diff options
Diffstat (limited to 'migration-unix.c')
| -rw-r--r-- | migration-unix.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/migration-unix.c b/migration-unix.c new file mode 100644 index 0000000000..a26587a3ea --- /dev/null +++ b/migration-unix.c @@ -0,0 +1,216 @@ +/* + * 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; +} |