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/*
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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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#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 "qmp-commands.h" |
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//#define DEBUG_MIGRATION
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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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enum {
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MIG_STATE_ERROR, |
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MIG_STATE_SETUP, |
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MIG_STATE_CANCELLED, |
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MIG_STATE_ACTIVE, |
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MIG_STATE_COMPLETED, |
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}; |
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#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ |
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static NotifierList migration_state_notifiers =
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NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); |
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/* When we add fault tolerance, we could have several
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migrations at once. For now we don't need to add
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dynamic creation of migration */
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static MigrationState *migrate_get_current(void) |
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{ |
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static MigrationState current_migration = {
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.state = MIG_STATE_SETUP, |
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.bandwidth_limit = MAX_THROTTLE, |
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}; |
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return ¤t_migration;
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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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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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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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/* Make sure all file formats flush their mutable metadata */
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bdrv_invalidate_cache_all(); |
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if (autostart) {
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vm_start(); |
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} else {
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runstate_set(RUN_STATE_PRELAUNCH); |
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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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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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MigrationInfo *qmp_query_migrate(Error **errp) |
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{ |
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MigrationInfo *info = g_malloc0(sizeof(*info));
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MigrationState *s = migrate_get_current(); |
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switch (s->state) {
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case MIG_STATE_SETUP:
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/* no migration has happened ever */
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break;
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case MIG_STATE_ACTIVE:
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info->has_status = true;
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info->status = g_strdup("active");
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info->has_ram = true;
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info->ram = g_malloc0(sizeof(*info->ram));
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info->ram->transferred = ram_bytes_transferred(); |
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info->ram->remaining = ram_bytes_remaining(); |
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info->ram->total = ram_bytes_total(); |
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if (blk_mig_active()) {
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info->has_disk = true;
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info->disk = g_malloc0(sizeof(*info->disk));
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info->disk->transferred = blk_mig_bytes_transferred(); |
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info->disk->remaining = blk_mig_bytes_remaining(); |
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info->disk->total = blk_mig_bytes_total(); |
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} |
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break;
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case MIG_STATE_COMPLETED:
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info->has_status = true;
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info->status = g_strdup("completed");
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break;
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case MIG_STATE_ERROR:
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info->has_status = true;
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info->status = g_strdup("failed");
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break;
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case MIG_STATE_CANCELLED:
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info->has_status = true;
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info->status = g_strdup("cancelled");
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break;
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} |
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return info;
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} |
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/* shared migration helpers */
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static void migrate_fd_monitor_suspend(MigrationState *s, Monitor *mon) |
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{ |
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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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static int migrate_fd_cleanup(MigrationState *s) |
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{ |
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int ret = 0; |
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qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); |
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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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} else {
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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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if (s->fd != -1) { |
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close(s->fd); |
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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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void migrate_fd_error(MigrationState *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, s); |
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migrate_fd_cleanup(s); |
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} |
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static void migrate_fd_completed(MigrationState *s) |
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{ |
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DPRINTF("setting completed state\n");
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if (migrate_fd_cleanup(s) < 0) { |
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s->state = MIG_STATE_ERROR; |
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} else {
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s->state = MIG_STATE_COMPLETED; |
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runstate_set(RUN_STATE_POSTMIGRATE); |
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} |
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notifier_list_notify(&migration_state_notifiers, s); |
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} |
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static void migrate_fd_put_notify(void *opaque) |
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{ |
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MigrationState *s = opaque; |
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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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if (s->file && qemu_file_get_error(s->file)) {
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migrate_fd_error(s); |
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} |
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} |
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static ssize_t migrate_fd_put_buffer(void *opaque, const void *data, |
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size_t size) |
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{ |
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MigrationState *s = opaque; |
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ssize_t ret; |
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if (s->state != MIG_STATE_ACTIVE) {
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return -EIO;
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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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if (ret == -1) |
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ret = -(s->get_error(s)); |
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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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} |
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return ret;
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} |
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static void migrate_fd_put_ready(void *opaque) |
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{ |
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MigrationState *s = opaque; |
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int ret;
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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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DPRINTF("iterate\n");
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ret = qemu_savevm_state_iterate(s->mon, s->file); |
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if (ret < 0) { |
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migrate_fd_error(s); |
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} else if (ret == 1) { |
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int old_vm_running = runstate_is_running();
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DPRINTF("done iterating\n");
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vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); |
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if (qemu_savevm_state_complete(s->mon, s->file) < 0) { |
