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 MigrationState
*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
= 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
;
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
);
135 return &s
->mig_state
;
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
);