xref: /openbmc/qemu/migration/fd.c (revision 77a8257e)
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-common.h"
17 #include "qemu/main-loop.h"
18 #include "qemu/sockets.h"
19 #include "migration/migration.h"
20 #include "monitor/monitor.h"
21 #include "migration/qemu-file.h"
22 #include "block/block.h"
23 
24 //#define DEBUG_MIGRATION_FD
25 
26 #ifdef DEBUG_MIGRATION_FD
27 #define DPRINTF(fmt, ...) \
28     do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
29 #else
30 #define DPRINTF(fmt, ...) \
31     do { } while (0)
32 #endif
33 
34 static bool fd_is_socket(int fd)
35 {
36     struct stat stat;
37     int ret = fstat(fd, &stat);
38     if (ret == -1) {
39         /* When in doubt say no */
40         return false;
41     }
42     return S_ISSOCK(stat.st_mode);
43 }
44 
45 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
46 {
47     int fd = monitor_get_fd(cur_mon, fdname, errp);
48     if (fd == -1) {
49         return;
50     }
51 
52     if (fd_is_socket(fd)) {
53         s->file = qemu_fopen_socket(fd, "wb");
54     } else {
55         s->file = qemu_fdopen(fd, "wb");
56     }
57 
58     migrate_fd_connect(s);
59 }
60 
61 static void fd_accept_incoming_migration(void *opaque)
62 {
63     QEMUFile *f = opaque;
64 
65     qemu_set_fd_handler2(qemu_get_fd(f), NULL, NULL, NULL, NULL);
66     process_incoming_migration(f);
67 }
68 
69 void fd_start_incoming_migration(const char *infd, Error **errp)
70 {
71     int fd;
72     QEMUFile *f;
73 
74     DPRINTF("Attempting to start an incoming migration via fd\n");
75 
76     fd = strtol(infd, NULL, 0);
77     if (fd_is_socket(fd)) {
78         f = qemu_fopen_socket(fd, "rb");
79     } else {
80         f = qemu_fdopen(fd, "rb");
81     }
82     if(f == NULL) {
83         error_setg_errno(errp, errno, "failed to open the source descriptor");
84         return;
85     }
86 
87     qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f);
88 }
89