xemu/migration/qemu-file-channel.c
Leonardo Bras 7de2e85653 yank: Unregister function when using TLS migration
After yank feature was introduced in migration, whenever migration
is started using TLS, the following error happens in both source and
destination hosts:

(qemu) qemu-kvm: ../util/yank.c:107: yank_unregister_instance:
Assertion `QLIST_EMPTY(&entry->yankfns)' failed.

This happens because of a missing yank_unregister_function() when using
qio-channel-tls.

Fix this by also allowing TYPE_QIO_CHANNEL_TLS object type to perform
yank_unregister_function() in channel_close() and multifd_load_cleanup().

Also, inside migration_channel_connect() and
migration_channel_process_incoming() move yank_register_function() so
it only runs once on a TLS migration.

Fixes: b5eea99ec2 ("migration: Add yank feature", 2021-01-13)
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1964326
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Peter Xu <peterx@redhat.com>

--
Changes since v2:
- Dropped all references to ioc->master
- yank_register_function() and yank_unregister_function() now only run
  once in a TLS migration.

Changes since v1:
- Cast p->c to QIOChannelTLS into multifd_load_cleanup()
Message-Id: <20210601054030.1153249-1-leobras.c@gmail.com>

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-06-08 18:50:03 +01:00

202 lines
5.8 KiB
C

/*
* QEMUFile backend for QIOChannel objects
*
* Copyright (c) 2015-2016 Red Hat, Inc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu-file-channel.h"
#include "qemu-file.h"
#include "io/channel-socket.h"
#include "io/channel-tls.h"
#include "qemu/iov.h"
#include "qemu/yank.h"
#include "yank_functions.h"
static ssize_t channel_writev_buffer(void *opaque,
struct iovec *iov,
int iovcnt,
int64_t pos,
Error **errp)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
ssize_t done = 0;
struct iovec *local_iov = g_new(struct iovec, iovcnt);
struct iovec *local_iov_head = local_iov;
unsigned int nlocal_iov = iovcnt;
nlocal_iov = iov_copy(local_iov, nlocal_iov,
iov, iovcnt,
0, iov_size(iov, iovcnt));
while (nlocal_iov > 0) {
ssize_t len;
len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
if (len == QIO_CHANNEL_ERR_BLOCK) {
if (qemu_in_coroutine()) {
qio_channel_yield(ioc, G_IO_OUT);
} else {
qio_channel_wait(ioc, G_IO_OUT);
}
continue;
}
if (len < 0) {
done = -EIO;
goto cleanup;
}
iov_discard_front(&local_iov, &nlocal_iov, len);
done += len;
}
cleanup:
g_free(local_iov_head);
return done;
}
static ssize_t channel_get_buffer(void *opaque,
uint8_t *buf,
int64_t pos,
size_t size,
Error **errp)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
ssize_t ret;
do {
ret = qio_channel_read(ioc, (char *)buf, size, errp);
if (ret < 0) {
if (ret == QIO_CHANNEL_ERR_BLOCK) {
if (qemu_in_coroutine()) {
qio_channel_yield(ioc, G_IO_IN);
} else {
qio_channel_wait(ioc, G_IO_IN);
}
} else {
return -EIO;
}
}
} while (ret == QIO_CHANNEL_ERR_BLOCK);
return ret;
}
static int channel_close(void *opaque, Error **errp)
{
int ret;
QIOChannel *ioc = QIO_CHANNEL(opaque);
ret = qio_channel_close(ioc, errp);
if ((object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS))
&& OBJECT(ioc)->ref == 1) {
yank_unregister_function(MIGRATION_YANK_INSTANCE,
migration_yank_iochannel,
QIO_CHANNEL(ioc));
}
object_unref(OBJECT(ioc));
return ret;
}
static int channel_shutdown(void *opaque,
bool rd,
bool wr,
Error **errp)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
if (qio_channel_has_feature(ioc,
QIO_CHANNEL_FEATURE_SHUTDOWN)) {
QIOChannelShutdown mode;
if (rd && wr) {
mode = QIO_CHANNEL_SHUTDOWN_BOTH;
} else if (rd) {
mode = QIO_CHANNEL_SHUTDOWN_READ;
} else {
mode = QIO_CHANNEL_SHUTDOWN_WRITE;
}
if (qio_channel_shutdown(ioc, mode, errp) < 0) {
return -EIO;
}
}
return 0;
}
static int channel_set_blocking(void *opaque,
bool enabled,
Error **errp)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
return -1;
}
return 0;
}
static QEMUFile *channel_get_input_return_path(void *opaque)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
return qemu_fopen_channel_output(ioc);
}
static QEMUFile *channel_get_output_return_path(void *opaque)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
return qemu_fopen_channel_input(ioc);
}
static const QEMUFileOps channel_input_ops = {
.get_buffer = channel_get_buffer,
.close = channel_close,
.shut_down = channel_shutdown,
.set_blocking = channel_set_blocking,
.get_return_path = channel_get_input_return_path,
};
static const QEMUFileOps channel_output_ops = {
.writev_buffer = channel_writev_buffer,
.close = channel_close,
.shut_down = channel_shutdown,
.set_blocking = channel_set_blocking,
.get_return_path = channel_get_output_return_path,
};
QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
{
object_ref(OBJECT(ioc));
return qemu_fopen_ops(ioc, &channel_input_ops);
}
QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
{
object_ref(OBJECT(ioc));
return qemu_fopen_ops(ioc, &channel_output_ops);
}