/* * 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 "migration.h" #include "console.h" #include "buffered_file.h" #include "sysemu.h" #include "block.h" #include "qemu_socket.h" //#define DEBUG_MIGRATION #ifdef DEBUG_MIGRATION #define dprintf(fmt, ...) \ do { printf("migration: " fmt, ## __VA_ARGS__); } while (0) #else #define dprintf(fmt, ...) \ do { } while (0) #endif /* Migration speed throttling */ static uint32_t max_throttle = (32 << 20); static MigrationState *current_migration; void qemu_start_incoming_migration(const char *uri) { const char *p; if (strstart(uri, "tcp:", &p)) tcp_start_incoming_migration(p); #if !defined(WIN32) else if (strstart(uri, "exec:", &p)) exec_start_incoming_migration(p); #endif else fprintf(stderr, "unknown migration protocol: %s\n", uri); } void do_migrate(int detach, const char *uri) { MigrationState *s = NULL; const char *p; if (strstart(uri, "tcp:", &p)) s = tcp_start_outgoing_migration(p, max_throttle, detach); #if !defined(WIN32) else if (strstart(uri, "exec:", &p)) s = exec_start_outgoing_migration(p, max_throttle, detach); #endif 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) { MigrationState *s = current_migration; if (s) s->cancel(s); } void do_migrate_set_speed(const char *value) { double d; char *ptr; d = strtod(value, &ptr); switch (*ptr) { case 'G': case 'g': d *= 1024; case 'M': case 'm': d *= 1024; case 'K': case 'k': d *= 1024; default: break; } max_throttle = (uint32_t)d; } void do_info_migrate(void) { MigrationState *s = current_migration; if (s) { term_printf("Migration status: "); switch (s->get_status(s)) { case MIG_STATE_ACTIVE: term_printf("active\n"); break; case MIG_STATE_COMPLETED: term_printf("completed\n"); break; case MIG_STATE_ERROR: term_printf("failed\n"); break; case MIG_STATE_CANCELLED: term_printf("cancelled\n"); break; } } } /* shared migration helpers */ void migrate_fd_error(FdMigrationState *s) { dprintf("setting error state\n"); s->state = MIG_STATE_ERROR; migrate_fd_cleanup(s); } void migrate_fd_cleanup(FdMigrationState *s) { qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); if (s->file) { dprintf("closing file\n"); qemu_fclose(s->file); } if (s->fd != -1) close(s->fd); /* Don't resume monitor until we've flushed all of the buffers */ if (s->detach == 2) { monitor_resume(); s->detach = 0; } s->fd = -1; } void migrate_fd_put_notify(void *opaque) { FdMigrationState *s = opaque; qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); qemu_file_put_notify(s->file); } ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size) { FdMigrationState *s = opaque; ssize_t ret; do { ret = s->write(s, data, size); } while (ret == -1 && ((s->get_error(s)) == EINTR || (s->get_error(s)) == EWOULDBLOCK)); if (ret == -1) ret = -(s->get_error(s)); if (ret == -EAGAIN) qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s); return ret; } void migrate_fd_connect(FdMigrationState *s) { int ret; s->file = qemu_fopen_ops_buffered(s, s->bandwidth_limit, migrate_fd_put_buffer, migrate_fd_put_ready, migrate_fd_wait_for_unfreeze, migrate_fd_close); dprintf("beginning savevm\n"); ret = qemu_savevm_state_begin(s->file); if (ret < 0) { dprintf("failed, %d\n", ret); migrate_fd_error(s); return; } migrate_fd_put_ready(s); } void migrate_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; migrate_fd_cleanup(s); } } int migrate_fd_get_status(MigrationState *mig_state) { FdMigrationState *s = migrate_to_fms(mig_state); return s->state; } void migrate_fd_cancel(MigrationState *mig_state) { FdMigrationState *s = migrate_to_fms(mig_state); if (s->state != MIG_STATE_ACTIVE) return; dprintf("cancelling migration\n"); s->state = MIG_STATE_CANCELLED; migrate_fd_cleanup(s); } void migrate_fd_release(MigrationState *mig_state) { FdMigrationState *s = migrate_to_fms(mig_state); dprintf("releasing state\n"); if (s->state == MIG_STATE_ACTIVE) { s->state = MIG_STATE_CANCELLED; migrate_fd_cleanup(s); } free(s); } void migrate_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 && (s->get_error(s)) == EINTR); } int migrate_fd_close(void *opaque) { FdMigrationState *s = opaque; return s->close(s); }