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migrate_fd_error(s); |
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} else {
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migrate_fd_completed(s); |
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} |
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if (s->state != MIG_STATE_COMPLETED) {
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if (old_vm_running) {
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vm_start(); |
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} |
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} |
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} |
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} |
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static void migrate_fd_cancel(MigrationState *s) |
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{ |
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if (s->state != MIG_STATE_ACTIVE)
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return;
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DPRINTF("cancelling migration\n");
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s->state = MIG_STATE_CANCELLED; |
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notifier_list_notify(&migration_state_notifiers, s); |
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qemu_savevm_state_cancel(s->mon, s->file); |
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migrate_fd_cleanup(s); |
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} |
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static void migrate_fd_wait_for_unfreeze(void *opaque) |
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{ |
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MigrationState *s = opaque; |
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int ret;
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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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do {
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fd_set wfds; |
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FD_ZERO(&wfds); |
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FD_SET(s->fd, &wfds); |
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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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if (ret == -1) { |
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qemu_file_set_error(s->file, -s->get_error(s)); |
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} |
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} |
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static int migrate_fd_close(void *opaque) |
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{ |
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MigrationState *s = opaque; |
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if (s->mon) {
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monitor_resume(s->mon); |
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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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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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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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bool migration_is_active(MigrationState *s)
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{ |
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return s->state == MIG_STATE_ACTIVE;
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} |
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bool migration_has_finished(MigrationState *s)
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{ |
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return s->state == MIG_STATE_COMPLETED;
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} |
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bool migration_has_failed(MigrationState *s)
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{ |
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return (s->state == MIG_STATE_CANCELLED ||
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s->state == MIG_STATE_ERROR); |
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} |
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void migrate_fd_connect(MigrationState *s)
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{ |
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int ret;
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s->state = MIG_STATE_ACTIVE; |
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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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DPRINTF("beginning savevm\n");
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ret = qemu_savevm_state_begin(s->mon, s->file, s->blk, s->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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migrate_fd_put_ready(s); |
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} |
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static MigrationState *migrate_init(Monitor *mon, int detach, int blk, int inc) |
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{ |
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MigrationState *s = migrate_get_current(); |
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int64_t bandwidth_limit = s->bandwidth_limit; |
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memset(s, 0, sizeof(*s)); |
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s->bandwidth_limit = bandwidth_limit; |
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s->blk = blk; |
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s->shared = inc; |
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/* s->mon is used for two things:
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- pass fd in fd migration
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- suspend/resume monitor for not detached migration
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*/
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s->mon = mon; |
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s->bandwidth_limit = bandwidth_limit; |
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s->state = MIG_STATE_SETUP; |
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if (!detach) {
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migrate_fd_monitor_suspend(s, mon); |
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} |
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return s;
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} |
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static GSList *migration_blockers;
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void migrate_add_blocker(Error *reason)
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{ |
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migration_blockers = g_slist_prepend(migration_blockers, reason); |
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} |
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void migrate_del_blocker(Error *reason)
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{ |
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migration_blockers = g_slist_remove(migration_blockers, reason); |
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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 = migrate_get_current(); |
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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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int ret;
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if (s->state == 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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if (qemu_savevm_state_blocked(mon)) {
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return -1; |
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} |
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if (migration_blockers) {
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Error *err = migration_blockers->data; |
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qerror_report_err(err); |
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return -1; |
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} |
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s = migrate_init(mon, detach, blk, inc); |
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if (strstart(uri, "tcp:", &p)) { |
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ret = tcp_start_outgoing_migration(s, 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_outgoing_migration(s, p); |
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} else if (strstart(uri, "unix:", &p)) { |
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ret = unix_start_outgoing_migration(s, p); |
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} else if (strstart(uri, "fd:", &p)) { |
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ret = fd_start_outgoing_migration(s, p); |
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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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ret = -EINVAL; |
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} |
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if (ret < 0) { |
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monitor_printf(mon, "migration failed: %s\n", strerror(-ret));
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return ret;
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} |
462 |
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if (detach) {
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s->mon = NULL;
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} |
466 |
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notifier_list_notify(&migration_state_notifiers, s); |
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return 0; |
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} |
470 |
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void qmp_migrate_cancel(Error **errp)
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{ |
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migrate_fd_cancel(migrate_get_current()); |
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} |
475 |
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int do_migrate_set_speed(Monitor *mon, const QDict *qdict, QObject **ret_data) |
477 |
{ |
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int64_t d; |
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MigrationState *s; |
480 |
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d = qdict_get_int(qdict, "value");
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if (d < 0) { |
483 |
d = 0;
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} |
485 |
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s = migrate_get_current(); |
487 |
s->bandwidth_limit = d; |
488 |
qemu_file_set_rate_limit(s->file, s->bandwidth_limit); |
489 |
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return 0; |
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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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d = qdict_get_double(qdict, "value") * 1e9; |
499 |
d = MAX(0, MIN(UINT64_MAX, d));
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max_downtime = (uint64_t)d; |
501 |
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return 0; |
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} |