/* * 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 = send(s->fd, data, size, 0); } while (ret == -1 && (socket_error() == EINTR || socket_error() == EWOULDBLOCK)); if (ret == -1) ret = -socket_error(); 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 && socket_error() == 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; socklen_t valsize = sizeof(val); dprintf("connect completed\n"); do { ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize); } while (ret == -1 && socket_error() == 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; } socket_set_nonblock(s->fd); 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 = -socket_error(); if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s); } while (ret == -EINTR); if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) { dprintf("connect failed\n"); close(s->fd); qemu_free(s); return 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 && socket_error() == EINTR); dprintf("accepted migration\n"); if (c == -1) { fprintf(stderr, "could not accept migration connection\n"); return; } f = qemu_fopen_socket(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 -socket_error(); 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 -socket_error(); }