2 * QEMU live migration via Unix Domain Sockets
4 * Copyright Red Hat, Inc. 2009
7 * Chris Lalancette <clalance@redhat.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
14 #include "qemu-common.h"
15 #include "qemu_socket.h"
16 #include "migration.h"
17 #include "qemu-char.h"
19 #include "buffered_file.h"
22 //#define DEBUG_MIGRATION_UNIX
24 #ifdef DEBUG_MIGRATION_UNIX
25 #define dprintf(fmt, ...) \
26 do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
28 #define dprintf(fmt, ...) \
32 static int unix_errno(FdMigrationState *s)
37 static int unix_write(FdMigrationState *s, const void * buf, size_t size)
39 return write(s->fd, buf, size);
42 static int unix_close(FdMigrationState *s)
44 dprintf("unix_close\n");
52 static void unix_wait_for_connect(void *opaque)
54 FdMigrationState *s = opaque;
56 socklen_t valsize = sizeof(val);
58 dprintf("connect completed\n");
60 ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
61 } while (ret == -1 && (s->get_error(s)) == EINTR);
68 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
71 migrate_fd_connect(s);
73 dprintf("error connecting %d\n", val);
78 MigrationState *unix_start_outgoing_migration(const char *path,
79 int64_t bandwidth_limit,
85 struct sockaddr_un addr;
88 addr.sun_family = AF_UNIX;
89 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
91 s = qemu_mallocz(sizeof(*s));
93 s->get_error = unix_errno;
94 s->write = unix_write;
95 s->close = unix_close;
96 s->mig_state.cancel = migrate_fd_cancel;
97 s->mig_state.get_status = migrate_fd_get_status;
98 s->mig_state.release = migrate_fd_release;
100 s->mig_state.blk = blk;
101 s->mig_state.shared = inc;
103 s->state = MIG_STATE_ACTIVE;
104 s->mon_resume = NULL;
105 s->bandwidth_limit = bandwidth_limit;
106 s->fd = socket(PF_UNIX, SOCK_STREAM, 0);
108 dprintf("Unable to open socket");
109 goto err_after_alloc;
112 socket_set_nonblock(s->fd);
115 migrate_fd_monitor_suspend(s);
118 ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
120 ret = -(s->get_error(s));
122 if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
123 qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s);
124 } while (ret == -EINTR);
126 if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
127 dprintf("connect failed\n");
130 migrate_fd_connect(s);
132 return &s->mig_state;
142 static void unix_accept_incoming_migration(void *opaque)
144 struct sockaddr_un addr;
145 socklen_t addrlen = sizeof(addr);
146 int s = (unsigned long)opaque;
151 c = accept(s, (struct sockaddr *)&addr, &addrlen);
152 } while (c == -1 && socket_error() == EINTR);
154 dprintf("accepted migration\n");
157 fprintf(stderr, "could not accept migration connection\n");
161 f = qemu_fopen_socket(c);
163 fprintf(stderr, "could not qemu_fopen socket\n");
167 ret = qemu_loadvm_state(f);
169 fprintf(stderr, "load of migration failed\n");
172 qemu_announce_self();
173 dprintf("successfully loaded vm state\n");
175 /* we've successfully migrated, close the server socket */
176 qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
185 int unix_start_incoming_migration(const char *path)
187 struct sockaddr_un un;
190 dprintf("Attempting to start an incoming migration\n");
192 sock = socket(PF_UNIX, SOCK_STREAM, 0);
194 fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
198 memset(&un, 0, sizeof(un));
199 un.sun_family = AF_UNIX;
200 snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
203 if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
204 fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno));
207 if (listen(sock, 1) < 0) {
208 fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno));
212 qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL,
213 (void *)(unsigned long)sock);