xref: /openbmc/qemu/migration/fd.c (revision d38ea87a)
1 /*
2  * QEMU live migration via generic fd
3  *
4  * Copyright Red Hat, Inc. 2009
5  *
6  * Authors:
7  *  Chris Lalancette <clalance@redhat.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  * Contributions after 2012-01-13 are licensed under the terms of the
13  * GNU GPL, version 2 or (at your option) any later version.
14  */
15 
16 #include "qemu/osdep.h"
17 #include "qemu-common.h"
18 #include "qemu/main-loop.h"
19 #include "qemu/sockets.h"
20 #include "migration/migration.h"
21 #include "monitor/monitor.h"
22 #include "migration/qemu-file.h"
23 #include "block/block.h"
24 
25 //#define DEBUG_MIGRATION_FD
26 
27 #ifdef DEBUG_MIGRATION_FD
28 #define DPRINTF(fmt, ...) \
29     do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
30 #else
31 #define DPRINTF(fmt, ...) \
32     do { } while (0)
33 #endif
34 
35 static bool fd_is_socket(int fd)
36 {
37     struct stat stat;
38     int ret = fstat(fd, &stat);
39     if (ret == -1) {
40         /* When in doubt say no */
41         return false;
42     }
43     return S_ISSOCK(stat.st_mode);
44 }
45 
46 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
47 {
48     int fd = monitor_get_fd(cur_mon, fdname, errp);
49     if (fd == -1) {
50         return;
51     }
52 
53     if (fd_is_socket(fd)) {
54         s->file = qemu_fopen_socket(fd, "wb");
55     } else {
56         s->file = qemu_fdopen(fd, "wb");
57     }
58 
59     migrate_fd_connect(s);
60 }
61 
62 static void fd_accept_incoming_migration(void *opaque)
63 {
64     QEMUFile *f = opaque;
65 
66     qemu_set_fd_handler(qemu_get_fd(f), NULL, NULL, NULL);
67     process_incoming_migration(f);
68 }
69 
70 void fd_start_incoming_migration(const char *infd, Error **errp)
71 {
72     int fd;
73     QEMUFile *f;
74 
75     DPRINTF("Attempting to start an incoming migration via fd\n");
76 
77     fd = strtol(infd, NULL, 0);
78     if (fd_is_socket(fd)) {
79         f = qemu_fopen_socket(fd, "rb");
80     } else {
81         f = qemu_fdopen(fd, "rb");
82     }
83     if(f == NULL) {
84         error_setg_errno(errp, errno, "failed to open the source descriptor");
85         return;
86     }
87 
88     qemu_set_fd_handler(fd, fd_accept_incoming_migration, NULL, f);
89 }
90