/* * QEMU live migration via Unix Domain Sockets * * Copyright Red Hat, Inc. 2009 * * Authors: * Chris Lalancette <clalance@redhat.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 "buffered_file.h" #include "block.h" //#define DEBUG_MIGRATION_UNIX #ifdef DEBUG_MIGRATION_UNIX #define dprintf(fmt, ...) \ do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0) #else #define dprintf(fmt, ...) \ do { } while (0) #endif static int unix_errno(FdMigrationState *s) { return errno; } static int unix_write(FdMigrationState *s, const void * buf, size_t size) { return write(s->fd, buf, size); } static int unix_close(FdMigrationState *s) { dprintf("unix_close\n"); if (s->fd != -1) { close(s->fd); s->fd = -1; } return 0; } static void unix_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, (void *) &val, &valsize); } while (ret == -1 && (s->get_error(s)) == EINTR); if (ret < 0) { migrate_fd_error(s); return; } qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); if (val == 0) migrate_fd_connect(s); else { dprintf("error connecting %d\n", val); migrate_fd_error(s); } } MigrationState *unix_start_outgoing_migration(const char *path, int64_t bandwidth_limit, int detach) { FdMigrationState *s; struct sockaddr_un addr; int ret; addr.sun_family = AF_UNIX; snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path); s = qemu_mallocz(sizeof(*s)); s->get_error = unix_errno; s->write = unix_write; s->close = unix_close; s->mig_state.cancel = migrate_fd_cancel; s->mig_state.get_status = migrate_fd_get_status; s->mig_state.release = migrate_fd_release; s->state = MIG_STATE_ACTIVE; s->mon_resume = NULL; s->bandwidth_limit = bandwidth_limit; s->fd = socket(PF_UNIX, SOCK_STREAM, 0); if (s->fd < 0) { dprintf("Unable to open socket"); goto err_after_alloc; } socket_set_nonblock(s->fd); if (!detach) migrate_fd_monitor_suspend(s); do { ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr)); if (ret == -1) ret = -(s->get_error(s)); if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s); } while (ret == -EINTR); if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) { dprintf("connect failed\n"); goto err_after_open; } else if (ret >= 0) migrate_fd_connect(s); return &s->mig_state; err_after_open: close(s->fd); err_after_alloc: qemu_free(s); return NULL; } static void unix_accept_incoming_migration(void *opaque) { struct sockaddr_un 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; } 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); out_fopen: qemu_fclose(f); out: close(c); } int unix_start_incoming_migration(const char *path) { struct sockaddr_un un; int sock; dprintf("Attempting to start an incoming migration\n"); sock = socket(PF_UNIX, SOCK_STREAM, 0); if (sock < 0) { fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno)); return -EINVAL; } memset(&un, 0, sizeof(un)); un.sun_family = AF_UNIX; snprintf(un.sun_path, sizeof(un.sun_path), "%s", path); unlink(un.sun_path); if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) { fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno)); goto err; } if (listen(sock, 1) < 0) { fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno)); goto err; } qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL, (void *)(unsigned long)sock); return 0; err: close(sock); return -EINVAL; }