qemu/migration/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

113 lines
3.4 KiB
C

/*
* QEMU live migration channel operations
*
* Copyright Red Hat, Inc. 2016
*
* Authors:
* Daniel P. Berrange <berrange@redhat.com>
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "channel.h"
#include "tls.h"
#include "migration.h"
#include "qemu-file-channel.h"
#include "trace.h"
#include "qapi/error.h"
#include "io/channel-tls.h"
#include "io/channel-socket.h"
#include "qemu/yank.h"
#include "yank_functions.h"
/**
* @migration_channel_process_incoming - Create new incoming migration channel
*
* Notice that TLS is special. For it we listen in a listener socket,
* and then create a new client socket from the TLS library.
*
* @ioc: Channel to which we are connecting
*/
void migration_channel_process_incoming(QIOChannel *ioc)
{
MigrationState *s = migrate_get_current();
Error *local_err = NULL;
trace_migration_set_incoming_channel(
ioc, object_get_typename(OBJECT(ioc)));
if (s->parameters.tls_creds &&
*s->parameters.tls_creds &&
!object_dynamic_cast(OBJECT(ioc),
TYPE_QIO_CHANNEL_TLS)) {
migration_tls_channel_process_incoming(s, ioc, &local_err);
} else {
if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS)) {
yank_register_function(MIGRATION_YANK_INSTANCE,
migration_yank_iochannel,
QIO_CHANNEL(ioc));
}
migration_ioc_process_incoming(ioc, &local_err);
}
if (local_err) {
error_report_err(local_err);
}
}
/**
* @migration_channel_connect - Create new outgoing migration channel
*
* @s: Current migration state
* @ioc: Channel to which we are connecting
* @hostname: Where we want to connect
* @error: Error indicating failure to connect, free'd here
*/
void migration_channel_connect(MigrationState *s,
QIOChannel *ioc,
const char *hostname,
Error *error)
{
trace_migration_set_outgoing_channel(
ioc, object_get_typename(OBJECT(ioc)), hostname, error);
if (!error) {
if (s->parameters.tls_creds &&
*s->parameters.tls_creds &&
!object_dynamic_cast(OBJECT(ioc),
TYPE_QIO_CHANNEL_TLS)) {
migration_tls_channel_connect(s, ioc, hostname, &error);
if (!error) {
/* tls_channel_connect will call back to this
* function after the TLS handshake,
* so we mustn't call migrate_fd_connect until then
*/
return;
}
} else {
QEMUFile *f = qemu_fopen_channel_output(ioc);
if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS)) {
yank_register_function(MIGRATION_YANK_INSTANCE,
migration_yank_iochannel,
QIO_CHANNEL(ioc));
}
qemu_mutex_lock(&s->qemu_file_lock);
s->to_dst_file = f;
qemu_mutex_unlock(&s->qemu_file_lock);
}
}
migrate_fd_connect(s, error);
g_free(s->hostname);
error_free(error);
}