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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 <[email protected]> | |
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 | ||
78 | MigrationState *unix_start_outgoing_migration(const char *path, | |
79 | int64_t bandwidth_limit, | |
80 | int detach) | |
81 | { | |
82 | FdMigrationState *s; | |
83 | struct sockaddr_un addr; | |
84 | int ret; | |
85 | ||
86 | addr.sun_family = AF_UNIX; | |
87 | snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path); | |
88 | ||
89 | s = qemu_mallocz(sizeof(*s)); | |
90 | ||
91 | s->get_error = unix_errno; | |
92 | s->write = unix_write; | |
93 | s->close = unix_close; | |
94 | s->mig_state.cancel = migrate_fd_cancel; | |
95 | s->mig_state.get_status = migrate_fd_get_status; | |
96 | s->mig_state.release = migrate_fd_release; | |
97 | ||
98 | s->state = MIG_STATE_ACTIVE; | |
99 | s->mon_resume = NULL; | |
100 | s->bandwidth_limit = bandwidth_limit; | |
101 | s->fd = socket(PF_UNIX, SOCK_STREAM, 0); | |
102 | if (s->fd < 0) { | |
103 | dprintf("Unable to open socket"); | |
104 | goto err_after_alloc; | |
105 | } | |
106 | ||
107 | socket_set_nonblock(s->fd); | |
108 | ||
109 | if (!detach) | |
110 | migrate_fd_monitor_suspend(s); | |
111 | ||
112 | do { | |
113 | ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr)); | |
114 | if (ret == -1) | |
115 | ret = -(s->get_error(s)); | |
116 | ||
117 | if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) | |
118 | qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s); | |
119 | } while (ret == -EINTR); | |
120 | ||
121 | if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) { | |
122 | dprintf("connect failed\n"); | |
123 | goto err_after_open; | |
124 | } else if (ret >= 0) | |
125 | migrate_fd_connect(s); | |
126 | ||
127 | return &s->mig_state; | |
128 | ||
129 | err_after_open: | |
130 | close(s->fd); | |
131 | ||
132 | err_after_alloc: | |
133 | qemu_free(s); | |
134 | return NULL; | |
135 | } | |
136 | ||
137 | static void unix_accept_incoming_migration(void *opaque) | |
138 | { | |
139 | struct sockaddr_un addr; | |
140 | socklen_t addrlen = sizeof(addr); | |
141 | int s = (unsigned long)opaque; | |
142 | QEMUFile *f; | |
143 | int c, ret; | |
144 | ||
145 | do { | |
146 | c = accept(s, (struct sockaddr *)&addr, &addrlen); | |
147 | } while (c == -1 && socket_error() == EINTR); | |
148 | ||
149 | dprintf("accepted migration\n"); | |
150 | ||
151 | if (c == -1) { | |
152 | fprintf(stderr, "could not accept migration connection\n"); | |
153 | return; | |
154 | } | |
155 | ||
156 | f = qemu_fopen_socket(c); | |
157 | if (f == NULL) { | |
158 | fprintf(stderr, "could not qemu_fopen socket\n"); | |
159 | goto out; | |
160 | } | |
161 | ||
162 | ret = qemu_loadvm_state(f); | |
163 | if (ret < 0) { | |
164 | fprintf(stderr, "load of migration failed\n"); | |
165 | goto out_fopen; | |
166 | } | |
167 | qemu_announce_self(); | |
168 | dprintf("successfully loaded vm state\n"); | |
169 | ||
170 | /* we've successfully migrated, close the server socket */ | |
171 | qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL); | |
172 | close(s); | |
173 | ||
174 | out_fopen: | |
175 | qemu_fclose(f); | |
176 | out: | |
177 | close(c); | |
178 | } | |
179 | ||
180 | int unix_start_incoming_migration(const char *path) | |
181 | { | |
182 | struct sockaddr_un un; | |
183 | int sock; | |
184 | ||
185 | dprintf("Attempting to start an incoming migration\n"); | |
186 | ||
187 | sock = socket(PF_UNIX, SOCK_STREAM, 0); | |
188 | if (sock < 0) { | |
189 | fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno)); | |
190 | return -EINVAL; | |
191 | } | |
192 | ||
193 | memset(&un, 0, sizeof(un)); | |
194 | un.sun_family = AF_UNIX; | |
195 | snprintf(un.sun_path, sizeof(un.sun_path), "%s", path); | |
196 | ||
197 | unlink(un.sun_path); | |
198 | if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) { | |
199 | fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno)); | |
200 | goto err; | |
201 | } | |
202 | if (listen(sock, 1) < 0) { | |
203 | fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno)); | |
204 | goto err; | |
205 | } | |
206 | ||
207 | qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL, | |
208 | (void *)(unsigned long)sock); | |
209 | ||
210 | return 0; | |
211 | ||
212 | err: | |
213 | close(sock); | |
214 | ||
215 | return -EINVAL; | |
216 | } |