate_fd_put_buffer,
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|                                       migrate_fd_put_ready,
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|                                       migrate_fd_wait_for_unfreeze,
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|                                       migrate_fd_close);
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| 
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|     DPRINTF("beginning savevm\n");
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|     ret = qemu_savevm_state_begin(s->mon, s->file, s->mig_state.blk,
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|                                   s->mig_state.shared);
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|     if (ret < 0) {
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|         DPRINTF("failed, %d\n", ret);
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|         migrate_fd_error(s);
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|         return;
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|     }
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|     
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|     migrate_fd_put_ready(s);
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| }
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| 
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| void migrate_fd_put_ready(void *opaque)
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| {
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|     FdMigrationState *s = opaque;
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| 
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|     if (s->state != MIG_STATE_ACTIVE) {
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|         DPRINTF("put_ready returning because of non-active state\n");
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|         return;
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|     }
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| 
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|     DPRINTF("iterate\n");
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|     if (qemu_savevm_state_iterate(s->mon, s->file) == 1) {
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|         int state;
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|         int old_vm_running = vm_running;
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| 
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|         DPRINTF("done iterating\n");
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|         vm_stop(VMSTOP_MIGRATE);
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| 
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|         if ((qemu_savevm_state_complete(s->mon, s->file)) < 0) {
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|             if (old_vm_running) {
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|                 vm_start();
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|             }
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|             state = MIG_STATE_ERROR;
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|         } else {
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|             state = MIG_STATE_COMPLETED;
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|         }
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|         if (migrate_fd_cleanup(s) < 0) {
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|             if (old_vm_running) {
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|                 vm_start();
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|             }
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|             state = MIG_STATE_ERROR;
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|         }
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|         s->state = state;
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|         notifier_list_notify(&migration_state_notifiers);
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|     }
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| }
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| 
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| int migrate_fd_get_status(MigrationState *mig_state)
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| {
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|     FdMigrationState *s = migrate_to_fms(mig_state);
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|     return s->state;
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| }
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| 
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| void migrate_fd_cancel(MigrationState *mig_state)
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| {
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|     FdMigrationState *s = migrate_to_fms(mig_state);
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| 
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|     if (s->state != MIG_STATE_ACTIVE)
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|         return;
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| 
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|     DPRINTF("cancelling migration\n");
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| 
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|     s->state = MIG_STATE_CANCELLED;
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|     notifier_list_notify(&migration_state_notifiers);
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|     qemu_savevm_state_cancel(s->mon, s->file);
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| 
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|     migrate_fd_cleanup(s);
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| }
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| 
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| void migrate_fd_release(MigrationState *mig_state)
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| {
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|     FdMigrationState *s = migrate_to_fms(mig_state);
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| 
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|     DPRINTF("releasing state\n");
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|    
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|     if (s->state == MIG_STATE_ACTIVE) {
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|         s->state = MIG_STATE_CANCELLED;
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|         notifier_list_notify(&migration_state_notifiers);
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|         migrate_fd_cleanup(s);
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|     }
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|     qemu_free(s);
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| }
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| 
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| void migrate_fd_wait_for_unfreeze(void *opaque)
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| {
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|     FdMigrationState *s = opaque;
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|     int ret;
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| 
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|     DPRINTF("wait for unfreeze\n");
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|     if (s->state != MIG_STATE_ACTIVE)
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|         return;
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| 
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|     do {
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|         fd_set wfds;
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| 
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|         FD_ZERO(&wfds);
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|         FD_SET(s->fd, &wfds);
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| 
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|         ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
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|     } while (ret == -1 && (s->get_error(s)) == EINTR);
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| }
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| 
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| int migrate_fd_close(void *opaque)
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| {
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|     FdMigrationState *s = opaque;
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| 
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|     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
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|     return s->close(s);
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| }
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| 
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| void add_migration_state_change_notifier(Notifier *notify)
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| {
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|     notifier_list_add(&migration_state_notifiers, notify);
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| }
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| 
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| void remove_migration_state_change_notifier(Notifier *notify)
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| {
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|     notifier_list_remove(&migration_state_notifiers, notify);
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| }
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| 
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| int get_migration_state(void)
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| {
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|     if (current_migration) {
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|         return migrate_fd_get_status(current_migration);
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|     } else {
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|         return MIG_STATE_ERROR;
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|     }
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| }
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