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"
18 #include "buffered_file.h"
21 //#define DEBUG_MIGRATION_UNIX
23 #ifdef DEBUG_MIGRATION_UNIX
24 #define DPRINTF(fmt, ...) \
25 do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
27 #define DPRINTF(fmt, ...) \
31 static int unix_errno(FdMigrationState *s)
36 static int unix_write(FdMigrationState *s, const void * buf, size_t size)
38 return write(s->fd, buf, size);
41 static int unix_close(FdMigrationState *s)
43 DPRINTF("unix_close\n");
51 static void unix_wait_for_connect(void *opaque)
53 FdMigrationState *s = opaque;
55 socklen_t valsize = sizeof(val);
57 DPRINTF("connect completed\n");
59 ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
60 } while (ret == -1 && (s->get_error(s)) == EINTR);
67 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
70 migrate_fd_connect(s);
72 DPRINTF("error connecting %d\n", val);
77 FdMigrationState *unix_start_outgoing_migration(Monitor *mon,
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 = g_malloc0(sizeof(*s));
93 s->get_error = unix_errno;
94 s->write = unix_write;
95 s->close = unix_close;
96 s->cancel = migrate_fd_cancel;
97 s->get_status = migrate_fd_get_status;
98 s->release = migrate_fd_release;
103 s->state = MIG_STATE_ACTIVE;
105 s->bandwidth_limit = bandwidth_limit;
106 s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
108 DPRINTF("Unable to open socket");
109 goto err_after_alloc;
112 socket_set_nonblock(s->fd);
115 ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
117 ret = -(s->get_error(s));
119 if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
120 qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s);
121 } while (ret == -EINTR);
123 if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
124 DPRINTF("connect failed\n");
129 migrate_fd_monitor_suspend(s, mon);
133 migrate_fd_connect(s);
145 static void unix_accept_incoming_migration(void *opaque)
147 struct sockaddr_un addr;
148 socklen_t addrlen = sizeof(addr);
149 int s = (intptr_t)opaque;
154 c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
155 } while (c == -1 && socket_error() == EINTR);
157 DPRINTF("accepted migration\n");
160 fprintf(stderr, "could not accept migration connection\n");
164 f = qemu_fopen_socket(c);
166 fprintf(stderr, "could not qemu_fopen socket\n");
170 process_incoming_migration(f);
173 qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
178 int unix_start_incoming_migration(const char *path)
180 struct sockaddr_un un;
183 DPRINTF("Attempting to start an incoming migration\n");
185 sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
187 fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
191 memset(&un, 0, sizeof(un));
192 un.sun_family = AF_UNIX;
193 snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
196 if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
197 fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno));
200 if (listen(sock, 1) < 0) {
201 fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno));
205 qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL,
206 (void *)(intptr_t)sock);