xref: /openbmc/qemu/migration/fd.c (revision 964d2a0c)
1 /*
2  * QEMU live migration via generic fd
3  *
4  * Copyright Red Hat, Inc. 2009-2016
5  *
6  * Authors:
7  *  Chris Lalancette <clalance@redhat.com>
8  *  Daniel P. Berrange <berrange@redhat.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2.  See
11  * the COPYING file in the top-level directory.
12  *
13  * Contributions after 2012-01-13 are licensed under the terms of the
14  * GNU GPL, version 2 or (at your option) any later version.
15  */
16 
17 #include "qemu/osdep.h"
18 #include "channel.h"
19 #include "fd.h"
20 #include "file.h"
21 #include "migration.h"
22 #include "monitor/monitor.h"
23 #include "qemu/error-report.h"
24 #include "qemu/sockets.h"
25 #include "io/channel-util.h"
26 #include "trace.h"
27 
28 static bool fd_is_pipe(int fd)
29 {
30     struct stat statbuf;
31 
32     if (fstat(fd, &statbuf) == -1) {
33         return false;
34     }
35 
36     return S_ISFIFO(statbuf.st_mode);
37 }
38 
39 static bool migration_fd_valid(int fd)
40 {
41     if (fd_is_socket(fd)) {
42         return true;
43     }
44 
45     if (fd_is_pipe(fd)) {
46         return true;
47     }
48 
49     return false;
50 }
51 
52 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
53 {
54     QIOChannel *ioc;
55     int fd = monitor_get_fd(monitor_cur(), fdname, errp);
56     if (fd == -1) {
57         return;
58     }
59 
60     if (!migration_fd_valid(fd)) {
61         warn_report("fd: migration to a file is deprecated."
62                     " Use file: instead.");
63     }
64 
65     trace_migration_fd_outgoing(fd);
66     ioc = qio_channel_new_fd(fd, errp);
67     if (!ioc) {
68         close(fd);
69         return;
70     }
71 
72     qio_channel_set_name(ioc, "migration-fd-outgoing");
73     migration_channel_connect(s, ioc, NULL, NULL);
74     object_unref(OBJECT(ioc));
75 }
76 
77 static gboolean fd_accept_incoming_migration(QIOChannel *ioc,
78                                              GIOCondition condition,
79                                              gpointer opaque)
80 {
81     migration_channel_process_incoming(ioc);
82     object_unref(OBJECT(ioc));
83     return G_SOURCE_REMOVE;
84 }
85 
86 void fd_start_incoming_migration(const char *fdname, Error **errp)
87 {
88     QIOChannel *ioc;
89     int fd = monitor_fd_param(monitor_cur(), fdname, errp);
90     if (fd == -1) {
91         return;
92     }
93 
94     if (!migration_fd_valid(fd)) {
95         warn_report("fd: migration to a file is deprecated."
96                     " Use file: instead.");
97     }
98 
99     trace_migration_fd_incoming(fd);
100 
101     ioc = qio_channel_new_fd(fd, errp);
102     if (!ioc) {
103         close(fd);
104         return;
105     }
106 
107     qio_channel_set_name(ioc, "migration-fd-incoming");
108     qio_channel_add_watch_full(ioc, G_IO_IN,
109                                fd_accept_incoming_migration,
110                                NULL, NULL,
111                                g_main_context_get_thread_default());
112 }
113