1 /* 2 * QEMU I/O channels block driver 3 * 4 * Copyright (c) 2022 Red Hat, Inc. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21 #include "qemu/osdep.h" 22 #include "migration/channel-block.h" 23 #include "qapi/error.h" 24 #include "block/block.h" 25 #include "trace.h" 26 27 QIOChannelBlock * 28 qio_channel_block_new(BlockDriverState *bs) 29 { 30 QIOChannelBlock *ioc; 31 32 ioc = QIO_CHANNEL_BLOCK(object_new(TYPE_QIO_CHANNEL_BLOCK)); 33 34 bdrv_ref(bs); 35 ioc->bs = bs; 36 37 return ioc; 38 } 39 40 41 static void 42 qio_channel_block_finalize(Object *obj) 43 { 44 QIOChannelBlock *ioc = QIO_CHANNEL_BLOCK(obj); 45 46 g_clear_pointer(&ioc->bs, bdrv_unref); 47 } 48 49 50 static ssize_t 51 qio_channel_block_readv(QIOChannel *ioc, 52 const struct iovec *iov, 53 size_t niov, 54 int **fds, 55 size_t *nfds, 56 Error **errp) 57 { 58 QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc); 59 QEMUIOVector qiov; 60 int ret; 61 62 qemu_iovec_init_external(&qiov, (struct iovec *)iov, niov); 63 ret = bdrv_readv_vmstate(bioc->bs, &qiov, bioc->offset); 64 if (ret < 0) { 65 return ret; 66 } 67 68 bioc->offset += qiov.size; 69 return qiov.size; 70 } 71 72 73 static ssize_t 74 qio_channel_block_writev(QIOChannel *ioc, 75 const struct iovec *iov, 76 size_t niov, 77 int *fds, 78 size_t nfds, 79 int flags, 80 Error **errp) 81 { 82 QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc); 83 QEMUIOVector qiov; 84 int ret; 85 86 qemu_iovec_init_external(&qiov, (struct iovec *)iov, niov); 87 ret = bdrv_writev_vmstate(bioc->bs, &qiov, bioc->offset); 88 if (ret < 0) { 89 return ret; 90 } 91 92 bioc->offset += qiov.size; 93 return qiov.size; 94 } 95 96 97 static int 98 qio_channel_block_set_blocking(QIOChannel *ioc, 99 bool enabled, 100 Error **errp) 101 { 102 if (!enabled) { 103 error_setg(errp, "Non-blocking mode not supported for block devices"); 104 return -1; 105 } 106 return 0; 107 } 108 109 110 static off_t 111 qio_channel_block_seek(QIOChannel *ioc, 112 off_t offset, 113 int whence, 114 Error **errp) 115 { 116 QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc); 117 118 switch (whence) { 119 case SEEK_SET: 120 bioc->offset = offset; 121 break; 122 case SEEK_CUR: 123 bioc->offset += whence; 124 break; 125 case SEEK_END: 126 error_setg(errp, "Size of VMstate region is unknown"); 127 return (off_t)-1; 128 default: 129 g_assert_not_reached(); 130 } 131 132 return bioc->offset; 133 } 134 135 136 static int 137 qio_channel_block_close(QIOChannel *ioc, 138 Error **errp) 139 { 140 QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc); 141 int rv = bdrv_flush(bioc->bs); 142 143 if (rv < 0) { 144 error_setg_errno(errp, -rv, 145 "Unable to flush VMState"); 146 return -1; 147 } 148 149 g_clear_pointer(&bioc->bs, bdrv_unref); 150 bioc->offset = 0; 151 152 return 0; 153 } 154 155 156 static void 157 qio_channel_block_set_aio_fd_handler(QIOChannel *ioc, 158 AioContext *ctx, 159 IOHandler *io_read, 160 IOHandler *io_write, 161 void *opaque) 162 { 163 /* XXX anything we can do here ? */ 164 } 165 166 167 static void 168 qio_channel_block_class_init(ObjectClass *klass, 169 void *class_data G_GNUC_UNUSED) 170 { 171 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass); 172 173 ioc_klass->io_writev = qio_channel_block_writev; 174 ioc_klass->io_readv = qio_channel_block_readv; 175 ioc_klass->io_set_blocking = qio_channel_block_set_blocking; 176 ioc_klass->io_seek = qio_channel_block_seek; 177 ioc_klass->io_close = qio_channel_block_close; 178 ioc_klass->io_set_aio_fd_handler = qio_channel_block_set_aio_fd_handler; 179 } 180 181 static const TypeInfo qio_channel_block_info = { 182 .parent = TYPE_QIO_CHANNEL, 183 .name = TYPE_QIO_CHANNEL_BLOCK, 184 .instance_size = sizeof(QIOChannelBlock), 185 .instance_finalize = qio_channel_block_finalize, 186 .class_init = qio_channel_block_class_init, 187 }; 188 189 static void 190 qio_channel_block_register_types(void) 191 { 192 type_register_static(&qio_channel_block_info); 193 } 194 195 type_init(qio_channel_block_register_types); 196