Merge remote-tracking branch 'agraf/xen-next' into staging
[qemu.git] / migration-unix.c
blobc8625c7f6501a0760cc9b7f32c947f7cb84f72be
1 /*
2 * QEMU live migration via Unix Domain Sockets
4 * Copyright Red Hat, Inc. 2009
6 * Authors:
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"
19 #include "block.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)
26 #else
27 #define DPRINTF(fmt, ...) \
28 do { } while (0)
29 #endif
31 static int unix_errno(FdMigrationState *s)
33 return errno;
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");
44 if (s->fd != -1) {
45 close(s->fd);
46 s->fd = -1;
48 return 0;
51 static void unix_wait_for_connect(void *opaque)
53 FdMigrationState *s = opaque;
54 int val, ret;
55 socklen_t valsize = sizeof(val);
57 DPRINTF("connect completed\n");
58 do {
59 ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
60 } while (ret == -1 && (s->get_error(s)) == EINTR);
62 if (ret < 0) {
63 migrate_fd_error(s);
64 return;
67 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
69 if (val == 0)
70 migrate_fd_connect(s);
71 else {
72 DPRINTF("error connecting %d\n", val);
73 migrate_fd_error(s);
77 MigrationState *unix_start_outgoing_migration(Monitor *mon,
78 const char *path,
79 int64_t bandwidth_limit,
80 int detach,
81 int blk,
82 int inc)
84 FdMigrationState *s;
85 struct sockaddr_un addr;
86 int ret;
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;
104 s->mon = NULL;
105 s->bandwidth_limit = bandwidth_limit;
106 s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
107 if (s->fd < 0) {
108 DPRINTF("Unable to open socket");
109 goto err_after_alloc;
112 socket_set_nonblock(s->fd);
114 do {
115 ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
116 if (ret == -1)
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");
125 goto err_after_open;
128 if (!detach) {
129 migrate_fd_monitor_suspend(s, mon);
132 if (ret >= 0)
133 migrate_fd_connect(s);
135 return &s->mig_state;
137 err_after_open:
138 close(s->fd);
140 err_after_alloc:
141 qemu_free(s);
142 return NULL;
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;
150 QEMUFile *f;
151 int c;
153 do {
154 c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
155 } while (c == -1 && socket_error() == EINTR);
157 DPRINTF("accepted migration\n");
159 if (c == -1) {
160 fprintf(stderr, "could not accept migration connection\n");
161 return;
164 f = qemu_fopen_socket(c);
165 if (f == NULL) {
166 fprintf(stderr, "could not qemu_fopen socket\n");
167 goto out;
170 process_incoming_migration(f);
171 qemu_fclose(f);
172 out:
173 qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
174 close(s);
175 close(c);
178 int unix_start_incoming_migration(const char *path)
180 struct sockaddr_un un;
181 int sock;
183 DPRINTF("Attempting to start an incoming migration\n");
185 sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
186 if (sock < 0) {
187 fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
188 return -EINVAL;
191 memset(&un, 0, sizeof(un));
192 un.sun_family = AF_UNIX;
193 snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
195 unlink(un.sun_path);
196 if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
197 fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno));
198 goto err;
200 if (listen(sock, 1) < 0) {
201 fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno));
202 goto err;
205 qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL,
206 (void *)(intptr_t)sock);
208 return 0;
210 err:
211 close(sock);
213 return -EINVAL;