1 /*
2 * QEMU live migration
3 *
4 * Copyright IBM, Corp. 2008
5 * Copyright Dell MessageOne 2008
6 *
7 * Authors:
8 * Anthony Liguori <aliguori@us.ibm.com>
9 * Charles Duffy <charles_duffy@messageone.com>
10 *
11 * This work is licensed under the terms of the GNU GPL, version 2. See
12 * the COPYING file in the top-level directory.
13 *
14 */
15
16 #include "qemu-common.h"
17 #include "qemu_socket.h"
18 #include "migration.h"
19 #include "qemu-char.h"
20 #include "sysemu.h"
21 #include "buffered_file.h"
22 #include "block.h"
23 #include <sys/types.h>
24 #include <sys/wait.h>
25
26 //#define DEBUG_MIGRATION_EXEC
27
28 #ifdef DEBUG_MIGRATION_EXEC
29 #define DPRINTF(fmt, ...) \
30 do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
31 #else
32 #define DPRINTF(fmt, ...) \
33 do { } while (0)
34 #endif
35
file_errno(FdMigrationState * s)36 static int file_errno(FdMigrationState *s)
37 {
38 return errno;
39 }
40
file_write(FdMigrationState * s,const void * buf,size_t size)41 static int file_write(FdMigrationState *s, const void * buf, size_t size)
42 {
43 return write(s->fd, buf, size);
44 }
45
exec_close(FdMigrationState * s)46 static int exec_close(FdMigrationState *s)
47 {
48 int ret = 0;
49 DPRINTF("exec_close\n");
50 if (s->opaque) {
51 ret = qemu_fclose(s->opaque);
52 s->opaque = NULL;
53 s->fd = -1;
54 if (ret != -1 &&
55 WIFEXITED(ret)
56 && WEXITSTATUS(ret) == 0) {
57 ret = 0;
58 } else {
59 ret = -1;
60 }
61 }
62 return ret;
63 }
64
exec_start_outgoing_migration(const char * command,int64_t bandwidth_limit,int detach)65 MigrationState *exec_start_outgoing_migration(const char *command,
66 int64_t bandwidth_limit,
67 int detach)
68 {
69 FdMigrationState *s;
70 FILE *f;
71
72 s = qemu_mallocz(sizeof(*s));
73
74 f = popen(command, "w");
75 if (f == NULL) {
76 DPRINTF("Unable to popen exec target\n");
77 goto err_after_alloc;
78 }
79
80 s->fd = fileno(f);
81 if (s->fd == -1) {
82 DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
83 goto err_after_open;
84 }
85
86 if (fcntl(s->fd, F_SETFD, O_NONBLOCK) == -1) {
87 DPRINTF("Unable to set nonblocking mode on file descriptor\n");
88 goto err_after_open;
89 }
90
91 s->opaque = qemu_popen(f, "w");
92
93 s->close = exec_close;
94 s->get_error = file_errno;
95 s->write = file_write;
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;
99
100 s->state = MIG_STATE_ACTIVE;
101 s->mon_resume = NULL;
102 s->bandwidth_limit = bandwidth_limit;
103
104 if (!detach)
105 migrate_fd_monitor_suspend(s);
106
107 migrate_fd_connect(s);
108 return &s->mig_state;
109
110 err_after_open:
111 pclose(f);
112 err_after_alloc:
113 qemu_free(s);
114 return NULL;
115 }
116
exec_accept_incoming_migration(void * opaque)117 static void exec_accept_incoming_migration(void *opaque)
118 {
119 QEMUFile *f = opaque;
120 int ret;
121
122 vm_stop(0); /* just in case */
123 ret = qemu_loadvm_state(f);
124 if (ret < 0) {
125 fprintf(stderr, "load of migration failed\n");
126 goto err;
127 }
128 qemu_announce_self();
129 DPRINTF("successfully loaded vm state\n");
130 /* we've successfully migrated, close the fd */
131 qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
132 vm_start();
133
134 err:
135 qemu_fclose(f);
136 }
137
exec_start_incoming_migration(const char * command)138 int exec_start_incoming_migration(const char *command)
139 {
140 QEMUFile *f;
141
142 DPRINTF("Attempting to start an incoming migration\n");
143 f = qemu_popen_cmd(command, "r");
144 if(f == NULL) {
145 DPRINTF("Unable to apply qemu wrapper to popen file\n");
146 return -errno;
147 }
148
149 qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
150 exec_accept_incoming_migration, NULL,
151 (void *)(unsigned long)f);
152
153 return 0;
154 }
155