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
32static int socket_errno(FdMigrationState *s)
33{
34    return errno;
35}
36
37static int socket_write(FdMigrationState *s, const void * buf, size_t size)
38{
39    return socket_send(s->fd, buf, size);
40}
41
42static 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
53static 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
71MigrationState *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
125static 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
161out_fopen:
162    qemu_fclose(f);
163out:
164    socket_close(c);
165}
166
167int 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
194err:
195    socket_close(s);
196    return -socket_error();
197}
198