qemu-e2k/migration/channel-block.c

198 lines
5.0 KiB
C

/*
* QEMU I/O channels block driver
*
* Copyright (c) 2022 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "migration/channel-block.h"
#include "qapi/error.h"
#include "block/block.h"
#include "trace.h"
QIOChannelBlock *
qio_channel_block_new(BlockDriverState *bs)
{
QIOChannelBlock *ioc;
ioc = QIO_CHANNEL_BLOCK(object_new(TYPE_QIO_CHANNEL_BLOCK));
bdrv_ref(bs);
ioc->bs = bs;
return ioc;
}
static void
qio_channel_block_finalize(Object *obj)
{
QIOChannelBlock *ioc = QIO_CHANNEL_BLOCK(obj);
g_clear_pointer(&ioc->bs, bdrv_unref);
}
static ssize_t
qio_channel_block_readv(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
int **fds,
size_t *nfds,
Error **errp)
{
QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc);
QEMUIOVector qiov;
int ret;
qemu_iovec_init_external(&qiov, (struct iovec *)iov, niov);
ret = bdrv_readv_vmstate(bioc->bs, &qiov, bioc->offset);
if (ret < 0) {
error_setg_errno(errp, -ret, "bdrv_readv_vmstate failed");
return -1;
}
bioc->offset += qiov.size;
return qiov.size;
}
static ssize_t
qio_channel_block_writev(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
int *fds,
size_t nfds,
int flags,
Error **errp)
{
QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc);
QEMUIOVector qiov;
int ret;
qemu_iovec_init_external(&qiov, (struct iovec *)iov, niov);
ret = bdrv_writev_vmstate(bioc->bs, &qiov, bioc->offset);
if (ret < 0) {
error_setg_errno(errp, -ret, "bdrv_writev_vmstate failed");
return -1;
}
bioc->offset += qiov.size;
return qiov.size;
}
static int
qio_channel_block_set_blocking(QIOChannel *ioc,
bool enabled,
Error **errp)
{
if (!enabled) {
error_setg(errp, "Non-blocking mode not supported for block devices");
return -1;
}
return 0;
}
static off_t
qio_channel_block_seek(QIOChannel *ioc,
off_t offset,
int whence,
Error **errp)
{
QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc);
switch (whence) {
case SEEK_SET:
bioc->offset = offset;
break;
case SEEK_CUR:
bioc->offset += whence;
break;
case SEEK_END:
error_setg(errp, "Size of VMstate region is unknown");
return (off_t)-1;
default:
g_assert_not_reached();
}
return bioc->offset;
}
static int
qio_channel_block_close(QIOChannel *ioc,
Error **errp)
{
QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc);
int rv = bdrv_flush(bioc->bs);
if (rv < 0) {
error_setg_errno(errp, -rv,
"Unable to flush VMState");
return -1;
}
g_clear_pointer(&bioc->bs, bdrv_unref);
bioc->offset = 0;
return 0;
}
static void
qio_channel_block_set_aio_fd_handler(QIOChannel *ioc,
AioContext *ctx,
IOHandler *io_read,
IOHandler *io_write,
void *opaque)
{
/* XXX anything we can do here ? */
}
static void
qio_channel_block_class_init(ObjectClass *klass,
void *class_data G_GNUC_UNUSED)
{
QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
ioc_klass->io_writev = qio_channel_block_writev;
ioc_klass->io_readv = qio_channel_block_readv;
ioc_klass->io_set_blocking = qio_channel_block_set_blocking;
ioc_klass->io_seek = qio_channel_block_seek;
ioc_klass->io_close = qio_channel_block_close;
ioc_klass->io_set_aio_fd_handler = qio_channel_block_set_aio_fd_handler;
}
static const TypeInfo qio_channel_block_info = {
.parent = TYPE_QIO_CHANNEL,
.name = TYPE_QIO_CHANNEL_BLOCK,
.instance_size = sizeof(QIOChannelBlock),
.instance_finalize = qio_channel_block_finalize,
.class_init = qio_channel_block_class_init,
};
static void
qio_channel_block_register_types(void)
{
type_register_static(&qio_channel_block_info);
}
type_init(qio_channel_block_register_types);