migration/qemu-file-channel.c

   1 /*
   2  * QEMUFile backend for QIOChannel objects
   3  *
   4  * Copyright (c) 2015-2016 Red Hat, Inc
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu/osdep.h"
  26 #include "qemu-file-channel.h"
  27 #include "qemu-file.h"
  28 #include "io/channel-socket.h"
  29 #include "qemu/iov.h"
  30 #include "qemu/yank.h"
  31 #include "yank_functions.h"
  32
  33
  34 static ssize_t channel_writev_buffer(void *opaque,
  35                                      struct iovec *iov,
  36                                      int iovcnt,
  37                                      int64_t pos,
  38                                      Error **errp)
  39 {
  40     QIOChannel *ioc = QIO_CHANNEL(opaque);
  41     ssize_t done = 0;
  42     struct iovec *local_iov = g_new(struct iovec, iovcnt);
  43     struct iovec *local_iov_head = local_iov;
  44     unsigned int nlocal_iov = iovcnt;
  45
  46     nlocal_iov = iov_copy(local_iov, nlocal_iov,
  47                           iov, iovcnt,
  48                           0, iov_size(iov, iovcnt));
  49
  50     while (nlocal_iov > 0) {
  51         ssize_t len;
  52         len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
  53         if (len == QIO_CHANNEL_ERR_BLOCK) {
  54             if (qemu_in_coroutine()) {
  55                 qio_channel_yield(ioc, G_IO_OUT);
  56             } else {
  57                 qio_channel_wait(ioc, G_IO_OUT);
  58             }
  59             continue;
  60         }
  61         if (len < 0) {
  62             done = -EIO;
  63             goto cleanup;
  64         }
  65
  66         iov_discard_front(&local_iov, &nlocal_iov, len);
  67         done += len;
  68     }
  69
  70  cleanup:
  71     g_free(local_iov_head);
  72     return done;
  73 }
  74
  75
  76 static ssize_t channel_get_buffer(void *opaque,
  77                                   uint8_t *buf,
  78                                   int64_t pos,
  79                                   size_t size,
  80                                   Error **errp)
  81 {
  82     QIOChannel *ioc = QIO_CHANNEL(opaque);
  83     ssize_t ret;
  84
  85     do {
  86         ret = qio_channel_read(ioc, (char *)buf, size, errp);
  87         if (ret < 0) {
  88             if (ret == QIO_CHANNEL_ERR_BLOCK) {
  89                 if (qemu_in_coroutine()) {
  90                     qio_channel_yield(ioc, G_IO_IN);
  91                 } else {
  92                     qio_channel_wait(ioc, G_IO_IN);
  93                 }
  94             } else {
  95                 return -EIO;
  96             }
  97         }
  98     } while (ret == QIO_CHANNEL_ERR_BLOCK);
  99
 100     return ret;
 101 }
 102
 103
 104 static int channel_close(void *opaque, Error **errp)
 105 {
 106     int ret;
 107     QIOChannel *ioc = QIO_CHANNEL(opaque);
 108     ret = qio_channel_close(ioc, errp);
 109     if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET)
 110         && OBJECT(ioc)->ref == 1) {
 111         yank_unregister_function(MIGRATION_YANK_INSTANCE,
 112                                  migration_yank_iochannel,
 113                                  QIO_CHANNEL(ioc));
 114     }
 115     object_unref(OBJECT(ioc));
 116     return ret;
 117 }
 118
 119
 120 static int channel_shutdown(void *opaque,
 121                             bool rd,
 122                             bool wr,
 123                             Error **errp)
 124 {
 125     QIOChannel *ioc = QIO_CHANNEL(opaque);
 126
 127     if (qio_channel_has_feature(ioc,
 128                                 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 129         QIOChannelShutdown mode;
 130         if (rd && wr) {
 131             mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 132         } else if (rd) {
 133             mode = QIO_CHANNEL_SHUTDOWN_READ;
 134         } else {
 135             mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 136         }
 137         if (qio_channel_shutdown(ioc, mode, errp) < 0) {
 138             return -EIO;
 139         }
 140     }
 141     return 0;
 142 }
 143
 144
 145 static int channel_set_blocking(void *opaque,
 146                                 bool enabled,
 147                                 Error **errp)
 148 {
 149     QIOChannel *ioc = QIO_CHANNEL(opaque);
 150
 151     if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
 152         return -1;
 153     }
 154     return 0;
 155 }
 156
 157 static QEMUFile *channel_get_input_return_path(void *opaque)
 158 {
 159     QIOChannel *ioc = QIO_CHANNEL(opaque);
 160
 161     return qemu_fopen_channel_output(ioc);
 162 }
 163
 164 static QEMUFile *channel_get_output_return_path(void *opaque)
 165 {
 166     QIOChannel *ioc = QIO_CHANNEL(opaque);
 167
 168     return qemu_fopen_channel_input(ioc);
 169 }
 170
 171 static const QEMUFileOps channel_input_ops = {
 172     .get_buffer = channel_get_buffer,
 173     .close = channel_close,
 174     .shut_down = channel_shutdown,
 175     .set_blocking = channel_set_blocking,
 176     .get_return_path = channel_get_input_return_path,
 177 };
 178
 179
 180 static const QEMUFileOps channel_output_ops = {
 181     .writev_buffer = channel_writev_buffer,
 182     .close = channel_close,
 183     .shut_down = channel_shutdown,
 184     .set_blocking = channel_set_blocking,
 185     .get_return_path = channel_get_output_return_path,
 186 };
 187
 188
 189 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 190 {
 191     object_ref(OBJECT(ioc));
 192     return qemu_fopen_ops(ioc, &channel_input_ops);
 193 }
 194
 195 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 196 {
 197     object_ref(OBJECT(ioc));
 198     return qemu_fopen_ops(ioc, &channel_output_ops);
 199 }