1 /*
2 * QEMU live migration
3 *
4 * Copyright IBM, Corp. 2008
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.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_TCP
23
24 #ifdef DEBUG_MIGRATION_TCP
25 #define dprintf(fmt, ...) \
26 do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
27 #else
28 #define dprintf(fmt, ...) \
29 do { } while (0)
30 #endif
31
socket_errno(FdMigrationState * s)32 static int socket_errno(FdMigrationState *s)
33 {
34 return errno;
35 }
36
socket_write(FdMigrationState * s,const void * buf,size_t size)37 static int socket_write(FdMigrationState *s, const void * buf, size_t size)
38 {
39 return socket_send(s->fd, buf, size);
40 }
41
tcp_close(FdMigrationState * s)42 static int tcp_close(FdMigrationState *s)
43 {
44 dprintf("tcp_close\n");
45 if (s->fd != -1) {
46 socket_close(s->fd);
47 s->fd = -1;
48 }
49 return 0;
50 }
51
52
tcp_wait_for_connect(void * opaque)53 static void tcp_wait_for_connect(void *opaque)
54 {
55 FdMigrationState *s = opaque;
56 int ret;
57
58 dprintf("connect completed\n");
59 ret = socket_get_error(s->fd);
60 if (ret < 0) {
61 dprintf("error connecting %d\n", val);
62 migrate_fd_error(s);
63 return;
64 }
65
66 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
67
68 migrate_fd_connect(s);
69 }
70
tcp_start_outgoing_migration(const char * host_port,int64_t bandwidth_limit,int detach)71 MigrationState *tcp_start_outgoing_migration(const char *host_port,
72 int64_t bandwidth_limit,
73 int detach)
74 {
75 SockAddress addr;
76 FdMigrationState *s;
77 int ret;
78
79 if (parse_host_port(&addr, host_port) < 0)
80 return NULL;
81
82 s = qemu_mallocz(sizeof(*s));
83
84 s->get_error = socket_errno;
85 s->write = socket_write;
86 s->close = tcp_close;
87 s->mig_state.cancel = migrate_fd_cancel;
88 s->mig_state.get_status = migrate_fd_get_status;
89 s->mig_state.release = migrate_fd_release;
90
91 s->state = MIG_STATE_ACTIVE;
92 s->mon_resume = NULL;
93 s->bandwidth_limit = bandwidth_limit;
94 s->fd = socket_create_inet(SOCKET_STREAM);
95 if (s->fd == -1) {
96 qemu_free(s);
97 return NULL;
98 }
99
100 socket_set_nonblock(s->fd);
101
102 if (!detach)
103 migrate_fd_monitor_suspend(s);
104
105 do {
106 ret = socket_connect(s->fd, &addr);
107 if (ret == -1)
108 ret = -(s->get_error(s));
109
110 if (ret == -EINPROGRESS || ret == -EWOULDBLOCK || ret == -EAGAIN)
111 qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
112 } while (ret == -EINTR);
113
114 if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK && ret != -EAGAIN) {
115 dprintf("connect failed\n");
116 socket_close(s->fd);
117 qemu_free(s);
118 return NULL;
119 } else if (ret >= 0)
120 migrate_fd_connect(s);
121
122 return &s->mig_state;
123 }
124
tcp_accept_incoming_migration(void * opaque)125 static void tcp_accept_incoming_migration(void *opaque)
126 {
127 SockAddress addr;
128 int s = (unsigned long)opaque;
129 QEMUFile *f;
130 int c, ret;
131
132 c = socket_accept(s, &addr);
133 dprintf("accepted migration\n");
134
135 if (c == -1) {
136 fprintf(stderr, "could not accept migration connection\n");
137 return;
138 }
139
140 f = qemu_fopen_socket(c);
141 if (f == NULL) {
142 fprintf(stderr, "could not qemu_fopen socket\n");
143 goto out;
144 }
145
146 vm_stop(0); /* just in case */
147 ret = qemu_loadvm_state(f);
148 if (ret < 0) {
149 fprintf(stderr, "load of migration failed\n");
150 goto out_fopen;
151 }
152 qemu_announce_self();
153 dprintf("successfully loaded vm state\n");
154
155 /* we've successfully migrated, close the server socket */
156 qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
157 socket_close(s);
158
159 vm_start();
160
161 out_fopen:
162 qemu_fclose(f);
163 out:
164 socket_close(c);
165 }
166
tcp_start_incoming_migration(const char * host_port)167 int tcp_start_incoming_migration(const char *host_port)
168 {
169 SockAddress addr;
170 int s;
171
172 if (parse_host_port(&addr, host_port) < 0) {
173 fprintf(stderr, "invalid host/port combination: %s\n", host_port);
174 return -EINVAL;
175 }
176
177 s = socket_create_inet(SOCKET_STREAM);
178 if (s == -1)
179 return -socket_error();
180
181 socket_set_xreuseaddr(s);
182
183 if (socket_bind(s, &addr) == -1)
184 goto err;
185
186 if (socket_listen(s, 1) == -1)
187 goto err;
188
189 qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
190 (void *)(unsigned long)s);
191
192 return 0;
193
194 err:
195 socket_close(s);
196 return -socket_error();
197 }
198