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