qemu/migration/fd.c
Fabiano Rosas decdc76772 migration/multifd: Add mapped-ram support to fd: URI
If we receive a file descriptor that points to a regular file, there's
nothing stopping us from doing multifd migration with mapped-ram to
that file.

Enable the fd: URI to work with multifd + mapped-ram.

Note that the fds passed into multifd are duplicated because we want
to avoid cross-thread effects when doing cleanup (i.e. close(fd)). The
original fd doesn't need to be duplicated because monitor_get_fd()
transfers ownership to the caller.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240229153017.2221-23-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-03-01 15:42:04 +08:00

121 lines
3 KiB
C

/*
* QEMU live migration via generic fd
*
* Copyright Red Hat, Inc. 2009-2016
*
* Authors:
* Chris Lalancette <clalance@redhat.com>
* Daniel P. Berrange <berrange@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* 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 "qapi/error.h"
#include "channel.h"
#include "fd.h"
#include "migration.h"
#include "monitor/monitor.h"
#include "io/channel-file.h"
#include "io/channel-util.h"
#include "options.h"
#include "trace.h"
static struct FdOutgoingArgs {
int fd;
} outgoing_args;
int fd_args_get_fd(void)
{
return outgoing_args.fd;
}
void fd_cleanup_outgoing_migration(void)
{
if (outgoing_args.fd > 0) {
close(outgoing_args.fd);
outgoing_args.fd = -1;
}
}
void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
{
QIOChannel *ioc;
int fd = monitor_get_fd(monitor_cur(), fdname, errp);
outgoing_args.fd = -1;
if (fd == -1) {
return;
}
trace_migration_fd_outgoing(fd);
ioc = qio_channel_new_fd(fd, errp);
if (!ioc) {
close(fd);
return;
}
outgoing_args.fd = fd;
qio_channel_set_name(ioc, "migration-fd-outgoing");
migration_channel_connect(s, ioc, NULL, NULL);
object_unref(OBJECT(ioc));
}
static gboolean fd_accept_incoming_migration(QIOChannel *ioc,
GIOCondition condition,
gpointer opaque)
{
migration_channel_process_incoming(ioc);
object_unref(OBJECT(ioc));
return G_SOURCE_REMOVE;
}
void fd_start_incoming_migration(const char *fdname, Error **errp)
{
QIOChannel *ioc;
int fd = monitor_fd_param(monitor_cur(), fdname, errp);
if (fd == -1) {
return;
}
trace_migration_fd_incoming(fd);
ioc = qio_channel_new_fd(fd, errp);
if (!ioc) {
close(fd);
return;
}
qio_channel_set_name(ioc, "migration-fd-incoming");
qio_channel_add_watch_full(ioc, G_IO_IN,
fd_accept_incoming_migration,
NULL, NULL,
g_main_context_get_thread_default());
if (migrate_multifd()) {
int channels = migrate_multifd_channels();
while (channels--) {
ioc = QIO_CHANNEL(qio_channel_file_new_fd(dup(fd)));
if (QIO_CHANNEL_FILE(ioc)->fd == -1) {
error_setg(errp, "Failed to duplicate fd %d", fd);
return;
}
qio_channel_set_name(ioc, "migration-fd-incoming");
qio_channel_add_watch_full(ioc, G_IO_IN,
fd_accept_incoming_migration,
NULL, NULL,
g_main_context_get_thread_default());
}
}
}