1 /* 2 * QEMU live migration channel operations 3 * 4 * Copyright Red Hat, Inc. 2016 5 * 6 * Authors: 7 * Daniel P. Berrange <berrange@redhat.com> 8 * 9 * Contributions after 2012-01-13 are licensed under the terms of the 10 * GNU GPL, version 2 or (at your option) any later version. 11 */ 12 13 #include "qemu/osdep.h" 14 #include "channel.h" 15 #include "tls.h" 16 #include "migration.h" 17 #include "qemu-file.h" 18 #include "trace.h" 19 #include "qapi/error.h" 20 #include "io/channel-tls.h" 21 #include "io/channel-socket.h" 22 #include "qemu/yank.h" 23 #include "yank_functions.h" 24 25 /** 26 * @migration_channel_process_incoming - Create new incoming migration channel 27 * 28 * Notice that TLS is special. For it we listen in a listener socket, 29 * and then create a new client socket from the TLS library. 30 * 31 * @ioc: Channel to which we are connecting 32 */ 33 void migration_channel_process_incoming(QIOChannel *ioc) 34 { 35 MigrationState *s = migrate_get_current(); 36 Error *local_err = NULL; 37 38 trace_migration_set_incoming_channel( 39 ioc, object_get_typename(OBJECT(ioc))); 40 41 if (migrate_channel_requires_tls_upgrade(ioc)) { 42 migration_tls_channel_process_incoming(s, ioc, &local_err); 43 } else { 44 migration_ioc_register_yank(ioc); 45 migration_ioc_process_incoming(ioc, &local_err); 46 } 47 48 if (local_err) { 49 error_report_err(local_err); 50 } 51 } 52 53 54 /** 55 * @migration_channel_connect - Create new outgoing migration channel 56 * 57 * @s: Current migration state 58 * @ioc: Channel to which we are connecting 59 * @hostname: Where we want to connect 60 * @error: Error indicating failure to connect, free'd here 61 */ 62 void migration_channel_connect(MigrationState *s, 63 QIOChannel *ioc, 64 const char *hostname, 65 Error *error) 66 { 67 trace_migration_set_outgoing_channel( 68 ioc, object_get_typename(OBJECT(ioc)), hostname, error); 69 70 if (!error) { 71 if (migrate_channel_requires_tls_upgrade(ioc)) { 72 migration_tls_channel_connect(s, ioc, hostname, &error); 73 74 if (!error) { 75 /* tls_channel_connect will call back to this 76 * function after the TLS handshake, 77 * so we mustn't call migrate_fd_connect until then 78 */ 79 80 return; 81 } 82 } else { 83 QEMUFile *f = qemu_file_new_output(ioc); 84 85 migration_ioc_register_yank(ioc); 86 87 qemu_mutex_lock(&s->qemu_file_lock); 88 s->to_dst_file = f; 89 qemu_mutex_unlock(&s->qemu_file_lock); 90 } 91 } 92 migrate_fd_connect(s, error); 93 error_free(error); 94 } 95 96 97 /** 98 * @migration_channel_read_peek - Peek at migration channel, without 99 * actually removing it from channel buffer. 100 * 101 * @ioc: the channel object 102 * @buf: the memory region to read data into 103 * @buflen: the number of bytes to read in @buf 104 * @errp: pointer to a NULL-initialized error object 105 * 106 * Returns 0 if successful, returns -1 and sets @errp if fails. 107 */ 108 int migration_channel_read_peek(QIOChannel *ioc, 109 const char *buf, 110 const size_t buflen, 111 Error **errp) 112 { 113 ssize_t len = 0; 114 struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; 115 116 while (true) { 117 len = qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, 118 QIO_CHANNEL_READ_FLAG_MSG_PEEK, errp); 119 120 if (len < 0 && len != QIO_CHANNEL_ERR_BLOCK) { 121 return -1; 122 } 123 124 if (len == 0) { 125 error_setg(errp, "Failed to peek at channel"); 126 return -1; 127 } 128 129 if (len == buflen) { 130 break; 131 } 132 133 /* 1ms sleep. */ 134 if (qemu_in_coroutine()) { 135 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); 136 } else { 137 g_usleep(1000); 138 } 139 } 140 141 return 0; 142 } 143