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4951f65b CL |
1 | /* |
2 | * QEMU live migration via Unix Domain Sockets | |
3 | * | |
4 | * Copyright Red Hat, Inc. 2009 | |
5 | * | |
6 | * Authors: | |
7 | * Chris Lalancette <clalance@redhat.com> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include "qemu-common.h" | |
15 | #include "qemu_socket.h" | |
16 | #include "migration.h" | |
17 | #include "qemu-char.h" | |
18 | #include "sysemu.h" | |
19 | #include "buffered_file.h" | |
20 | #include "block.h" | |
21 | ||
22 | //#define DEBUG_MIGRATION_UNIX | |
23 | ||
24 | #ifdef DEBUG_MIGRATION_UNIX | |
25 | #define dprintf(fmt, ...) \ | |
26 | do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0) | |
27 | #else | |
28 | #define dprintf(fmt, ...) \ | |
29 | do { } while (0) | |
30 | #endif | |
31 | ||
32 | static int unix_errno(FdMigrationState *s) | |
33 | { | |
34 | return errno; | |
35 | } | |
36 | ||
37 | static int unix_write(FdMigrationState *s, const void * buf, size_t size) | |
38 | { | |
39 | return write(s->fd, buf, size); | |
40 | } | |
41 | ||
42 | static int unix_close(FdMigrationState *s) | |
43 | { | |
44 | dprintf("unix_close\n"); | |
45 | if (s->fd != -1) { | |
46 | close(s->fd); | |
47 | s->fd = -1; | |
48 | } | |
49 | return 0; | |
50 | } | |
51 | ||
52 | static void unix_wait_for_connect(void *opaque) | |
53 | { | |
54 | FdMigrationState *s = opaque; | |
55 | int val, ret; | |
56 | socklen_t valsize = sizeof(val); | |
57 | ||
58 | dprintf("connect completed\n"); | |
59 | do { | |
60 | ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize); | |
61 | } while (ret == -1 && (s->get_error(s)) == EINTR); | |
62 | ||
63 | if (ret < 0) { | |
64 | migrate_fd_error(s); | |
65 | return; | |
66 | } | |
67 | ||
68 | qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); | |
69 | ||
70 | if (val == 0) | |
71 | migrate_fd_connect(s); | |
72 | else { | |
73 | dprintf("error connecting %d\n", val); | |
74 | migrate_fd_error(s); | |
75 | } | |
76 | } | |
77 | ||
f327aa0c JK |
78 | MigrationState *unix_start_outgoing_migration(Monitor *mon, |
79 | const char *path, | |
4951f65b | 80 | int64_t bandwidth_limit, |
c163b5ca | 81 | int detach, |
82 | int blk, | |
83 | int inc) | |
4951f65b CL |
84 | { |
85 | FdMigrationState *s; | |
86 | struct sockaddr_un addr; | |
87 | int ret; | |
88 | ||
89 | addr.sun_family = AF_UNIX; | |
90 | snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path); | |
91 | ||
92 | s = qemu_mallocz(sizeof(*s)); | |
93 | ||
94 | s->get_error = unix_errno; | |
95 | s->write = unix_write; | |
96 | s->close = unix_close; | |
97 | s->mig_state.cancel = migrate_fd_cancel; | |
98 | s->mig_state.get_status = migrate_fd_get_status; | |
99 | s->mig_state.release = migrate_fd_release; | |
100 | ||
c163b5ca | 101 | s->mig_state.blk = blk; |
102 | s->mig_state.shared = inc; | |
103 | ||
4951f65b | 104 | s->state = MIG_STATE_ACTIVE; |
f327aa0c | 105 | s->mon = NULL; |
4951f65b | 106 | s->bandwidth_limit = bandwidth_limit; |
40ff6d7e | 107 | s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0); |
4951f65b CL |
108 | if (s->fd < 0) { |
109 | dprintf("Unable to open socket"); | |
110 | goto err_after_alloc; | |
111 | } | |
112 | ||
113 | socket_set_nonblock(s->fd); | |
114 | ||
f327aa0c JK |
115 | if (!detach) { |
116 | migrate_fd_monitor_suspend(s, mon); | |
117 | } | |
4951f65b CL |
118 | |
119 | do { | |
120 | ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr)); | |
121 | if (ret == -1) | |
122 | ret = -(s->get_error(s)); | |
123 | ||
124 | if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) | |
125 | qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s); | |
126 | } while (ret == -EINTR); | |
127 | ||
128 | if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) { | |
129 | dprintf("connect failed\n"); | |
130 | goto err_after_open; | |
131 | } else if (ret >= 0) | |
132 | migrate_fd_connect(s); | |
133 | ||
134 | return &s->mig_state; | |
135 | ||
136 | err_after_open: | |
137 | close(s->fd); | |
138 | ||
139 | err_after_alloc: | |
140 | qemu_free(s); | |
141 | return NULL; | |
142 | } | |
143 | ||
144 | static void unix_accept_incoming_migration(void *opaque) | |
145 | { | |
146 | struct sockaddr_un addr; | |
147 | socklen_t addrlen = sizeof(addr); | |
148 | int s = (unsigned long)opaque; | |
149 | QEMUFile *f; | |
150 | int c, ret; | |
151 | ||
152 | do { | |
40ff6d7e | 153 | c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen); |
4951f65b CL |
154 | } while (c == -1 && socket_error() == EINTR); |
155 | ||
156 | dprintf("accepted migration\n"); | |
157 | ||
158 | if (c == -1) { | |
159 | fprintf(stderr, "could not accept migration connection\n"); | |
160 | return; | |
161 | } | |
162 | ||
163 | f = qemu_fopen_socket(c); | |
164 | if (f == NULL) { | |
165 | fprintf(stderr, "could not qemu_fopen socket\n"); | |
166 | goto out; | |
167 | } | |
168 | ||
169 | ret = qemu_loadvm_state(f); | |
170 | if (ret < 0) { | |
171 | fprintf(stderr, "load of migration failed\n"); | |
172 | goto out_fopen; | |
173 | } | |
174 | qemu_announce_self(); | |
175 | dprintf("successfully loaded vm state\n"); | |
176 | ||
177 | /* we've successfully migrated, close the server socket */ | |
178 | qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL); | |
179 | close(s); | |
180 | ||
181 | out_fopen: | |
182 | qemu_fclose(f); | |
183 | out: | |
184 | close(c); | |
185 | } | |
186 | ||
187 | int unix_start_incoming_migration(const char *path) | |
188 | { | |
189 | struct sockaddr_un un; | |
190 | int sock; | |
191 | ||
192 | dprintf("Attempting to start an incoming migration\n"); | |
193 | ||
40ff6d7e | 194 | sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0); |
4951f65b CL |
195 | if (sock < 0) { |
196 | fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno)); | |
197 | return -EINVAL; | |
198 | } | |
199 | ||
200 | memset(&un, 0, sizeof(un)); | |
201 | un.sun_family = AF_UNIX; | |
202 | snprintf(un.sun_path, sizeof(un.sun_path), "%s", path); | |
203 | ||
204 | unlink(un.sun_path); | |
205 | if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) { | |
206 | fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno)); | |
207 | goto err; | |
208 | } | |
209 | if (listen(sock, 1) < 0) { | |
210 | fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno)); | |
211 | goto err; | |
212 | } | |
213 | ||
214 | qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL, | |
215 | (void *)(unsigned long)sock); | |
216 | ||
217 | return 0; | |
218 | ||
219 | err: | |
220 | close(sock); | |
221 | ||
222 | return -EINVAL; | |
223 | } |