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Paolo Bonzini5ac1fad2009-08-18 15:56:25 +02001/*
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 *
Paolo Bonzini6b620ca2012-01-13 17:44:23 +010012 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020014 */
15
16#include "qemu-common.h"
17#include "qemu_socket.h"
18#include "migration.h"
19#include "monitor.h"
20#include "qemu-char.h"
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020021#include "buffered_file.h"
22#include "block.h"
23#include "qemu_socket.h"
24
25//#define DEBUG_MIGRATION_FD
26
27#ifdef DEBUG_MIGRATION_FD
malcd0f2c4c2010-02-07 02:03:50 +030028#define DPRINTF(fmt, ...) \
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020029 do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
30#else
malcd0f2c4c2010-02-07 02:03:50 +030031#define DPRINTF(fmt, ...) \
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020032 do { } while (0)
33#endif
34
Juan Quintela22f00a42010-05-11 15:56:35 +020035static int fd_errno(MigrationState *s)
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020036{
37 return errno;
38}
39
Juan Quintela22f00a42010-05-11 15:56:35 +020040static int fd_write(MigrationState *s, const void * buf, size_t size)
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020041{
42 return write(s->fd, buf, size);
43}
44
Juan Quintela22f00a42010-05-11 15:56:35 +020045static int fd_close(MigrationState *s)
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020046{
Gerd Hoffmannaab22932011-10-27 09:12:04 +020047 struct stat st;
48 int ret;
49
malcd0f2c4c2010-02-07 02:03:50 +030050 DPRINTF("fd_close\n");
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020051 if (s->fd != -1) {
Gerd Hoffmannaab22932011-10-27 09:12:04 +020052 ret = fstat(s->fd, &st);
53 if (ret == 0 && S_ISREG(st.st_mode)) {
54 /*
55 * If the file handle is a regular file make sure the
56 * data is flushed to disk before signaling success.
57 */
58 ret = fsync(s->fd);
59 if (ret != 0) {
60 ret = -errno;
61 perror("migration-fd: fsync");
62 return ret;
63 }
64 }
65 ret = close(s->fd);
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020066 s->fd = -1;
Gerd Hoffmannaab22932011-10-27 09:12:04 +020067 if (ret != 0) {
68 ret = -errno;
69 perror("migration-fd: close");
70 return ret;
71 }
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020072 }
73 return 0;
74}
75
Juan Quintela07af4452010-05-11 22:27:45 +020076int fd_start_outgoing_migration(MigrationState *s, const char *fdname)
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020077{
Juan Quintela07af4452010-05-11 22:27:45 +020078 s->fd = monitor_get_fd(s->mon, fdname);
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020079 if (s->fd == -1) {
malcd0f2c4c2010-02-07 02:03:50 +030080 DPRINTF("fd_migration: invalid file descriptor identifier\n");
Juan Quintela07af4452010-05-11 22:27:45 +020081 goto err_after_get_fd;
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020082 }
83
84 if (fcntl(s->fd, F_SETFL, O_NONBLOCK) == -1) {
malcd0f2c4c2010-02-07 02:03:50 +030085 DPRINTF("Unable to set nonblocking mode on file descriptor\n");
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020086 goto err_after_open;
87 }
88
89 s->get_error = fd_errno;
90 s->write = fd_write;
91 s->close = fd_close;
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020092
93 migrate_fd_connect(s);
Juan Quintela07af4452010-05-11 22:27:45 +020094 return 0;
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +020095
96err_after_open:
97 close(s->fd);
Juan Quintela07af4452010-05-11 22:27:45 +020098err_after_get_fd:
99 return -1;
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +0200100}
101
102static void fd_accept_incoming_migration(void *opaque)
103{
104 QEMUFile *f = opaque;
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +0200105
Juan Quintela511c0232010-06-09 14:10:55 +0200106 process_incoming_migration(f);
Juan Quintelacfaf6d32010-03-10 00:10:35 +0100107 qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +0200108 qemu_fclose(f);
109}
110
111int fd_start_incoming_migration(const char *infd)
112{
113 int fd;
114 QEMUFile *f;
115
malcd0f2c4c2010-02-07 02:03:50 +0300116 DPRINTF("Attempting to start an incoming migration via fd\n");
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +0200117
118 fd = strtol(infd, NULL, 0);
119 f = qemu_fdopen(fd, "rb");
120 if(f == NULL) {
malcd0f2c4c2010-02-07 02:03:50 +0300121 DPRINTF("Unable to apply qemu wrapper to file descriptor\n");
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +0200122 return -errno;
123 }
124
Juan Quintela1c39e2a2010-03-11 17:55:38 +0100125 qemu_set_fd_handler2(fd, NULL, fd_accept_incoming_migration, NULL, f);
Paolo Bonzini5ac1fad2009-08-18 15:56:25 +0200126
127 return 0;
128}