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
36static int file_errno(FdMigrationState *s)
37{
38    return errno;
39}
40
41static int file_write(FdMigrationState *s, const void * buf, size_t size)
42{
43    return write(s->fd, buf, size);
44}
45
46static 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
65MigrationState *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
110err_after_open:
111    pclose(f);
112err_after_alloc:
113    qemu_free(s);
114    return NULL;
115}
116
117static 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
134err:
135    qemu_fclose(f);
136}
137
138int 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