Merge remote branch 'mst/for_anthony' into staging
[qemu/mdroth.git] / migration-unix.c
blob57232c07a934156ff8948418970ce925d0da5191
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 "sysemu.h"
19 #include "buffered_file.h"
20 #include "block.h"
22 //#define DEBUG_MIGRATION_UNIX
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
32 static int unix_errno(FdMigrationState *s)
34 return errno;
37 static int unix_write(FdMigrationState *s, const void * buf, size_t size)
39 return write(s->fd, buf, size);
42 static int unix_close(FdMigrationState *s)
44 DPRINTF("unix_close\n");
45 if (s->fd != -1) {
46 close(s->fd);
47 s->fd = -1;
49 return 0;
52 static void unix_wait_for_connect(void *opaque)
54 FdMigrationState *s = opaque;
55 int val, ret;
56 socklen_t valsize = sizeof(val);
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);
63 if (ret < 0) {
64 migrate_fd_error(s);
65 return;
68 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
70 if (val == 0)
71 migrate_fd_connect(s);
72 else {
73 DPRINTF("error connecting %d\n", val);
74 migrate_fd_error(s);
78 MigrationState *unix_start_outgoing_migration(Monitor *mon,
79 const char *path,
80 int64_t bandwidth_limit,
81 int detach,
82 int blk,
83 int inc)
85 FdMigrationState *s;
86 struct sockaddr_un addr;
87 int ret;
89 addr.sun_family = AF_UNIX;
90 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
92 s = qemu_mallocz(sizeof(*s));
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;
101 s->mig_state.blk = blk;
102 s->mig_state.shared = inc;
104 s->state = MIG_STATE_ACTIVE;
105 s->mon = NULL;
106 s->bandwidth_limit = bandwidth_limit;
107 s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
108 if (s->fd < 0) {
109 DPRINTF("Unable to open socket");
110 goto err_after_alloc;
113 socket_set_nonblock(s->fd);
115 do {
116 ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
117 if (ret == -1)
118 ret = -(s->get_error(s));
120 if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
121 qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s);
122 } while (ret == -EINTR);
124 if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
125 DPRINTF("connect failed\n");
126 goto err_after_open;
129 if (!detach) {
130 migrate_fd_monitor_suspend(s, mon);
133 if (ret >= 0)
134 migrate_fd_connect(s);
136 return &s->mig_state;
138 err_after_open:
139 close(s->fd);
141 err_after_alloc:
142 qemu_free(s);
143 return NULL;
146 static void unix_accept_incoming_migration(void *opaque)
148 struct sockaddr_un addr;
149 socklen_t addrlen = sizeof(addr);
150 int s = (unsigned long)opaque;
151 QEMUFile *f;
152 int c;
154 do {
155 c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
156 } while (c == -1 && socket_error() == EINTR);
158 DPRINTF("accepted migration\n");
160 if (c == -1) {
161 fprintf(stderr, "could not accept migration connection\n");
162 return;
165 f = qemu_fopen_socket(c);
166 if (f == NULL) {
167 fprintf(stderr, "could not qemu_fopen socket\n");
168 goto out;
171 process_incoming_migration(f);
172 qemu_fclose(f);
173 out:
174 qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
175 close(s);
176 close(c);
179 int unix_start_incoming_migration(const char *path)
181 struct sockaddr_un un;
182 int sock;
184 DPRINTF("Attempting to start an incoming migration\n");
186 sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
187 if (sock < 0) {
188 fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
189 return -EINVAL;
192 memset(&un, 0, sizeof(un));
193 un.sun_family = AF_UNIX;
194 snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
196 unlink(un.sun_path);
197 if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
198 fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno));
199 goto err;
201 if (listen(sock, 1) < 0) {
202 fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno));
203 goto err;
206 qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL,
207 (void *)(unsigned long)sock);
209 return 0;
211 err:
212 close(sock);
214 return -EINVAL;